Pyrex Patent

Pyrex patent. Certified copy of presentation patent specification letter dated May 27, 1919 for patent number 1,304,623. Original application for this patent was filed June 24, 1915. U.S. Department of Commerce, Patent & Trademark Office. CMGL 139156.

Certified copy of presentation patent specification letter dated May 27, 1919 for patent number 1,304,623. Original application for this patent was filed June 24, 1915. U.S. Department of Commerce, Patent & Trademark Office. CMGL 139156.

Link to original patent can be found here: http://rakow.cmog.org/vwebv/holdingsInfo?bibId=139156