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Originally published in the Bulletin of the Scientific Instrument Society No.113, June 2012
William Ford Stanley was possibly the premier maker of drawing instruments in Britain in the late nineteenth century, as well as being an important maker of surveying instruments. However, he was more than just a manufacturer; he was a prolific inventor as well. His authoritative books on drawing instruments and surveying instruments1,2 made claims to various inventions, but it was a statement in Cecil J Allen’s history of the firm3 that 78 patents were registered at the patent office in his name that really awakened my interest. As I was making regular visits to London for SIS meetings, I decided that this would be an ideal opportunity to hunt these patents down in the British Library.

In fact, searching the index, I found 79 in the name of W F Stanley and I already had a copy of one US patent of his. Not all of these were instrument patents and I will mention some of the others in due course. Of the 79 listed in the index, 26 could not be found, mostly because they were abandoned or void, but in at least one case the number in the index appears incorrect. All 79 from the index are listed in Appendix A. Whilst one can look at the patent specifications in the British Library they cannot be copied there. The later ones (from ca. 1895) can be downloaded and printed from the espacenet web site whilst copies of the remainder have to be ordered from the Intellectual Property Office. In general the date quoted is that of the application.

Drawing Instruments
The earliest patents were for drawing instruments so I shall commence with these:

Application of Aluminium in the Manufacture of Mathematical Instruments, 1861 (10th December) No. 3092 (Provisional only)

This patent was intended to cover the use of aluminium in all sorts of geometric drawing, surveying and nautical instruments.  However the claim appears to really cover the use of a steel plate in the centre and steel washers between other mating surfaces in sector and knee joints to avoid the soft aluminium wearing. He also claimed this improvement to apply to other metals.
Fig 1 - Stanley’s type B, nut and bolt needle point (Patent GB1863/226)
Mathematical Drawing Instruments, 1863 (26th January) No. 226

This patent was far more significant and actually included a number of unrelated devices; in all, five claims:

1. An instrument for drawing large radius arcs based on the same principle as a centrolinead.
2. Compasses having crossing or converging stay rods between the legs to keep them parallel.
3. Spring bows with knee joints and the adjusting screw below the knee joints, to the points perpendicular to the drawing surface.
4. Securing the needle of a compass by passing it through a hole in a bolt drawn tight by a nut (later known as Stanley’s type B point or a ‘nut and bolt needle point’. (Fig.1)
5. A spring loaded needle point for compasses (later know as Stanley’s type A point). (Fig.2)

Stanley provided both the types of needle point in his highest quality sets and the nut and bolt type (claim 4) became virtually a universal standard once the patent expired.
Fig 2 - Stanley’s type A, spring needle point
(Patent GB1863/226)
Fig 3 - Conchoidograph (Mathematical Drawing Instruments, W F Stanley, 1900)
Fig 4 -
Optical compass (Mathematical Drawing Instruments, W F Stanley, 1900)
Mathematical Drawing Instruments, 1866 (5th March) No. 664 (Provisional only)

This patent also included five claims:

1. An improvement to the geometrical pen to produce hypocycloid and epicycloid curves.
2. An improvement to the instrument used to draw conchoid curves by changing the bed from an inverted L shaped one to a T shaped one. The instrument could also be used as a semi-elliptic trammel. (Fig.3).
3. Improvements to the rolling centrolineut (sic) for producing curves and radial lines in perspective drawing.
4. The addition of two mirrors to as pair of compasses, functioning in the same way as the mirrors on a sextant, together with an eyepiece to give the perspective position of objects by reflection, such that they can be transferred directly to a drawing (Fig 4).
5. A variant of the optical compass described in 4 where the legs are parallel bars.

Drawing Boards, Straight Edges, &c, 1870 (15th August) No. 2264

This patent was concerned with the use of metal reinforcing to drawing boards and other wooden drawing apparatus to resist the unequal contractile forces in the wood. The metal reinforcing could be through the wood across the grain or at the edge where it could also form a sliding or drawing edge. Various embodiments of this were illustrated.

Where rods were inserted through several boards they could be threaded at the end and used to clamp the boards together. Stanley’s ‘Portable Drawing Board’, as shown in the 1912 catalogue, incorporated this feature. Metal reinforcing bars, as described elsewhere in this patent were also used in Stanley’s ‘Patented Steel Lined Drawing Boards’, quoted as ‘suitable for tropical climates’.

Points for Mathematical Drawing Instruments, 1874 (2nd February) No. 412 (Provisional only)

The use of steel wire, soldered in a prepared groove, as the point for a compass or dividers. I have never seen this type of point in a drawing instrument or even in a catalogue or book. Was it ever used in practice?

Colours, 1877 (12th September) No. 3438

This patent related to the use of colours for tinting drawings, a practice that was standard at the time. There were three claims:

1. Colours, diluted with water to a state ready for use, with details of the colours to represent different materials.
2. Naming the colours with the names of the materials they would represent.
3. Placing the colours in bottles labelled with the name of the represented material and with the actual tint enamelled or varnished into a recess in the top of stopper.

The filed drawing was partly coloured, presumably with 24 tints as there are 24 named boxes (stone, brass, etc.) on the copy of the drawing.
Fig 5 - Reading to centre protractor (author’s collection)
Improvements in Protractors, 1885 (13th April) No. 4530

This patent was for a circular protractor with two concentric rings, one rotating within the other, each having a straight edge attached to it that terminated in a point at the centre.

Stanley sold this instrument as his ‘Reading to Centre Protractor’. The vernier read to minutes. Fig. 5 shows the example in my collection.
Fig 6 - Patent scale (Patent GB1886/5407)
Fig 7 - Improved dotting pen (Patent GB1887/8985)
Improvements in Mathematical Scales, 1886 (19th April) No. 5407

This patent covered the use of small inset scales, away from the main scale edge, for use with divider points to avoid damaging the main scale (Fig, 6). Stanley catalogued these scales, at least up to 19124. The patent also covered the method of attachment.

Improvements in Dotting Pens, 1887 (24th June) No. 8985

The patent describes the use of an inner blade to feed ink to the rowel wheel of the pen. (Fig. 7)
Writing Pen Extractor, 1888 (23rd November) No. 17,078

This invention was described in several forms. However the main feature was that the jaws were shaped to match that of a typical dip pen nib so that they would clamp on it without damaging it for its extraction.

This was also patented in the USA; patent no. 479,959 dated August 2nd 1892.
Fig 8 - Planimeter with shrinkage compensation scale (Patent GB1894/13567)

Improvements in Planimeters, 1894  (13th July) No. 13,567

This was a joint patent with Alfred Amsler. It related to the use of a small vernier scale on the arm of an adjustable planimeter to enable the planimeter to be adjusted to give a true reading of area from shrunk plans where the shrinkage could be determined by measuring the scale drawn on the plan (Fig. 8). It was catalogued in 1912 as the ‘Stanley Amsler Patented Compensating Planimeter’.

Improvements in Combined Drawing Board and Tee Square for Geometrical Drawing, 1895 (8th August) No. 15,023

This was a joint patent with Joseph Charles Howard.  The stock of the tee square was arranged to slide in a groove at the edge of the board and a lever-operated cam was provided to lock the tee square in any position against the edge of the board. This device was a feature of Stanley’s ‘New Patent Drawing Table’ and the ‘Stanley Howard Patented Drawing Board and Tee Square’ as shown in the 1912 catalogue.

Improvements in Drawing Boards and Tee Squares, 1898 (28th October) No. 22,710

Another joint patent, this one with Robert William Fieldwick. This was a simpler patent covering the use of projecting, inset metal edges to both the board and tee square stock, where the two metal edges slid in contact with each other. These were made with a brass tongue to the tee square stock and a gunmetal edge to the board, 1912 catalogue numbers K3295, 3296 and 3297.
Fig 9 - Perspective drawing table (1912 W F Stanley & Co Ltd catalogue)
Improvement in and relating to Perspective Drawing Tables, 1905 (23rd March) No. 6167

The patent describes a board mounted on a stand, such that it can be raised to any height and tilted to any angle, that incorporates a tee square, running in a groove and lockable by a lever and cam arrangement, and also right and left centrolineads, mounted at the edges. The latter are arranged with a hinged blade so that it can be lifted clear of the board.

This was also shown in the 1912 catalogue when it was available in two sizes at £4 and £4 10s respectively. (Fig. 9).
Fig 10 - Sighting telescope for triangulation (Patent GB1880/2142)
Surveying Instruments
Apparatus for Measuring Distances, 1880 (26th May) No. 2142

This patent covered a set of equipment for determining distance by triangulation from near and distant bases. The base line was established by a steel wire extended between either two vertical rods (distant base), or between two telescopes (near base).  The telescopes could be mounted on a or hand held The steel wire (for near base triangulation) was attached to each telescope such that it directed its axis, so that when the telescope was turned to the distant object or rod, the angle could be read directly in the eyepiece. For triangulation using a distant base, the steel wire was stretched between two vertical rods and a single telescope was used to measure the angle between them. In this case the telescope required to be mounted on a stand and set up in the same manner as the lower part of a theodolite and the baseline had to be at right angles to the line from one of the rods to the telescope. The telescope is illustrated in Fig, 10.

Improvements in Mining Stadiometers, Theodolites and Tacheometers, 1889 (9th August) No. 12,590

The purpose of this invention was to enable mining instruments to be used conveniently in workings with severely restricted headroom. The improvements were in two related parts:

1. A folding stadia rod for subtense measurements or levelling
2. Any mining instrument used for subtense measurements with the stadia, in which the compass was illuminated from below by a lamp and mirror
3. A tribrach with a sliding stage for accurate centring of the instrument
4. Screw up adjustment of the tripod legs

Improvements in Apparatus for Measuring Distances, 1890 (8th March) No. 3683

This was essentially a special form of stopwatch set in motion when a flash was observed and stopped when the associated sound was heard. It could be calibrated in distance (or time). The version illustrated was mounted on the stock of a rifle. Although this patent can be read in the British Library the IPO were unable to supply a copy of it.
Improvements in Tribrachs for Instruments of Precision, 1892 (18th August) No. 14,934

This patent covers the use of longitudinal holes to retain the ball ends of the tribrach adjusting screws instead of a retaining plate. This arrangement was used on many Stanley theodolites. (Fig. 11)

Fig 11 - Improved location for tribrach adjusting screw foot (Patent GB1892/14934)
Improvements in Surveyors’ Levels, 1895 (26th March) No. 6229

This was a form of tilting level with a screw inside a screw inside a graduated drum enabling it to be used for reading or indicating gradients in elevation or depression from 1 in 12 to 1 in 1,200 although this range was not stated in the patent. This was Stanley’s ‘Patent Gradiometer’, which was also fitted with a subtense diaphragm for measuring distances. (Fig. 12).

Improvements in Mining Surveying Instruments, 1898 (20th April) No. 9134

This patent covered two solutions to the problem of taking readings at high angles of depression with surveying instruments in mines without the use of an auxiliary telescope:

1. A mirror in front of the object glass, set  accurately to take readings at 90 degrees to the line of collimation of the telescope.
2. A cranked gimbal ring on a mining dial to enable the telescope to be set at 90 degrees up or down whilst clearing the support structure. This featured in ‘K301 Stanley’s New Patent Dial’ and K304 ‘Stanley’s 6 inch Cranked Gimbal Dial (Patent)’ in the 1912 catalogue (Fig. 13)
Fig 12 - Stanley’s Gradiometer (1912 W F Stanley & Co Ltd catalogue)
Fig 13 - Improved mining dial with cranked gimbal ring (1912 W F Stanley & Co Ltd catalogue)
Improvements in Surveying Instruments, 1899 (14th April) No. 7864

The purpose of this invention was to enable all the readings to be taken from the face of the instrument without requiring access to the sides for reading the vernier plates as would be the case with an ordinary theodolite, thus enabling its use in confined spaces, for instance in mines.

To achieve this the patent had a number of features:
1. A rack and gear train to a series of dials to indicate the precise rotation about the horizontal and vertical axes.
2. For distance measurements by stadia or subtense reading telescopes, a diaphragm with compensating points giving direct base reading allowing for the difference between hypotenuse & base for inclination. The 1912 catalogue lists the ‘Patent Compensating Subtense Diaphragm’ as a separate item.
3. A means of adjusting the spirit level from the same face.
Fig 14 - Stanley patent engineer’s level (1912 W F Stanley & Co Ltd catalogue)
Improvements in Surveyor’s Levels, 1901 (20th May) No. 10,447

Although detailed as five claims there are really two significant improvements described in this patent:

1. The casting of the telescope body in one piece with the centre and also the long and cross bubble fittings.
2. The positioning of the internal focussing rack under the drawtube such that the pinion shaft could be supported at both ends.

Both of these improvements were embodied in ‘Stanley’s New Engineer’s Dumpy Levels (three patents)’ in the 1912 catalogue and similarly constructed levels were still available in the 1958 catalogue5. (Fig.14). To my mind, this patent shows how advanced Stanley’s thinking was, particularly with regard to simplifying manufacture whilst also improving the robustness of the instrument.

Dividing Engines, 1865 (4th May) No. 1245

“Improvements in straight-line dividing engines and tools for regulating distances.”

The first improvement described is the use of a lead screw that is oblique to the line of the bed and for which the oblique angle could be varied to vary the distance travelled by the knife per revolution so that the scales of any country could be divided.

The second improvement was a means of making the dividing engine self-acting. This used a ratchet wheel and pawl to rotate the lead screw the desired amount for each division.

The third improvement was a means of regulating the length of the lines divided onto the scale by means of a detent wheel with teeth of differing lengths corresponding to the line lengths required.

Typically a lever would be used and worked backwards and forwards to cut the lines to the required length, regulated by the detent wheel, and also to effect the rotation of the lead screw to give the distance between the lines as described in the second claim.

Meteorological Instrument, 1867 (25th November) No. 3335

Stanley’s ‘Meteorometer’ for predicting the probable weather. This combined a number of instruments on a single mount as follows:
An aneroid or preferably mercury barometer to show the air pressure, the mercury barometer having a float and vernier instead of an adjusting screw
A compass dial connected to a weather vane on a high point on the building connected by rods and Hook’s joints to show the wind direction
A manometer connected by a thin tube to the weather vane to show the wind force
Instruments to show the temperature, humidity and electric state of the atmosphere
An inverted barometer tube to indicate rising or falling pressure (but not the pressure itself)
A barometer wheel and index hand responding to the atmospheric pressure pointing to the words fair, rain, storm, etc on the dial which was rotated according to the wind direction
An indicator showing the rain fall in a given period connected to a rain gauge on the roof of the building

It could be ‘of ornamental construction, and be fixed in any gentleman’s hall.’

Machines for Exciting Frictional Electricity, 1868 (21st December) No. 3878

This was a hand held version of the plate glass electrical machine. The improvements claimed were:

1. A frame consisting of two strips of wood with a handle connecting them at one end and a spacing block at the other.
2. The exciting rubbers attached directly to the frame
3. A wood axle rather than metal
4. A sheet glass disc rather than plate glass
5. A woven wire gauze collector rather than a comb of metal points.
Fig 15 - Battery and Ruhmkorff coil (Patent GB1872/2213)
Electrical Apparatus, 1872 (25th July) No. 2213

This invention was a portable electric battery. The battery described, with zinc and carbon plates, was essentially a Leclanché cell without the porous pot containing the manganese peroxide depolariser around the carbon electrode.  However the purpose of the patent was not the method of generating the electricity but the means by which the battery was rendered portable and the description of the battery internals was purely illustrative. The claims were basically as follows:

1. The jar or bottle containing the electrodes would be twice the height internally of the electrodes and filled to half height with the electrolyte so that the electrodes were normally out of the liquid and the battery would need to be inverted for operation.
2. The cell would be sealed against liquid leakage but incorporate a relief valve to allow gases to escape.
3. One or two screwed caps to allow replacement of fluid and the zinc electrode
4. A wooden box to contain the cells, packed in tightly with wool or other matter
5. The incorporation in the box of an electric bell or Ruhmkorff coil or other apparatus (Fig. 15)
6. The incorporation of this portable battery in fixed apparatus

Pendulums for Equalizing (sic) Pressure and Temperature and Calculating Time, 1875 (29th November) No. 4130

This was very curious patent that relied on the period of the pendulum of a ‘clock’ being influenced by and proportional to atmospheric pressure or temperature. The accompanying illustration shows three ‘clocks’ labelled ‘pressure’, ‘time’ and ‘temperature’. These do not show time at all but each have four dials showing hundreds, thousands, ten thousands and 100 thousands of pendulum swings. The pendulum on the ‘pressure’ clock incorporates a barometer to change its period, that on the ‘temperature’ clock a thermometer or bimetallic system to change its period and the pendulum on the ‘time’ clock is compensated to remain constant irrespective of pressure or temperature. By comparing the number of swings recorded by the pressure and temperature clocks with that of the time clock the pressure and temperature could be determined. The patent particularly described various means of arranging the pendulums to respond to pressure and temperature, and also to keep accurate time.

Integrating Anemometer, 1883 (7th February) No. 672 (Provisional only)

The purpose of this invention was to indicate in one operation both the velocity and direction of the wind. The axis of revolution of the anemometer cups was arranged to rotate around a second, principal axis by the action of the wind to a position opposite to the direction of the wind. A series of recorders, one for each wind direction would be placed around the periphery of the instrument. A crown wheel on top of each recorder would be rotated only when the axis of rotation of the cups was directly over it, when it would be rotated by a conoid under the axis of rotation of the cups with its axis at an oblique angle to the cup axis and connected to it by a Hook’s joint.

Actinometers for Photography, 1886 (2nd April) No. 4024

Stanley had a number of photography patents, mostly for camera improvements such as focussing methods. As cameras are not normally classed as scientific instruments I have omitted to describe them in this paper. However I have included this one as it is for a meter. It was a very short patent with two claims:

Enclosing the actinometer in a small round case similar to that used for a magnetic compass, that could be hung on a watch chain
Filling the actinometer with a paper made sensitive with a salt of Bromine.

The patent was joint with William Low Sarjeant
Machine for Measuring the Height of Human Beings Automatically, 1886 (5th April) No. 4726

The machine in appearance resembled an automatic weighing machine with a platform to stand on and a tall box behind this housing the mechanism and the dial on which the height was displayed. Below the dial a light bar with a disc attached to it descended in a slot to the head of the person whose height was being measured. This was released by the person standing on the platform pressing a ball on an adjacent standard and could be interlocked with a penny in a slot mechanism. Once released the bar & disc gently descended under the action of a counterbalanced weight and pulley system. The platform housed a treadle on which the person stood, which initially zeroed the pointer and could return the bar and disc to the uppermost position via a weight and pulley mechanism when the person stepped off it.

Improvements in Height Measuring Machines, 1887 (22nd August) No. 11,416

This patent claimed a number of improvements to the machine described in the previous patent.

Replacing the dial at the top of the instrument (too high to read easily) by a window nearer eye height, through which the height could be read on a disc revolving inside or a straight scale moving up and down inside.
The use of the straight scale as a counterbalance weight
Improvements to the mechanism used to return the index back to zero
Air cushioning of the counterbalance weights to prevent concussion & noise and ensure smooth operation
Improvements to the penny in a slot mechanism
Means to stop the head plate being pushed up from outside the case

Fig. 16 shows the general arrangement of the machine.
Fig 16 - Improved automatic height measuring machine (Patent GB1887/11416)
Apparatus Connected with Spirometers, 1887 (26th September) No. 13,013

Having patented his invention of a coin operated height-measuring machine, Stanley now patented a coin operated spirometer for people to measure their lung capacity. The spirometer was enclosed in a case with a dial and pointer at the top. The patent covered two basic features:

1. Coin operation and its associated mechanism
2. The delivery of a disposable cone or mouthpiece to fit on the mouth tube and the use of disinfectants, etc in connection with the machine.

Improvements in Slide Rules, 1890 (27th March) No. 4803

This patent was joint with Arthur Honeysett and was a patent for a hydraulic slide rule. Its purpose was the calculation of velocities and discharge of pipes and conduits. Hopp6 lists the Honeysett slide rule as made by Stanley with a date of 1902 against it, but it is not listed in the 1912 catalogue.

A slide rule basically consists of two parts, the stock and the slide. In this case there are one scale on the stock above the slide, two on the slide and five on the stock below the slide. These are, in that order:

A scale labelled A divided to give the square root of the fifth powers of the values on scale B
A scale labelled B divided for areas
A scale labelled 1 in divided for inclination
A scale for velocities
Four scales to correspond to four classes of channel and their coefficients, divided for hydraulic mean depth

On the reverse were instructions and tables giving area and hydraulic mean depth for full pipes and segments of circles and ovals.

The patent had two claims:
The nature and layout of the scales and tables on  the slide rule
2.      The use of a transparent cursor (claimed for any slide rule)
Fig 17 - Patent triple standard (1912 W F Stanley & Co Ltd catalogue)
Improvements in Gauges and Rods for Standard Measures, 1903 (7th December) 26,754

This patent was joint with W F Stanley and Co Ltd.; the business had become a limited liability company in 1900 according to C J Allen.
The purpose of this patent was to enable one gauge to be used for inside, outside and scale measure. Figure 17 illustrates the gauge. A metal bar was first divided to form the scale and precisely ground back to the end divisions. Two extension pieces were then affixed as shown in the illustration.
The 1912 catalogue lists two feet and yard standards to this design, described as ‘Stanley’s Patent “Konstat” Steel Standards’.
William Ford Stanley was a prolific inventor. Several of his instrument patents were commercially successful and some of them, once they had expired, were widely copied. However many of his instrument patents were in fields outside his business interests and were ingenious even if they had little commercial value.

A look at Appendix A will show that his inventions ranged far wider than instruments. Some were in related fields, such as photography and spectacles, but others related to such things as cooking and building, and even rotary engines.

From 1885 onwards, increasing numbers of his patents were either void or abandoned. I do not know why this was so. Was it because they didn’t meet the test of being new inventions or was it because he chose to abandon them?
1. Mathematical Drawing and Measuring Instruments, William Ford Stanley, 7th Edition, E & FN Spon, 1900 (This book was published in eight editions from 1866 to 1925)
2. Surveying and Levelling Instruments: Theoretically and Practically Described (1901), William Ford Stanley, 3rd edition, Kessinger Publishing reprint
3. A Century of Scientific Instrument Making 1853-1953, Cecil J Allen, Stanley, 1953
4. W F Stanley & Co catalogue, 29th ‘K’ Edition, 1912
5. W F Stanley & Co catalogue, 33rd ‘A’ Edition, 1958
6. Slide Rules, Their History, Models, and Makers, Peter M Hopp C.Eng,MBCS, Astragal Press, 1999, ISBN 1-879335-86-7
Appendix A - List of GB Patents from the Patents Indexes
Patents shown in italics were either void, abandoned, or could not be found. Patents shown in bold have been described in this article.







10 Dec

The use of aluminium for the construction of mathematical instruments used for geometrical drawing, surveying and nautical purposes, and improvements connected therewith



26 Jan

Mathematical drawing instruments



4 May

Straight line dividing engines and tools for regulating distances



5 Mar

Mathematical drawing instruments



25 Nov

A new meteorological instrument



21 Dec

Construction of machines for exciting frictional electricity



15 Aug

Construction of true surfaces and edges applicable to drawing purposes



25 Jul

Electrical apparatus



2 Feb

Circular saw bench



2 Feb

Mathematical drawing instruments



29 Nov




12 Sep




26 May

Measuring distances



18 Aug

Photographic cameras



10 Jul

Photographic cameras



7 Feb

An integrating anemometer



13 Apr

Photographic cameras



13 Apr

Actinometer for photography



13 Apr




28 Oct




9 Dec

Tooth injector



24 Feb

Chandeliers and pendants



26 Feb

Focussing arrangements for cameras



10 Mar




22 Mar

Heat conductors for cooking flesh quickly



22 Mar

Presses for rendering steaks tender



2 Apr

Actinometers for photography



5 Apr

Measuring height of human beings



19 Apr

Mathematical scales



18 Aug

Portable saws



13 Oct

Sinking surfaces of steel dies, stamps and punches by combined photographic and etching processes



28 Feb

Levels and clinometers



18 May

Heat conductors for baking and boiling



24 Jun

Dotting pens



4 Jul




22 Aug

Height measuring machines



25 Sept




6 Jan

Explosives &c  for producing instantaneous light for photography



23 Jul




23 Nov

Writing pen extractor       (also patented in USA)



9 Aug

Mining stadiometers



Lemon squeezers






8 Mar

Measuring distances



27 Mar

Slide rules



31 Oct

Portable photographic apparatus



22 May

Artificial horizons



21 Jul

Portable photographic apparatus



18 Aug

Instruments of precision



9 May

Mantles for incandescent lighting by gas



20 Oct

Combined drawing board and tee square



10 Apr

Compressing and refrigerating apparatus



13 Jul




26 Mar

Surveyor’s tools



9 Aug

Drawing board and tee square



7 Jul

Rendering candles &c wicks waterproof



23 Jul

Route indicator for vehicles



10 Oct

Tramcars, motor cars, &c



6 Jan




29 Jan




30 Aug

Calculating apparatus



23 Apr

Mining surveying instruments



11 Oct

Advertising signs



28 Oct

Drawing boards &c



3 Nov

Representing life movements



14 Apr

Surveying instruments



14 Sept

Instruments of precision



30 Jan




25 Apr

Camera dark slides



8 Oct

Rotary engines



7 Feb

Photographic cameras



20 May

Surveyor’s levels



11 Sep

Eye glasses



16 Sep

Fitting stone skirtings



1 Sep

Phonographs &c records



2 Dec




7 Dec

Standard measure gauges and rods



23 Mar

Drawing tables



10 Jan

Rotary steam engines

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