Notes: "The UTO No. 1 slide rule is a simplex slide rule primarily for multiplication and division. There are no trig or log-log scales, and although there are A and K scales, there is no B scale. There are, however, DF and DF scales, plus CI and CIF scales, all to facilitate multiplication and division. It is only slightly more advanced than the “Merchant” slide rules sold by K&E. "
