Except that if you have e.g. the W1 and W2 scales on a shorter (e.g. 10″) slide rule, you can use those to get the precision of a much larger (20″) slide rule, as [Bob] demonstrates.

This inexpensive one-sided white plastic slide rule has A, D, and K scales on the base, with S, L, and T scales on one side of the slide and B, CI, and C scales on the other side of the slide. The ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. ID number 1988.0807.01 was received ...