Fig. 1. Rev. Ellison as he appeared on the frontispiece of the 2nd edition of The Amateur’s Telescope
Rev. W.F.A. Ellison
Rev. William Frederick Archdall Ellison was the sixth Director of the Armagh Observatory and was appointed to the role on 15 October 1918. He would remain in this position until his death on 31 December 1936. During that time, he made several telescopes and mirrors, both for the Observatory, and to supplement his income, which was very low compared to other Astronomers in the United Kingdom. He had been making mirrors for twenty years when he arrived in Armagh and had built up a reputation as by publishing articles and pamphlets about telescope-making in The English Mechanic and other periodical journals.
Fig. 2. The Ellison Reflector as it appears in The Amateurs Telescope (1920)
He kept a detailed optical notebook, which remains in the archives of the Armagh Observatory and Planetarium. This indicates he may have made well over two hundred mirrors, and dozens of complete telescopes. They were made for clients in Japan, the United States of America, France, Australia and many other countries, as well as some closer to home in Northern Ireland. Very few have survived into the twenty-first century, and none remained in the Armagh Observatory and Planetarium. As of 2024, only one hand made Ellison telescope has been identified and is still functional.
The Ellison Reflector
The last known Ellison rejoined the collection of the Armagh Observatory and Planetarium in September 2024. This was thanks to the support of the Esme Mitchell Trust, and the owner, Keith Venables. Keith found the telescope in East London, in 2009, looking significantly worse for wear after ninety-seven years. He restored the telescope over several years, and documented the process on his website: The Rev. WFA Ellison telescope | AstroKeith
Fig. 3. The Ellison Refractor, back in Armagh after a century
The telescope is a 6.25-inch reflector, which is one of the smallest sizes that Rev. Ellison offered for public sale. He initially began to offer them for sale in the early 1900’s, for the price of £3.10s (about £450 today). This was for just the mirror, the tube, stand and eyepieces would all have to be sought out, or made by the buyer. This example was featured in his famous book The Amateur’s Telescope (1920) which was adapted from a series of articles he published in 1918 in The English Mechanic. The Ellison Reflector was included in figure 29 to illustrate how an alt-azimuth stand could be made cheaply and effectively from discarded furniture legs.
Ellison mentions that the tube and mount were made for the telescope by an engineer at the Great Southern and Western Railway yard in Inchicore, Dublin. No further information is known about the maker, but the design, as the tripartite supporting structure for the mirror, is referenced in The Amateur’s Telescope. The telescope was found with a single eyepiece still in the focus aperture, a Steinheil-München eyepiece, likely a few decades older than the telescope itself. This is also likely to be the original eyepiece, as several similar Steinheil-München eyepieces are part of the Armagh Observatory and Planetarium historical collection.
We know the telescope is an Ellison because the back of the mirror is engraved with “Wm. F. A. Ellison” and “WFAE” engraved between two shamrocks. Further from the optical notebooks we know that Ellison identified his mirrors by pairs (and later trios) of Greek characters. The mirror on this telescope was identified as λ ζ (Lambda Zeta) 1912. Ellison was fluent in Greek, Latin, French and Hebrew, and also shared an interest in other languages with astronomers such as William John Roberts (William John Roberts – Engineer, Astronomer, Linguist and Theologian – Astronotes (armaghplanet.com)).
In September 2024 the telescope was delivered to the Armagh Observatory and Planetarium by Keith Venables, to rejoin the collection of scientific instruments and archives. Julian Ellison also visited to see the telescope and is the Great-Grandson of the Rev. W.F.A. Ellison. Julian had previously visited the Observatory with his father to donate much of the archival material that survives on the Ellison family, which in turn has made much of the historical research into the period 1918-1937 possible.
Armagh Observatory and Planetarium would like to thank the Esme Mitchell Trust for making this acquisition possible and to Keith Venables for his outstanding dedication and careful work restoring the telescope to its original condition.
Fig. 4. Prof. Michael Burton (Director of Armagh Observatory and Planetarium), Keith Venables and Julian Ellison with the Ellison Reflector.
source: armaghplanet.com