Extremely rare large proportionnal pair of dividers built in nickel silver.
The instrument is not signed but English, attributable to Stanley datable around 1860-1870. It measures 24cm in length, 1.7cm in width and 1.8cm in thickness.
This form of proportionnal dividers or compass seems unknown from the specialized works on mathematical instruments. We only know another example, preserved at the Science Museum and coming from the Stanley collection, which the company gave to the London Museum when it was dispersed.
This compass has four branches or legs, two of which, on the same side, are folding.
This is a proportional instrument : the more you bend/curve the foldable legs, the greater the reduction. Furthermore, the folding branches can be bent to different degrees, which could allow use as a four-pointed compass, i.e. a sculptor’s compass.
This reduction compass is quite much larger in size and volume compared to usual reduction compasses.
A rare mathematical, engineering or architectural instrument
Ask the Dealer
Established by Alexandre Piffault in 2014 and based in Paris at 5 rue de Condé, 75006, very close to Odéon, Le Zograscope specializes in antique and rare books in Science, Medicine and Technology, and rare antique instruments in the same fields. We have especially a strong interest in early and continental microscopy, early and special mathematical/drawing instruments, medical and surgical instrument, and rare technology.
Personnal website : https://www.lezograscope.com/