| 摘要 |
<p>PURPOSE:To calculate magnification to be set immediately by a slide rule consisting of a rule having a logarithmic scale of the length of a part used as the standard of an original and another rule having scales of length of expansion and contraction, and magnification. CONSTITUTION:A magnification calculation rule consists of a bse rule 1 made of a circular plastic plate, a slide rule 2 made of a plastic disk as well, and a fitting member 3 to which the two are fitted rotatably in the centers. On the slide rule 2, numbers of a logarithmic scale 6 of [reference length of an original] are provided on the basis of a base line 5 connecting its center part and an index 4 mutually. On the base rule 1, on the other hand, numbers of a logarithmic scale 7 of [length of expansion and contraction] are provided on the basis of a base line connecting its center part and an optional point mutually.</p> |
