Quarter 2 Astronomer Post -- William "Eagle Eye" Rutter Dawes

Astronomer Project: William Rutter Dawes

            Dawes was born in West Sussex, London in 1799. His mother died when he was very young and his father was a very accomplished man who was often called away from the home. William Rutter Dawes’ father, William Dawes, was an Officer of the Royal Marines, an astronomer, engineer, botanist, surveyor, explorer, abolitionist and colonial administrator. Needless to say, our William Rutter Dawes was not always cared for by his immediate nuclear family, entrusted instead to relatives and friends. His father wished that he would become a clergyman, but Dawes had other intentions. He studied medicine at St. Bartholomew’s Hospital and then opened a country practice in Berkshire. When his sister died in 1826, he moved to Liverpool and took control of a small congregation in Ormskirk. It was in Liverpool that Dawes found his lifelong friend and companion, William Lassell. Dawes began documenting his observations of the sky in 1829, specifically the study of binary stars. According to Lassell’s notebooks, they had been studying together for some time.

            Dawes had been interested in astronomy as a boy, so by striking a friendship with astronomer William Lassell, Dawes’ fate was secured. He started out using a small refracting telescope to make his observations. In a letter to Sir John Herschel, he recalls how he obtained a copy of Rees’s Encyclopedia and copied from it Sir William Herschel’s catalogue of double stars and sat down each night to locate them and diagram them. He soon began work on a small observatory at Ormskirk. With his five foot Dolland refractor set at an aperture of 3.8 inches, Dawes was able to make extremely precise measurements of the binary stars that fascinated him so much. Between the period of 1830 and 1833, he measured 121 double stars, published in 135. Between 1834 and 1839 he measured 100 more, which were published in 1851. The discoveries helped to christen him William “Eagle Eyes” Dawes. He was elected a Fellow of the Royal Astronomical Society in 1830, but in 1839 with the death of his wife, ill health had caught up with him and he was forced to give up pastoral work and move to London.

            Friend George Bishop had amassed a large fortune from the production of wine and had become a patron of science, thus erecting a large private observatory with a seven inch refractor in London. Bishop allowed Dawes to continue his astronomical study until 1844. Studying at Bishop’s he measured and published 250 binaries in 1852 in Bishop’s Astronomical Observations at South Villa. Dawes married again in 1842 to a wealthy woman and was able to erect an observatory of his own, installing a 6.5 inch Merz refractor. With it, he co-discovered Saturn’s crepe ring. WC Bond had also found the ring at the Harvard Observatory, but before news had crossed the Atlantic, Dawes had made his claim. Dawes had established himself as a leader in the observation of Saturn, carefully studying the planet and its rings.

            He received the Gold Medal of the Royal Astronomical Society in 1855. He moved in 1857 to Haddenham where he continued observations despite rapidly deteriorating health, especially worsened when his second wife died in 1860. His extensive drawings of Mars during its 1864 opposition helped Richard Anthony Proctor’s mapping of Mars in 1867. He died at Haddenham on February 15, 1868. Dawes lends his name to certain craters on the Moon and Mars as well as a gap in Saturn’s C Ring. The Dawes limit is a formula discovered by W. R. Dawes used to describe the optical phenomenon that expresses the maximum resolving power of microscope or telescope.