Illustrated catalogue and price-list of drawing and tracing papers, sun print papers and equipments, drawing instruments and materials, surveying instruments, accessories, etc / Kolesch & Company. . 2050 Isograph Precision Protractor each, $ .SC Made of transparent celluloid and has the degrees indicated by notchesinstead of lines (see cut). To lay off a degree put the pencil in the notchcorresponding to the degree wanted. For z/2 degrees set pencil at the pro-jecting points between the notches. When a number of angles are to belaid off from a common apex, the protractor instead of being held
Illustrated catalogue and price-list of drawing and tracing papers, sun print papers and equipments, drawing instruments and materials, surveying instruments, accessories, etc / Kolesch & Company. . 2050 Isograph Precision Protractor each, $ .SC Made of transparent celluloid and has the degrees indicated by notchesinstead of lines (see cut). To lay off a degree put the pencil in the notchcorresponding to the degree wanted. For z/2 degrees set pencil at the pro-jecting points between the notches. When a number of angles are to belaid off from a common apex, the protractor instead of being held by hand,can be fastened to the paper by two thumb tacks inserted in the notch,at each end of the base line. 84 KOLESCH <fe CO. ffi»K»m NEW YORK. Semi Circular Protractors.
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License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidillustratedc, bookyear1917
