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1945 Theatre Catalog, 4th Edition, Page 322 (298)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 322
Page 322

1945 Theatre Catalog, 4th Edition, Page 322

A FINAL SPRAYING of the familiar white finish is sprayed in several coats and slow-baked to extreme hardness. To prevent the spray from getting on the inner surface of the reflector, the center hole is plugged during this process. Next came the final tests of the complete reflector, cleaning and wrapping, and it is finished.

The rhodium is electroplated upon the surface after the latter has been formed tomthe proper curvature.

Thin transparent films of platinum have been used to a limited extent as semi-rehectors or beam splitters. Thin hlms of gold have been used for the same purpose in three-color cameras.

Other metals*such as copper, stainless steel, chromium, and berylliumee have been tried for various purposes,

INSPECTIONS, MANY OF THEM, from the beginning to the and, insure optically perfect reflectors for the motion-picture theatre. The inspection shown at the left is that which follows the polishing of the glass reflector shell, and reveals any flaws in the glass brought out in the polishing process. The inspection and test

but their use has never become widespread.

During the War a searchlight reflector was made from Haynes Stellite, a development of the Electro Metallurgical Company. The materialean alloy of cobalt, chromium, and tungsten-etakes a high polish and is said to be so hard and corrosion-resistant that the reflector surface is not marred by salt air, the heat of the arc, nor the constant use of

CAREFUL CLEANING of the reflector, prior to wrapping, is the last step in the manufacturing process. All reflectors carry a serial number, and the engineering department keeps complete files and records on all tests made with each reflector. The serial numbering and trade marking is done iust before the silvering process.

nitric acid in cleaning it.

In retrospect, it is apparent that no developments of a startling character or farmeaching importance have been made with respect to metallic films for mirrors. Silver still retains its position of preeminence, far outdistancing its nearest competitor, aluminum, in quality and quantity. Methods of manufacture are the same as have beennlsed for years.

Shown at the right is the final one in which the finished reflector is checked and rechecked to insure optical accuracy of the curvatures. The accuracy of the curvatures and the perfection of the optical glass all play important parts in insuring the theatre man that he will have the best results from his carbon arcs.

1945 Theatre Catalog, 4th Edition, Page 322