tation occurs, and also to examine the phenomena usually attending a total solar eclipse. However, I agree with Mr. Dawes that binocular vision has no superiority over vision with one eye for the minute and careful scrutiny of difficult objects. The only instance in which I perceived any advantage from its use with my telescope was in the examination of the head of the Comet II., 1862. The true direction of the fan-like brush of light from the nucleus was remarkably well brought out when both eyes were used. It may be that, in a few rare instances, binocular vision will be found of service to observational astronomy. It is scarcely necessary to say that all observations in which measures have to be taken must continue to be made with one eye. For several reasons I am of opinion that the best method of obtaining binocular vision with achromatic telescopes will be found to be by the employment of a modified form of Mr. Wenham's prism. Upper Tulse Hill, S.: I am, Sir, truly yours, WILLIAM HUGGINS. BRIEF CORRESPONDENCE. I hear that an oxide of zinc glass possesses excellent optical properties. Can any of your readers state where it is procurable, or any further particulars? S. B. K, NOTES AND GLEANINGS. TELESCOPE DRIVING APPARATUS.-A very simple and practical apparatus for driving equatorials is described in the January Intellectual Observer, by Mr. F. Bird. It depends on a familiar application of the hydrostatic principles of buoyancy. A POPULAR POSITION MICROMETER forms the subject of another very useful paper in the same number of the same periodical. The author is Mr. Charles Grover, who is described as a working man of an ingenious turn of mind and fond of our science. His contrivance, though in one sense crude, seems admirably adapted for arriving at approximate results, in the absence of anything better. AIRY'S LECTURES.-A new edition of this well-known work is announced as in the press by Macmillan & Co. A NEW TREATISE ON ASTRONOMY, for the use of Colleges and Schools and for students preparing for the three days' examination in the Senate House, is announced as just published by Deighton, Bell, & Co., Cambridge. The author is Mr. P. T. Main, Fellow of St. John's College, Cambridge. NEW PLANET.-A new minor planet (No. 86 of the series) was discovered at Berlin on January 4, by M. Tietjen, whilst preparing to observe No. 85. Both objects were in the field at the same time. COMETARY INTELLIGENCE. NEW COMET. A new telescopic comet was discovered at the Naval Observatory, Washington, D. C., on the evening of January 5, 1866. Position at 8h. 5 22.9 I 32 20 ... The comet is described as round, about 2' in diameter, and possessing a slight central condensation. Jan. 26, 1866. G. F. C. THE PLANETS FOR FEBRUARY. Mercury is not well situated for observation this month; it is in superior conjunction with the sun at the end of February: the same may be said of Venus, which comes to superior conjunction on the 26th. These planets may be observed by those who have powerful equatorials, and who wish to discover how near the sun they can be seen. Mars also is too near the sun to be seen to advantage. Jupiter may now be observed in the morning, rising about half-past six at the beginning of February, and about five o'clock at the end of the month. Saturn rises about one o'clock in the morning at the beginning of the month, and about a quarter past eleven in the evening at the end of February. 13 8 Diameter 15" 4 h. m. 8. O 1st R.A. 15th 14 41 27 15"-8 Dimensions of ring-Outer major axis, 39′′5; Outer minor axis, 13′′7. Uranus is still well placed for observation. The following are the minor planets which will arrive at opposition this month: SOME SHORTCOMINGS OF THE "REGISTER.” We have been getting into 'hot water' lately with our publication, and a little explanation is perhaps necessary: at the termination of last year the original proprietor and editor of the Astronomical Register found the labour of conducting it, (in addition to other necessary engagements), so heavy that he called in a co-adjutor, and as often happens, the experiment of 'two at the helm' has resulted in some want of smoothness which it is hoped will speedily be removed. In the first place, owing to the Report of the Meeting of the Royal Astronomical Society in December having been corrected by a different hand to that which prepared it, a number of errors escaped notice; of these we subjoin a list some of the errors, however, would be obvious to those to whom the subjects are familiar. A more serious matter, however, is, that a paragraph having been hastily adopted from a contemporary, a charge of inaccuracy has been repeated against a scientific work without sufficient investigation-the reference was understood to be to the lumière cendrée, and not to the crescent arms of the moon. For this inadvertence, which is referred to in the following letter, we beg to express our regret. TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-In noticing the new edition of Brande's Dictionary in your last number, you say that your readers "will probably be amused to learn that the phenomenon popularly spoken of as 'the new moon in the old moon's arms' is in this learned work described as an effect of irradiation!!" I cannot imagine that this illustration of the phenomenon of irradiation will produce any such effect upon the more intelligent portion of your readers, but lest any of them should share your opinion in the matter, I beg to say that the illustration which I have used is neither new nor unsupported by authority. Professor Plateau, Sir W. Herschel, and Professor Tyndall have employed it, and there is probably no physicist living, who would for a moment doubt the fact that the appearance in question is due to irradiation. In proof of this I will content myself with quoting a single paragraph from Professor Plateau's celebrated memoir on irradiation published in Poggendorf's Annalen for 1842. "Irradiation is the phenomenon which causes a luminous object, surrounded by a dark space, to appear more or less enlarged. As an example of this it is usual to adduce the appearance of the moon when crescent shaped, and when the remainder of her disc is perceptible by a feeble ashgrey luminosity: the outer edge of the luminous portion then appears to project beyond the dark portion, or, in other words, the crescent appears to belong to a very perceptibly larger disc than the rest of the moon. There is in the dictionary article an obvious error in quoting the popular phrase, which you do not appear to have noticed: the expression should be 'the old moon in the new moon's arms.'" I am, Sir, Your obedient servant, Royal Institution of Great Britain: Jan. 8th, 1866. In the third case, however, we think we may stand upon our defence, and merely giving the paragraphs upon which our review' was founded, we leave the matter in the hands of our readers. TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-Dr. Lee, who patronises your publication, has sent me its last number for December 1865, containing I find what you term a "review of "The Simplicity of the Creation" by Mr. Adolph, in which the following passages occur:-" He (Mr. Adolph) attributes great influences to the appearances of comets, and is of opinion that the minds of Arago, Humboldt, Sir D. Brewster, Sir J Herschel, and others, were more or less affected by those bodies. . Mr Adolph quotes largely from a work entitled "Baby Worlds," by Von Gumpach, and also refers to the works of Lieut. Morrison (Zadkiel) as confirmatory of his views." The drift of these remarks it would be difficult to misapprehend. You not only gratuitously drag my name into your "review," but you do so for |