emersion of the star it would become visible to us before it had actually emerged from behind the moon. I assume that "A. L. S." is aware that our terrestrial atmosphere causes the sun to appear above the horizon both after it has really set and before it actually rises.

Finally, I think that the sincere thanks of all interested in the "Moon Controversy" are due to "W. M." for having met Mr. Perigal on his own ground with a mechanical illustration of lunar rotation at once complete, satisfactory, and unassailable. I am, sir, obediently yours, WILLIAM NOBLE.

Forest Lodge, Maresfield: Feb. 8.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-A correspondent, on date Jan. 12, requires to know the magnitudes of the 5th and 6th stars in the Trapezium of Orion. Now I am not able to answer that question, but I can the other, viz. What aperture will show both the above stars? I have a 5-in. achromatic by Dallmeyer; with it I see the 5th star easily on any fair average night, and the 6th on fine nights-though the latter often disappears in the rays of the principal, reappearing afterwards.

I am, sir, your obedient servant, The Warren, Bushey Heath, Herts.

W. E. JONES.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir, It is stated in Slugg's "Observational Astronomy," that a good 4-inch object-glass will show five stars in Orionis; and in "Darby's Handbook" it is stated that Mr. Dawes sees the 5th star distinctly with a 5-foot refractor. Now I have gazed earnestly and repeatedly upon this interesting group this winter through a 44-inch by Cooke and Sons, but have never yet been able to discern more than four stars; and, as I can constantly see the minute companion to Aldebaran with the same instrument, am unwilling to believe that either my eyes or the telescope are at fault.

Perhaps some of your readers will kindly inform me where the 5th star is situated, in relation to the four principals, and also if it can be generally seen, under favourable skies, with a similar aperture to that above mentioned, viz. 4 in.

I am, &c.

C. W.

HIND'S CRIMSON STAR: TRAPEZIUM OF ORION.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir, Mr. Chambers will find some observations of Hind's Crimson Star Leporis by the indefatigable Schmidt in Nos. 1221, 1244, 1294, 1358, 1410, and 1449 of the Astronomische Nachrichten. M. Schmidt assigns a period of 448 days to the star, and remarks on the similarity of the period to that of R. Hydræ.

I had hoped to have said a few words in reply to Mr. Freeman's enquiry relative to the Trapezium in Orion, but cloudy skies night after night have prevented my making a few experimental observations, and I must content myself, therefore, with remarking generally that more is to be hoped from sharp definition than from large aperture in a telescope. Mr. De la Rue has an exquisite refractor by Dallmeyer of 4 in. aperture, which shows both the 5th and the 6th stars, and I have myself seen both stars when the aperture of my 9-ft. equatoreal was reduced to 4 inches.

Woodcroft Observatory, Cuckfield : I am, sir, yours faithfully, February 15, 1865. GEORGE KNOTT.

η

SILVERED REFLECTORS.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir, In a recent number of the Astronomical Register there was a sort of comparison of the respective merits of the silvered reflectors and the achromatic. The whole matter, however, was confined to lighttests, and on one object, viz. the small stars preceding the debilissima couple in Lyra. It may not be uninteresting to know what the reflectors will do in dividing. I have very lately purchased an 8-inch speculum of only 53 ft. focus, from Mr. With, of Hereford, of excellent make; and although I have no observatory, and have never used a higher power than 320, yet I have distinctly divided & Cancri, 52 Arietis, and n Orionis-three tolerably difficult stars; the two former are about equally difficult (I should be glad to know their present distances) for light-tests. I can clearly make out Bond's canals, Andromedæ, and can trace both of them a considerable distance. Í can clearly see the 15th mag. comes to 52 Arietis, and the 16th mag. following-u Andromedæ, the 5th star in trapezium, easily with 6 in. aperture; and also 15 Monocerotis (quadruple) with a like aperture. I should much like to know in what sized achromatic, and of what focal length, all the above objects can be seen; the three close double stars must be divided-not merely elongated or notchedand the power used must not exceed 320; for, with a higher power, those who possess an observatory would have too great an advantage to make the trial fair one. The following are easier tests seen :12 Lyncis, e Arietis, 52 Orionis, 36 Andromeda, 170 P. Canis Minoris, 72 P. Cassiopeæ, & Orionis, e and 5 Lyræ. Other tolerably easy light-tests are: 41 Arietis, Geminorum, y and Persei, T Orionis, &c. All the last-mentioned tests can easily be made out with 190; and Lyræ and some others with quite a low power. As I do not possess a catalogue in which the angles of position are given, I have not had the advantage of knowing where to look for the different objects. I shall be very much obliged to any one who will tell me the present position and distances of the close stars Andromeda, 32 Orionis, and 7 Tauri. On one or two occasions I have had great suspicions of more than one of these, even with as low a power as 320.

Hill House, Gorleston :

I am, sir, yours, &c.,

W. MATTHEWS.

Feb. 15, 1865.

EPSILON LYRÆ.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-In reference to the minute stars in the neighbourhood of and 5 Lyræ, your correspondents appear to have overlooked a diagram by Mr. Lassell in the Monthly Notices for January 1857, in which he describes a minute star, "north of the most following of the 'debilissimæ,' and about one-fifth of the way towards the northern double." Mr. L. looked at this star-speck with his 24-inch aperture, to test the relative efficiency of the plane speculum and the Munich prism, and with powers 430 and 1018 "came to the conclusion that, though this minute point might be called the 'minimum visibile,' with either plane, yet it was somewhat more constantly seen with the prism than with the speculum, especially with the lower power, which scarcely sufficed to show it steadily with the speculum." It would be a great triumph if some of our silvered glass mirrors should succeed in picking up this minute star on the approaching apparition of € Lyræ.

I am, sir, yours obediently,

GEORGE HUNT.

OBSERVATIONS OF OCCULTATIONS, &c.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir, I believe that I do but join in the opinion of many of your readers in thanking you for putting on the drag to the controversy on the Moon's rotation. It is on quite another point, though still having reference to our satellite, that I venture to propose what appears to me a suitable subject for occasional if not monthly record.

Could you, Sir, with the means at your command, obtain at as early dates as they are available, and devote a few lines in the Register to, the Greenwich observations of the occultations of stars by the Moon, including, of course, eclipses, and occasionally of moon culminations, and of eclipses of Jupiter's satellites, when the latter have been observed both in disappearance and reappearance?

These observations could not fail to be interesting to amateurs who wish to determine their longitudes astronomically, and have not the means of obtaining in extenso the published observations which are at the command of only a few.

Wimbledon :

Jan. 6, 1865.

Sir, your obedient servant,

F. C. P.

THE SOLAR DISC; COLOURED STAR IN CRATER.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-If for Mr. "Harrington we read Mr. "Carrington," I think that Mr. Webb will have no difficulty in calling to mind the curious

observations recorded in vol. xx. of the Monthly Notices, the precise tenour of which is well known.

Permit me to take this opportunity of pointing out a little oversight which occurs on p. 202 of Mr. Webb's Celestial Objects. He says: "Had I ever been able to find H.'s 8th mag. star 'scarlet, almost blood colour, a most intense and curious colour,' which follows ɑ [Hydræ] 42 58., 1' S., I should have included it in the list; but I have failed repeatedly, probably from want of light."

The star which precedes this coloured one is not a Hydræ but a Crateris, distant from a Hydra an hour and a half in Ř.A. By some uranographers Hydra and Crater are reckoned as one constellation; hence some confusion.

The position of a Crateris for 1865'0 is:

R. A.
h. m. 8.

10 53 13

Decl.

-17 34.8

I saw the little star at Uckfield on Jan. 20, and can testify to its being an interesting and by no means difficult object. I am, sir, your obedient servant,

GEORGE F. CHAMBERS.

Feb. 1, 1865.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER.

Sir,-The passage in the paper by Mr. Vaughan contained in the Report of the British Association for 1861, which has puzzled the Rev. T. W. Webb, will be explained by correcting the misprint of "Harrington" to Carrington." Mr. Webb will, then, at once see that the author is referring to the unique phenomenon witnessed by Messrs. Carrington and Hodgson on Sept. 1, 1859, independently at Red Hill and Highgate, of the sudden outburst of intense luminosity on a group of solar spots, the details of which are given in the Monthly Notices of the R.A.S., vol. xx. pp. 13-15. I am, sir, yours, &c.,

Islington : Feb. 11, 1865.

THE SOLAR SPOTS.

T. W. BURR.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir, I have been greatly interested in the discussion concerning the nature of the solar spots, as well as surprised at the contradictory accounts given by various observers, whose names stand beyond all suspicion of prejudice or error. I have myself many times looked for the willow leaves in vain; but on January 20, at 12.30, I again looked at the sun, and, to my surprise and delight, I distinctly saw "the willow leaves" lying across the black central chasm, and also interlacing each other irregularly around the margin, and up to the surface of the photosphere, but I could not detect them on the surface. They appeared like long blunt-pointed crystals. I could not detect them in two smaller groups of spots following the principal

one. My telescope is a 7-inch, 9-ft. focal length, by Troughton and Simms. The object-glass is a very beautiful one. I saw the willow leaves best with a power of 86, which I used with a common diagonal adapter. On the 21st I made the following entry:

Jan. 21, 12.30.-Wind N.; clear atmosphere, with light shifting vapours. Power 86. Distinctly saw "willow leaves" in large spot, also in one of the smaller spots following. The granulations of surface occasionally very distinct, but could not detect willow leaves except in the cavities and overlying the chasms. I tried powers 100 and 156, but the atmosphere would not allow of their use. My son also examined them at the same time, and independently corroborated the observation. I am, sir, your obedient servant,

St. Bartholomew's Parsonage, Southsea : N. S. GODFREY. Feb. 6, 1865.

VISIBILITY OF STARS FROM COAL-MINES.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-Referring to "Lydia's " query-stars of the 1st magnitude can undoubtedly be seen from deep pits during daylight. Why this phenomenon is seldom observed I shall explain. The angle subtended by the mouth of a deep pit, viewed from the bottom, is very small; and large stars are not numerous. On the Tyne there are many coalpits, and yet there are but two stars of the 1st magnitude possibly to be seen from Newcastle pits, situate about 55° N. Lat. These stars are Delta and Zeta Ursa Majoris. The length of time during each day which these stars will take to traverse the pit-mouth will depend on the angle which this subtends to the spectator from below-a minute or two in the case of each star.

He, or she, who would see stars from a pit-bottom must observe the proceedings required to take an observatory transit.

Apropos, I may state that I have more than once, when voyaging down a creek in Equatorial America, seen stars by day. Towards evening the lofty and leafy forest excludes horizontal rays, and the only light that reaches the voyager comes from a chasm in the foliage where the trees fail quite to arch over the creek. In these strips of blue a twinkling star may often be seen by the traveller, who is, by and by, surprised, when he reaches the main river, by the glare of full day, which pains the eyes distended by the forest gloom.

February 1865.

"THE ASTRONOMICAL OBSERVER."

M. D.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-The reviewer of my book, "The Astronomical Observer," in the Register for January, asks me some questions, and I claim the liberty to reply.

I. 'Why, in the references made to 'Bishop's Catalogue,' 'Bishop's