of earnestness and humility, "Yes, I have
been a very fortunate man in life. I have discovered Uranus, and I
have gauged all the depths of heaven, as none before ever gauged them,
with my own great telescope."

Still, those who cannot sympathize with the pure love of knowledge for
its own sake--one of the highest and noblest of human aims--should
remember that astronomy is also of immense practical importance to
mankind, and especially to navigation and commerce. Unless great
astronomical calculations were correctly performed at Greenwich and
elsewhere, it would be impossible for any ship or steamer to sail with
safety from England to Australia or America. Every defect in our
astronomical knowledge helps to wreck our vessels on doubtful coasts;
every advance helps to save the lives of many sailors and the cargoes
of many merchants. It is this practical utility of astronomy that
justifies the spending of national money on observatories and transits
of Venus, and it is the best apology for an astronomer's life to those
who do not appreciate the use of knowledge for its own beauty.

At Datchet, Herschel not only made several large telescopes for sale,
for which he obtained large prices, but he also got a grant of 2000
pounds from the king to aid him in constructing his huge forty-foot
instrument. It was here, too, in 1783, that Herschel married. His
wife was a widow lady of scientific tastes like his own, and she was
possessed of considerable means, which enabled him henceforth to lay
aside all anxiety on the score of money. They had but one child, a
son, afterwards Sir John Herschel, almost as great an astronomer as his
father had been before him. In 1785, the family moved to Clay Hall, in
Old Windsor, and in 1786 to Slough, where Herschel lived for the
remainder of his long life. How completely his whole soul was bound up
in his work is shown in the curious fact recorded for us by Carolina
Herschel. The last night at Clay Hall was spent in sweeping the sky
with the great glass till daylight; and by the next evening the
telescope stood ready for observations once more in the new home at
Slough.

To follow Herschel through the remainder of his life would be merely to
give a long catalogue of his endless observations and discoveries among
the stars. Such a catalogue would be interesting only to astronomers;
yet it would truly give the main facts of Herschel's existence in his
happy home at Slough. Honoured by t