Thomas Grubb was born to the Quakers William Grubb and his wife Eleanor (née Fayle) in 1800. Around 1832 Grubb established a mechanical engineering workshop in Dublin and began constructing modest reflector telescopes for his own use. Through his interest in astronomy he began undertaking various commissions for the erection and construction of telescopes, including a fifteen-inch reflector for the Armagh observatory. In order to mount this large telescope Grubb designed a system of triangle levers to reduce stress on the mirror. A similar system was employed by William Parsons, third earl of Rosse, in the construction of his six-foot reflector, ‘the leviathan’, at Birr Castle in the 1840s. In this early period Grubb’s work was primarily funded by private individuals.
These commissions soon brought him to the attention of scientific figures throughout the United Kingdom, and he was hired to construct telescopes for the Royal Observatory, Greenwich, and the University of Glasgow. He also fabricated twenty sets of magnetometers for Professor Humphrey Lloyd’s (Trinity College, Dublin) efforts to establish a network of magnetic observatories throughout the British Empire. These were to further scientific understanding of geo-magnetism and, eventually, thirty-three observatories were set-up throughout the world on the same model as the magnetic observatory based in Trinity College, Dublin.
A great deal of this research was not driven by ‘pure’ scientific interest. The British state, as a maritime nation, was strongly motivated to fund astronomy and the production of star charts. In fact, George Airy, Astronomer Royal, saw the main tasks of the Royal Observatory, Greenwich, as producing accurate stellar and planetary maps and the regulation of ships chronometers, all essential for navigation. Thus, the successful trajectory of Grubb’s business was, in many ways, firmly tied to wider British Imperial and trading interests. As the nineteenth century progressed the British state was to begin funding ‘pure’ research to a greater extend and this was to provide Grubb with much work.
It was the success of the Rosse telescope, which had gone someway to answering the question of the resolvability of nebulae, that was to prompt calls for a similar telescope to be erected in the southern hemisphere. This was realised in 1869 when a four-foot Grubb reflector was installed in Melbourne. Unfortunately, this telescope was to be a resounding failure, probably due to the inability of staff in Melbourne to polish the mirrors (these had been made using polished metal instead of the silver-on-glass method that was becoming popular). Thomas Grubb was to die in 1878 but the company was to remain in operation under the guidance of his son, Howard, who had taken control in 1868.
Howard Grubb was to remain in charge for fifty-seven years and in this time constructed most of the large telescopes erected across Britain and its empire, including five for the Royal Observatory. In addition, the company also constructed telescopes for a number of others, including a twenty-seven-inch reflector for the University of Vienna, 1881. In this period the majority of Howard’s large instruments were refractors. In the closing years of the nineteenth century the company also began making photographic instruments for astronomical observations. The previous system of human observers sketching their observations had been open to error and encountered difficulties when attempting to draw large and detailed star charts. In 1890 the company delivered seven, of thirteen, such instruments that were used as part of the Carte du ciel (map of the sky) project, the rest were constructed by the Henry brothers of France. (It was on one of these Grubb telescopes that Arthur Eddington was to show the distortion of a star’s position when its light passed near the sun, thus providing the first proof of Einstein’s theory of relativity).
In the twentieth century the company was to put its optical expertise to military use, designing rangefinders, gunsights and the first submarine periscope. This was to tie the fortunes of the company to the state in an even more obvious manner. Due to its increased importance to the war effort, the company transferred to the south of England in 1918. This move was to prove decisive and, with the end of the First World War, Grubb was unable to meet increasing costs. The firm was sold to Charles Parson, the youngest son of the third earl of Rosse, in 1925 and the new firm, ‘Sir Howard Grubb, Parsons and Co.’ was to continue in operation until 1985.
Ian Elliott, ‘Grubbs of Dublin: telescope makers to the world’ in Juliana Adelman and Éadaoin Agnew (eds), Science and technology in nineteenth-century Ireland (Dublin, 2011), pp 47-62.
Anita McConnell, ‘Scientific instrument makers’ in Oxford Dictionary of National Biography (Oxford, 2015), available at (www.oxforddnb.com) (19 Mar. 2016).
John Burnett, ‘Grubb, Thomas, engineer and telescope builder’ in Oxford Dictionary of National Biography (Oxford, 2015), available at (www.oxforddnb.com) (19 Mar. 2016).
Adrian James Kirwan, co-editor of Holinshed Revisited, is an Irish Research Council funded Ph.D. candidate at the Department of History, National University of Ireland, Maynooth. His research focuses on the interaction between society and technology, more about his research can be found here.