A magician comes up to our table and does a card trick.
Impressed, I asked him how he did it.
He says "I can tell you, but I'd then have to kidnap you and take you away."
I said, "Can you tell my mother-in-law?"
Portland cement US patentIn 1871, U.S. patent No. 119,413 for the composition of portland cement was issued to David Oliver Saylor, of Allentown, Pa. In 1871, Saylor tried his hand at selecting and mixing different kinds of rock from his quarries to produce portland cement at the first US plant in Coplay, Pa. After initial difficulties, he succeeded with a mixture of magnesium clay with limestone clay. Samples shown at the 1876 Philadelphia Centennial Exhibition compared well with the best imported portland cements. In England, William Aspdin had patented "Portland cement," and coined the name (1852). The first recorded shipment of portland cement to the US was in 1868, when European manufacturers began shipping cement as ballast in tramp steamers at very low freight rates.[Image: Kilns at Coplay, Pa.] |
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