Page:The slide rule; a practical manual by Pickworth, Charles N.djvu/5

 ADVERTISEMENTS DRAWING INSTRUMENTS DRAFTING MACHINES THE SMITH DAYIS PIECE WORK BALANCE CALCULATOR ENGINE INDICATORS. ANEMOMETERS STEAM AND YACUUM GAUGES REPAIRS TO STEAM GAUGES Write for Catalogue, No. 55 JOHN DAVIS & SON f DERBY ), LD. ALL SAINTS WORKS . . . DERBY