chapter  26
WithPatrick Moore
Pages 6

Galaxies are external systems; many of them are much smaller than our Galaxy, while others are far larger and more populous. Many are included in Messier’s Catalogue, but their true nature was not then recognized. A major breakthrough came in 1845, when the third Earl of Rosse, using his remarkable home-made 72 inch reflector at Bin-Castle in Ireland, found the first spiral – M.51 in the constellation of Canes Venatici, now generally called the Whirlpool. Other spirals were soon found, although for some years only the Birr telescope was capable of showing them as such; other ‘starry nebulæ’ were spherical in form, so that superficially they looked very like globular clusters, while others were elliptical, and some irregular in outline.