William Ellis (1828-1916)
William Ellis (1828-1916) FRS of the Greenwich Observatory
1917 Obituary [1]
WILLIAM ELLIS, F.R.S., was born at Greenwich in the year 1828.
At the early age of 13 years he entered the service of the Royal Observatory, as a member of the computing staff then engaged upon the reduction of the important series of observations of the moon, made in the years 1750 to 1830.
After the completion of these reductions, he received the appointment of junior assistant on the Observatory staff in 1853, and two years later was placed in sole charge of the time signals, and control of the Time Department. In that capacity the development of the system for the distribution of correct time throughout the country claimed a considerable share of his official duties, and the system was gradually brought to a state of perfection. The scheme which he developed, in concert with the Post Office as distributing agents, was fully described by him in Nature in 1876, and afterwards reprinted as an Appendix to the Greenwich Volume for 1879.
As an extraneous portion of the work connected with his department, he took part in the telegraphic work involved in the following longitude determinations:— Edinburgh, 1857-1858 ; Valentia, 1862 ; Glasgow, 1865 ; and the observing stations included in the Transit of Venus expedition of 1874.
At the end of the year 1874 he was appointed to succeed Mr. Glaisher as Superintendent of the Magnetical and Meteorological Department at the Royal Observatory. His knowledge of that department was then confined to occasional inspections of the adjustments of the earth current galvanometers and wires, and regular attention to the standard sidereal clock.
On taking up the official work of his new charge he turned his attention to the investigation of the connection between the 11 years' sun-spot period and magnetic variations, which had been suggested by Sir Edward Sabine but had not yet been subjected to scientific examination. For this task he employed the magnetic records which had been accumulating at the Royal Observatory since 1848. He pursued his investigation with great thoroughness and completed his task by the year 1879, when he communicated the result in a paper to the Royal Society which is published in their Transactions for 1880. He subsequently expanded his research to include all the results of the observations for the 56 years 1841-1896, and the final results obtained in this important inquiry are given in a paper printed in the 63rd volume of the Proceedings of the Royal Society. The relation between the sun-spot frequency and the magnetic elements is clearly shown in both of these investigations.
Many other magnetic papers followed at brief intervals contributed either to the Royal Society or to the Royal Astronomical Society, and are published in the records of those Societies. As relating to the meteorological section of his charge, he contributed many abstract papers to the Royal Meteorological Society during his term of office as President of that Society in the session 1887-1888.
At the end of the year 1893, having completed his full term of service, he retired from official life at the age of 65 years, but still continued to interest himself in scientific work until he became disabled from physical exertion by increasing age and gradual loss of sight.
He died at Blackheath on the 11th December, 1916, at the venerable age of 88 years.
He was elected a member of the Institution in 1873.