Page:Gods Glory in the Heavens.djvu/110

92 gathered up the fragments of time, and it was these fragments that made him the friend of monarchs, and the first of astronomers.

Let us now return to the cross-questioning of the Imperial astronomer. In order to be convinced that the story is not a fabrication, he must have proof that the observer had proper instrumental means for making the observation. The astronomer must be so exact in his observation, that seconds and fractions of seconds must be taken into account. He must be able, for example, to tell the precise second when Vulcan, in his progress across the sun's disc, touches the border. He listens to the beats of a pendulum, counting them all the time, and he must be able to note the second that coincides with the instant of contact; nay, more, it may happen that the contact takes place between two successive beats; and, in that case, he must be able to estimate to the tenth of a second. Leverrier interrogates, still maintaining the grand attitude of the lion, "Where is your chronometer, sir?" "My chronometer! I have only this minute watch, the faithful companion of all my professional visits." "What! with that old watch, marking only minutes, do you dare to speak of estimating seconds? I fear my suspicions are too well founded." The doctor shewed to his satisfaction how he accomplished the object. With the aid of a ball hung by a silk thread, and swinging seconds, combined with the counting of his