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134 30. . . even 1 to 300 is sufficiently striking to draw our attention." These were the words of a wise observer, uttered long before geologists had begun to use similar language in their own researches.

The conclusion which Herschel drew from these alterations, real or imagined, in the light of the stars was that they will "much lessen the confidence we have hitherto placed upon the permanency of the equal emission of light of our sun. Many phenomena in natural history seem to point out some past changes in our climates. Perhaps the easiest way of accounting for them may be to surmise that our sun has been formerly sometimes more and sometimes less bright than it is at present. At all events it will be highly presumptuous to lay any great stress upon the stability of the present order of things; and many hitherto unaccountable varieties that happen in our seasons, such as a general severity or mildness of uncommon winters or burning summers, may possibly meet with an easy solution in the real inequality of the sun's rays." If our sun be a variable star diffusing heat in greater or less degrees at different times, or if it be a star growing old and burning out, the credit of the idea as well as of "lost" stars in the ocean of infinitude may justly be claimed, in our day at least, for this poetic and musical observer of the heavens. To shed a ray of light on this question of sunshine Herschel sought, but sought in vain, for temperatures in ages that were past. He could get none. He was not aware of the thermometers made by the school of Galileo