1 8 



NA TURE 



[March 29, 1906 



produces marsh gas (methane). We learn from the Zeit- 

 schrift fur Elektrochemie (vol. xii., p. 20) that in St. 

 I 1 ance, a carbide is now being manufactured from 

 which ethylene is evolved when it is acted upon by water. 

 The ethylene so obtained is pumped into sulphuric acid, by 

 which it is absorbed with production of ethyl hydrogen 

 sulphate. Now when ethyl hydrogen sulphate is acted upon 

 by water, alcohol and sulphuric acid are produced. By 

 distillation the alcohol can be obtained free from the 

 sulphuric acid, and the sulphuric acid can again be obtained 

 in the concentrated condition by evaporation. Further- 

 more, the metallic oxide which is used in the production 

 oi the carbide is again obtained when the carbide is acted 

 upon b> water, so that the production of alcohol is summed 

 up in the equation carbon + energy = alcohol. Up to the 

 present it has been found necessary to use four times 

 the quantity of carbon which should theoretically be re- 

 quired. Mow much more energy it is necessary to employ 

 than is required by the theory is not stated. We remember 

 that so far back as 1893, when the calcium carbide industry 

 was in its infancy, it was suggested that the acetylene 

 might by reduction with hydrogen be converted into 

 ethylene, and the ethylene so obtained be employed for the 

 manufacture of alcohol. In fact, we believe that several 

 patents were taken out upon the subject. Owing to the 

 difficulty of reducing acetylene, the process could hardly 

 be expected to be a success. In the present case, however, 

 provided the formation of the carbide is not too costly and 

 the recovery of the sulphuric acid and metallic oxide not 

 too expensive, the process seems to possess at any rate the 

 elements of sui 1 1 



The first part has been received of an " Atlas of the 

 World's Commerce," by Mr. J. G. Bartholomew, which is 

 to be published by Messrs. George Newnes, Ltd., in twenty- 

 two parts. The parts, which cost 6d. each net, are to 

 appear fortnightly. 



Mr. David Nutt has issued a ninth edition of the late 

 Prof. A. Milnes Marshall's well known book on "The 

 Frog : an Introduction to Anatomy, Histology, and 

 Embryology." The work has been edited by Dr. F. W. 

 Gamble, who has revised the chapter on development and 

 added some figures. 



A new monthly periodical, entitled Science and Teeh- 

 price sixpence net, has just appeared. It is in- 

 tended to be of interest and assistance to teachers and 

 students. The first number contains articles dealing with 

 educational administration, examination syllabuses, and re- 

 ports of meetings. The only contribution of a wholly 

 scientific character is a reprint of Prof. S. P. Thompson's 

 lecture at the Royal Institution on the electric production 

 of nitrates from the atmosphere. 



A third edition of Sir William Ramsay's " Gases of 

 the Atmosphere. The History of their Discovery," has 

 been published by Messrs. Macmillan and Co., Ltd. The 

 first edition of the book, published in 1896, included a 

 non-technical description of argon, discovered in the atmo- 

 sphere in 1894. To the second edition of 1900 a new 

 chapter was added describing the other four inactive gases 

 discovered to be present in air — helium, separated from the 

 atmosphere in 1900, and neon, krypton, and xenon, dis- 

 covered in 189S, and separated from argon and from each 

 other during 1899 and 1900. The present edition has also 

 been enlarged by the addition of another chapter, this one 

 treating of the radio-active gases produced by the dis- 

 integration of radium and radium-thorium, which have 

 been added recently to the list of constituents of the atmo- 

 sphere. 



NO. I9OO, VOL. J 2>] 



OUR ASTRONOMICAL COLUMN. 

 Comet 1906c. — From observations made on March 19, 

 20, and 21, Dr. Stromgren has computed the following 

 elements and ephemeris for the comet discovered by Mr. 

 Ross on March iS : — 



Elements. 

 T = i906 Feb. 22-216 Berlin M.T. 

 00 = 281° 24''I \ 

 8 = 73° 2't -1906-0 

 i = 80° 34' -o J 

 'og'7 =9' 8 S336 



Ephemeris 12/1. M.T. Berlin. 

 1906 o 5 log 2, Bright 



Mar. 29 .. 2 38 33 



April 2 ... 2 48 40 



6 ... 2 58 9 



+ 4 1 1 -5 ... 0-2356 ... 063 

 + 7 38-4 ... o 2547 . 0-53 

 + 10 47 5 ... 0-2732 ... 0-44 

 (Kiel Circular, No. 87.) 



Observation of Comet 1905c after Perihelion. — A 

 letter received from Prof. H. R. Morgan (Glasgow, U.S.A.) 

 by Prof. Pickering states that the former observed 

 Giacobini's comet, 1905c, on February 21, that is, since 

 it appeared to the east of the sun. 



The comet's apparent position at 7I1. 40m. 44s. (Glasgow 

 M.T.) was a=ih. 8m. 29.2s., S = — 11° 9' 11", which gave 

 corrections of — us. and — 3'-4 to Herr Wedemeyer's 

 ephemeris on the date of observation (Astronomischt 

 Nachrichten, No. 4079). 



New Variable Stars in the Region about 7 Sagiti i 

 From (he comparison of several photographs taken with the 

 Bruce telescope, Prof. Wolf has discovered fifty-five new 

 variable stars in the region about y Sagittae. 



In No. 4079 of the Astronomische Nachrichten he gives 

 1 In- details concerning the discovery and measurement of 

 each star, and, in addition, a list showing the position 

 (18550) and the magnitude on various dates between 19007 

 and 19057. Forty-seven circular charts which accompany 

 the paper show the region immediately surrounding each 

 variable. 



The Supposed Nebulosity around Nova Aouil.f. No. 2. 

 — In the opinion of Prof. Frost, the suggestion that the 

 nebulous appearance of images of Nova Aquilae No. 2 is 

 entirely due to chromatic aberration is the correct one. 



Plates taken with the 24-inch reflector at Yerkes Observ- 

 atory on September 21 and 27, and October 23, 1905, show 

 no nebulosity, whilst Prof. Wolf has obtained similar 

 effects to this apparent nebulosity with other stars having 

 peculiar spectra. A third argument against the pheno- 

 menon being due to true nebulosity is that, in order to 

 produce the image obtained, the intrinsic brightness would 

 have to be at least 1800 times as bright, in proportion to 

 the light of the star, as that of the nebula known to exist 

 around Nova Persei (Astronomische Nachrichten, No. 4070). 



Some Tests of the Snow Telescope. — A very interest- 

 ing note by Prof. Hale, published in No. 1, vol. xxiii., of 

 the Astrophysical Journal, describes the present condition, 

 and some tests, of the large Snow telescope which has 

 been erected at the Solar Observatory, Mount Wilson. 



The greatest inconvenience encountered in the early use 

 of this instrument was in connection with the spectro- 

 heliograph work. Three mirrors are employed, of which 

 the first, the 30-inch coelostat mirror, reflects the solar rays 

 on to a 24-inch plane mirror, which in turn directs the 

 beam on to the 24-inch concave mirror of 60-feet focus, 

 which forms the image of the sun on the primary slit. 



When the instrument was used, with a high sun, on a 

 hot, windless day, it was found that a serious change of 

 focus, amounting in some cases to 12 inches, occurred, and, 

 worse still, the mirrors became distorted, giving a differ- 

 ence of focus for the opposite limbs of the image of as 

 much as 3 inches. 



On days when a cool breeze blew across the surface of 

 the mirror the change was less, so arrangements have now 

 been made to send a current of air across the face of each 

 mirror between the exposures, by means of fans. 



Prof. Hale has found that an hour after sunrise is the 

 best time for solar work, and after that an hour before 

 sunset. 



