Alfred Wolfer, who died on 1931 October 8, was for fifty years associated with the Federal Observatory at Zürich. Throughout that time he worked specially on sunspots - a subject which had been taken up by his predecessor, Rudolf L. Wolf, the first director of the observatory. The activity of the observatory in discussing the frequency of sunspots from records back to 1610, and in collecting later data, led to it being chosen as the centre for sunspot data by the International Astronomical Union.
Wolfer was born at Schönenberg, near Zürich, on 1854 January 27. His early circumstances were not favourable to a scientific career, but by perseverance he succeeded in entering the Technical High School at Zürich. After studying mathematics he took his diploma for an essay on the division errors of the transit circle. He found no suitable opening, and worked for a year as a voluntary assistant at the observatory till a vacancy occurred. His astronomical work at first included meridian circle observations and planetary observations with the refractor. He also discussed meteorological observations. Although he was for most of his life very interested in meteorology and was an active member of the Swiss Meteorological Commission, he refused an appointment in the meteorological observatory at Pawlowsk. As Wolf, the Director of the Zürich Observatory, became more and more occupied with his discussions, he left the practical work of the observatory to Wolfer, who finally succeeded him as Director in 1893.
Wolfer obtained additional support for the observatory - a second assistant and new instruments. The latter included a 13-inch telescope, as compared with the 6 + 1/2-inch which had been the largest telescope of the observatory for about fifty years, and a spectrohelioscope. The publications of Zürich Observatory are concerned principally with observations of the Sun and and with statistical work on the frequency of sunspots and their connection with terrestrial magnetism. During Wolfer's directorate there were issued 31 numbers of the Astronomische Mitteilungen and 5 volumes of publications. The latter gave heliographic charts of all the phenomena of the Sun's photosphere for all rotations for an 11-year period. Work by Wolfer's pupils on the proper motions of spots are also included in the volumes.
Although Wolfer is best known to astronomers for his work on sunspots, he did valuable teaching and administrative work at the university. He took an active part in the Swiss Meteorological Commission. He was naturally a member of the International Commission on Terrestrial Magnetism. Through these Commissions he became widely known to scientific colleagues throughout the world. His enthusiasm took him back regularly to the observatory to observe after his retirement in 1926, and later, when this was too great a strain for him, he made observations at his own home. He corresponded regularly with those interested in his work, and his friendly presence will be missed from international meetings of astronomers.
He was elected an Associate of the Royal Astronomical Society in England on 1913 June 13.
(MNRAS Vol. 92, p.267-8 )
At the meeting of 1903-12-22, on motion of Mr. Harvey, seconded by Mr. Elvins, Professor A. Wolfer, Director, the Observatory, Zurich, Switzerland was nominated a Corresponding Fellow of the Royal Astronomical Society of Canada. He was declared elected at the meeting of 1904-01-19. At the meeting of 1904-05-03 the Secretary reported the receipt of a communication from Professor Wolfer accompanying some valuable contributions to the Society's library.