Case for drawing instruments
Jacob & Halse
London, 1809 - 1810
It measures 6.69 x 2.95 x 1.25 in (17 x 7.5 x 3.2 cm); weight0.49 lb (223 g)
State of conservation: the case and instruments are in good condition
Pocket drawing cases - often called etui, from the French étui- were popular objects for almost a century in Europe, indispensable for storing instruments used for drawing and calculation.The dimensions of the case could vary, depending on whether it was intended for use by architects, civil engineers, mechanical ones or others.
Some treatises, including that of William Ford Stanley, entitled A Descriptive Treatise on Mathematical Drawing Instruments, provide us with a lot of information about the production, use, shape and materials used in the making of these instruments. Stanley focuses not only on the morphology of the cases, but also on the materials generally used in the construction of drawing instruments: brass, silver, steel and ivory, with some differences between the German, Swiss or English manufacturers.
Our etui is tapered, oblong and covered in shagreen, with a closure button and iron zipper supports.The term "shagreen" derived from the French “chagrin” - in Italian "zigrino" - and refers to a type of leather tanned in such a way as to maintain its roughness. Between the 17th and early 18th centuries this leather tanning method, already in use in the Ottoman Empire, began to be applied to shark skin or the skin of a ray fish (the pearly breed, Hypolophus sephen) and was used in the production of luxury items with variations in tanning and dyeing.
The interior is divided into the various housings for the instruments.
These are:
- two brass and steel compasses with one fixed tip and a removable one;
- an ivory geometric or proportional sector complete with a brass pin signed JACOB & HALSE LONDON.This particular instrument can be traced back to an idea by Galileo Galilei. The first geometric compasses for calculation, also known as "proportional compasses", began to appear between 1500 and 1600. Galileo calls the instrument a "geometric and military compass", since it could also be used in topography, surveying and ballistics, thanks to the different scales dedicated to these areas. The fundamental principle of this tool exploits the proportionality existing between the lengths of the sides of similar triangles to perform multiplication and division operations;
- a brass protractor: a semicircle with a graduated circumference and a pointer in the center for measuring angles;
- an ivory scales ruler: to perform multiplication and division, it is similar to the proportional compass and, in particular, it exploits the proportionality existing between the lengths of the sides of similar triangles;
- a thin inking pen with awl.
The case under analysis can be dated thanks to the signature on the geometric compass: JACOB & HALSE LONDON. The company is listed by Gloria Cliford as operating in London selling globes and measuring instruments between 1809 and 1810. See: Gloria Cliford,Directory of British Scientific Instrument Makers 1550-1851,National Maritime Museum (GB), 1995.
For similar comparative examples of other manufacturers, including the choice of covering, reference can be made to large collections of scientific instruments such as, for example, the one kept in the Science & Society Picture Library in London (invv. 10683373 -10683384) or, among others, the T. Blunt case kept at the Harvard University Museum (Inv. DW0712), similar for morphological choice and tools.
For a similar case, albeit in galuchat, see the English link of mathsinstrument.
The name of the two partners also appears on some drawing instruments preserved in a private English collection and on two pocket globes that have passed through the market, one of which was exhibited in an exhibition held in London. (T. Lamb; J. Collins; R. Schmidt; Museum Boerhaave; Christie, Manson & Woods, The world in your hands: an exhibition of globes and planetaria: from the collection of Rudolf Schmidt: an exhibition at Christie's Great Rooms, 25 August - 9 September 1994, and 18 March - 24 September, 1995 at the Museum Boerhaave London, Christie's, 1994).
Bibliography:
- W. Ford Stanley, Mathematical Drawing and Measuring Instruments, E. & F. N. Spon, 1900;
- J. W. Queen & Company Priced and illustrated catalogue of mathematical instruments and materials for drawing, surveying and civil engineering, Philadelphia, James W. Queen & Co., New York 1873;
- F. Edward Hulme, Mathematical drawing instruments and how to use them, New York, W.T. Comstock 1883;
- Gloria Clifton, Oxford Dictionary of National Biography, Directory of Scientific Instrument Makers, Oxford University Press, 2004;
- Gloria Clifton, Directory of British Scientific Instrument Makers, 1550-1851, National Maritime Museum (GB), 1995.