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mark’d as doubtful on Account of the Undulation of the Air, &c. And this does not differ 3" from the Hypothefis.
The Agreement between the Hypothefis and the Observations of this Star is the more to be reguarded, since it proves that the Alteration of Declination, on account of the Proceflion of the Equinox, is (as I before SuppoSed) regular thro’ all Parts of the Year; fo far at least, as not to occasion a Difference great enough to be difcovered with this Instrument. It like-wiSe proves the other part of my former Supposition, •viz. that the annual Alteration of Declination in Stars near the Equinoctial Colure, is at this Time greater than a PreceSIion of 50" would occasion : for this Star was io" more Southerly in September 1718, than in September 17x7, that is, about x" more than it would have been, if the PreceSIion was but 50". But I may hereafter, perhaps, be better able to determine this Point, from my Observations oS those Stars that lie near the Equinoctial Colure, at about the same Distance Srom the North Pole of the E-quator, and nearly opposite in right Ascension.
I think it needleSs to give you the Comparison between the Hypothefis and the Observations of any more Stars; since the Agreement in the foregoing is a kind of Demonstration (whether it be allowed that I have difcovered the real Cauie of the Phenomena or not;) that the Hypothefis gives at least the true Law of the Variation of Declination indifferent Stars, with RefpeCt to their different Situations and Al-peCts with the Sun. And if this is the CaSe, it must be granted, that the Parallax of the fixt Stars is much fmaller, than hath been hitherto suppofed by thofe,
S ff f 2, who
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who have pretended to deduce it from their Observations. I believe, that I may venture to say, that in either of the two Stars last mentioned, it does not amount to 2". I am of Opinion, that if it were 1", I should have perceived it, in the great number of Observations that I made especially of ycDraconis\ which agreeing with the Hypothesis (without allowing any thing for Parallax) nearly as well when the Sun was in Conjunction with, as in Opposition to, this Star, it Seems very probable that the Parallax of it is not fo great as one single Second ; and consequently that it is above 400000 rimes farther from us than the Sun.
There appearing therefore after all, no sensible Parallax in the fixt Stars, the Anti-Copernicans have still room on that Account, to objeCt against the Motion of the Earth; and they may have (if they please) a much greater Objection against the Hypothefis, by which I have endeavoured to fblve the fore-mentioned Phenomena ; by denying the progressive Motion of Light, as well as that of the Earth.
But as I do not apprehend, that either of these Postulates will be denied me by the Generality of the Astronomers and Philofophers of the present Age; fb I shall not doubt of obtaining their ASIent to the ConSequences, which I have deduced from them ; if they are fuch as have the Approbation of fo great a Judge of them as yourself. I am,
Sir, lour rnojl Obedient
Humble Servant
J. Bradley,
