United States or Sudan ? Vote for the TOP Country of the Week !


Yet more remarkable, because of the greater difficulties involved, was Hipparchus's attempt to measure the actual distance of the moon. Aristarchus had made a similar attempt before him. Here, then, was the measure of the base-line of that famous triangle with which Aristarchus had measured the distance of the sun.

But the grandeur and boldness of Hipparchus's mind rested not here: he attempted, and in some measure succeeded in doing, what seems above human knowledge and power: he numbered the stars, laid down rules by which their rising and setting might be ascertained beforehand; and, finally, he constructed an apparatus on which the position of each star was accurately given, and a miniature picture of the heavens, with the motions of the celestial bodies, their rising and setting, increase and diminution.

When the new splendour dies out again, it is not that a star has ceased to exist; but simply that a faint star which had increased greatly in lustre has resumed its original condition. Hipparchus's star must have been a remarkable object, for it was visible in full daylight, whence we may infer that it was many times brighter than the blazing Dog-star.