ENPages
(seq. 1)
Cambridge 8 {February} 1784
Dear Sir:
I thank you for your attention to Phil. Trans. Have the Memoirs of the {French} {Academy} of Sciences arrived & how late?
Your Salem Gazette is the only one which furnishes either Observations or Ramarks on the Comet. I was in hopes that many bservations would have been made; but am sorry to find it otherwise. I got four & had not the moon been in the way should have had more. As it is we must rest satisfied till we see whether it appears again in the east, a little before sunrise. I suppose it passed its Perihelion about the fourth of this Month, & was on its descent when we saw it. If this idea is well founded we may expect to see it on its retreat in the eastern gemisphere, unless the distance from the earth should be too great before it emerges from the twilight.
I have endeavored to ascertain its Elements, as well as I can, graphically; for it is too much trouble & takes too much time to go through the Calculations. The method of exhibiting its trajectory is described by Delalande LIV {Livre} XIX. of his Astronomy in familiar language. Of three parabolas, I think it that were tried, I think that answers best which was projected for the same perihelion distance as that of the Comet in 1661; But some of the Elements seen in this methid (tho' it is but a coarse one) to differ too much. Yet the differences are not greater that [?] than in some calculations that have been oade of the same Comet; witness two calculations of that in 1264, that in 1337, that of 1596; & one which Delalande has supposed to be the same in 1698 & 1699, but has made two entries for it on account of the differences. That there should be diffferences in calculations of the same Comet at the same
(seq. 2)
appearance are is more remarkable in those Comets which have been observed since 1680, that being the year when Newton gave a specimen of his method of Calculating their Elements; so that astronomers have had a fresh inducement to be accurate in their observations.
After all that can be said on the matter, the Comet of 1661 is expected in 1789 or 1790; & until we can know the result of the calculations that will be made of this comet in Europe, for I suppose America will not yield any [unless they come from my next neighbour] we cannot determine with sufficient accuracy. It is only [?] reasoning on facts which you know do not bear it. Ir is possible it may be the same, or it may be different. One observation of it in the morning would do more towards determining the question, than all of the reasonings of all Mankind.
Do not let my name go abroad in talking on this subject. As it appears to me possible this for this to be the Comet of 1661, I have thought it not improper to give you an hint before it is determined. If it should not be the same, It will be no disappointment; but it would be curious if this should be set aside, & one not be found to agree more nearly.
I believe my lecture is nearly long enough on a subject that is not a favorite one of yours; & will therefore only give you my observations, with which you may if you please furnish {William} Hall, but not by any means give them to him if it shall be necessary to tell who made them. My sole view is to induce others to communicate theirs.
Time {observed} 1784 {January} 21 .. 29 ... 30 ... 31 ... {South} {Latitude} 23°.30' .... 3.55 1.10 ...0.0 {Longitude} of Comet Pisces 16°.40' 21.0 20.20 19.10
They were made in the usual way by the intersection of lines. [I suppose its perihelion dist. 40, & Sun's mean distance from the earth 100, & its ascending node about the end of Gemini]
In a loose paper If you publish the {Observations}: remember that they are "the geocentric [Names?] of the Comet"
I have been able to collect only six printed sermons of {Doctor} Cooper. Election sermon 1756, Quebec Sermon 1759, {Mister} Jackson's Ordination 1760, Death {George} III 1761, Dudleian Lecture 1773, New Constitution 1780. It is said there were three others, Death {Queen} {Caroline} - Artillery Election, - & to a society for promoting manufactures. I wish to know how many he published.
Can you get me No. 112 of Salem Gazette {Volume III}. I have all the others that you have sent me & wish to preserve the series. If you can lay your hands (with propriety I mean) on {Doctor} Winthrop's [?] Lecture on Earthquakes, I will thank to do it at a tolerable price.
Yours sincerely, James Winthrop
{Reverend} {William} Bentley
How will the Academy succeed at Salem?
