Establishing the first comprehensive catalogue of the stars of the southern sky
Over four years Lacaille studied the sky at the Cape of Good Hope in present-day South Africa, observing over 10,000 stars using a half-inch refractor. He also introduced 14 new constellations which have since become standard, and determined the lunar and solar parallaxes as well as determining the radius of the earth in the southern hemisphere. As well as this, he prepared the first set of tables of the Moon's position that was accurate enough to use for determining time and longitude by the method of 'Lunars' (Lunar distances) and apart from constructing astronomical ephemerides and mathematical tables, he calculated a table of eclipses for 1800 years. Lacaille's observations to measure the French meridian were part of evidence which confirmed Isaac Newton's idea that the Earth was a sphere flattened at the poles. William Herschel is credited with discovering Uranus; the first useful reflecting telescopes were built by John Hadley (on designs developed from those by James Gregory and then Robert Hooke; many proposals re establishing longitude were proposed, but none by Lacaille.
