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. . 7960 7962 Angle Mirror, for right angles, with small plumb bob, detach-able handle, in case $ 7962 Angle Mirror, for right angles, plain, in case 262 KOLESCH <fc CO. NEW YORK. Miners Compass or Dipping Needle Made by Short & Mason, England. In the hands of the prospector theMiners Compass or Dipping Needleproves a serviceable guide to the dis-covery and location of magnetic ir
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. . 7960 7962 Angle Mirror, for right angles, with small plumb bob, detach-able handle, in case $ 7962 Angle Mirror, for right angles, plain, in case 262 KOLESCH <fc CO. NEW YORK. Miners Compass or Dipping Needle Made by Short & Mason, England. In the hands of the prospector theMiners Compass or Dipping Needleproves a serviceable guide to the dis-covery and location of magnetic ironore. In this instrument the magneticneedle is carefully balanced upon ahorizontal axis within a graduatedcircle, and in which the needle willbe found to assume a position in-clined to the horizon. This angle ofdeviation is called the inclination ordip, and varies in different latitudes,and even at different times in thesame place. Hence, in reading theneedle for the suspected presence ofmagnetic iron ore, the observer mustnot only be governed by his instru-ment, but must also draw into requisi-tion his knowledge of the general geo-logical formation of the place of hissurvey; and depend
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Keywords: ., bookcentury1900, bookdecade1910, bookidillustratedc, bookyear1917
