- Johann von Mädler (1794-1874)
- Born in Germany.
See: Wilhelm Beer.
- Born in England.
- From the measurement of the mass of a Scottish mountain, he deduced a figure for the density of Earth, just a little less than later determined.
- He realized that William Herschel had discovered Uranus, not a comet.
- He produced the first nautical almanac.
- Born in France.
- He found more than one dozen comets.
- He catalogued star clusters because these had misled him in his search for comets.
Nevil Maskelyne (1732-1811)
Charles Messier (1730-1817)