Dividers & CompassesBeam Compasses
Mechanical and architectural drawings have sometimes required circles with diameters of several feet instead of the several inches possible with a standard drawing compass. A beam compass was usually sold with just the points, which the user attached to the ends of a metal rod or wooden slat the length of the desired radius of the circle. One end was held in place, and the other end was pivoted around that end, maintaining contact with the paper. The patent model in the collection is a beam compass.
"Dividers & Compasses - Beam Compasses" showing 1 items.
- This metal instrument has two I-shaped beams, one 13" long and one 7" long. Needle, pencil, and pen points are moved along a beam by rolling wheels at the top of the trammels. The trammels are each marked with the logo for the Frederick Post Company that was in use from 1944 until 1970 and with the word ERA. A cardboard box covered with black imitation leather holds the objects. The box has two empty 2" slots. The end of the box has a red and white Post label with the model number 940. According to a Post catalog, purchasers could also choose beams as long as 26", 38", 50", 62", 74", 86", and 100".
- Reference: Frederick W. Post Company, Dependable Drawing Materials, 19th ed. (Chicago, 1950), 61.
- Currently not on view
- date made
- Frederick Post Co.
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center