John Farrar's observations

(in John Winthrop and A. Oliver, Two Lectures on Comets, 1811)

From September 6, to December 10, the comet described an arc of about 121, as seen from the earth. When it first appeared, it moved at the rate of about 1 per day. Its velocity increased till it amounted to a little more than 1 3/4 per day, and then began to decrease till about the middle of November, when it returned to its former rate of 1; and now, 10th December, it is about three fourths of a degree. It came within the circle of perpetual apparition, about the 20th of September, and continued about 20 days. It reached its greatest northern declination, 50, near the 2d of October, and its greatest northern latitude, 63 1/2, about the 17th. At this time also its motion in longitude was at its maximum. On the 6th of September, when it was first seen, it was about 18, west of the sun in longitude. After continuing for some time at about the same distance, it gained upon the sun, and about the 11th it came up with it, and passing it, arrived at its greatest elongation, 53, about the 10th November. From this time it has been continually falling back, with respect to the sun. It loses now at the rate of more than half a degree per day; and this quantity is increasing, and of course must soon reduce its present direct distance, 46, within the compass of the twilight, when the comet will disappear, again to come into conjunction with the sun. After which the sun will move on to the east of the comet, leaving the comet behind, to pass off into the southern hemisphere. The comet will now rise in the morning before the sun; and, when it gets out of the twilight, may perhaps be seen again by the help of the best glasses. Its present distance, from the earth, is about double what it was when in perigee.







How to cite this article:  John Farrar, observations, 10 Dec. 1811, in John Winthrop and A. Oliver, Two Lectures on Comets (Boston: Wells & Wait, 1811), pp. 170-171, available at http://history.hanover.edu/texts/1811.


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