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Two golden rules to a happy marriage
Two golden rules to a happy marriage...
What is hidden in 3D image?
Brain Teasers
[6359] What is hidden in 3D image? - Stereogram - 3D Image - #brainteasers #stereogram #3Dimage
2020-04-17
PatentsIn 1873, the first U.S. patent for a gold crown was issued: to Dr. John B. Beers of San Francisco, California on "artificial crowns for teeth" (No. 144,182). His technique was to prepare a hollow metal crown which would be slipped over the projecting portion of the old tooth and secured to it so that it would continue to function for chewing as before, while also preventing further decay. A gold screw was mounted in the old tooth, the hollow crown slipped over it and cemented with oxychloride of zinc. This replaced the old method of restoring decayed or broken teeth by condensing gold upon it with a hammer until it had taken the desired shape - which difficult process was costly, tedious, and frequently resulted in inflammation from the hammering on the jaw. |