Technical supply co., Scranton. [from old catalog] · Scranton, Pa., Technical supply co · leaf 366
^ PLANIMETERS … 4118. Rolling Ball Planimeter, German silver andbrass, having tracer arm 111 inches long,which can be increased by a lengthener to191 inches. Its angular motion is about90°. The two rollers are made of exactlyequal diameters, insuring the motion of the instrument,as a whole, in a straight line. A…
Engineering instruments · Drawing instruments
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