ABSTRACT
Hipparchus attempted to work from the diameter of the earth's shadow as shown by the progress of a lunar eclipse. It is time for us to leave the fascinating study of comets and consider the progress of solar astronomy. We have already referred to the attempt of Lacaille at the Cape, in conjunction with Lalande and others in Europe. We have seen how among the many discoveries following inevitably from the invention of the telescope, that of sun-spots was made by Galileo and others, of whom, according to many authorities, Fabricius was really the earliest, though priority is also claimed for Galileo, Scheiner, and Harriot. Such was briefly what may be considered the first physical theory of the constitution of the sun. From that date onwards the corona was regularly observed, with notes as to stars and planets visible during the obscuration of the sun, and in 1733 we have the first mention of reddish spots near the moon's limb.
