SLIDE RULE, Pocket, Mannheim—A convenient, compact little rule for the pocket. Made of thoroughly seasoned white celluloid, accurately divided. Measures 1¼ inches wide, 1/8 inch thick and 5½ inches long over all ; with a 5-inch scale on the face. Furnished in soft leather sheath, with directions.
SLIDE RULE, Polyphase—The Polyphase has, in addition to the regular scales of the Mannheim, a scale of cubes on the face of the rule below the D scale, and an inverted scale (Cl) on the face slide, which scales may readily be used in conjunction with the other scales, by means of the indicator. This arrangement combines some of the features of the Duplex Rule with the regular Mannheim type. The inverted scale enables taking three factors at one setting of the slide, and reading reciprocals by means of the indicator. Adjustable, 10-inch engine divided, divisions on white facings, “Frameless” glass indicator, in morocco covered case, with directions.
SLIDE RULE, Polyphase Duplex—A combination of the polyphase and the duplex rules, with the addition of several special scales. It is valuable for the solution of problems involving exponentials, reciprocals and extended combinations of factors. Involved computations may be performed with a minimum number of settings, decreasing the possibility of error in reading, and reducing the time required to perform calculations. Any one of the scales may be read in connection with any other one by means of the indicator, which encircles the rule. Adjustable, 10-inch, in sewed leather case with directions.
PENCIL, Multi-Vider, Gold-Filled—A combination pencil and slide rule for multiplication, division percentage and proportion. The pencil movement is of the highest quality. It propels and repels the leads. There is an oversized eraser, and a convenient, spacious container for extra leads. The graduations are engraved with machine accuracy. Results may be read to two places and estimated to three. Gold-filled, with ivory barrel.
SOLDERING IRON, Electric—This midget soldering iron is a perfect tool but being fitted with 3/8-inch tip and having total length of only 12 inches and 7/8-inch diameter makes it of most convenient size for use in laboratory. For repair of apparatus, the soldering of electrical connections in radio work and the like it is almost indispensable. Its rating is 100 watt. Total weight, 18 oz. Complete with cord.