384 



NA TURE 



[August 19, 1897 



morning. The distance to Trouville is about io8 miles, and 

 the motor cycle and car first in the Dieppe race also arrived 

 first on Sunday. M. Jannin on his cycle rode the distance 

 under four hours, while M. Gille's Hourgieres-Bollee carriage 

 covered the io8 miles in four hours and twenty minutes. 

 Twelve of the motor cycles arrived in less than six hours, and 

 seven of the cars in the same time. 



The first annual report on the work of the Geological 

 Survey of Cape Colony has just been published. Prof. G. S. 

 Corstorphine, the geologist to the Colony, throws cold water 

 upon the belief that payable coal-seams exist beneath the 

 Karoo. He points out that, though it is just possible a coal- 

 seam may be found among the shales of the Karoo, the hope 

 of such a lucky find becomes almost daily less, and the prob- 

 ability of an extensive coal deposit underlying the Karoo is very 

 slight. Deep boring has been again and again advocated as a 

 sure means of discovering coal, but Dr. Corstorphine says 

 that so far there is no evidence geologically to warrant the 

 renewal of such an expensive procedure as deep boring with 

 such a purpose ; and this conclusion is not only based upon the 

 work carried out under his direction last year, but also on the 

 results of previous investigations. The question of a probably 

 water-supply from deep boring having been brought before the 

 Commission, Dr. Corstorphine and Mr. A. W. Rogers (assistant 

 geologist) made a preliminary survey of the Oudtshoorn and 

 Prince Albert districts with a view to the selection of a site for 

 a deep bore-hole. But so little is known about the structure of 

 the country and the rocks composing it, that the people who are 

 crying out for deep boring for artesian water will have to exercise 

 a little patience, unless they are willing to provide a large sum 

 of money to be spent upon a series of purely experimental 

 bores. A large amount of information has yet to be obtained 

 before a geologist would give an opinion as to the existence 

 of considerable quantities of water at great depths in the Colony. 

 The Commission, therefore, concludes (and rightly so) that an 

 expenditure upon a deep bore-hole with the idea of finding 

 water would be premature in the present state of knowledge. 



At the International Meteorological Conference held at Paris 

 in September last, Mr. C. L. Wragge, Government Meteor- 

 ologist for Queensland, drew attention to the importance of 

 establishing an observatory on the top of Mount Kosciusko, 

 in the south-eastern extremity of Australia, at a height of about 

 8000 feet. The conference expressed the opinion that such a 

 station would possess really scientific importance, and that it 

 would be useful to publish hourly observations made there. 

 We are glad to learn from the Brisbane Courier that the Hon. 

 R. Barr-Smith, of Torrens Park, South Australia, has offered 

 to subscribe the whole amount necessary for the establishment 

 of a tentative station at the summit of the above-mentioned 

 mountain. Mr. Wragge hopes that the comparison of the 

 results with those obtained from low-level stations will ensure 

 a permanent observatory being established in the interest of 

 Australasia. 



During the last thirteen years the Indian Department of 

 Revenue and Agriculture has published memoranda on the 

 snowfall in the mountain districts, with forecasts of the probable 

 character of the south-west monsoons. These statements and 

 forecasts are drawn up by the Government Meteorological 

 Reporter, and have been found of considerable use in predicting 

 the probability of abnormal rainfall during the monsoon period 

 of June to September, heavy and prolonged snowfall in the 

 Western Himalayan area either preventing or delaying the 

 extension of the monsoon current during the rainy season. The 

 investigation seems to show that the general conditions are not 

 unfavourable to the establishment of at least normal monsoon 

 currents, although in parts there has been more snow than 

 NO. 145 I, VOL. 56] 



usual. It also shows that there has been a cyclical variation in 

 the rainfall during the past five years ; 1892-94 were character- 

 ised by excessive rain, and in the next two years the rainfall 

 was deficient. The conclusion drawn from this is that there is 

 considerable probability that the present year will be one of 

 deficient rainfall and be the last year of the cycle, but that 

 it will be much less unfavourable than last year. The variations 

 in the rainfall are supposed to be due to some general, but 

 as yet unknown, causes affecting a much larger area than India. 



There are so many unsettled points with reference to the 

 mode of formation of hailstones that careful observations of the 

 internal structure of hailstones are always of interest, inasmuch 

 as they may prove of assistance in working out the development- 

 history of these meteoric objects. For this reason we are glad 

 to note the following details which Dr. Alex. Hodgkinson ob- 

 served in hailstones that fell in Wilmslow, Cheshire, during a 

 storm of great severity on August 5. The hail varied in size 

 from seven-eighths of an inch downwards, and the general 

 shape was more or less conical with convex bases. As to the 

 internal structure, Dr. Hodgkinson writes as follows :— " A 

 nucleus of variable size existed in each hailstone, and this was 

 surrounded by an outer layer of clear ice. In some of the 

 larger specimens an intermediate zone of slightly opaque ice was 

 seen, but more transparent than the nucleus. Under the micro- 

 scope, with a power of about twenty diameters, the structure of 

 the nucleus was seen to be coarsely crystalline, and profusely 

 interspersed with minute air-bubbles, reminding one forcibly of 

 the vacuoles which so frequently occur in specimens of quartz, 

 and give rise to its opalescent appearance. The intermediate 

 zone, when present, was constituted by the existence of similar 

 vacuoles, but far smaller, and no crystalline structure was here 

 perceptible. The outermost layer consisted of clear ice, ap- 

 parently structureless under the microscope ; but with the naked 

 eye, and by variations in the incident light, this might be seen 

 to possess a coarsely radiating structure, as if composed of large 

 radiating crystals. On embedding a hailstone in a piece of 

 perforated card, and examining with polarised light, there was 

 no indication of tangential and radial strain in the body as a 

 whole. The outer and intermediate layers were isotropic, but 

 the individual crystals of the nucleus were distinctly double- 

 refractive." 



A DETAILED description of the large seismometrograph 

 recently placed in the observatory of Catania is contributed by 

 Prof. A. Ricco to vol. x. series 4^ of the Dagli Atti deW Ac- 

 cademia Giocnia di Saenze Naturali in Catania. Prof. Ricco 

 was led to erect this instrument because those of a similar 

 character at Rome and Rocca di Papa gave such excellent 

 results. The description is accompanied by an excellent photo- 

 graph taken by means of the flash light. 



From Profs. Elster and Geitel we have received a reprint of 

 their last paper, published in Wiedemann's Annalen, dealing 

 with the relation between the photo-voltaic current and the 

 kathodic absorption of light when the angle of incidence and 

 direction of polarisation of the incident light are varied. The 

 experiments, which were conducted with the assistance of the 

 Elizabeth Thompson Science Fund, of Boston, show that the 

 current, so far as it depends on these factors, ig determined by 

 the amount of light absorbed at the kathode, and the agreement 

 between the curves representing the current and the absorption 

 affords a striking confirmation of the theory of metallic reflection. 



About a quarter of a century has elapsed since Father 

 Bertelli made his first observations on the microseismic move- 

 ments of the ground. The accuracy of his results was soon 

 disputed, because his pendulums were suspended from a bracket 

 attached to the wall of his observatory, and a long and indecisive 



