The precise date of the invention is not known; but in 1767 he employed John Kay, a watchmaker at Warrington, to assist him in the preparation of the parts of his machine, and he took out a patent for it in 1769.
He was a watchmaker named Rodolph Stadler, who had slain a Persian on suspicion of intrigue with his wife.
He was originally a watchmaker, but retired from business about the age of thirty and devoted himself to experimental and observational science.
The son of a goldsmith, he learned the trade of a watchmaker at Flensburg, and exercised it at Berlin and Tondern, 1818-1820.
Our body is like a perfect watch that should go for a certain time.