Biographical and Historical Notes on the Pioneers of Photometry in Ireland

Abstract

As the circumstances of the early electrical measurements of starlight in Ireland are not widely known we wish to take this opportunity to set down the facts, as far as they are known to us. Corrections or new information will be welcomed.The observations made in Dublin in 1892 were the result of a collaboration between four graduates of Trinity College: George M. Minchin, William H.S. Monck, Stephen M. Dixon and George F. Fitzgerald. The observations in 1895 were made at Daramona Observatory, Co. Westmeath with a 24-inch reflector by Minchin, Fitzgerald and the owner of the telescope, William E. Wilson. In 1875 Minchin was appointed Professor of Applied Mechanics at the Royal Indian Engineering College at Coopers Hill, near Staines in London. In 1877 he started a long series of investigations of photoelectricity using a small optical laboratory at Coopers Hill and the laboratories of University College London. His initial aim was to transmit images electrically but he became skilled in making photovoltaic cells of selenium.By September 1891 Minchin had succeeded in making some working cells and he wished “to test them on the stars”. He contacted his friend Monck who had recently set up an observatory in his back garden in Dublin. Monck in turn asked Fitzgerald for the loan of a galvanometer or electrometer and for advice in its use. As Fitzgerald did not have a suitable instrument, he ordered Clifton’s form of Thomson’s quadrant electrometer, which arrived near the end of the year. It seems that Minchin also sent some of his cells to Dr Boeddicker in the spring of 1892 for trials on the 72-inch telescope but no reports are available.