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. (1917)
Kolesch & Company · Kolesch & Company · leaf 265
robable mass and thedepth of the ore from the surface. When used for tracing ore the observershould hold the ring in his hands and keep the needle north and south,standing with his face to the west. The inclination of the needle as read offon the graduated scale will show the dip. If the compass is…
Drawing instruments · Surveying -- Instruments
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