SCIENTIFIC SUMMARY. 
443 
the truth, and that Mr. Lassell has no claim to he regarded as an indepen- 
dent discoverer. I was misled "by depending on the Monthly Notices of the 
period, and by the phraseology adopted by Mr. Lassell in communicating to 
the Society his account of certain observations made by him in company 
with Mr. Dawes.” 
The Lunar Crater Alhazen has often been a puzzle to selenographers, from 
the various appearances it has presented to observers, and from its general 
indistinctness. Recently, however, it has been very satisfactorily observed 
by Mr. W. R. Birt, F.R.A.S., who had previously (vide Monthly 
Notices, vol. xxii., p. 230) given considerable attention to the subject. In 
his earlier account of the appearance, Mr. Birt was unable to give a descrip- 
tion of the crater. On the 5th of July last, however, at 9 p.m., he saw 
the crater under very favourable circumstances with the Royal Society’s 
achromatic of 4| inches aperture, power 230, Schroter’s pair of craters y and 
$ in its neighbourhood being very distinct (see Astronomical Register , No. 
xliii., July 1866, p. 188). He then ascertained that Schroter’s Alhazen is 
really a crater situated on the surface between the two ranges of mountains, 
and but slightly depressed below it. Although not greatly depressed, it is 
sufficiently so to present, under this illumination and visual angle, the true 
crater-form. It would seem, says Mr. Birt, that its apparition as a crater is 
rare , probably from a variety of causes. It is quite of sufficient magnitude 
to have been seen with an aperture of 2| inches, and it would be very im- 
portant to ascertain if, under nearly similar circumstances to those of July 
5, 1867, it would present a similar aspect. “ The selenographical conditions 
of its visibility on July 5 were as follows Morning illumination, after 
Perigee, 102 hours ; before Apogee, 215 hours. Eastward of its mean 
position in longitude, Moon’s latitude, S. 0° 43' 55", a little southward of 
its mean position in latitude. For illumination, longitude of termination, 
W. 42° 12' 54", angle of terminator and meridian — 1° 23'. South pole of 
the Moon in sunlight 25 days after the winter solstice in the Moon’s 
northern hemisphere.” 
Neivly-discovered Comes of Vega . — An observer (R.C.) states that Mr. 
Buckingham, of Walworth Common, has discovered two new comes, much 
closer than those so well known to astronomers. R. C., who ought to have 
given his name in full, states that, on being asked by Mr. Buckingham to 
examine Alpha Lyra, and in turning the telescope to the star, he saw one 
of the stars which Mr. Buckingham had already discovered, and described 
the position and the distance by comparison with the known distance of the 
companion-star, fixing it at five or six seconds. These data coincided with 
Mr. Buckingham’s. But, owing to the fitful and unsteady atmosphere, it 
was some time before he was able to catch up the second companion, which 
seemed fainter and somewhat more distant. He believes that Mr. Bucking- 
ham first discovered these two companions with his 20-inch refractor, and 
was able afterwards to verify his discovery with the 9-inch equatorial in 
which he saw them ; but, though he recorded the fact at the time, he did 
not publish his discovery. As he was also able to see the companions 
clearly, and tested the sight by turning consecutively half-round the eye- 
piece and object-glass with the same result, and as he has no doubt pos- 
sessors of similar telescopes will be able to make them out easily, it seemed 
