M

• Born in Germany.
  See: Wilhelm Beer.

Nevil Maskelyne (1732-1811)

• 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.

Charles Messier (1730-1817)

• Born in France.
• He found more than one dozen comets.
• He catalogued star clusters because these had misled him in his search for comets.