A busload of tourists arrives at Runnymede, just west of central London.
They gather around the guide who says: “This is the spot where the barons forced King John to sign the Magna Carta."
A guy at the front of the crowd asks: "When did that happen?”
“1215,” answers the guide.
The man looks at his watch and says: “Damn! Missed it by a half hour.”
Guncotton patentIn 1846, Christian Frederick Schönbein of Basle, Switzerland, was issued a U.S. Patent for guncotton titled “Improvement in Preparation of Cotton-Wool and Other Substances as Substitutes for Gunpowder”(No. 4874). The process uses a mixture of concentrated acids to convert the cellulose present in well-cleaned cotton-wool, C6H10O5 into cellulose nitrate C6H8(NO2)2O5 (nitrocellulose). In 1891, James Dewar and Frederick Abel incorporated nitrocellulose in a mixture that could be handled more safely. Until WW II, this invention replaced gunpower on the battlefield, where it had been used for five centuries. It was also useful for blasting because it generates about six times the gas of an equal volume of gunpowder and produces less smoke and heat. |
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