us that at nine he was called away by business of the highest
importance--referring, no doubt, to his official duties; but the service
was quickly performed, and a little before ten he was again on the
watch, only to find the brilliant face of the sun without any unusual
feature. It was marked with a spot, but nothing that could be mistaken
for a planet. Again, at noon, came an interruption; he went to church,
but he was back by one. Nor were these the only impediments to his
observations. The sun was also more or less clouded over during part of
the day. However, at a quarter past three in the afternoon his clerical
work was over; the clouds had dispersed, and he once more resumed his
observations. To his intense delight he then saw on the sun the round,
dark spot, which was at once identified as the planet Venus. The
observations could not last long; it was the depth of winter, and the
sun was rapidly setting. Only half an hour was available, but he had
made such careful preparations beforehand that it sufficed to enable him
to secure some valuable measurements.

Horrocks had previously acquainted his friend, William Crabtree, with
the impending occurrence. Crabtree was therefore on the watch, and
succeeded in seeing the transit; a striking picture of Crabtree's famous
observation is shown in one of the beautiful frescoes in the Town Hall
at Manchester. But to no one else had Horrocks communicated the
intelligence; as he says, "I hope to be excused for not informing other
of my friends of the expected phenomenon, but most of them care little
for trifles of this kind, rather preferring their hawks and hounds, to
say no worse; and although England is not without votaries of astronomy,
with some of whom I am acquainted, I was unable to convey to them the
agreeable tidings, having myself had so little notice."

It was not till long afterwards that the full importance of the transit
of Venus was appreciated. Nearly a century had rolled away when the
great astronomer, Halley (1656-1742), drew attention to the subject. The
next transit was to occur in 1761, and forty-five years before that
event Halley explained his celebrated method of finding the distance of
the sun by means of the transit of Venus.[15] He was then a man sixty
years of age; he could have no expectation that he would live to witness
the event; but in noble language he commends the problem to the notice
of the learned, and thus addresses the Royal Society of