Society of Glass Technology · [Sheffield] · leaf 556
eedle points. When the parts were well made, the needle pointswould reseat themselves, after moving, to within OOOOl mm.The glass window, C, was of Pyrex glass, which was opticallypolished to prevent distortion of the light reflected from the mirror,H, of 2 metre focal length, and was fused in… … Fig. 74. tube, since silver was attacked by the mercury and it was notfeasible to employ a protective coating. The instrument wasmounted in plaster in an iron frame, a thin layer of litharge andglycerin being interposed between the plaster and glass to preventcracking. Whilst these changes…
Glass
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
