Page:History of the Royal Astronomical Society (1923).djvu/169

 1860-70] ROYAL ASTRONOMICAL SOCIETY 143 mutual influences made Smyth an antiquarian, and Lee an amateur astronomer. There is a human touch in the description of the meridian marks which Smyth had made for Lee's transit instrument. The adjustable metallic marks were let into blocks of marble, the northern block being a representation of the Temple of Janus, as given on a large brass medal of Nero, whilst the southern block was a miniature of the fa9ade of the Temple of Concord at Girgenti, with its central columns omitted for the insertion of the meridian plate. Smyth had moved from Bedford in 1842 to St. John's Lodge, within a short walk from Hartwell House. Lee purchased his instruments, and the two friends pursued their astronomical studies together. Dr. Lee employed James Epps (17711839) and Norman Pogson (1829-91) as assistants, Pogsori coming in 1859 January from the Radcliffe Observatory at Oxford, and remaining at Hartwell till he was appointed Government Astro- nomer at Madras in 1860 October. Pogson's work at Hartwell, relating mainly to the study of variable stars after the method of Argelander, was directed to the formation of an atlas of variable stars, and he had completed nineteen charts, 80' square, on a scale of 3 inches to a degree, with stars noted down to the twelfth magnitude, and with accurate magnitudes of certain comparison stars. Pogson carried on the work at Madras, and it appears that out of the nineteen charts and catalogues reported by Pogson as completed in 1860, six had been engraved and printed for Dr. Lee ; for copies of them were found by Dr. Copeland in the library of the Edinburgh Observatory. But Pogson's systematic work had to wait till 1908 before it was published, after being prepared for press by the volunteer labour and helpful generosity of Mr. C. L. Brook, with an illuminating introduction by Professor H. H. Turner, who has done so much to save from oblivion vast materials of early observations relative to variable stars. To Pogson we owe the discovery of many variable stars, and to him we owe the suggestion of the definition of the magnitude relation 2-512 times the logarithm of the brightness a relation that lies at the founda- tion of all modern photometric work. In these last paragraphs we have an instance of the difficulty which the history of the Society imposes on a writer charged with a single decade. He is diverted from a record of a single President into an inadequate reference to work upon variable stars. But still it is possible thereby to indicate the kind of service the Society is able to render in a single branch when indivi- dual members are willing by their loyalty and their labours to advance the cause of Astronomy. We see the influence of Dr. Lee, a generous patron of Astronomy, stimulated by that out-