DescriptionBeginner's slide rule, model 4058W (Mannheim type), 10 inch, made by Keuffel & Esser Co.in Hoboken, no date, circa 1928-1940. White paint on boxwood with black divisions and lettering; slide is white paint with black markings; back has white paint with black printing, frameless glass cursor with wood slide blocks (four screws; do not go through back of wood.) This item was not issued with a serial number. With: two piece storage slipcase; paper covered; lettered in dull gilt. With: 16 page instruction book, copyright 1928 which is catalogued separately as archives 2008.012.0086. See related. Printed on back: Beginner's Slide Rule. 4058 W. Keuffel & Esser Co., N.Y. (although marked "N.Y." the company did its manufacturing in Hoboken at this time.) Back has printed chart of Equivalents and Abbreviations from U.S. Bureau of Standards Circular No. 47. Note: the model name and number on the back is centered at the top. Chart source and company name is printed below the chart. Note the B,C scales on front; back has celluloid window with S, L, T scales. The dating of this item is only approximate, but the style of the slipcase suggests that it is earlier than later; also the instruction booklet/manual that accompanied was a style that did not have a cover which also suggests the earlier part of the date period.