Page:Williamherschel00simegoog.djvu/52

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40
HERSCHEL AND HIS WORK

crack, and broke into two pieces. On looking at Fahrenheit's thermometer, I found it to stand at 11°." And, in the height of summer that year, "the telescope ran with water all the night," that is, "the condensing moisture on the tube has been running down in streams." "The small speculum, which sometimes gathers moisture, was never affected in the 7-feet tube, but was a little so in the 20-feet. The large eyeglasses and object-glasses of the finders required wiping very often." Such were some of the discomforts cheerfully undergone by this votary of science in pursuit of truth.[1]

Amid labours so continuous and so heavy it cannot occasion surprise that Caroline sometimes found relief in a fit of grumbling. When her brother was polishing a mirror, "by way of keeping him alive, she was constantly obliged to feed him by putting the victuals by bits into his mouth. This was once the case when, in order to finish a seven-foot mirror, he had not taken his hands from it for sixteen hours together."[2] The delicate lad, who, by his mother's address, escaped soldiering in 1757, had grown into a powerful athlete in 1772. This sometimes happens. Four years later he tried to improve on Newton's telescope by almost doubling the light let fall on the mirror at the bottom of the tube. He then experimented with a ten-feet reflector, but failed. He repeated the attempt with a twenty-feet in 1784, but again was disappointed: "it was too hastily laid aside." He succeeded shortly after, and found "it to be a very convenient and pleasant as well as useful way of observing": it inverts the north

  1. Phil. Trans., 1803, pp. 215-19.
  2. Lalande told the some story in 1783. See Arago.