As an opportunity offers of sending a note to town, I beg to mention that I have somewhat impatiently waited for some appearance of settled weather, in order to press your coming here to inspect Halley's comet, before it should have become visible to the unassisted eye. That unerring monitor, however, the barometer, held forth no hope, and the ceaseless traveller is already an object of conspicuous distinction without artificial aid, except, perhaps, to most eyes an opera-glass, magnifying three or four times, will be found a pleasant addition. It is now gliding along with wonderful celerity, and the nucleus is very bright. It is accompanied with a great luminosity, and the nucleus has changed its position therein; that is, on the 29th August, the nucleus was like a minute star near the centre of the nebulous envelope; on the 2nd September it appeared in the n. f. quarter, and latterly it has been in the s. f.
How remarkable that the month of August this year should rattle Halley's name throughout the globe, in identity with an astonishing scientific triumph, and that in the selfsame month the letters of Flamsteed should have appeared! How I wish some one would give us a life of Newton, with all the interesting documents that exist of his labours! Till such appears, Flamsteed's statements, though bearing strong internal evidence of truth, are ex-parte, and it is evident his anxiety made him prone to impute motives which he could not prove. The book is painfully interesting, but except in all that relates to the personal character of Flamsteed, I could almost have wished the documents had been destroyed. People of judgment well know that men without faults are monsters, but vulgar minds delight in seeing the standard of human excellence lowered.
Dear Madam,
Yours faithfully,
W.H. Smyth.
We were deprived of the society of Sir John and Lady Herschel for four years, because Sir John took his telescope and other instruments to the Cape of Good Hope, where he went, accompanied by his family, for the purpose of observing the celestial phenomena of the southern hemisphere. There are more than 6,000 double stars in the northern hemisphere, in a large proportion of which the angle of position and distance between the two stars have been measured, and Sir John determined, in the same manner, 1081 in the southern hemisphere, and I believe many additions have been made to them since that time. In many of these one star revolves rapidly round the other. The elliptical orbits and periodical times of sixteen or seventeen of these stellar systems have been determined. In Gamma Virginis the two stars are nearly of the same magnitude, and were so far apart in the middle of the last century that they were considered to be quite independent of each other. Since then they have been gradually approaching one another, till, in March, 1836, I had a letter from Admiral Smyth, informing me that he had seen one of the stars eclipse the other, from his observatory at Bedford.
FROM ADMIRAL SMYTH TO MRS. SOMERVILLE.
Crescent, Bedford, March 26th, 1836.
Knowing the great interest you take in sidereal astronomy, of which so little is yet known, I trust it will not be an intrusion to tell you of a new, extraordinary, and very unexpected fact, in the complete occultation of one "fixed" star by another, under circumstances which admit of no possible doubt or equivocation.
You are aware that I have been measuring the position and distance of the two stars γ1 and γ2 Virginis, which are both nearly of similar magnitudes, and also, that they have approximated to each other very rapidly. They were very close last year, and I expected to find they had crossed each other at this apparition, but to my surprise I find they have become a fair round disc, which my highest powers will not elongate—in fact, a single star! I shall watch with no little interest for the reappearance of the second γ.
My dear madam,
Your truly obliged servant,
W.H. Smyth.