Page:The slide rule; a practical manual by Pickworth, Charles N.djvu/126

xiii ADVKKTI8KMENTS - ? -^T ANDERSON'S IMPROVED SLIDE RULE GREAT INCREASE IN ACCURACY T^ Y this invention Lieut.-Col. Anderson has supplied the for all practical purposes without being unduly cumber- some. This improved Slide Rule is eight times as accurate as an ordinary Slide Rule of the same length, and equally simple to use. To Engineers, Electricians, Architects, Sur- veyors, Accountants, Builders, Excise Officials, Statisticians, and others who have to deal with laborious calculations, the improved instrument is indispensable. A special handbook with useful conversion and other tables accompanies each Slide Rule, which is packed in a neat cardboard box, all complete. Price 21s. Box and Postage, 6d. extra - Full particulars sent on application C. F. CASELLA & CO. Scientific Instrument Makers II, 13 and 15 ROCHESTER ROW, VICTORIA STREET LONDON S.W.
 * -' long-felt want of a SLIDE RULE sufficiently accurate