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fHA, xxxv (2004) MENAGE A TROIS: DAVID PECK TODD, MABEL LOOMIS TODD, AUSTIN DICKINSON, AND THE 1882 TRANSIT OF VENUS WILLIAM SHEEHAN, Willmar, Minnesota, and ANTHONY MISCH, Lick Observatory Background to the 1882 Transit The first application of photography to a transit of Venus was eagerly anticipated in advance of the 1874 transit. One hundred and five years had passed since the last such event, and the new technology promised great improvement in the determination of that fundamental astronomical constant, the solar parallax. Yet the 1874 results were not as impressive as hoped, and there was widespread disillusionment with the whole transit-of- Venus triangulation method for working out the solar parallax. Moreover, the availability of other techniques for measuring the parallax - the observation of Mars near opposition, successfully applied by David Gill from Ascension Island in 1877; the observation of asteroids near opposition; timings of phenomena of the satellites of Jupiter combined with laboratory determinations of the speed of light - lessened astronomers' enthusiasm for the forthcoming 1882 transit, compared with that attaching to earlier transits. Nevertheless, expeditions were still planned. For instance, the United States Naval Observatory's Transit of Venus Commission received an $85,000 appropria­ tion from Congress, despite the fact that Simon Newcomb, the leading figure of the Commission, was unenthusiastic. Though a pacesetter in the preparations for the 1874 transit, by 1882 Newcomb had clearly lost the faith, though he signed on for an overseas expedition himself, and in the end observed the transit from a site outside Cape Town, South Africa. The New York Times, calling attention to the 1882 transit's superb visibility from the United States (see Figure 1), questioned whether government funding for these expensive overseas expeditions could still be justified. Indeed, the Times, perhaps the public generally, seems to have confused the transit-of- Venus method of determining the solar parallax with the method applied by Gill in 1877 which relied on measures of Mars near opposition relative to the background stars: It so happens that a transit of Mars [sic] is just about as useful for astronomical purposes as a transit of Venus. After the Government had sent astronomers all over the earth to observe the transit of Venus in 1874, the public was astonished to learn that a transit of Mars was to take place a year or two later. Why, it was asked, had not the astronomers, who insisted that a transit of Venus was an event happening only once a century, mentioned that a transit of Mars was also close at hand? ... It has finally become evident to all thinking people that as long as astrono­ mers can induce Governments to send them to China and Peru the necessity of 0021-8286/04/3502-0123/$5.00 © 2004 Science History Publications Ltd Downloaded from jha.sagepub.com at UNIV OF CALIFORNIA SANTA CRUZ on October 24, 2016 tv .p. Downloaded from jha.sagepub.com ;'~ 3 CIl atUNIV OFCALIFORNIA SANTA CRUZonOctober 24,2016 ::r (1l ::r(1l § § 0.. ;J:> ;:: oS- ;:: '< ~ Vi' ::ro S{;~.\'F.W or TIlE EARTII AT TilE DEGI~~~G or TlI& TBA.'(srr 01' 1882. SUS·\·IEW OF TIlIl F..,nTIl AT TOE EXD Oft TIlE Tn.vxsrr OF 1882. 1. Sir G. Airy's proposed station at Repulse Bay. J. Sir G. Airy'. proposed station at Repulse nay, 2.., on P~"<'s,'Sion Island. 2... .. 011 Possession Island. FIG. I. Transit visibility in 1882, diagrams from Richard A. Proctor's Transits ofVenus (4th edn, London, 1882). Menage aTrois 125 FIG. 2. David Peck Todd. from the Mary Lea Shane archives ofLick Observatory. observing transits of Venus will never come to an end, and the distance of the sun from the earth will never be definitely settled. I An Astronomer in the Wings One astronomer who would have jumped at the chance to participate in a transit expedition to China or Peru was Amherst University's David Peck Todd (Figure 2), who in the years leading up to the transit had appeared to be one of the most prom­ ising young astronomers in America. Todd is little remembered today - Thomas Hardy's Swithin St Cleeve, the astronomer in the May/December romance Two on a tower published in the Atlantic Monthly on the eve of the transit of 1882, could have been speaking for him when he said: "My reputation - what is it! Perhaps I shall be dead and forgotten before the next Transit of Venus.,,2 But Todd had once been one of Newcomb's proteges at the U.S. Naval Observatory, and Newcomb had charged him with the task of reducing all the 1874 transit observations to a value for the solar parallax. Downloaded from jha.sagepub.com at UNIV OF CALIFORNIA SANTA CRUZ on October 24, 2016 126 William Sheehan and Anthony Misch Born in 1855 on a farm at Lake Ridge, on the eastern slope of Cayuga Lake in upstate New York,Todd was a direct descendant, in the sixth generation, of the Puritan divine Jonathan Edwards. When he was ten, the Todds moved to Brooklyn, and began attending Plymouth Church, whose minister was the famous Henry Ward Beecher. Todd was more intrigued by the hand-pumped organ than Beecher's sermons, and from that moment forward "fell in love with organs".3 Years later he would include some of their features in the design of an astronomical instrument. He was mechanically inclined, built his own steam engine as a boy, and received a scholarship to Columbia University where, with a homemade telescope, he timed the eclipses ofthe satellites of Jupiter. As a junior, he transferred to Amherst. After his graduation in 1875 he was recruited to the U.S. Naval Observatory by Newcomb, then Superintendent of the Nautical Almanac office in Washington, D.C. Todd's later life was sometimes full of wistfulness and nostalgia for what might have been. It was about this time that Todd, on a visit to Newark, met young Thomas Alva Edison, who was working by day as a Western Union telegraph operator and by night on electrical experiments in the cellar of his office. Edison tried to lure Todd from astronomy, but without SUCCfiSS. Only much later in life - and then too late - did Todd realize that his real genius had been in mechanical engineering. In addition to Newcomb, Todd's colleagues at the Naval Observatory included Asaph Hall, the son of a clockmaker, who before becoming an astronomer had worked for a time as a schoolteacher in Shalersville, Ohio (not far from Edison's birthplace of Milan). As a staff astronomer at the U.S. Naval Observatory, Hall had led an expedition to photograph the transit of Venus of 1874 from Vladivostok, Russia, at Peter the Great Bay on the Sea of Japan. In August 1877, Hall was using the 26-inch (66-cm) refractor of the Naval Observatory to search for satellites of Mars. He discovered the first, Deimos, on 11 August. (He was on the verge of giving up when he was encouraged by his wife, Angelina, to return to the dome for one last look, and this yielded the satellite.) On 18 August, Hall, Newcomb, and Todd were all there, gathered to confirm the discovery. Todd was the last to the eyepiece. As soon as he looked, he noticed a tiny point of light staring out of the glare of the planet's disk. It was the inner moon, Phobos, which Hall had recorded some nights earlier, but dismissed as a star. Thus Todd merits at least a footnote in the history of this celebrated discovery." At the end of 1877, Todd mounted a little-known, secretive search of trans­ Neptunian space for a planet; he failed to find any. Nor was he successful in spotting "Vulcan", the intra-Mercurial planet then widely believed to exist at the other extreme of the solar system, though he looked for it intently during the 'great' solar eclipse of 29 July 1878. As the sole member ofaone-man expedition to Dallas, Texas, one of the southernmost points along the eclipse's curving track across the western United States, he was foiled by thin clouds in his attempt to detect the planet." His two-months' absence from Washington coincided, incidentally, with a flurry of letter-writing to Mabel Loomis, daughter of an elderly assistant in the Nautical Almanac Office. He had met Mabel in June of the summer in which Hall discovered the moons of Mars. Downloaded from jha.sagepub.com at UNIV OF CALIFORNIA SANTA CRUZ on October 24, 2016 Menage ii Trois 127 On a rainy day, when dropping by the office looking to borrow a telescope, he saw her standing there, wearing a blue waterproof. He could not forget the impression. They were married two years later. The Todds' courtship and the passionate early years of their marriage seem to show that at first they had a highly compatible and mutually satisfying relationship. Mabel had grown up in rambling boarding houses in Washington. She was early aware of her personal magnetism and attractiveness to men. A social climber, she was a self-centred extravert - David described her as his "perpetual blue sky"," an extraordinary compliment coming from an astronomer. She was gifted in art and music, and was a lively and entertaining conversationalist who would later become a spellbinding lecturer. Her writings reveal enormous energy and enthusiasm. Her effusive journals record her resolution to experience life always in the upper ranges of the emotional register. For instance, even before she met Todd, she constantly went on about her "intense happiness" and regular "ecstasies".

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