By Matthew McMahon (Museum Collections Officer) and Malcolm McCleery (Volunteer Researcher)
Determine 1. Dr Lindsay, the seventh Director, posing with the Grubb 10 within the late 1940’s for the Irish Occasions (Armagh Observatory and Planetarium)
Curators and Historians are usually not meant to have favorites. Like good mother and father or carers (the basis of the phrase curator is to care in spite of everything), we are supposed to love all our costs equally, from the oldest manuscripts to the latest computer systems, that we maintain for future generations. Nonetheless, in case you press any of them, you’ll uncover all of them secretly have a favourite and that is ours.
140 years in the past, workmen had been bustling throughout the summer time of 1885 on School Hill, Armagh, to arrange a brand new dome and telescope to be used by the Director, Dr John Louis Emil Dreyer. The telescope had been paid for by a authorities grant, the primary of its type to be awarded to the Observatory, in addition to the donations from the chums of the earlier Director who wished to see a memorial to him raised in Armagh. The earlier Director, Dr Robinson, had additionally wished to put in a brand new instrument, and the sort had been chosen by him earlier than his dying in 1882.
An Equatorial is needed appropriate to the current necessities of Astronomy. That which now we have is of solely 2 ½ inches aperture; a correct instrument of this type would price from 600 to 700 kilos.
{Armagh Observatory and Planetarium Historic Assortment M 80.2 (1879)}
To construct such an instrument, there was just one alternative.
Determine 2. Dr John Louis Emil Dreyer (Armagh Observatory and Planetarium)
While many nice devices have been being made in America, London and Germany, domestically in Dublin there was an much more completed maker. Howard Grubb had grown up serving to his father forge nice telescopes, and in his early twenties had labored within the searing warmth to construct the Nice Melbourne Telescope. Additional, Dr Dreyer used the South Telescope at Dunsink Observatory, the primary of what Howard would name his ‘Commonplace Equatorial’. This expertise left him satisfied that to complete his lengthy work on the New Normal Catalogue, he would wish a contemporary telescope that he may take exact measurements with and function rapidly with a small workforce.
Having settled on Howard Grubb as a maker, the choice remained about what kind of telescope to buy. The event of photographic telescopes had already begun, and the competitors between producers to make the following leap in know-how was fierce. Howard Grubb tried to influence Dr Dreyer to take a danger on a novel design that might see the consumer sit comfortably contained in the Observatory and management the telescope from afar, utilizing a sequence of mirrors to watch the sky. While this may need been an interesting thought within the chilly months, Dr Dreyer knew the kind of work he wished to perform, and knew that the Commonplace Equatorial, mounting what was then thought-about a medium sized optical telescope, would supply him with a superb compromise between the optical energy he wanted, and the flexibility to deal with it himself with out counting on assistants. The telescope additionally contained a dependable and highly effective clock drive (Determine 4), which allowed it to trace the celebs throughout the night time sky and enabled him to make detailed drawings on the eyepiece, as he had discovered throughout his time at Birr.
Determine 3. The entrance cowl of the Catalogue of the Grubb Telescope Firm in 1883, the identical version that Dr Dreyer referenced in his choice to purchase a Grubb (with because of Museums Victoria)
The telescope arrived from the Grubb foundry and was mounted on 28 July 1885, although it could take till 8 October 1885 for it to be adjusted and ready to be used. By this time it was the primary new telescope for the reason that Grubb 15-Inch had been put in in 1834, by Howard Grubb’s father, 10 years earlier than Howard had even been born! Working with a micrometer, a tool hooked up to the eyepiece finish of the telescope which permits the consumer to take exact measurements between two objects within the night time sky, in addition to the angle, Dr Dreyer put the ending touches on his New Normal Catalogue which he revealed in 1885. He continued to make use of the telescope till he retired in 1916, albeit a lot much less often and centered on particular phenomena that he was alerted to by previous pals on the Continent.
Determine 4. The clock drive, because it was refinished within the 1990’s (Armagh Observatory and Planetarium)
Following the appointment of Rev. Ellison to the function of Director in 1917, the following astronomer to make use of the instrument was the younger Mervyn Ellison, the eldest surviving son of Rev. Ellison. Between the age of 13 and 16 Mervyn started an intensive examine of double stars, fastidiously measuring and remeasuring the gap between two stars to find out in the event that they orbited one another, or simply occurred to be in step with one another. To do that he relied on correspondence from essentially the most completed double star observer on the planet at the moment, T.E. Espin, who was practically fifty years older than {the teenager}. Mervyn developed an ingenious system, positioning a second lens between the micrometer and the telescope to provide him even higher magnification for accuracy. He revealed his work within the prestigious Month-to-month Notices of the Royal Astronomical Society just a few months earlier than his 18th birthday.
{Ellison MA (1927) Micrometrical Measures of Double Stars, made with the 10-in. Refractor of the Armagh Observatory. Month-to-month Notices of the Royal Astronomical Society 87(5): 465–466.}
Determine 5. The Micrometer mounted on the telescope, photographed by Mervyn Ellison when he started to work on the issue of Double Stars as an adolescent (Armagh Observatory and Planetarium)
Underneath the following Director, Dr Lindsay, the telescope acquired an entire new line of labor; public engagement. Opening the Observatory to the general public for the primary time in over a century, Dr Lindsay started in 1937 to point out the general public the planets and different celestial objects with the Grubb 10-Inch. In 1950 he had it repaired and all the time tried to search out methods to make use of it for contemporary analysis. The success of this diversified, nevertheless it remained a agency spotlight of any go to to the general public. In 1974 it was dismantled with the intention of rebuilding it nearer to the newly opened Planetarium, for use for this goal. Nonetheless, the sudden dying of Dr Lindsay in the summertime of 1974, and his succession by the non permanent management of Prof. Öpik, noticed the telescope rebuilt in its unique website, and the Planetarium was compelled to look elsewhere.
Determine 6. Pat Corvan exhibiting faculty youngsters the Grubb 10-Inch within the 1990’s. Pat was the longest consumer of the telescope having used it first in 1950, and had his final observing session with it in 2023 (Armagh Observatory and Planetarium)
Nearing its ninetieth birthday, and having seen the event of photographic astronomy, astrophysics, the galactic debate, the nuclear bomb and the area race, it appeared that the scientific days of the Grubb have been over. Nonetheless, in 1975 Dr Ray Wilson, an American, joined the employees and efficiently used the instrument on each clear night time to proceed his work on Double Stars. His work is considered the final scientific work of the telescope, and since then it has continued to serve in different roles.
Within the early 2000’s an in depth restoration venture was funded by the Heritage Fund, and noticed the telescope restored to its unique state and the dome repaired. Since then, the telescope has been used for occasions such because the Transit of Venus, occultations and eclipses. It’s also used to coach our new PhD college students and employees in historic astronomical abilities, to provide them a connection to their scientific ancestors who walked the identical streets in Armagh and sat in the identical rooms they proceed to work in to today. In chilly winter nights they huddle across the dome, listening to the low whirring sound of the clock drive, and the rumble of the big metallic dome transferring round their heads, and look by eyepieces that left the workshops in Rathmines 100 and forty years in the past. This October Armagh Observatory and Planetarium will probably be operating a sequence of occasions between 8 October (140 years for the reason that telescope was completed) and 15 October (140 years because it was first used efficiently), we hope you’ll be part of us to rejoice the birthday of this unbelievable telescope.
Determine 7. The restored Grubb 10-Inch in 2018 (Armagh Observatory and Planetarium).
