The Manufacture of Optical Glass and of Optical Systems: A War-time Problem |
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aberration amount angle annealing aperture arsenious oxide barium crown batch Bausch & Lomb birefringence blanks block boron oxide borosilicate borosilicate crown bubbles Canada balsam carbonate cemented cent centimeter Ceram chemical color commonly composition cooling cracks crown glasses crystallization cullet curvature curves diameter disk entrance pupil exit pupil eyepiece factory figure film flat flint glass Flint.-Schott focal length Frankford Arsenal glass mass glass melt glass plate glass surface glassmaker heated high temperatures illumination inches inspection iron Jour lead oxide lens surfaces light flint measured Medium flint method molding molten glass operation optical constants optical glass optical instruments optical system photometer plane pot arch pot of glass potassium potassium carbonate prism surfaces produce radial rays reflecting refractive index result rotating satisfactory side silica solution source of light spherical aberration stirring strain stresses striæ telescope test plate thick tool types of glass viscosity Zsch
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Page 273 - Thus the angle bf = abl — bfl'. Or, where i is the angle of incidence, r...
Page 12 - Co. and given virtual charge of the plant; its men were assigned to the different factory operations and made responsible for them. By November, 1917, the manufacturing processes at this plant had been mastered and large quantities of optical glass of good quality were being produced. In December, 1917, the work was extended, men from the Geophysical Laboratory taking practical charge of the plants of the Spencer Lens Co. and of the Pittsburgh Plate Glass Co.
Page 105 - ... (1918). (Papers on Optical Glass, No. 6). Analyses show that in all the glasses tested, both plate and optical glasses, the major part of the arsenic present exists in the pentavalent state, but nevertheless a portion exists in the trivalent state. It appears that arsenic trioxide is oxidized at a low temperature and the product formed is stable enough to remain until a high temperature is reached and the glass becomes fluid, when it slowly dissociates into oxygen and arsenic trioxide, both of...
Page 282 - The angular magnification of a telescope is therefore equal to the ratio of the focal length of the objective to that of the ocular.
Page 214 - The intensity of each beam of light, as observed through the analyzer, is proportional to the square of the cosine of the angle...
Page 152 - Allen 52 on borax glass in the heating of which "a slight but persistent absorption of heat appeared in the same region (490°-500° C) and continued over some 20° C, after which the original rate of heating returned.
Page 110 - ... chemical composition. The information at hand was not adequate for this purpose and our war-time interest was not concerned with this problem, which still awaits satisfactory...
Page 225 - On the construction of a silvered glass telescope, 15J inches in aperture, and its use in celestial photography, by Dr.
Page 5 - ... Bausch & Lomb Glass Plant served as a training ground for technicians who went to other glass plants to develop optical glass manufacture. How this worked out may be summarized in Lt. Col. Wright's report to the Chief of Ordnance, in May, 1921: "The records show that in the short period of nineteen months we did accomplish much to overtake the decades of German experience. In certain instances, as in optical glass and instruments, there has been developed in this country an industry which more...
Page 167 - ... then rolled out into a sheet of the desired thickness by means of a heavy cylindrical iron drum 20 inches in diameter. The sheet of glass is then pushed into a heated annealing oven or lehr where it cools down to room temperature in the course of a day or so, depending on the thickness of the sheet. The empty melting pot is returned at once to the melting furnace and is gradually refilled with raw batch for a new run. Casting pots may be used for 10, 20, and even 30 or more runs. The quality...