Charles Babbage's First Difference Engine

CHARLES BABBAGE'S
DIFFERENCE ENGINE NO. 1
SURVIVING ARCHIVES
AND OTHER SOURCES

Compiled by
C.J.D. Roberts M.A.

A. PRINCIPAL COLLECTIONS

Science Museum Library,
Imperial College Way,
South Kensington, London SW7

Notes on the Drawings of Babbage's First Difference Engine

in the [K] and [U] Series

General Notes

Drawings in the [K] Series were rediscovered in modern times at King's College University of London, where they had been deposited by the Government in the Summer of 1843. They were transferred to the Science Museum Library in 1971.

Drawings in the [U] Series were donated to the Science Museum by Major General Henry P. Babbage (Babbage's youngest son) in 1905.

THE [K] SERIES

Reference: [K 1] Folder 1

Size: 35 7/16" x 20 27/32"

Caption: End View of Printing Part nearly all of which has been altered since this was drawn.

Watermark: None

Condition: Very dirty and bottom edge torn. The centres of the various wheels drawn on it have been patched with small pieces of paper.

Notes:

No date. Drawing comprises a single figure: viz. an end view of the printing part for an early version of DE1. Details on this drawing should be compared with those on drawings [U2[a&b]].

Reference: [K 2] Folder 1

Size: 36 1/4" x 25 1/4"

Caption: Endless screw, clutches, &c. &c. for moving the copper [plate]

Watermark: J. Whatman 1831

Condition: Dirty and torn edge. Some grease spots.

Notes:

This drawing comprises several figures illustrating the details (plan, elevation section etc.) of the Endless Screw Wheel, levers, cones and other mechanisms which are used to move the Copper Plate from figure to figure across a line of results in the table being punched by DE1. Details on this drawing should be compared with those shown on drawings [U7] and [K11].

There are also a number of rough pencil sketches on the drawing.

Reference: [K 3] Folder 1

Size: 47 1/4" x 27 1/2"

Caption: Frame for holding the copper [printing plate]

Watermark: J. Whatman Turkey Mill Kent 1824

Condition: Torn and mouldy

Notes:

No date. This is a drawing (plan and section) of the frame which holds, stretches and keeps flat the copper plate upon which are stamped by punch the results of DE1's calculations. It seems to work like a vice for very clearly shown is a device for adjusting the position of a smaller frame within a larger outer frame. The screw is shown having 20 threads per inch.

There are also some rough pencil sketches on this drawing as well.

Reference: [K 4] Loose

Size: 36 3/4" x 54 1/8"

Caption: 3 Fig[ure] Motion [Device]

Watermark: None

Condition: Torn, torn edges, relatively clean

Notes:

No date. On the face side of the drawing are details (side, top and end views etc.) of the 3-Figure Motion Device. This is the device which allows the first 3 (or 4) significant figures of a result to be punched when at the beginning of a line. Among the details shown are the arms fixed at the base of the Table's Difference Carrying (Figure Wheel) Axis which trigger the Device. On the back side of the drawing are detailed drawings (plan, side view etc.) of the Type Sector and its Axis.

Note and amendment on drawing in Babbage's handwriting referring to the lever which connects this device to the printing control mechanisms:

"These levers, detents &c. will not now be wanted; their work is done by the returning crank. May 18 -1832."

Reference: [K 5] to [K 10] Missing

Reference: [K 11] Loose in Map Press Unit (cf also [K100])

Size: 90 3/4" x 45"

Caption: None

Watermark: None

Condition: Relatively clean, torn edge, torn where it has been folded (4 times).

Notes:

No date. This is a large drawing comprising a plan view over the driving and printing part of DE1 showing all the drive and control mechanisms. Similar to [U7] which is a copy. Parts nearest the driving handle have been drawn faintly in pencil. This is one of the more important drawings of DE1 to have survived.

Several amendments in a heavy ink have been made on this drawing.

The parts, Spiral Axis and Ribbon Axis, have been labelled as such.

Reference: [K 12] to [K 26] Missing

Reference: [K 27] Folder 1

Size: 39 1/8" x 26 3/16"

Caption: Plan of Machinery intended to be attached to planing machine

Watermark: J. Whatman 1826

Condition: Illegible, in pencil only. Oil marks. Damaged and fragile.

Notes:

No date. The purpose of the parts on this drawing have not been identified.

Reference: [K 28] Missing

Reference: [K 29] Folder 1

Size: 38 1/4" x 27"

Caption: 60-wheel and levers - old plan

Watermark: J. Whatman 1826

Condition: Dirty. Some oil and grease spots.

Notes:

No date. Drawing is a plan and section of an early version of the 1st 60-Wheel and the intermediate/communicating wheels which drive the 2nd 60-Wheel (shown in section). Also included are detailed diagrams (section, side view etc.) of 2 levers. Some pencilling.

Note on drawing next to the Sine-Qua-Non Wheel.:

"This sine qua non wheel to be altered. It now moves by 20ths instead of 24ths. Jan^y 1832."

Note on drawing adjacent to the 60-Wheel:

"When a 20-Wheel had been substituted for the 24-Wheel other 60-Wheels were drawn. They are now lighter".

Reference: [K 30] Missing

Reference: [K 31] Folder 1

Size: 39" x 26 7/16"

Caption: Calculating Machine. Details of various wheels.

Watermark: J. Whatman 1826

Condition: V. dirty. One large oil spot. Centre of wheels damaged by dividers/compass points.

Notes:

No date. Appears to be figures (end views, side views etc) of an early version of DE1's 24-Wheel [Printing Axis control] mechanisms, in which case the details on this drawing should be compared with those on drawings [U1[a&b]], [U2[a&b]], [K78] and [K1].

Various wheels, including Locking or Roller Wheels and Stud Wheels with 12, 20 or 24 teeth scallops or studs shown on them, have been drawn. Shown also at the bottom left hand side of the drawing are figures (side and end view) of a driving wheel and its driven partner (unidentified purpose) both with starting teeth and the plumbing block which keeps them in position on the axis.

Reference: [K 32] Loose

Size: 26" x 39 1/2"

Caption: Motions for decimal point &c.- Old plan: taken off board July 1831.

Watermark: J. Whatman 182[?]

Condition: Some oil marks, frayed edges

Notes:

No date. Detailed drawings of the parts (levers, springs, 24-Stud Wheel, ratchet wheel, adjusting knob etc.) controlling the positioning and punching of the decimal point in the early version of DE1. Apparatus superseded in later (1833) version of DE1.

Reference: [K 33] Folder 1

Size: 38 3/8" x 25 3/16"

Caption: Type Sector. Various cams and details.

Watermark: J. Whatman 183[3?]

Condition: Oily and dirty, some grease spots.

Notes:

No date. Details (plan, section etc.) of the Type Sector, the Cam (for raising/lowering/steadying the Type Sector, i.e. vertical motion?), Cam (for causing the Type Sector to swing in/out i.e. circular motion?), the Mitre Wheels which drive the Cams, and a Plumbing Block which supports the shaft around which one of the Cams rotates. The Type Sector itself is held in position by three screws on a tongue fitted to the Type Sector Axis, and it therefore appears that it is exchangeable for another which has punches of a different size or typeface fitted to it.

Various parts on drawing struck out as "not wanted", (in particular that Cam which causes the Type Sector to swing in/out?) and its Sector Wheel at the base of the Type Sector Axis.

Reference: [K 34] Folder 1

Size: 38 11/16"x 25 3/16"

Caption: Forcer of punches.

Watermark: J. Whatman 1828

Condition: Frayed at edges, in pencil and indistinct.

Notes:

No date. The upper end of a Punch appears to be able to fit inside barrel of the Forcer. Springs to return forcer after punching are clearly shown.

Reference: [K 35] to [K 39] Missing

Reference: [K 40] Folder 1

Size: 37 1/4" x 25 3/8"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition: In relatively clean and good condition

Notes:

No date. This drawing is a plan view of the first three Difference Axes (Table, 1st and 2nd Difference) of the calculating part of DE1. A vertical section through a calculating cage is also shown. Drawing shows in considerable detail the general layout of the Figure Wheels, Calculating Axes, Bolts, a Snail Wheel on the Table Axis, the spiral of Bolting Arms etc., etc.

This is one of the more important drawings to have survived.

Notes made on drawing:

Re the bolting arms: "This was drawn from directions in a written memorandum but the position relative to the highest bolting arm seems to be wrong."

Re the Eccentrics/Lockings Axis: "The Direction in which this moves is reversed by the alteration in the 20 Axis."

Reference: [K 41] Missing

Reference: [K 42] Folder 1

Size: 38" x 25 5/16"

Caption: Levers for cones, single teeth &c. &c.

Watermark: J. Whatman 183[1?]

Condition: Some smudges and dirt otherwise relatively clean.

Notes:

No date. This drawing shows the details of single teeth on the First Axis which drive the 1st and 2nd 20-Wheels, their starting orientation and also the Key and the end of the lever which slide them horizontally along the First Axis in and out of gear with the wheels that they drive.

Also shows details of the levers which squeeze the Cones on the Endless Screw Mechanism for Figure to Figure Motion (see also drawing [K 2]).

Reference: [K 43] Folder: 2

Size: 24 3/4" x 38 1/8"

Caption: 3 figure motion

Watermark: J. Whatman 1828

Condition:

Notes:

No date. This is a detailed drawing (plan, section, side view etc.) of the 3-Figure Motion device. It shows clearly the trip arms fitted to the Result Axis' Figure Wheel/Carrying Axis just on the top side of the Upper Platform. The spring which returns the arms after they have been acted upon is fitted to the General Platform. Also shown are the levers upon which these arms act.

Reference: [K 44] Folder: 2

Size: 25 1/2" x 38 1/2"

Caption: No caption

Watermark: J. Whatman 1831

Condition:

Notes:

This drawing comprises details (end views and sections) of the 2nd 20-Wheel group of mechanisms.

Also drawn are the two pivoting cranks which drive the ratchets on the Ratchet Wheel Axis of the Endless screw mechanism for Figure to Figure Motion.

Figures on drawing from top left (scanning from top to bottom of page then left to right):

i) in section the Ratchet Wheel (Long Eccentric) and the Arm which holds its Claw

ii) end of Pivot (Long Eccentric) which moves the Claw

iii) top view of Claw

iv) side view of the Ratchet Wheel (Long Eccentric) on its Axis and the Pivot Crank which drives it from the First Axis.

v) [from top of drawing again] section through 2nd 20-Wheel mechanism (a) Arms (fixed on the 20-Axis) which drive the 2nd 20-Wheel forward which engage suitable arms on the 3rd component of the 2nd 20-Wheel mechanism, i.e. the Stud Wheel which moves the Starting Teeth for the Great Wheel. (b) the second wheel on the Boss of the 2nd 20-Wheel, which has studs on both sides, i.e. that Stud Wheel which controls the movement of the Shades on both the (Long and Short Eccentric) Ratchet Wheels which control the movement of Figure to Figure Motion via the Endless Screw mechanism. (c) the 3rd component of the 2nd 20-Wheel mechanism, i.e. the 2nd Sine Qua Non Wheel (fixed part) for Cones, which also has the 20 teeth by which the whole of the 2nd 20-Wheel is driven by a single tooth on the First Axis. Note the long tooth on this wheel for allowing horizontal for and giving circular movement to the Movable Part of this Sine Qua Non Wheel.

vi) end view (from calculating end of DE1) of 2nd 20-Wheel group of mechanisms. Note 3 teeth of the 3rd 60-Wheel shown. Note how the 2nd 20-Wheel mechanism acts on levers which control shades on the Ratchet Wheels which allow their claws to be engaged or disengaged from their (24 toothed) ratchets. Note the Spring and Roller Wheel which locks the group of 20-Wheel mechanisms (20 positions, loose locking). Note the Single Tooth on the First Axis (also shown) in this drawing is rotating clockwise, hence the 2nd 20-Wheel and its components will move anti-clockwise in this drawing.

vii) [from top of drawing again] two figures of sections through the Short and Long Eccentric Cranks which move the Claws on the Ratchet Wheels on the Ratchet Wheel Axis.

viii) [from top of drawing again] end view of the 2nd Sine Qua Non Wheel on the 20 Axis, both the Fixed and Movable Parts, which causes the Male Cones on the Endless Screw Wheel mechanism to engage and disengage the Female Cones.

ix) section through the Movable part of the 2nd Sine Qua Non Wheel, note that its boss has short Arms by which a lever moves it horizontally along the 20-Axis to engage the Fixed Part of the Sine Qua Non Wheel.

x) [slightly to left] top view of Claw for the Short Eccentric Ratchet Wheel.

xi) section through the Short Eccentric Ratchet Wheel and its Arm which holds the Claw.

xii) [on the extreme right hand side of the drawing] end view of the Pivoting Crank on the First Axis driving the Short Eccentric Ratchet Wheel.

This drawing should be read in conjunction with drawings [U7] and [K11].

Reference: [K 45] to [K 57] Missing

Reference: [K 58] Loose

Size: 38 7/8" x 25 3/4"

Caption: Framing plates and details of rejected plans. 14th September 1831.

Watermark: None

Condition: V. dirty: oil marks, grease spots and frayed edges. Centres of wheels have been pierced using dividers or compass points.

Notes:

This drawing contains the details for some parts of the Calculating Part of DE1. Apart from the figure of a plan view over two calculating cells on the bottom, left hand side of the drawing, and the Carrying Lever with its claw on the middle of the right hand side of the drawing, the other parts remain unidentified.

Note this drawing shows details for an early version of DE1, compare the differences in these on this drawing with those on [K40] and [U4]; e.g. note the hair springs controlling the Carrying Lever and the cylinder springs used later for the same purpose.

Reference: [K 59] to [K 61] Missing

Reference: [K 62] Loose

Size: 25 3/4" x 39 5/8"

Caption: Calculating Machine, Elevation of figure wheel framing, and calc wheels, section of bolt.

Watermark: None

Condition: Torn edges, some pencilling. Dirty with oil marks and grease spots.

Notes:

This drawing contains a side and end view of the elevation of DE1. It appears to refer to an early version of DE1.

Reference: [K 63] to [K 70] Missing

Reference: [K 71] Folder 2

Size: 30 1/4" x 51 3/4"

Caption: No caption

Watermark: None

Condition:

Notes:

Drawing comprises details (end view and section) of the Frame which spans the printing end of the DE1 and which supports various shafts e.g. the 60 Wheel Axis, the Ratchet Wheel Axis (Motion from Line to Line), and Crank Axis (motion from line to line). It is clearly shown bolted to the General Platform of DE1.

Drawing shows marking out levels for the following axes (beginning at the rear side of the Engine):

i) Ratchet wheel axis motion from figure to figure

ii) Shade belonging to motion from figure to figure [fulcrum of]

iii) 60 stud wheel axis

iv) First Axis

v) The height above the General Platform of the centre of the Endless Screw Wheel upon the Long Pinion Axis [for line to line motion] is shown with a note: "The Red Line is the true, extreme line.". [See [U7] for plan view of this wheel; this component should not be confused with the Endless Screw Wheel for Figure to Figure Motion].

vi) Centre of Machine

vii) Centre of Frame

viii) Ratchet Wheel Axis motion from line to line

ix) Crank Axis Motion from Line to Line

Other notes on drawing:

Next to bolt No.1 "To the carriage of the spindle for driving returning crank &c."

Next to bolt No.3 "To fixed copper frame"

Next to bolt No.6 "To carriage of returning crank &c."

Next to bolt No.4 "To carriage of returning crank &c."

Next to bolt No.5 "No. 5 reaches from a to b [as shown]"

In middle of top view of frame about the dimension between the two frames: "To be made wider 1832".

Reference: [K 75] Folder 2

Size: 26 1/8" x 39 1/8"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition:

Notes:

This drawing appears to be a detailed drawing of an early version of the Returning Crank. Shown on the right hand side of the drawing is an end view of the Crank Arm and Wheel which drives it. On the left hand side is a plan view of the pinions which drive it. There are differences between the number of teeth shown on the wheels in this drawing from those shown in [K 86], which is in agreement with those indicated in [U11].

Reference: [K 76] Missing

Reference: [K 77] Folder 2

Size: 24 3/4" x 38 1/2"

Caption: No caption

Watermark: J. Whatman 1828

Condition: Dirty

Notes:

Drawings of the Pinion (overall 50 teeth) on the First Axis driving the Great Wheel (overall 80 teeth) in end-view and section. Shows sets of stepped, starting teeth on both wheels. Two turns of the First Axis are required for one whole turn of the Great Wheel. Note the two locking positions on the Great Wheel and the sprung Roller Lever which locks it. Note the starting teeth on the Pinion slide horizontally about an inch along the First Axis in and out of position, and that the Great Wheel cannot be moved by the Pinion when they are out of contact with those on the Great Wheel. Note the missing teeth on the Great Wheel.

Also some unidentified accounts scribbled on drawing

Reference: [K 78] Folder 2

Size: 25 3/8" x 38 7/8"

Caption: End views of general platform. Plan of framing plates next type sector &c. &c. superimposed.

Watermark: J. Whatman [1830s? not legible]

Condition: Dirty

Notes:

No date. End view of the lower part of the printing end for an early version of DE1. Cf with [K1], [K31] and [K78]. Shows some control wheels (20-Wheel Axis? and Lower 20-Wheel Axis? each has either 12 or 20 teeth etc. on it) and a section through one the main columns supporting DE1. The framing plate superimposed on the drawing in plan view.

Reference: [K 79] Loose

Size: 25 1/2" x 39 1/2"

Caption: End view of general platform and framing plate. 16th May 1832.

Watermark: J. Whatman 182[8?]

Condition: Dirty: oil marks, grease spots and frayed edges.

A similar drawing to [K 78] but not showing the control wheels.

Reference: [K 80] Folder 2

Size: 25 1/2" x 37 3/4"

Caption: No caption

Watermark: None

Condition: Dirty

Notes:

No date. Unidentified parts of DE1 (various components for driving the calculating part of DE1?). Among the figures are various plumbing blocks and bevel wheels, including a double-ended one with 50 teeth.

Notes on drawing:

Next to one of the wheels: "There had better be two recesses for the roller to drop into as the vertical axes may be put out at the end of ½ turn"

Some parts are indicated as "not wanted".

Reference: [K 81] Folder 2

Size: 25 1/2" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 1828

Condition: Very dirty

Notes:

Drawing consists of detailed figures together with numbers to be made of each of various Roller Levers which deal with the lifting and lowering (in/out of gear) of the Pin Clutches located at the bases of the various Vertical Axes in the Calculating Dept of DE1. Also shown are their Springs and support carriages. Compare details with [U4]

Among the many notes made on the drawing include the following:

"One roller lever &c. 48 Wheel"

"One roller lever the carrying axis"

"[?] roller lever the bol. axis"

"2 carriages for lever of intermediate axes

"4 carriages complete and one ... dotted line for Levers of Carrying and intermediate axes."

"The holes drawn to be used at one end of the fulcrum and the [bolts] at the other."

"Two carriages for lever of boltg axes"

"13 spring cases ... withdrawing ..."

"For ... of 48-Wheels"

"Levers of Carrying Axes"

Reference: [K 82] Folder: 2

Size: 25 3/4" x 38 5/8"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes:

Drawing comprises details of the 48-Wheels. Only one set of the driver and driven wheel has been drawn, though DE1 was to have had two identical, connected sets of 48-Wheels. See origin of motion chart, [U11].

Note the movable teeth on the driving 48-Wheel. These can be retracted in or turned into an outward active position.

Note the driving 48-Wheel has half square/half saw teeth. See [U ?].

Also shown on the same drawing are the detailed designs of various Mitre/Bevel Wheels (for driving the Vertical Carrying Axes and Bolting Axes), Plumbing Blocks, Framing Bolts (short).

Note the single locking position on the Locking Wheel fitted to the Vertical Carrying Axis' Mitre Wheel.

Notes on drawing:

Referring to the sockets for the Short Framing Bolts: "One with Boss B and three without it".

Also shown on diagram numbers of various parts to have been made: "4" of the Pillar Sockets. "4" of the Short Framing Bolts. Referring to the brackets and plumbing blocks: "4 for the 1/3 inch neck and one for the 3/4 in neck".

Reference: [K 83] Folder: 2

Size: 25 1/4" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition:

Notes:

No date. Drawing comprises details (section, side view and sketch) of an unidentified wheel with a sprung claw for a ratchet wheel and a pivot. (Part for the early version of DE1?).

Reference: [K 84] Folder: 3

Size: 25 1/2" x 37 5/8"

Caption: No caption

Watermark: J. Whatman 1827 [v. faint]

Condition: Drawing is in parts very faint.

Notes:

No date. Drawing comprises details (plan, side view etc.) of the Intermediate Wheels and Axes used to transfer results from one axis to another during difference calculations involving feedback functions.

Reference: [K 85] Folder: 3

Size: 25" x 37 5/8"

Caption: No caption

Watermark: J. Whatman Turkey Mill 1824

Condition:

Notes:

¼ scale outline plan and elevation of the main structural framing of DE1. Note central location of the punching apparatus and the location of the frame which carries the copper plate [measurements indicate Babbage allowed ca 15 inches for the length of the page (in line to line motion in the direction back to front of DE1) and ca 9 inches breadth of movement across the page (in Fig to Fig or Returning Motion) along the main longitudinal axis of the Engine]. Note the castors upon which DE1 rides are not shown on this drawing.

This drawing would have probably been used by Babbage and Clement to organise the rest of the layout of the machinery in DE1.

It seems that a sheet from an old stock of paper has been used to draw this design on. Query the watermark for the design drawn on it seems to be for the later (1832/33) version of DE1.

Reference: [K 86] Folder 3

Size: 25 5/16" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes

No date. Drawing is of the 60-Wheel group of mechanisms in side view and section showing details of the teeth, studs etc.

On the left hand side of the drawing is the 20-Axis in section. On it are shown the tooth for driving the 1st 60-Wheel (with note: "to be made to receive a 2d arm"), the 1st Communicating Wheel, and the 2nd Communicating Wheel, which drives the 2nd 60-Wheel loose on the 60 Axis.

In the middle of the drawing (in section is the 60-Axis with its wheels. Looking at the 3 wheels from bottom to top of the drawing: The first is the 1st 60-Wheel which has movable teeth. This is fixed on the 60-Axis. It has crown/transverse studs on both sides for controlling levers which put the Returning and Zig-Zag Cranks in and out of gear. The second wheel is the 2nd 60-Wheel, which has 60 crown/transverse studs for controlling the levers which operate the shade for the line to line ratchet wheel. This is loose on the Axis. The third wheel is the 3rd 60-Wheel fixed on the 60-Axis. It has spur studs which put the movable part of the 2nd SineQuaNon Wheel (see drawing [K44]) in and out of gear, and also similarly the Sector Wheel on the 20-Axis movable part. On it is written two notes: "This wheel to be left as strong as the casting will admit of" and "It will be necessary to alter this stud wheel or the levers on which it acts or both". The direction of DE1's driving handle is towards the bottom of this drawing.

On the extreme right hand side of the drawing are 2 side views of the 1st 60-Wheel and 1 of the 2nd 60-Wheel. The levers/fingers which put the Cranks in/out of gear are shown acting on the studs on the two sides of the 1st 60-Wheel. Note also that they are also connected to a Roller running round the eccentric edge of one of the SineQuaNon wheels. Shown also in side view is the manner in which the 1st 60-Wheel drives the 2nd 60-Wheel via the communicating Wheels, one which has 21 teeth driven by 60 teeth on the 1st 60-Wheel, the other has 84 teeth driving the 2nd 60-Wheel which has 240 teeth. Note the shape of the teeth on the 1st communicating wheel, half square/half saw.

There is also a side view of the Sine Qua Non Wheel with a note "To be divided and figured on the edge".

Reference: [K 87] Loose

Size: 39 5/8" x 25 5/8"

Caption: End view of printing part, frame and castor

Watermark: J. Whatman 1826

Condition: Relatively clean, torn edges

Notes:

No date. Drawing comprises details (elevation, plan, section etc.) for the two types of castor upon which DE1 was to ride. There is also a sketch drawing of the framing of DE1 in pencil.

Reference: [K 88] Folder 3

Size: 35 3/16" x 39 1/2"

Caption: Old 24 wheel and sectors &c. &c.

Watermark: J. Whatman Turkey Mill 1824

Condition: Damaged and dirty

Notes:

No date. Drawing shows details (end view and section) of the three sets of the movable sector wheels which could be screwed to the 24-Wheel on the early version of DE1. These were used when the 24-Wheel needed to be returned in fast-forward motion to its initial orientation upon completion of the punching of a whole result.

Reference: [K 89] Folder 3

Size: 25 1/4" x 38 1/4"

Caption: No caption

Watermark: J. Whatman 18[??] [too faint]

Condition: Relatively clean

Notes:

No date. Drawing comprises details (plan and end view) of the drive for the Returning and Zig-Zag Motion Cranks.

Beginning on the right hand side of the drawing there is a plan view of the First Axis with two bevel wheels (each with 36 teeth) on it, one held out of gear by means of a screw. The direction of driving handle of DE1 is towards the bottom of the drawing. Next to these bevel wheels is written "Before the groove for the tongue is cut in either of these bevil pinions care must be taken that it is fixed in the right place to bring the spur wheels in contact with the clutches at the proper time".

These bevel wheels engage one of two bevel wheels on the left. One has 72 teeth, the other 108 teeth. They drive a shaft at right angles to the First Axis which has a Spur Pinion on it with 54 teeth. This is turn drives two other wheels each with 72 teeth, one for driving the Returning Crank Axis (at the top of the drawing) and the other the Zig-Zag Motion Crank Axis (at the bottom of the drawing).

Clearly shown are the two clutches which can slide horizontally along each of their shafts in and out of gear with these wheels. Arms on the bosses of these for the levers which perform this action are shown.

On the Returning Crank Axis is another Bevel Wheel (44 teeth) which drives another Bevel Wheel (44 teeth) at right angles to the Returning Crank Axis. This is the Axis of the Crank for Moving from Line to Line. This leads off the top of the drawing.

Adjacent to the Zig-Zag Crank is the following note: "Care must be taken to fix the clutch on this axis at the same angular distance from the arms of the spur wheel as the clutch upon the axis of the returning crank is from its spur wheel when both cranks are in the position in which they rest. To secure this the clutch must not be fixed until the teeth of the wheels are cut."

On the left hand side of the drawing is the above shown in side view.

Reference: [K 90] Folder 3

Size: 25 3/16" x 38 3/4"

Caption: Clutch for ZigZag motion [Crank]. Also some framing pieces.

Watermark: J. Whatman 1826

Condition: Relatively clean.

Notes:

No date. Detailed drawing (plan and side view) of the ZigZag Motion Crank. And of two brackets which presumably support its axis above the surface of the General Platform of DE1.

Reference: [K 91] Missing

Reference: [K 92] Folder 3

Size: 25 9/16" x 39"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes:

No date. End view (viewed from the calculating end of DE1) of the frame and arch which supports the General Platform in the middle of the Engine. Note the two small additional columns underneath the engine which give rigidity and support to the General Platform. Note one has an elongated hole in it to allow horizontal axes to pass through.

Various marking out levels are given. They are the following (from the right hand side of the drawing or front of engine):

Level Distance

i) Studs 0"

ii) Barrel Axis 2.625"

iii) 3 Fig motion 4.8125"

iv) Spiral Axis 6.1875"

v) Carrying Axes and 10.2"

Long Framing Bolts

vi) Centre of the Arch 13.95"

and Machine

vii) Short framing bolts 16.7"

viii) Bolting Axes 19.23"

ix) Columns-columns 22.2"

x) Barrels-barrels 28.8"

xi) Studs 31.4"

Reference: [K 93] Missing

Reference: [K 94] Loose

Size: 39 11/16" x 25 3/4"

Caption: Sine-qua-non wheel for 3 fig motion.

Watermark: J. Whatman 1832

Condition: Relatively clean, torn edges.

Notes:

No date. This is a drawing of the Sine-Qua-Non Wheel for 3 figure motion. Note how its eccentric surface is increased by a lever which slides a movable part into place.

Note that normal eccentric surface applies to figures decimal places 5 to 18 whereas the extended applies to decimal places 1 to 4.

Drawing shows front and back views of the SQN Wheel.

The Roller lever acting on the circumference of the SQN Wheel turns on the 20-Axis.

Note the detent for releasing the Roller Lever.

Reference: [K100] Identified as [K11]. [U7] is a copy.

Reference: [K101] Marked as [U4]

Reference: [K102]

Reference: [K103] Marked as [U6]

Reference: [K104] Marked as [U3[b]]

THE U SERIES

Reference: [U 1[a]] Loose

Size: 36 7/8" x 23 5/8" Trimmed

Caption: Plan and Side Elevation of Difference Engine 1830 [in pencil: ¼ scale]

Watermark: J Whatman 1841

Condition: Relatively clean

Notes:

Also labelled: "197 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines, (Spon, London 1889) by H.P. Babbage.

Drawing is a copy of [U 1[a]], but with less detail shown. The main difference between the two is that a figure wheel has been drawn in each cage on this drawing, but not on the other.

Reference: [U 1[b]] Loose

Size:

Caption: No caption

Watermark: None

Condition: Paper greying.

Also labelled as "199 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is 1/4 scale of the Side Elevation and Plan of the Difference Engine of which [U 1[a]] is a copy. Shows more detail than [U 1[a]]. This is a drawing of an early version of DE1.

Measurements taken from the drawing:

That the length of DE1's chassis is 55.99 cms (true size 88.17").

That the length of the Calculating Part (centre of left hand end column to centre of the central column) on the drawing is 22.64 cms (true size 35.65").

That the length of the Printing Part (centre of right hand end column to centre of the central column) on the drawing is 27.20 cms (true size 42.83").

That the height of the Printing Part (from ground to top of support column) on the drawing is 28.45 cms (true size 44.80").

That the height of the General Platform (from ground to top surface of General Platform) on the drawing is 13.80 cms (true size 21.73").

That the height of the Upper Platform (from top surface of the General Platform to top surface of the Upper Platform) on the drawing is 4.14 cms (true size 6.52").

Reference: [U 2[a]] Loose

Size: 24 3/8" x 36 3/8" Trimmed

Caption: End Elevations of the Difference Engine 1830

Watermark: J. Whatman 1841

Condition: Relatively clean

Notes:

Also labelled "198 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is a copy of [U 2[b]], but shows less detail.

Scale of Drawing: ¼.

Reference: [U 2[b]] Loose

Size: 22 3/4" x 37 1/2" Trimmed

Caption: No caption

Watermark: None

Condition: Paper greying. Torn and edge torn.

Notes:

Also labelled as "198 Duplicate H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is of the end elevations of the early version of DE1. Scale: ¼.

Measurements taken from drawing:

Width of DE1 (Centre of back side columns to centre of front side columns) 15.595 cms (true size 24.56").

Width of DE1 (Centre of punch support columns (outer columns) back side to front side) 21.21 cms (true size 33.40").

Height of Calculating Part of DE1 (Ground level to top of Columns) 62.42 cms (true size 98.30").

Reference: [U 3[a]] Loose

Size: 38 1/2" x 24 1/2"

Caption: Copy of Drawing of End Elevation of the Lower Portion of the Calculating Part of Difference Engine. March 1833.

Watermark: J Whatman 1831

Condition: Relatively clean

Notes:

Also labelled "198 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix of Babbage's Calculating Engines (Spon, London 1889 by H.P. Babbage.

Drawing is a vertical section through calculating end of DE1.

Measurements taken from drawing:

Centre of Back Columns to Front Side Columns: 31.25".

Pitch diameter of that 48-Wheel which drives the 48-Wheel on the Axis on which the Barrels turn: 11.77 ins.

Pitch diameter of that 48-Wheel on the Axis on which the Barrels turn: 11.725 ins.

Outer radius of Barrel (centre of barrel to surface of stud) 4.17 ins.

Inner radius of Barrel (centre of barrel to surface of drum (in absence of stud)) 3.90 ins.

Upper surface of General Platform to upper surface of Upper Platform 7.24 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Carrying Axis 9.65 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Bolting Axis 6.08 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Calculating Axis 6.08 ins.

Pitch diameter of Wheel on Horizontal Bolting Axis 6.04 ins.

Pitch diameter of Wheel on Horizontal Calculating Axis 6.12 ins.

Height of centre of First Axis above General Platform 2.80 ins.

Diameter of First Axis 1.36 ins.

Centre of Barrels at rear of Engine to Centre of Barrels on front side 24.16 ins.

Centre of Horizontal Bolting Axis below top surface of General Platform 1.76 ins.

Centre of Horizontal Calculating Axis below top surface of General Platform 1.76 ins.

Centre of Great Axis below top surface of General Platform 7.27 ins.

Centre of Horizontal Carrying Axis below top surface of General Platform 3.84 ins.

Distance of centre of Great Axis from centre of First Axis (which is in the central plane of DE1) 10.79 ins.

Reference: [U 3[b]] Loose

Size: 24 3/4" x 39 1/16"

Caption: None

Watermark: J Whatman 1826

Condition: Dirty. Centre of some wheels patched with small pieces of paper.

Notes:

The original of [U 3[a]]. Almost the same. Main difference is that the centre of the First Axis is drawn as displaced 2 1/8" to the rear of DE1 and 1/2" lower than on [U 3[a]].

Notes on drawing:

Horizontal Bolting Axis "to be 1 inch diam.".

Horizontal Carrying Axis "to be 7/8 [inch diam.]".

On the shoe or stud at the foot of the Vertical Bolting Axis on which it rotates "to be the same size as those on the Caln Axis".

On the shoe or stud at the foot of the Vertical Calculating Axis on which it rotates "to be the same size as those on the Bolting Axis".

On the Roller Lever which runs round the surface of a front side Barrel "Mem[orand]a: All these levers to be made stronger".

Both [U3[a]] and [U3[b]] show an unidentified oblique axis (Communicating Axis?) running underneath the machine connecting (by means of a shaft and bevel wheels) the front side the Spiral Axis to the Horizontal Bolting Axis (or Eccentrics Axis's Mitre Wheel??) on the rear side of DE1. The 2 drawings of this Oblique Axis show a small difference in design of this component; one has more bevel wheels than the other.

Reference: [U 4] Loose in plan press

Caption: Plan of Difference Engine [Calculating Part] 1823-33

Size: 52 2/5" x 40"

Watermark: None

Condition: Torn and Mended

Measurements taken from drawing:

Distance between centre of Columns on front side of Engine 35.89 ins

Distance between centre of Columns front to back side of Engine 33.84 ins?

4 colours of ink used.

This is an important drawing.

Reference: [U 5[a]] Loose in plan press

Caption: Difference Engine 1823-1833

Size: 53 1/10" x 38 3/5"

Watermark: None

Notes:

This is a drawing of the an end-view taken from the calculating end of the Difference Engine.

Measurements taken from drawing

Distance of centre of First Axis to centre of 20-Axis = 6.04 ins.

Distance of centre of 20-Axis to centre of Lower 20-Axis = 2.83 ins.

Distance of centre of First Axis to centre of Great Axis = 10.87 ins.

Distance of centre of Great Axis to centre of Horizontal Calculating Axis = 6.20 ins.

Distance of centre of 20-Axis to centre of 60-Axis = 13.27 ins.

Reference: [U 5[b]] Loose in plan press

Caption: None

Size: 62 1/2" x 41" (trimmed in modern times)

Condition: Poor. Some mould spots.

Watermark: None

Notes:

Incorrectly labelled as [U6] as drawing is very similar to [U 5[a]]. Made up of two sheets joined together.

Reference: [U 6] Loose

Caption: None

Size: 26 1/2" x 25 3/4" (trimmed in modern times)

Watermark: J ... (trimmed off)

Notes:

Is a diagram of a vertical section through the Calculating Part of DE1 viewed from the calculating end of the Engine. Shows clearly in end-view the horizontal driving axes of the Calculating Part of DE1 and the Pin Clutches which drive the Vertical Bolting, Calculating and Carrying Axes. Also shows the manner in which the Barrels front and backside of the Engine and the Roller Levers which act upon them to put the Vertical Axes in and out of gear.

Reference: [U 7] Loose in plan press

Caption: Difference Engine 1823 to 1833

Size: 94 1/4" x 45 2/5"

Watermark: None

Condition: Has torn edges. Made up of two sheets of paper joined together.

Notes:

Drawing is a plan view over the printing/driving/control end of DE1, cf also [K11]. Is a layout of all the components in this part of the Engine. Taken together with [U4] this is probably the most important of the drawings of DE1 to have survived.

Reference: [U 10/1] and [U 10/2] Loose

Caption: None

Size: 25 9/16" x 19 3/16" and 25 1/4" x 20"

Watermark: None and JR 182[3?]

Condition: Torn edge, folded, in part mouldy with grease spots.

Notes:

ff 2. Incomplete mechanical notation for an early version (ca 1826) of DE1, possibly the first draft of a mechanical notation for DE1 Babbage ever drew up. Should be read in conjunction and compared with drawings [U 1[a]], [U 1[b]], [U 2[a]] and [U 2[b]].

In ink, amendments in pencil

Verso on f2 of Notation: outline of a spanner and a lever and a small incomplete timing chart of various parts of DE1's Printing Department.

Reference: [U 11] Loose

Caption: None

Size: 91 1/2" X 47"

Watermark: [Not searched for as chart too large]

Notes:

Complete mechanical notation chart for DE1 dated (in pencil) September or October 1834. Shows details for 228 parts: their names, no. of teeth in each wheel, the number of turns of the First Axis required for one complete revolution of the part concerned, chart of the Origin of Motion (trains), and timing chart showing details of the motion of each part for 3 result cycles (2 of 6 Turns of the First Axis and one of 10 Turns of the First Axis) representing the penultimate, ultimate and first result cycles on a line in the table being produced.

Reference: [U 12] Loose

Caption: None

Size: 21 3/8" x 14 1/2"

Watermark: J Whatman 1823

Notes:

Mechanical Notation Timing Charts of

(1) The operations of carriage of tens by succession (in red ink)

(2) Calculation sub-cycle (in red ink) drawn specially to show the times of locking and unlocking of the lower calculating wheels dated 26 Sep 1831. Note Calcⁿ = 4 turns of [First] Axis. Actions shown: Bolt, Half-Turn, Add and Carrying interspersed with the locking/unlocking of the Lower Calculating Wheels.

(3) A chart of options for the calculation cycles in DE1 (in pencil), i.e. settings for the barrels .

Reproduced on Microfilm B27 reel n.

Reference: [U 13] Loose

Size: 21 3/8" x 29 1/4"

Watermark: J Whatman 1823 with design

Notes:

Mechanical Notation Timing Chart in pencil of the motions of the following parts of DE1:

20-Wheel, Spiral Axis (vertical and circular motions), Crank for returning Copper Frame, First 60-Wheel, Second 60-Wheel, Third 60-Wheel, 20 Axis SineQuaNon Wheel for withdrawing Clutch of Returning Crank, First Axis, Great Axis, 20 or Printing Axis, 48-Wheel Axis, Carrying [Axis of] Table, Type Sector, Snail Wheel, Lower Calculating Wheel of 1st Difference Axis and Carrying [Axis] of 1st Difference. Details of the movement of each part for each tenth of turn of the First Axis for 14 turns of the First Axis are shown. Seems to be a chart of the operations of DE1 upon which a single column of 3 digits is being calculated and punched [Punching of the arguments of a table?]

Also (upside down) a small incomplete chart of the cycle of operations (Add, Carry, Half-Turn, Bolting/Locking) in the calculation sub-cycle for 6th, 5th ... 1st and Table Axes, also charted for 14 turns of the First Axis.

Reference: [U 20] Loose

Caption: None

Size: 24 3/4" x 20 1/16"

Watermark: Mould M...

Notes:

Printed broadsheet or poster version of Benjamin Herschel Babbage's pamphlet Babbage's Calculating Machine, 28th September 1872 on how to operate the 1832 fragment of or model Difference Engine. Reproduced on Microfilm B27 reel o.

Reference: [U 21/1] and [U 21/2] Loose

Caption: [See below]

Size: 15" x 9 4/10" (when folded)

Watermark: None

Notes:

Two folded sheets of lined paper upon which in a 'copperplate' hand copied extracts in French of M. Prony's paper on the production of his tables, Sur les grandes tables logarithmiques et trigonometriques, adaptées au nouveau système métrique décimal séance de l'Académie Royale des Sciences [de France] du 7 Juin 1824. Reproduced on Microfilm B27 reel n.

Babbage's Quarto Scribbling or Sketch Books

BAB [S14]

Q.S.B. Vol 12*: Mislabelled on cover as "List of parts before Aug 1821". Contains notes and description of Difference Engine No. 1 ca May 1830 to January 1831.

Front end of book in ink: Incomplete description by Babbage of the calculating part of DE1.

Back end of book in pencil: Rough notes and sketches by Babbage of the printing part of DE1.

Reproduced on Microfiche D15 1-2:

BAB [S16]

Q.S.B. Vol 16: Babbage's so-called Great Scribbling Book. Material Dates from 1829 onwards. Contains on page stamped with '1801' the original sketch Sept 1834 of the Great Calculating Machine (First version of the Analytical Engine). Contains also Babbage's Address list ca 1829, an inventory of his Dorset Street house. Last date in volume Aug 1853. Includes 17 loose sheets. On Microfilm B27 reel b.

BAB [S17]

Q.S.B. Unnumbered: First page of notes date from 12/9/1865. Labelled Mss on spine. This is probably volume 10 noted Babbage's Calculating Engines page 294 as the one claimed to have been used in Devonshire Street before 1825. Is Babbage's general notebook containing material dated 1825 onwards. Includes 2 loose sheets and a letter from Babbage to a pattern maker April 1836. Also lists of persons who were presented or sent a complimentary copy of the paper on Mechanical Notation, Diving Bell, Decline of Science, Life Assurance and the book of logarithms is inserted in this volume. Contains among other things notes on difference tables of logarithms, the Mechanical Notation, list of persons invited to the meeting of friends held in May 1829 to discuss the calculating machine, some rough costings of work done by Clement to put to the latter-mentioned meeting. On Microfiche D18 1-17.

Field Archives Volume 2 f57:

Amount owing by Charles Babbage to Joseph Clement for work done to his Calculating Engine to 31st December 1831. References each item to cost statements in previous accounts (item costs not given). Balance of account is given (p.19) as £1720-14s-4d with an itemised error in Clement's favour of £4-18s-0d making Babbage's debt £1725-12s-4d. Ie. some pages from the accounts for Babbage's first Difference Engine when Field acted as one of the arbitrators. They are signed 17.7.1832 by Joshua Field and Bryan Donkin.

New Developments for a Difference Engine 1834-1842

Drawings from the Analytical Engine Series [A]

BAB [A]39 12/11/1836

Adding and Circular Carrying for Difference Engine. Wheels numbered 1 to 100

Adding No. 6, Carrying No. 14 Sketch of a method of Adding and Carrying Intended for a Difference Machine Designed between 31/10/1836 and 12/11/1836 [Plan, elevations, details, description].

BAB [A]40 18/11/1836

Circular Carriage no. 5 and Difference Engine

Adding No. 7. Carriage no. 15 Sketch of a Method of Adding and Carrying with Anticipation. Intended for a Difference Machine or an Equation Difference Machine. [Plan, elevation, description] 18/11/1836.

BAB [A]99 1/3/1842

Long Pinions for Giving off Complement

Long Pinions for giving off Complement [Algebraic Addition Sketch Book 3 pp.389, 395] [Plan and Elevation] 1/3/1842

Rough sketch of an element of a Difference Engine and method of carrying consecutively 17/4/1842. (20/5/1842) [Sketch Book 5 p.119] [Plan, elevation and description]

Other Items in the Science Museum

a) Photograph of plan, side elevation and end elevation of Babbage's Difference Engine. INV 1878-4

b) Two packets containing card cutouts of gear-wheels, cams etc for Babbage's Difference Engine No. 1. Presented by King's College, London. Kept in Museum, location S.B53. CU.08.05. INV 1971-266.

Packet I labelled "Models"

In envelope

a) Card cut-out of Great Wheel dated 16th Oct 1831

80 teeth in whole circle (0.473+ Pitch, Radius 6.025-).

b) Card cut-out of Pinion for driving Great Wheel dated 16th Oct 1831. 50 teeth in whole circle (0.473+ Pitch, Radius 3.756+). Last effective tooth indicated.

c) Card cut-out of Pinion for driving Sector of 20-Wheel on Printing Axis. (30 teeth, 4" pitch diameter).

d) Card cut-out of Cam for raising Spiral Axis dated 21 Sep 1832 (Timing: .1 for raising, .1 rest up, lowering .1, .7 rest down. Minimum radius 1 15/16" Maximum radius 2 7/16").

e) Notes and Sketches

i) Levers for moving 20 Teeth from 48 Wheel. Labelled 'Approved'.

ii) Levers for moving Sine-Qua-Non Wheel and Sectors. Labelled 'Approved'. dated 17th Jan 1833.

f) Card cut-out of Bolting Lever

g) Card cut-out of Carry Lever

h) Unidentified card cut-out

i) Rejected plan for Great Wheel and its Starting Teeth, undated.

j) Final plans for the Great Wheel, its Starting Teeth ('Wings') and the Pinion which drives it , dated 19th March 1833.

i) Card cut out of Great Wheel with its Wings (88 teeth in whole circle arranged thus : 5.5 teeth Wing I, 38.5 normal teeth, 5.5 teeth Wing II, 38.5 normal teeth).

ii) Card cut-out of Pinion which drives Great Wheel (55 teeth in whole circle arranged thus : 5.5 stepped teeth, 38.5 normal teeth and 11 cut away. Timing: .1 rest, .2 increase velocity, .7 to complete revolution).

Between cardboard boards

a) Notes on Levers for putting Starting Teeth of Great Wheel in gear. Labelled 'Approved'.

b) Various models or card cut-outs of the 'Wings' of the Great Wheel of the calculating department of the Difference Engine and of the Pinion which drives it.

c) Collection of miscellaneous unidentified parts (19).

d) Scrap card for cut-outs ?

e) Card cut-out models of miscellaneous components

i) Roller Lever

ii) 60-Stud Wheel model of a Stud dated 24th Jan 1832

iii) Bolting Lever

iv) Finger on Bolting Axis

v) 3 Miscellaneous unidentified Gear Wheels

f) Card cut-out models of components for the Printing or 20-Axis department

i) 2 Models of the Single Tooth which drives the 20-Wheel dated Sep ?? [date unreadable].

ii) Model of 20-Wheel.

iii) Model of Locking Wheel and Roller Lever for locking 20-Axis, dated 15th Nov 1831.

iv) Model of a Stud for a Stud Wheel?

g) Card cut-out models of components for the Punching and Spiral Axis departments

i) Cam of Punching Apparatus (Timing: descent of punch .1875, ascent of punch .0625: total .25 of tunr of First Handle).

ii) 2 Cams from printing department.

iii) Arm for raising Spiral Axis, dated 21 Sep 1832.

iv) Roller and Arm for raising Spiral Axis, dated 3rd Sep 1831.

Packet II labelled "Models of Rejected Contrivances"

Between cardboard boards

a) Miscellaneous unidentified components. Some not Difference Engine material (Pendulum experiments?).

b) Card cut-out models of components from Punching department

i) Enlarged Type Sector Cam, dated 16th Jul 1832. (Timing: .3 lowering, .25 rest down, .15 move up, .3 rest up).

ii) Type Sector Cam. (Timing: .3 lowering, .25 rest down, .15 move up, .3 rest up).

iii) Cam for raising Spiral Axis, dated 3rd Sep 1831.

iv) 2 more Type Sector Cams.

v) Type Sector Arm.

c) Card cut-outs of components from the 20 or 24-Wheel (Printing Axis) department

i) Lever for lifting Locking Roller of 20-Wheel, dated 15 Nov 1831

ii) Cam for lifting Locking Roller of 20-Wheel, dated 15 Nov 1831

iii) Pinion and Cam for 24-Wheel, dated Sep 1831. Note by CB "Rejected the 20-Wheel and single tooth of Sepr 19 preferred".

iv) Unidentified component.

v) 24-Wheel, dated Sep 1831. Note by CB "Rejected the 20-Wheel and single tooth of Sepr 19 preferred".

vi) Lever for Shade.

d) Miscellaneous card cut-outs of components from an early (1828) verison of Difference Engine No. 1. Notes on cut-outs not in CB's handwriting. Components unidentified, one dated 10 Jan 1828.

e) 2 miscellaneous components

i) A Snail Wheel

ii) Lever upon which the stud acts to move the Shade of the line to line motion, dated 24 Jan 1832.

f) More card cut-outs or models of the Great Wheel, its starting teeth and the Pinion on the First Axis which drives it.

i) 2 Models of the Great Wheel with 'Wings'.

ii) Rejected plan of Pinion and Starting Teeth for driving Great Wheel

iii) Starting Teeth for Great Wheel, dated 16 Oct 1831

iv) Starting Teeth for Pinion which drives Great Wheel, dated 16 Oct 1831

g) Various models of the Pinion on the First Axis which drives the great Wheel of the calculating department.

Various models of the 'Wings' or Starting teeth of the Great Wheel.

c) 17 Technical Drawings of the replica of the Fragment of the First Difference Engine (1832) drawn by J.W. Harding of Munro Ltd, London N11 in 1957 for IBM. Science Museum Library reference no. M.S.P. 19.

Drg 1 Bolting Arms and Index Arms drawn 1.7.1957

Drg 2 Adding Wheel and Locking Mechanisms drawn 2.1.1957

Drg 3 Bolting and Carrying Mechanisms drawn 15.7.1957

Drg 4 Plan sectional view drawn 28.6.1957

Drg 5 Framing Plates and spacers drawn 19.7.1957

Drg 6 Miscellaneous parts drawn 25.7.1957

Drg 7 Alarm mechanisms drawn 7.8.1957

Drg 8 'Eating one's own tail' Mechanisms drawn 9.8.1957

Drg 9 Plan, side view and elevation view of top and driving mechanisms drawn 10.8.1957

Drg 10 Top Framing Plate drawn 26.8.1957

Drg 11 Driving Gear drawn 6.9.1957

Drg 12 Driving Gears drawn 10.9.1957

Drg 13 Shafts drawn 12.9.1957

Drg 14 Bottom Framing Plate drawn 12.9.1957

Drg 15 Springs and Spring Cases drawn 14.9.1957

Drg 16 Miscellaneous Parts drawn 16.9.1957

Drg 16a Carry Lever Springs drawn 7.1.1957

Total number of parts in replica: 1976

British Library Manuscripts Department,

British Museum, Great Russell Street, London WC1.

Babbage's General Correspondence and Miscellaneous Scientific Papers Additional Manuscripts 37182-37205

This is the British Library's principal collection of Babbage manuscripts. It contains the correspondence with Babbage from many of the famous mathematicians and scientists of the time from both home and abroad, interspersed with the drafts of some of his own letters, as well as a set of the manuscripts of some of his non-calculating engine scientific papers and notes. The collection was deposited by his son, Henry Prévost Babbage, in 1905.

Correspondence Files

Add. Ms. 37182 1806 - Dec 1822 ff 464

Add. Ms. 37183 Jan 1823 - Mar 1827 ff 466

Add. Ms. 37184 Apr 1827 - Dec 1829 ff 480

Add. Ms. 37185 Jan 1830 - Jun 1831 ff 561

Add. Ms. 37186 Jul 1831 - Jun 1832 ff 520

Add. Ms. 37187 Jul 1832 - Jun 1833 ff 569

Add. Ms. 37188 Jul 1833 - Dec 1834 ff 559

Add. Ms. 37189 Jan 1835 - Dec 1836 ff 509

Add. Ms. 37190 Jan 1837 - Sep 1838 ff 578

Add. Ms. 37191 Oct 1838 - Dec 1841 ff 696

Add. Ms. 37192 Jan 1842 - Dec 1843 ff 499

Add. Ms. 37193 Jan 1844 - May 1847 ff 551

Add. Ms. 37194 Jun 1847 - Dec 1851 ff 659

Add. Ms. 37195 Jan 1852 - Sep 1854 ff 570

Add. Ms. 37196 Oct 1854 - Apr 1856 ff 490

Add. Ms. 37197 May 1856 - Mar 1860 ff 507

Add. Ms. 37198 Apr 1860 - Sep 1863 ff 557

Add. Ms. 37199 Oct 1863 - 1899 ff 610

Add. Ms. 37200 Undated: Correspondents A - L ff 513

Add. Ms. 37201 Undated: Correspondents M - Z ff 645

Sir Robert Peel Collection:

Add Ms 40419 f154 Letter from Babbage to Sir Robert Peel, dated 7th April 1835: transmitting to him a copy of the statement he had made to the Duke of Wellington about his Calculating Machine on 23th Dec 1834.

Add Ms 40516 f265 Letter from Babbage to Sir Robert Peel, dated 8th October 1842: requesting the latter to come to a decision about the government's intention on the question of the Difference Engine.

Add Ms 40516 f267 Peel's reply to Babbage on the above, dated 4th November 1842. Passing responsibility to Goulburn to convey their joint views.

Add Ms 40611 f181 Copy of the Statement addressed to the Duke of Wellington dated 23rd December 1834 on the Calculating Machine.

Cambridge University Library

West Road, Cambridge CB3 9DR

Telephone 0223-333000

Cambridge Philosophical Society Archives.

Babbage Collection

Mathematical and Astronomical Tables

ADD 8705 37.

(a) Proof copy (17x10) printed from stereotype plates of part of the great French table made under the direction of Prony. The table was never published. There is a note by Babbage to the effect that this copy was given to him by Didot on his first visit to Paris.

(b) Manuscript of a table of logarithms (15x9.5) with a note by Babbage stating that it was copied from an original Ms at the Observatory of Paris.

(c) A double sheet (15x9.5) containing a fair copy of some series for computing logarithmic differences. The computed differences would be used as settings for the Difference Engine.

ADD 8705 18.

A bundle consisting mainly of correspondence and working papers from the year 1827 relating to the comparisons made by Babbage of logarithmic and trigonometrical tables from various sources. The letters are from Henry Jenkins to Dr Young, from David Booth to Babbage, from Woolgar to Davies Gilbert, and from Davies Gilbert to Babbage. Some of them are quite critical of the design and layout of Babbage's Table of Logarithms. Included also in the bundle are notes on the Errors in Chinese tables; Notes on the Trials of colored paper by candlelight; A sheet dated 14 Dec 1826 of Logarithmic comparisons made by Sergt. James McKay and Private John Strahen Royal Sappers, Ordnance Survey Office, Phoenix Park [Dublin]; and a printed table of Proportional Parts. A single sheet (7.5x6) has noted on it some errors in Taylor's tables. On the back are 'Hints for Travellers'; for example, 'do not be afraid to ask the price of articles and meals'. The bundle includes a bill from the printer for preparing Babbage's table of logarithms, and some correspondence with a bookbinder.

ADD 8705 44.

A copy of the ultimate edition dated 1889 of Babbage's logarithms. It contains Henry P. Babbage's autograph together with details of the financial arrangements made by him with William Clowes, the printer.

ADD 8705 19.

A single sheet (11.5x9.5) containing a note dated 21 March 1858 and initialled by Babbage recording a conversation with Mr Hind, Director of the Nautical Almanac, about Hansen's new lunar tables. They give better results than the previous tables, but the computations take twice as long. Sixty errors, not mentioned in the list of errata, have been discovered.

Machinery

ADD 8705 21.

A single sheet (9x8) headed On a method of expressing the action of machinery. Evidently an introductory paragraph for some projected account.

ADD 8705 22.

A double sheet (15.5x9.5) on one side of which is a notation for division in the Analytical Engine. Also, a single sheet of the same size with a rough notation - apparently also for division- on one side, and some jottings and a couple of rough sketches on the other. A third sheet (16x12.5) has roughly written on it, in pencil, charts illustrating options for the general calculation and printing cycles of Babbage's first difference engine, n.d. watermark 1826.

Notebooks and scribbling books

ADD 8705 23.

A small notebook (8.5x7) Labelled 1825 on front cover and endorsed on the first page 'St Michael's Hill, 29 July 1825' and full of miscellaneous notes on the things that caught Babbage's attention at the time. There is an index at the front. Contains notes on his stay in Paris in 1826, including a visit to Gambey's workshop where those techniques which inspired him were copied down in this notebook. Notebook contains what appear to be sketches of designs for various components of the printing part of Difference Engine No. 1.

ADD 8705 38.

Account book used as a notebook. Much of it is taken up with notes on the rotation of needles by electricity. These have dates 1826 and 1830. Between December 1832 and 1838 the book was used to record calculations made by Babbage using the Fragment Difference Engine (1832), now in the Science Museum. Also contains notes on turning tool edges.

Public Record Office

PRO Kew Division,

Ruskin Avenue, Kew, South West London.

Treasury Department Archives

The following are the papers relating to the development of Babbage's Difference Engine No. 1 to be found in the British Government's Treasury Department's archives.

The following list was compiled from the box of Babbage papers referenced as T1/3428, also known as 'Long Bundle 17', and the Treasury Papers and Letters-In Register T2. Each item in the list below is headed by its year of entry in the T2 Registers and the serial number assigned to it by the then clerks of the Treasury.

The Minute Books of the meetings of the Board of the Treasury are to be found in T29; Out-Letters to the Auditors in T6; Out-Letters General File T27; Out-Letters to the Commissioners of Woods, Forests and Land Revenues in T25.

1823-6158

Copy of the 12 page printed quarto edition of Babbage's letter to Sir Humphry Davy dated 3rd July 1822.

Registered/Received 21st March 1823

Read 25th March 1823

1823-9621

Letter from the Secretary of the Royal Society [Wm. Thos. Brande] to the Treasury dated 1st May 1823 on Mr Babbage's Invention for the purpose of Calculating and Printing Mathematical tables. [Item printed: see Papers of the Parliamentary Session 1823 Accounts and Papers (2) Vol XV page 9 Paper No. 370 -Copies of the Correspondence between the Lords Commissioners of His Majesty's Treasury and the President and Council of the Royal Society, relative to an Invention of Mr Babbage.]

Registered/Received 1st May 1823

1823-15012

Letter from members of the Royal Society respecting Mr Babbage's Invention for constructing numerical tables dated London, 3rd July 1823.

Registered/Received 11th July 1823

Read 11th July 1823

1828-22672

Mr Babbage with a statement and papers respecting his Calculating Machine dated 11th December 1828.

Registered/Received 23 Dec 1828

Read 23 Dec 1828

a) Copy of Babbage's letter to Duke of Wellington, 11th Dec 1828

b) Minute of the Board of Treasury, 23rd Dec 1828

c) Statement (11th Dec 1828) respecting Mr Babbage's Calculating Machine and Of the Utility and Present State of the Calculating Engine.

Enclosures:

A. Parliamentary Paper 1823 No. 370 reprint of Babbage's Letter to Sir Humphry Davy and including the correspondence between the Treasury and the Royal Society, and the Report of the Committee of the Royal Society convened to examine the proposal.

B. Speech of the President of the Astronomical Society, Mr Colebrooke on presenting Babbage with the gold medal of the Society.

C. Offrint of Francis Baily's paper on the Utility of Mr Babbage's Calculating Engine, published as Article LVIII in Phil. Mag. May 1824, pp 355-366. Printed by Richard Taylor, London.

D. Reply as published in the Times 19 Aug 1828 of Mr Herschel to a statement re Babbage's Engine.

d) Tied up in same bundle 3 pages of a foolscap printed paper signed by I.T.W. Herschel Chairman: "Report of the Committee, appointed by the Council of the Royal Society, to consider the subject referred to in Mr. Stewart's Letter, relative to Mr Babbage's Calculating Engine and to report thereon."

1829-2964

Secretary of Royal Society with copy of a report and resolution respecting Mr Babbage's Calculating Engine dated 16th February 1829

Registered/Received 21st February 1829

Read 24th April 1829

a) Letter from P.M. Roget, Secretary of the Royal Society to J. Stewart, 16th Feb 1829.

b) Report of the Committee of the Royal Society Feb 1829

c) Handwritten minute of the Council of the Royal Society 12th Feb 1829.

d) Minute of the Treasury 28th April 1829

e) Babbage to Richard Penn 18th April 1829

Associated papers held in same bundle:

a) 12th May 1829 Opinion of Mr Babbage's Personal Friends respecting the Calculating Machine in Babbage's handwriting.

b) Babbage to Duke of Wellington 13th August 1829

c) Babbage to Henry Goulburn 24th November 1829

d) Babbage to Lord Ashley 25th November 1829

e) Minute of Treasury 24th November 1829 second reading of 2964/1829

1830-21516

A letter from Babbage to the Chancellor of the Exchequer requesting payment of a sum due to him on Account of his Calculating Machine dated 20th December 1830

Registered/Received 21st Dec 1830

Read 21st December 1830

a) Babbage to Chancellor of the Exchequer 21st Dec 1830 together with an Account of Expenditure on the Machine

b) Minute of the Treasury 21st Dec 1830

1830-21785

A letter from Chas. Babbage to the Treasury relative to the expenses of the Calculating Machine invented by him dated 23rd December 1830

Registered/Received 23rd Dec 1830

Read 24th December 1830

a) Babbage to Treasury 23rd December 1830

b) Minute of Treasury 24th December 1830

1830-22144

A letter from the Secretary of the Royal Society acknowledging receipt of a communication relative to Mr Babbage's application for an additional sum of money towards carrying on the construction of his calculating machine dated 27th December 1830.

Registered/Received 30th Dec 1830

Read 31 Dec 1830

a) P.M. Roget Secretary of Royal Society to Treasury 27th Dec 1830

1831-8557

Letter from the Secretary of the Royal Society dated 14th April 1831 enclosing reports of Committee and Council of the Royal Society.

Registered/Received 2nd May 1831

Read 5th July 1831

a) P.M. Roget Secretary of Royal Society to Treasury 14th April 1831

b) Report of Committee of the Royal Society Feb 1829

c) Report of the Council of the Royal Society (printed) Feb 1829

d) Handwritten Report of Committe of Royal Society March 26th 1831.

Associated papers in same bundle:

a) Letter P.M. Roget to Treasury 9th May 1831

b) Letter P.M. Roget to Treasury 22nd June 1831

c) Minute of the Board of Treasury 5th July 1831

1831-8558

Communication from the Commissioners of Wood, etc. with a report relative to the proposed removal of Mr Charles Babbage's Calculating Engine, from Lambeth to Dorset Street [Nr.] Portman Square dated 30th April 1831

Registered/Received 2nd May 1831

Read 3rd May 1831

a) Letter and Report 30th April 1831

b) Minute of Treasury 3rd May 1831

1831-13178

A letter from Babbage to the Treasury with an application for sums advanced by him for works done to his Calculating Machine dated 5th July 1831.

Registered/Received 5th July 1831

Read 12th July 1831

a) Babbage to Lords of the Treasury 5th July 1831

b) Babbage to J. Stewart 5th July 1831

c) Minute of the Treasury 12th July 1831

d) Babbage to Lords of Treasury 18th July 1831 with an account of expenditure of sums issued to him to defray charges for the Calculating Machine.

1831-15302

A letter from P.M. Roget Secretary of the Royal Society to the Treasury on the subject of appointing an engineer to examine Mr Babbage's Calculating Machine dated 29th July 1831.

Registered/Received 3rd August 1831

1831-15310

Communication from the Commissioners of H.M. Woods, etc. with a Report with drawings, in specification, and estimate of cost of proposed arrangement for removal of Mr Babbage's Calculating Engine to Dorset Street Manchester Square dated 29th July 1831.

Registered/Received 3rd August 1831

Read 19th August 1831

Action: Write to Commissioners of Woods, etc. (19th August 1831)

a) Commissioners of Woods report 29th July 1831

b) Minute of Treasury (4th Div) as to purchase of Mr Babbage's premises, 19th August 1831

1831-16283

Mr Speer and Mr Brooksbank (Treasury Auditors) report on the account of Chas. Babbage Esq. in respect of sums issued to him to defray the expenses of the Calculating Engine dated 12th August 1831.

Registered/Received 18th August 1831

Read 26th August 1831

a) Speer and Brooksbank letter 12th August 1831

b) Copies of Babbage's Statement 5th August 1831

c) Speer and Brooksbank's Statement 12th August 1831

d) Letter Praeds and Co. to Babbage dated 4th August 1831 re a draft paid to Clement for £144-9-3 on 2nd April 1830.

e) Note Babbage to Speer and Brooksbank 15th August 1831

f) Report of Committee of Royal Society March 26th 1831

g) Minute of Treasury (6th Div) 26th August 1831.

1831-19114

Babbage to the Treasury for a further issue on account of his calculating machine dated 29th September 1831.

Registered/Received 29th September 1831

Read: 30th September 1831

a) Babbage's Letter to the Treasury 29th September 1831

b) Minute of the Treasury 30th Sept 1831

1831-20002

Commissioners of His Majesty's Woods, Forests and Land Revenues further report relative to the proposed arrangement for the removal of Mr Charles Babbage's Calculating Engine to Dorset Street Manchester Square dated 13th October 1831.

Registered/Received 14th October 1831

Read 25th October 1831 (Sundries, 4th and 6th Div)

a) Report of the Commissioners of Woods, Forests etc. 13th October 1831

b) Minute of Treasury on Buildings for Calculating Engine 25th October 1831

c) Letter Babbage to Lord Althorp 6th January 1831

d) Babbage's Instructions to Jearrad No.1

e) Babbage's Instructions to Jearrad No.2

f) Letter Babbage to Wickham 6th January 1831

g) Chas. Jearrad's Surveys

Report No. 1 Jan 6th 1831

Report No. 2 and abstract of expenditure Jan 15th and 18th 1831

h) Abstract of Expenditure and Rental as according with Report No. 2 [Jearrad Jan 18th 1831]

1832-2503

Surveyor General of Works to Treasury with application from Mr Decimus Burton Architect employed in erecting buildings for reception of Mr Babbage's Calculating Machine for an advance of £1000 dated

Registered/Received 7 February 1832

Read 10th February 1832

a) Letter from the Surveyor General of Works

b) Minute of Treasury 10th February 1832

1832-3720

Charles Babbage to Treasury enclosing Account and Voucher of Sums expended on his Calculating Machine and requesting an issue on account thereof dated 23rd February 1832.

Registered/Received 25th February 1832

a) Babbage's Letter and sundry enclosure 23rd Feby 1832

b) Account (July 1831-December 1831) for £1701-10-5½.

1832-5123

Report of Mr Speer and Mr Brooksbank on the second account [see 3702 above] of Chas. Babbage Esq. in respect of sums issued to him to enable him to proceed in constructing a Calculating Engine dated 10th March 1832

Registered/Received 17th March 1832

Read 27th March 1832

a) Speer and Brooksbank's report and statement of account 10th March 1832

b) Minute of Treasury 27th March 1832

1832-7943

Commissioner of Woods, etc. request for an issue of a further sum [£683-9-0] for the completion of the Building for Mr Babbage's Machine dated 13th April 1832

Registered/Received 25th April 1832

Read 1st May 1832

a) Letter 13th April 1832 Office of Woods to Treasury

b) Minute of Treasury 1st May 1832

c) Copy of D. Burton to Milne 29th March 1832 and 5th April 1832

1832-9546

Mr Babbage further for issue of £1701-10-5½ on account of Calculating Machine, dated 18th May 1832

Registered/Received 18th May 1832

a) Babbage to Treasury 18th May 1832

b) Babbage to J. Stewart 18th May 1832

1832-9862

Treasury Auditors (Speer and Brooksbank) on letter from Mr Babbage requesting further issue of money on account of Calculating Machine dated 23rd May 1832.

Registered/Received 24 May 1832

Read 29th May 1832

a) Speer and Brooksbank to Treasury 23rd May 1832

b) Minute of Treasury 29th May 1832

1832-13451

Babbage to Treasury with copies of the correspondence respecting removal of his calculating machine to premises in East Street dated 14th July 1832 with 4 enclosures. (see 33149)

Registered/Received 16th July 1832

Read 12th September 1832

a) Letter Babbage to Treasury 14th July 1832

b) Letter Babbage to J. Stewart 14th July 1832

c) Letter Clement to Babbage 6th July 1832 Memorandum No.1

d) Letter Clement to Babbage 6th July 1832 Memorandum No.2

e) Copy of Letter Babbage to Clement 18 May 1832

f) Minute of Treasury 12th September 1832

g) An Account of Sums issued on account of Mr Babbage's Calculating Engine [Total expended including Building £14938- 17-6 excluding estimated cost of the building for housing the Calculating Engine £12340-16-6]

h) Particulars of the proposal, or demand made by Mr Clement, the Engineer employed upon Mr Babbage's Engine upon its removal to East Street.

1832-14777

Mr Babbage with Bill for Calculating Machine to 30th June 1832 and requesting issue of that amount of money dated 4th August 1832.

Registered/Received 4th August 1832

a) Babbage to J. Stewart 4th August 1832

1832-16205

Messrs Speer and Brooksbank's report to the Treasury on the account of Mr Chas. Babbage in respect of the sum of £1701- 10-7 paid him by Mr Sargent on the 9th June 1832 on account of the Calculating Engine and relative to the payment of a further claim of £1956-5-11½ for works performed by Mr Clement requested in 14777/32 above to the 30th June 1832. Report dated 20th August 1832.

Registered/Received 23rd August 1832

Read 1st Sept 1832

a) Speer and Brooksbank to Treasury together with a statement of the account dated 20th August 1832

b) Minute of the Board of the Treasury, 23 Augt 1832

1833-6049

Mr Chas. Babbage to Treasury detailing certain difficulties between himself and Mr Clement in regard to the Calculating Machine dated 28th March 1833.

Registered/Received 29 March 1833

a) Babbage to J. Stewart 28th March 1833

b) Copy of Clement to Babbage 26th March 1833

c) Babbage to J. Stewart 28th March 1833 (Letter No.2)

1833-6050

Mr C. Babbage with Mr Clement's Account for the Calculating Engine and requesting an issue for payment thereof dated 28th March 1833

Registered/Received 29th March 1833

a) Babbage to Treasury 28th March 1833

b) Statement of Account to 29th Dec 1832 £1782-11-4¼: examined articles Feby 8th, examined account Feby 20th: signed Donkin and Field.

1833-6570

Commissioners of Woods, etc. to Treasury for an amount to pay the expenses of the erection of the building for Mr Babbage's Calculating Machine [total expended £2452-3-6] dated 4th April 1833.

Registered/Received 4th April 1833

Read 4th April 1833

a) Office of Woods etc (H.H. Seward) to Treasury (A.G. Spearman): Total Amount spent £2190-13-6 or estimated total when complete £2452-3-6 for building works.

b) Minute of Treasury: Commissioners of Woods, etc to repay the sum of £1000 advanced from Civil Contingencies fund, dated 4th April 1833.

1833-9626

Speer and Brooksbank to the Treasury on the Account of Mr C. Babbage in respect of sums on account of the Calculating Engine in respect of the Sum of £1956-5-11 paid to him by Mr Sargent on the 20th September 1832 and on the subject of a further Bill of £1782-11-4 for works performed by Mr Clement for the Engine to 31st Dec 1832, dated 7th May 1833. [See 1833-6050].

Registered 17th May 1833

Read 24 May 1833 and 13th August 1833

a) Speer and Brooksbank to Treasury 7th May 1833 with a statement of the Account.

1833-9883

Mr Babbage Esq. requests that future issues on account of Calculating Machine may not pass thro' his hands dated 20th May 1833. See 1833-9626.

Registered/Received 21st May 1833

Read 24th May 1833 and 30th August 1833

a) Babbage to J. Stewart 20th May 1833

b) Copy of Letter Clement to Babbage 13th May 1833

c) Minute of Treasury 24th May 1833

d) Babbage to J. Stewart 20th May 1833 (2nd Letter)

1833-14368

Mr Joseph Clement's proposals for continuing work on Mr Babbage's Calculating Machine and for payment of his accounts dated 22nd July 1833.

Registered/Received 23rd July 1833

Read 13th August 1833

a) Clement to the Lords Commissioners of the Treasury, 22nd July 1833.

1833-14836

Mr Babbage regarding the removal of the drawings and finished parts of the Calculating Engine into the fire proof house dated 29th July 1829.

Registered/Received 30th July 1833

Read 13th August 1833

a) Copy of Letter Clement to Babbage 22nd July 1833

b) Babbage to Treasury 29th July 1833

c) Babbage to Stewart 29th July 1833

1834-2043

Joseph Clement requesting that some measures be adopted for the Examination of his accounts in regard to the Calculating Machine, and for a settlement of his claim, dated 30 January 1834.

Registered/Received 30th January 1834

Read 4 February 1834

a) Clement to Treasury 30th January 1834

b) Minute of Treasury 4th Feb 1834

1834-13850

Mr Babbage apprizing the Board [of Treasury] of the Drawings etc. of the Calculating Machine having been all deposited in the fire proof building and requesting instructions as to the further progress thereof, dated 16th July 1834.

Registered/Received 17th July 1834

Read 18th July 1834 and again 12th Aug 1834

a) Babbage to Treasury 16th July 1834

1834-14831

Mr J. Clement enclosing his account for work done to the Calculating Machine to the 12th March 1833, dated 29 July 1834.

Registered/Received 30th July 1834

a) Clement to Treasury 29th July 1834

b) Statement of Account to 12th March 1834 [1833] signed Bryan Donkin and Joshua Field 13 June 1834 £1200-13-6½

1834-14932

Mr Clement that the Expense of removing the Calculating Engine to the Fire Proof Building in East Street amounts to £156-16-2, dated 31st July 1834.

Registered/Received 1 August 1834

Read 4th August 1834

a) Clement to Treasury about Removal Costs of £156-16s-2d included in account above dated 31st July 1384

1834-15159

Mr Speer with a report on Mr Clement's Bill for works performed to the Calculating Machine subsequent to the termination of the year 1832 and for the expense of its removal to East Street amounting together to £1200-13s-6½d. See 13850, 14831, 14932. Dated 4th August 1834.

Registered 5th August 1834

Read 12th August 1834

a) Speer to Treasury 4th August 1834

b) Minute of the Treasury 12th August 1834

1835-20447

Commissioner of Woods Etc. Estimate of the Sum requested for certain repairs of the Building erected for Mr Babbage's Machine, dated 17th October 1835

Registered/Received 19th October 1835

Read 13th November 1835

a) Commissioners of Woods and Forests to Treasury 17th October 1835

b) Copy of letter from Decimus Burton 5th October 1835 to Henry Hake Seward of the Office of Woods etc.

1842-16942

Letter from Babbage to Treasury

Registered/Received Friday 19 August 1842

Assigned Sir G. Clerk

Archives of the Surveyor General of Works

Current File Reference: WORK 12-62/8

Is contained in two folders: ff 1-40 and 41-68

[Maps and Plans of the Building intended to house the Difference Engine have gone missing].

Files Contain copies of the following letters and reports.

Folder 1 ff 1-40:

Babbage to D. Burton 19th April 1831

D. Burton to Milne of the Office of Woods 21st April 1831

Office of Woods to Treasury 30th April 1831

Treasury to Office of Woods 6th May 1831

Office of Woods to D. Burton 20th May 1831

D. Burton to Milne of the Office of Woods 1st July 1831

Copy of Letter Babbage to D. Burton 19th April 1831

Babbage to D. Burton 1st July 1831

D. Burton's Specification for the Building 1st July 1831

Milne to D. Burton 12th July 1831

Burton to Milne 14th July 1831

Babbage to D. Burton 14th July 1831

Office of Woods to Treasury 29th July 1831

Treasury to Office of Woods 19th August 1831

Milne to Burton 12th September 1831

Burton to Milne 24th September 1831 with statement of the separate expenses of construction the different buildings required.

Babbage to D. Burton 16th September 1831

Office of Woods to Treasury 13th October containg Babbage's reasons for making the workshops a permanent erection dated 31st August 1831.

Another Letter Office of Woods to Treasury dated 13th October 1831.

Folder 2 ff 41-68:

Treasury to Surveyor General 31st October 1831

Treasury to Commissioners of Woods 31st October 1831

Office of Woods to Major General Stephenson 15 Nov 1831

William and Lewis Cubitt (Grays Inn Road) to Stephenson 30th November 1831 willing to build for £1890

D. Burton's certificate of 2/3rds completion by the Cubitts February 2nd 1832, £1000 due to them.

D. Burton to Stephenson 6th February 1832

D. Burton's full "Specification for Erecting and finishing, building to contain Mr Babbage's Calculating Engine, Workshops &c. and of Alterations and repairs to the adjoining house in East Street Manchester Square": tender k document dated 12th November 1831.

PRO Chancery Lane Division

Chancery Lane, London WC1

Papers of the Crown Estate Commissioners (Formerly Commissioners of H.M. Woods, Forests and Land Revenues). The CONSTAT Papers or papers containing instructions from the Treasury to the Commissioners of Woods, Forests etc.. Papers relate to the construction of a building and workshops for Babbage's first Difference Engine next to his house in Dorset Street in 1831/32. :

CRES 6 152 volume H7 Pages 173-225

Office of Woods, etc to Treasury 30th April 1831

D. Burton to Office of Woods, etc 21st April 1831

Babbage to Decimus Burton 19th April 1831

Treasury to Office of Woods, etc 6th May 1831

Office of Woods, etc to Treasury 29th July 1831

D. Burton to Office of Woods, etc 1st July 1831

Babbage to Decimus Burton 19th April 1831

Babbage to Decimus Burton 1st July 1831

D. Burton to Office of Woods, etc 14th July 1831

Babbage to D. Burton 14th July 1831

Treasury to Office of Woods, etc 19th August 1831

Office of Woods, etc to Treasury 13th October 1831

D. Burton to Office of Woods, etc 24th Sept 1831

Babbage to D. Burton 16th September 1831

Babbage on making the workshops permanent 31st Aug 1831

Treasury to Office of Woods, etc. 31st Oct 1831

Office of Woods to Treasury 13th April 1832

Treasury to Office of Woods, etc 9th May 1832

CRES 6 174 volume F8 Pages 310-319

Office of Woods,etc to Treasury 22nd November 1842

Treasury to Office of Woods 7th November 1842

Extract of Lease of Babbage's land 1st Dec 1831

Treasury to Office of Woods, etc 21st December 1842

Royal Society of London,

6 Carlton House Terrace, London SW1Y 5AG

Babbage/Herschel Correspondence

Volume 2 of the Herschel Collection (HS.2): 418 letters with Sir John Herschel beginning 1812. Both sides of the correspondence is contained in the collection. Also included are letters from both Babbage's mother and wife to Herschel and his replies to them.

Volume 20: Herschel's replies to Babbage's letters

Box 27 Items 42 to 54 Herschel's 1827/28 correspondence relating to Babbage's Calculating Engine when Herschel was superintendent of the work during Babbage's year long continental tour:

42 Herschel's notes for Babbage 13th Feb and 17th Apr 1828

43 Clement to Herschel 5th Dec 1827

44 Clement to Herschel 1st Feb 1828

45 Clement to Herschel 27th Mar 1828

46 Clement to Herschel 10th Jun 1828

47 Clement to Herschel 21st Jul 1828

48 Herschel to Clement 24th Jul 1828

49 Herschel's Accounts 1828

50 H. Goulburn to Airy 15th Sept 1842

51 Herschel to Goulburn 1842 report on Babbage's Difference Engine

52 Herschel to Babbage n.d.

53 William Parsons to Herschel 6th Jul 1852

54 Herschel Notes and cuttings n.d. and 1828

Other Collections

Mss of 5 Scientific papers submitted by Babbage to the Royal Society 1815-26

25 Letters Babbage to Sir J.W. Lubbock 1829-60

Letters and papers of three committees set up by the Royal Society in 1823, 1829 and 1831 to consider Babbage's difference engine and the question of Government aid towards its construction. DM.4.129-50.

Museum of the History of Science,

Old Ashmolean Building,

Broad Street, Oxford OX1 3AZ.

Harry Wilmot Buxton Collection

Buxton Ms 3: Neat fair copies in a single volume of the following Babbage Mss: (a) The Science of Number reduced to Mechanism, dated part way through November 1822 otherwise undated; and (b) On the mathematical powers of the Calculating Engine, dated December 26 1837. The volume bears a watermark for 1832. 1 vol folio.

Buxton Ms 5: Statement of the circumstances ... by Sir Harry Nicolas, 1843 Printed.

Buxton Ms 7: Babbage Mss notes and some correspondence dated 1822-1858 and 1 undated mainly concerning his engines. Another copy of Ms 5 above and a printed copy of Babbage's letter to the Head of Government (Earl of Derby) dated June 8th 1852: the letter deals with the history of Babbage's relations with Government; it has manuscript annotations requesting its return to Babbage which seem to indicate that it was circulated by Babbage on loan to various persons.

Buxton Ms 8: Transcriptions of Babbage Mss dated 1824-1843 by Buxton on Babbage's engines, 1 file.

Buxton Ms 9: The science of number reduced to mechanism, notes and drawings on the engines, letter from Babbage to Buxton (1863).

Buxton Mss 16 and 17: Ms of the Memoir of the life and labours of the late Charles Babbage, ... by H.W. Buxton (1871). 2 volumes.

B. MINOR COLLECTIONS

Board of Longitude Papers

Royal Greenwich Observatory

[Now transferred to Cambridge University Library]:

J.F.W. Herschel was appointed a commissioner of the Board of Longitude on 7th June 1821: he attended a meeting of the Board that day and also on 1st November 1821. This latter date is significant as it was the day Babbage considerably revised the design of his first Difference Engine. Suprisingly Babbage's Difference Engine is not mentioned in any of the BoL's papers, but a note for November 1825 did say that Babbage was in possession of a set of logarithms more accurate than Taylor's.

Wanganui Regional Museum,

PO. Box 352, Wanganui, North Island, New Zealand.

Collection of Charles Babbage and Family Papers, Box 22:

Donated by Henry Herschel Babbage (1873-1946) and Mrs Jean Babbage.

Babbage's manuscript for his autobiography Passages from the Life of a Philosopher (1864), with many corrections, insertions etc., in envelopes bearing postmarks dated 1862- 1863. Published version in some instances considerably revised from original manuscript draft version(s) especially in the chapter on the 1862 Exhibition and Babbage's views on Disraeli: the published versions of the condemnations are quite mild in comparison with the original Ms versions. The Chapter on the Difference Engine is entitled Boy's Own View of Cal

DE1 Archives