HISTORY OF SET SQUARE

Set Square Signed Nicolas Bion

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DESCRIPTION

A square is an instrument used to draw lines perpendicular to other lines. It also can be used to test whether two lines are perpendicular. Squares in which the arms are fixed date from ancient times. By the 16th century, they also were made from two rules hinged together at one end so that they fold up compactly, allowing them to fit conveniently into a case of drawing instruments. See MA.316914, MA.335353, 1979.0876.01, and 1984.1070.01.

Early modern squares often had plumb bobs for finding a vertical axis, as in a building under construction. While most others in the collection were lost before they arrived at the Smithsonian, this fixed-leg, L-shaped brass instrument retains its plumb bob, which is tied to a string that runs through a pinhole at the square's vertex. On one side, the long leg of this instrument has a scale divided into units of about 7/16". The scale is numbered by tens from 10 to 100 and is marked: Echelle De 100 parties [scale of 100 parts]. The first unit is divided into tenths and numbered from 1 to 10. This side is also marked: N Bion AParis.

On the other side, the long leg has a scale divided into units of about 7/8". The scale is numbered by tens from 60 to 10 and is marked: Echelle de 60 parties [scale of 60 parts]. The first unit is divided into tenths and numbered from 10 to 1. The outer edge has a scale of French inches (about 1-1/16" English inches) numbered by ones from 5 to 1. The largest unit is divided into twelfths and numbered by threes from 12 to 3. This scale is marked: Pouce de Roy [inch of the French king].

The short leg has a scale divided into units of about 1-25/32". The scale is numbered by tens from 10 to 20 and is marked: Echelle de 20 parties [scale of 20 parts]. The first unit is divided into tenths and numbered from 1 to 10. The outer edge has a scale of French inches numbered by ones from 1 to 4. The largest unit is divided into twelfths and numbered by threes from 3 to 12. This scale is marked: pouce de roy [inch of the French king].

Nicolas Bion (about 1652–1733) made and sold mathematical instruments in Paris in his own shop and as royal maker for Louis XIV. He prepared a famous 1709 manual on the construction and use of mathematical instruments. 1980.0580.05 and MA.321675, two sectors in the collections, also came from his workshop. The Smithsonian acquired this object in 1959. Henry Russell Wray, the previous owner, graduated from the University of Pennsylvania and was a businessman in Colorado Springs, Colo., in the early 20th century.

References: Maya Hambly, Drawing Instruments, 1580–1980 (London: Sotheby's Publications, 1988), 105; Nicholas Bion, The Construction and Principal Uses of Mathematical Instruments, trans. Edmund Stone (London: for John Senex, 1723), 12, Plate 2.