On Thursday afternoon, the 5th of August, some showers occurred, but not sufficient, according to ordinary experience, to have much effect in clearing the atmosphere; and on Friday morning the sky became overcast with mackerel clouds of a most unpromising character. All the preparations were, however, hopefully continued, and the photographer, Mr. Whipple, of Boston, took on that day some very successful views of Shelbyville, of the college buildings, and of the party of observers. The principal station had been established in the grounds of the college, the instruments being protected by a large tent; close by was the Coast Survey station, where the chronographs just described for recording time, as well as a transit instrument for observing it, had been placed. Friday evening was cloudy at Shelbyville, but without rain, and the chance seemed to be gradually diminishing of any thing like a good observation of the eclipse. The plans for photographing the successive phases were most perfect. The movement of the sun from east to west of course made it necessary that the plate should also move correspondingly, but this was readily accomplished by connecting it with a telescope mounted on an axis parallel to the earth's equator, which axis is itself fixed to another at right angles to it, or parallel to that of the earth; this second axis being turned by clock-work once in twenty-four hours in a direction opposite to that of the earth's rotation, all the parts of the instrument evidently follow the movement of the heavens or of any celestial object to which the telescope may be directed. The axis around which the telescope turns can be rotated by hand or clamped in position, and in connection with the other, which can be disengaged from the clock-work, enables the instrument to be pointed in any direction at pleasure. This style of mounting is known as the equatorial, and is almost always used for astronomical telescopes. It is similar to the ordinary tripod used for small instruments, except in the addition of clock-work, and in having the principal axis inclined toward the pole-star instead of being vertical. But it was necessary not only to take photographs, but to know the time at which they were taken, that they might accurately measure the movement of the lunar disc over that of the sun. This might have been secured by simply noting them from the face of the chronometer; but the object was more neatly and certainly attained by having the slide itself, as it dropped at the end of the exposure, break the electric circuit, and record its own time on the chronograph.