Sets of Drawing Instruments

A Eugene Dietzgen Company set of drawing instruments.

Drawing instruments have been essential to mathematics, architecture, surveying, navigation, engineering design, and other technical endeavors from antiquity through the 20th century, although recently computer-aided drawing has largely superseded the use of instruments for drawing by hand. The mathematics collections document the stories of several of these objects individually, including pens and pencils, dividers and compasses, squares and triangles, protractors, parallel rules, sectors, and scale rules. By the 17th century, European makers of scientific instruments also sold drawing and calculating tools in sets. These were typically made of wood, often covered with leather, and came in sizes and shapes ranging from vertical cases that fit within a pocket to single-level flat boxes to large boxes with multiple drawers, called magazine cases. In the 20th century, European and American firms often put sets of instruments in folding cases that resembled wallets.

Mathematicians and instrument makers wrote several manuals explaining how to assemble sets of instruments and use their contents. For instance, in 1792 John Barrow, a former schoolteacher and private tutor, recommended that a pocket case contain the following:

  1. A pair of large compasses with a plain point, an ink point, a pencil point, and sometimes a dotting point.
  2. A pair of small plain compasses.
  3. A drawing pen, which contains likewise a protracting pin.
  4. A pair of bow compasses.
  5. A parallel ruler.
  6. A protractor, sometimes semicircular, but most commonly of the form of a parallelogram, one side of which is a plane scale.
  7. A sector.
  8. A black lead pencil. (John Barrow, A Description of Pocket and Magazine Cases of Mathematical Drawing Instruments (London, [1792]), 5–6.)

Catalogs from retailers and manufacturers also depicted numerous possible combinations of instruments. However, very few of the nearly five dozen sets in NMAH's mathematics collections match up perfectly with any one of these descriptions. Many of them were used by their previous owners for decades before they came to the museum, so pieces logically wore out or became lost over time. Users sometimes purchased replacement parts, from the same maker or from other makers. Additionally, makers allowed buyers to put together their own sets, placed in cases that were sometimes custom-made to fit the instruments selected and that were sometimes sold separately in generic configurations. This means that some cases of instruments that now appear to have empty slots in fact never held tools in those positions. Joint tighteners found in many of the sets were employed in adjusting and maintaining the instruments.

Even though it is often not possible to trace what each set was originally supposed to look like, these cases can give us insights into the types of drawing instruments that were valued in engineering practice (and those that were not, when an instrument was included in a set but clearly never used). We see changes in the kinds of instruments included over time; for example, sectors and set squares are more likely to be found in 18th-century sets than in those made in the 20th century. We see changes in technology, particularly with new types of ink pens. We also see changes in materials, as brass and ivory gave way to German silver and steel and then to aluminum and plastic. And, these sets illustrate globalization, as makers imported and exported instruments, the materials used to make instruments, and the styles in which instruments were manufactured.

 Acknowledgement

The digitization of this group of artifacts was made possible through the generous support of Edward and Diane Straker.