Hopkins was an American inventor who was granted the first US patent in 1790—just months after President George Washington signed the new patent statute into law—for an improved process for making potash and pearl ash, substances used in the manufacture of glass, soap, and fertilizer. There was no Patent Office at the time, so his petition was approved by a committee that included the US president, secretary of state, and attorney general. What other US patents were issued that year? Discuss
Now used to refer to a convenient principle with a broad application not intended to be strictly accurate in every situation, the term "rule of thumb" first appeared in print in Sir William Hope's The Compleat Fencing-Master in 1692. The phrase is thought to have originated with woodworkers who used the length of their thumbs, rather than rulers, for measurements. However, it is often erroneously claimed that the term originally referred to a law that limited the thickness of what?
In July 2001, red-colored rain began falling in the Indian state of Kerala. For the next two months, it returned intermittently. A number of theories explaining the origins of the coloration were proposed, including that it was contamination from a dust cloud, debris from a volcanic eruption, and even extraterrestrial cells. The Indian government initially speculated that the red rain was caused by an exploding meteor but later issued an official report asserting that it had been caused by what?