le. The lower row of figure holes records the number of turns ofthe handle and the upper row gives the result. The machine willmultiplty two factors, each of which may have as many figures as thereare groves in the plate. No. 1739 A. No 1739 B. No. 1739 C. Reckoning Machine,upper row, . 6 grooves,… … 1740. Thachers Calculating Instrument for performingthe greatest variety of useful calculations withunexampled rapidity and great accuracy. Cylin-der 18 inches, in a polished mahoghany box, each, Thachers Calculating Instrument, with the additionof a 3 inch Reading Glass, sliding on a brass…
