April 16. 1903] 



NA TURE 



565 



be otherwise meteorologically unknown. The volume in 

 question contains full results of rainfall or other statistics 

 at no less than forty-two stations in German South-West 

 Africa, and at thirty-two stations in German East Africa. 

 In the latter Protectorate values for several years are given, 

 with useful particulars relating to the instruments and their 

 exposure. The work is accompanied by a very clear map 

 of the north-western portion of Cameroon, between Rio- 

 del-Rey and Bali. 



We have received a catalogue of new experimental 

 apparatus from the firm of E. Leybold, which describes a 

 number of instruments suitable for general and special ex- 

 perimental and demonstration work. Amongst these may 

 be noted a convenient form of hand regulated arc lamp, 

 having an arrangement by which any one of six carbons 

 can be used, apparatus for wireless telegraphy, selenium 

 cells, and other apparatus for wireless telephony, &c. We 

 also note that the firm includes in the list Poulsen's tele- 

 graphone, which was described in Nature some time ago ; 

 this is, we presume, only an experimental apparatus, as 

 we have not heard that the invention is sufficiently per- 

 fected yet for commercial purposes. 



A method of electrically locating ore deposits which has 

 been devised by Messrs. L. Daft and A. Williams was 

 demonstrated a short time back at the Telacre Mine in 

 North Wales. The method is practically an application of 

 wireless telegraphy by earth conduction. An induction coil 

 which is used as transmitter has the terminals of the 

 secondary connected to two metal stakes, which are pushed 

 into the soil ; radiating currents are thus produced which 

 can be detected by a telephone connected to similar stakes. 

 Normally, the telephonic disturbance is greatest in a line 

 at right angles to, and bisecting, the line joining the trans- 

 mitting electrodes, but the presence of ore disturbs the 

 current distribution, and the amount of shifting of the point 

 of maximum disturbance enables the position of the deposit 

 to be determined. It is also said that the nature of the 

 sounds can, in some cases, indicate the depth and mineral 

 richness. The demonstration in Wales passed off very 

 successfully, and it seems that the system, on further de- 

 velopment, may possibly become of considerable assistance 

 in prospecting for ore. 



We have received from Dr. Hubert Jansen, the editor of 

 the trilingual technical dictionary which is being 

 published by the Society of German Engineers, a batch of 

 circulars relating to the publication. The object, as our 

 readers are probably aware, is to bring out a thoroughly 

 comprehensive vocabulary of technical terms in German, 

 English, and French ; mathematical, physical and chemical 

 words are to be included, as if not now of technical im- 

 portance they may become so at any time. Special effort 

 is to be made to include all " trade " expressions used in 

 particular industries, local dialectical terms, and even work- 

 men's " slang " names for machines, &c, as these often 

 pass in time into general use. In order to make the 

 dictionary as complete as possible, collaboration is asked 

 from technical men, institutions, or works; the publishers 

 will supply note-books for jotting down technical expressions 

 (with or without their foreign equivalents) to anyone who 

 is willing to collaborate, and these will be collected some 

 time next year, and collated by the editors. The editors 

 also ask that circulars, price-lists, &c, may be sent to 

 them, as these are a fruitful source of technical expressions. 

 We would strongly urge all who have the time and oppor- 

 tunity to give what assistance they can, as there can be 

 no question of the need for the dictionary, which will be 

 NO. I746, VOL. 67] 



more valuable the more complete it is made. A little help 

 from a larger number of collaborators is likely to be of 

 greater use than a greater amount of work by a few whose 

 experience must necessarily be limited to one or two branches 

 of technical work. 



Prof. C. Le Neve Foster, F.R.S., in the fourth part of 

 his general report and statistics concerning the mines and 

 quarries of the world in 1901, provides much information 

 concerning the relative importance of different countries in 

 the mining industries. For instance, the total amount of 

 coal produced in the world amounted in 1901 to 789 million 

 tons, of which the United States yielded rather more than 

 one-third and the British Empire rather less than that 

 proportion; Germany's output was almost one-fifth. The 

 United States, the British Empire, and Germany produced 

 six-sevenths of the world's supply. Of the total output 

 of minerals the British Empire produces about one-third 

 of the coal, one-ninth of the copper, half of the gold, one- 

 eighth of the iron, one-fifth of the lead, one-seventieth of 

 the petroleum, one-quarter of the salt, one-ninth of the 

 silver, five-eighths of the tin, and one-fiftieth of the zinc. 

 More than four and a half millions of persons are engaged 

 in mining and quarrying at home and abroad, of whom, 

 roughly speaking, one-fifth are employed in the United 

 Kingdom and one-third in the British Empire. 



The Charnwood Forest rocks form the subject of a well- 

 illustrated essay by Dr. F. W. Bennett (Trans. Leicester 

 Lit. and Phil. Soc, January). As the author remarks, he 

 joined the excursion of the Geologists' Association under 

 the leadership of Prof. W. W. Watts, and he has expounded 

 in a clear and useful way the views arrived at by that 

 geologist in his detailed survey of the area. 



Is the first annual report, for 1902, of the Rhodesian 

 Museum, Bulawayo, it is stated that the rock and mineral 

 collections have been fully classified and arranged, and 

 that a geological map of Southern Rhodesia, on a scale 

 of an inch to four miles, is being compiled. The report 

 contains a brief sketch of the geology of the country around 

 Bulawayo, by the curator, Mr. F. P. Mennell ; also a list 

 of Rhodesian minerals. 



The Western Australian tellurides form the subject of 

 an essay by Mr. L. J. Spencer (Mineralog. Mag., February). 

 The author observes that since 1896, when tellurides 

 of gold were first recognised in Western Australia, these- 

 minerals have proved of the greatest importance, and the 

 telluride mines at Kalgoorlie, in the east Coolgardie gold- 

 field, now yield as much gold as all the remaining gold- 

 fields in the colony. The tellurides occur as large lenticular 

 masses and as impregnations in schistose rocks, and they 

 are only found below a certain depth ; nearer the surface, the 

 minerals have been decomposed with the separation of native 

 gold. At present no definite crystals of tellurides have 

 been found, and the author suggests that cavities in the 

 ores should be searched. He describes several tellurides, 

 including lead telluride (altaite), which has not hitherto 

 been recorded from Western Australia. He further brings 

 forward evidence to show that " Kalgoorlite " and " Cool- 

 gardite " are not homogeneous minerals, but mixtures of 

 known tellurides. 



In the Proceedings of the Royal Society of Victoria (vol. 

 xv. part ii. 1903) all the subjects dealt with relate to 

 natural history. Mr. Frederick Chapman has commenced 

 the description of the new or little-known Victorian fossils 

 in the National Museum at Melbourne. Mr. G. B. Prit- 

 chard continues his account of the Tertiary mollusca, and 



