14 



NATURE [May 5, 1904 



soluble silicates derived from decomposition of the felspathic 

 cement in the sandstone. 



The delegates of the Clarendon Press have in preparation, 

 and will shortly publish, an authorised translation of " Das 

 Antlitz der Erde," by I'rof. Eduard Suess. This English 

 edition of a standard work will be prepared by Dr. Hertha 

 Sollas under the supervision of Prof. W. J. SoUas, F.R.S., 

 and will contain a preface written for it by Prof. Suess. 



The Electrician Printing and Publishing Co. announce 

 the early publication of a work by IVIr. F. Soddy entitled 

 " Radio-activity : an Elementary Treatise from the Stand- 

 point of the Disintegration Theory." The same company 

 will issue in a few days a book by Prof. S. Lemstrom, 

 entitled " Electricity Applied to Agriculture and Horti- 

 culture." 



A NEW edition of an illustrated price list of chemical 

 apparatus has been published by Messrs. Brewster, Smith 

 and Co., of Cross Street, Finsbury Pavement, E.C. The 

 new catalogue contains above four hundred more illus- 

 trations than the previous issue, and also full particulars 

 of several new devices of which we have already given 

 descriptions. 



The eighth volume of the new half-yearly series of the 

 Transactions of the Leicester Literary and Philosophical 

 Society has reached us. It is edited by Mr. O. T. Elliot. 

 The volume contains the presidential address of Dr. R. 

 Pratt dealing with the subject of " over-strain " and 

 *' nervous-breakdowns, " which are traced to a wrong use 

 of leisure ; four papers read before the society ; and the 

 quarterly reports of si.K of the sections into which the 

 association is divided. We notice that this Leicester society 

 was founded in 1S35, and has thus had nearly seventy years 

 of useful work. 



On account of the ease with which gold can be obtained 

 in the pure state, the exact determination of its melting 

 point is an important datum for high temperature measure- 

 ments. Previous observers have given values ranging from 

 1061° (Callendar, Heycock and Neville) to 1091° (Barus), 

 the average of the more recent work being 1064° C. In 

 the current number of the Comptes rendus cL new determin- 

 ation of this constant is described by MM. A. Jacquerod and 

 F. L. Perrot, in which direct comparison with the gas 

 thermometer, with fused silica bulb, is adopted. The heat- 

 ing was carried out in an electrical resistance furnace of 

 special type, giving a complete control over the temperature 

 in the neighbourhood of 1000° C. Owing to the smallness 

 of the coefficient of expansion of silica, the correction for 

 the expansion of the bulb amounts to only 2°, as against 

 35° to 40° for the same instrument with a platinum bulb. 

 The mean result with the nitrogen thermometer was 

 io67°2 C, and the results obtained when the bulb was filled 

 with other gases showed that the coefficients of e.xpansion 

 of oxygen and carbon monoxide are very close to that of 

 nitrogen. 



The additions to the Zoological Society's Gardens .during 

 the past week include a Lesser White-nosed Monkey 

 (Cercopithecus petaurista) from West Africa, presented by 

 Mr. T. P. Eykyn ; two Mountain Ka-Kas {Nestor notabilis) 

 from New Zealand, presented by Mr. T. E. Doune ; a 

 White-tailed Ichneumon (Herpestcs albicauda) from Africa, 

 six White-crowned Pigeons {Columba leucocephala) from 

 the West Indies, two Large-billed Weaver-birds (Ploceus 

 mcgarhynchiis) from India, deposited. 



NO. 1801, VOL. 70] 



OUR ASTRONOMICAL COLUMN. 



Comet 1904 a. — Herr M. Ebell has calculated a new set 

 of elements and an ephemeris for Brooks's comet, the former 

 differing slightly from that published by Prof. Pickering. 

 They have been derived from observations made on .^pril 17, 

 20 and 24, and are given below : — 



T=I904 February 28-8792 



«== 50 5.V'2 

 a =275 18-5 

 i = 125 00 

 log (7 = 0-42950 



Ephemeris oh. «.T, Berlin. 



1904 a 6 log A Brightness 



h. m. s. . , 



May 2 ... 16 6 56 +52 44-4 o'3S56 o'95 

 6 ... 15 50 5 +54 23'i 

 10 ... 15 32 16 +55 448 0-3672 o 8S 

 14 ... 15 13 50 +56 47 2 

 18 ... 14 55 15 H-57 31-9 0-3831 o-Si 



(I-viel Centralstelle Circular. No. 6b). 



It will be seen from the above ephemeris that the comet 

 is travelling along just inside the southern border of Draco 

 towards Ursa Major, and is becoming fainter. On May 6 

 it will be very near to, and south of, a small triangle of 

 stars which is situated about 4° south of d Draconis. 



Diminution of the Intensity of the Solar Radiation. 

 — In a communication to the Paris Academy of Sciences 

 M. Ladislas Gorczyriski publishes two tables showing, in 

 the first, the mean monthly values of the solar intensity 

 and the absolute humidity, and in the second the maximum 

 values of these two quantities for each month during the 

 years 1901, 1902 and 1903. The tables give the differences 

 between the values for the corresponding month of each 

 year, and show that the diminution in the intensity, which 

 M. Dufour stated (Coinptcs renchts, vol. cxx.xvi. p. 713) 

 commenced in December, 1Q02, really commenced at 

 Warsaw in May of that year. Until more positive evidence 

 as to the effect of the dust ejected from Mont Pel^e on the 

 observed solar intensity is forthcoming, M. Gorczvnski 

 hesitates to ascribe the diminution to this cause (Comptes 

 rendus, No. 5). 



The Periodical .\pparition or the Martian Canals. — 

 In a paper read before the American Philosophical Society 

 Mr. Percival Lowell discusses the 375 drawings of the 

 Martian surface made by him during the opposition of 1903. 

 Having plotted the values allotted to the " visibility " of 

 eighty-five canals, at different periods, with regard to the 

 time of their minima visibilities after the Martian summer 

 solstice, he found that these minima appeared in regular 

 sequence from the North Pole towards the equator. Air. 

 Lowell believes that the canals are strips of vegetation 

 dependent for their growth — and therefore for their visibility 

 — upon the simultaneous presence of sunlight and water, 

 and he points out that on a planet, such as the earth, where 

 water is constantly present all over the surface, the appear- 

 ance of vegetation solely depends upon the amount of sun- 

 light received ; therefore in the northern hemisphere it 

 simply progresses northward with the sun. On the other 

 hand, he concludes, from his curves, that there is no con- 

 stant supply of moisture on the surface of Mars, and, there- 

 fore, although the sun may have reached the summer 

 solstice, it is not until the snowcap melts and looses the 

 water supply that the vegetation appears. Further, his 

 curves indicate that when loosed the water moves south- 

 ward at a remarkably steady rate of 53 miles per day, 

 and, as the figure of the planet is shown by its spheroidity 

 to be in a state of fluid equilibrium, he contends that the 

 water must of necessity be conveyed southwards by artificial 

 means. 



The curves discussed are reproduced on seventeen plates 

 which accompany the paper in No. 174, vol. xlii., of the 

 Proceedings of the society. 



