Slide rule. (Machine-translation by Google Translate, not legally binding)

摘要

Calculation type, of the type which are constituted by a tubular and flat body, preferably cardboard or the like, one face of which a plurality of suitably sized windows are established and distributed to allow viewing through the same a plurality of groups of data set to a shiftable blade within the tubular body, characterized in that said sheet has a substantially triple length of the tubular body, settling in the same two transverse lines determinants folded to said sheet of a third susceptible intermediate stay within the tubular body, and two end-thirds susceptible to turn folded successively about said tubular body, in order that a considerable length for the carrier sheet information, the rule has minimum dimensions inoperative making it an element of pocket. (Machine-translation by Google Translate, not legally binding)