wer end of the vertical spindle. tool, so that as the toolrevolves the disk is also made to For many of the points given above we are indebted to The workman dashes emery and water or rouge and water Mr. Chas. F. Usner, a practical optician of this city, from over the form; and the upper tool, in… … dersrun. The stuffing boxes lens the other is proceeded for the journals are packed with in precisely the same way. The treatment is the from the front by an arrange same for both convex and concave lenses. In grinding the best quality of telescopic objectives the operation is wholly performed by…
Internet Archive · Public domain (published before 1931). Free to use for anything.
