"HORROCKS, JEREMIAH (1619-1641), an astronomer of extraordinary promise, blighted by a premature death, was born in 1619 at Toxteth Park, near Liverpool. Of the circumstances of his family little is known, further than that they were poor, but the register of Emmanuel College, Cambridge, testifies to his entry as sizar, May 18, 1632. Isolated in his scientific tastes, and painfully straitened in means, he pursued amid numerable difficulties his purpose of self-education. His university career lasted three years, and on his return to Lancashire he devoted to astronomical observations the brief intervals of leisure snatched from the harassing occupations of a laborious life. In 1636 he met with a congenial spirit in William Crabtree, a draper of Broughton, near Manchester ; and encouraged by his advice he exchanged the guidance of Lansberg, a pretentious but inaccurate Belgian astronomer, for that of Kepler. He now set himself to the revision of the Rudolphine Tables (Published by Kepler in 1627), and in the progress of his task became convinced that a transit of Venus overlooked by Kepler would nevertheless occur on the 24th of November (O.S.) 1639. He was at this time curate of Hoole, near Preston, having recently taken orders in the Church of England, although, according to the received accounts, he had not attained the canonical age. The 24th of November falling on a Sunday, his clerical duties threatened fatally to clash with his astronomical observations ; he was, however, released just in time to witness the punctual verification of his forecast, and carefully noted the progress of the phenomenon during half an hour before sunset (3.15 to 3.45). This transit of Venus is remarkable as the first ever observed, that of 1631 predicted by Kepler having been invisible in Europe. Notwithstanding the rude character of the apparatus at his disposal, Horrocks was enabled by his observation of it to introduce some important corrections into the elements of the planet's orbit, and to reduce to its exact value the received estimate of its apparent diameter.
After a year spent at Hoole, he returned to Toxteth, and there, on the eve of a long-promised visit to his friend Crabtree, unexpectedly expired, January 3, 1641, in the twenty-second year of his age. It is difficult to over-estimate the services which, had his life been prolonged, this singularly gifted youth might have rendered to astronomical science. To the inventive activity of the discoverer he already united the patient skill of the observer and the practical sagacity of the experimentalist. Before he was twenty he had afforded a specimen of his powers by an important contribution to the lunar theory. He first brought the revolutions of our satellite within the domain of Kepler's laws, pointing out that her apparent irregularities could be completely accounted for by supposing her to move in an ellipse with a variable eccentricity and directly rotatory major axis, of which the earth occupied one focus. These precise conditions were afterwards demonstrated by Newton to follow necessarily from the law of gravitation.
In his speculations as to the physical cause of the celestial motions, his mind, though not as yet wholly emancipated from the tyranny of gratuitous assumptions, was working steadily towards the light. He clearly perceived the significant analogy between terrestrial gravity and the force exerted in the solar system, and used an ingenious experiment to illustrate the composite character of the planetary movements. He also reduced the solar parallax to 14" (less than a quarter of Kepler's estimate), corrected the sun's semi-diameter to 15' 45", recommended decimal notation, and was the first to make tidal observations."
More, indeed probably all there is to find, can be read about this great, scouse pioneer of science at this page hosted by the University of Central Lancashire's Transit of Venus webpage. Unfortunately, if you missed it in 2004, it will be another 120 or so years before anyone can take the opportunity to repeat Jeremiah's historic observation. There are plaques and so forth to Horrock's memory at the Ancient Chapel of Toxteth (where he is presumed to have prayed and studied as a boy, and thought to have been buried in an unmarked grave), the nearby St Michael's church (the one with the pink tower), and opposite Newton's memorial in Westminster Abbey. Lower Lodge, where Horrocks is believed to have been born, stands no more, but was within spitting distance of Barleycorn Towers, where this electro-aetheric remembrance has been composed.