330-PS-357 (USN 707812):  Navy’s New Color Filter To Help Astronomers Study Sun Spots.   Dr. William Markowitz, an astronomer at the Naval Observatory, Washington studies sun-spots, planes and other solar disturbances that affect radio communications.  Through the first color filter made commercially using artificially grown crystals. (The filter, 6 inches in diameter and about 10 inches long, in just above the eyepiece).   The color filter, now temporarily mounted, will be installed in a special telescope at the Naval Observatory for use in making a continuous photographic record of the sun’s entire surface.  It has been impracticable before to have such a record with a complicated spectroscopic apparatus now in use.  Since solar flames can affect radio communication by producing fadeouts, and excessive sonar activity can affect telegraphic and even cable communications on rare occasions, the prediction of such phenomena is considered a matter of military and commercial importance.  Developed for the Navy by Baird Associates, Inc, of Cambridge, Massachusetts, photograph released June 29, 1950.  (7/22/2015).
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