Andrew Aynsley Common

Andrew Aynsley Common (1841-1903), FRS, FRAS.

1841 Born in Newcastle, son of Thomas and Mary Common, brother of John Freeland Fergus Common

By 1851 his father had died

1861 A miller, living in Gayton, Norfolk with his uncle, Walter Hall, and family; Hall was a miller and baker

1867 Married Ann Mathews in Kings Lynn

1871 Engineer, living in Marylebone

1875 Birth of son Thomas Andrew Common

1881 Became a member of the Institution of Electrical Engineers

1881 Electrical engineer and lead merchant, living in Ealing

1885 Gold medal for invention of celestial photographs

1891 Building contractor, living in Ealing, with Ann Common 47, Violet M Common 21, artist, Thomas A Common 16, Lilian M Common 13, Ida Common 11

1901 Telescope lens and sight maker, employer, living in Ealing

1903 Died in Brentford

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1903 Obituary

WE regret to have to announce the sudden death of Dr. Common on Tuesday morning at Ealing. With the exception of the late Earl of Rosse, no one has done so much in the development of the reflecting telescope. Indeed, he did everything that has been done to popularise the instrument by the substitution of silvered glass for the enormously expensive speculum metal of Lord Rosse. Nothing more is needed than glass that is fully annealed and will admit of being ground and polished to a smooth parabolic surface. The texture of the glass in a refractor is all important, because the light passes through the lens. The surface of the reflector is coated with an excessively thin coating of silver, obtained by the action of sugar of milk on nitrate of silver. The process is very inexpensive.

Dr. Common brought the simple mechanism for grinding and polishing to perfection, and, beginning with small reflectors, proceeded to undertake the task of making a 5ft. reflector with a focal length of 27.5ft. The first mirror for this was finished in 1888, but was rejected because it was found to give elliptical instead of circular star-images. The new mirror, however, ready in 1891, completed an instrument which at that time was unsurpassed for light-concentrating power, since, although it was smaller than Lord Rosse's famous telescope at Parsonstown, which has a 6ft. mirror, the silvered glass is more reflective than the speculum metal. The Times gives particulars of various important instruments made by Dr. Common, such as the magnificent 3ft. reflector with which wonderful moon photographs were obtained. This found its way to Lick Observatory, where it enabled Keeler to obtain his extraordinary results in the discovery of new nebulae. Among other telescopes in the construction of which Dr. Common had a share may be mentioned the 30in. reflector at Greenwich, and the 3ft. reflector at the Solar Physics Laboratory, South Kensington.

Dr . Common, who of recent years had devoted much attention to improvements in the sighting of guns, was an honorary LLD., St. Andrew's. He was born in 184l. He became a Fellow of the Royal Astronomical Society in 1876, received its gold medal in 1884, and acted as its president in 1895-96. He was chosen a Fellow of the Royal Society in 1885. He leaves a wife, son, and three daughters.

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1903 Obituary

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