276 



NATURE 



[January 19, 1905 



gold leaf. Generally speaking, the capacity in electro- 

 static units is found to be of the same order as the 

 length of the wire. In this or a slightly altered form, 

 the instrument is suitable for experiments on spon- 

 taneous ionisation and the radio-activity of ordinary 

 materials. 



In experiments on emanations, induced activity, and 

 very penetrating rays it is often convenient to increase 

 the magnitude of the effects by allowing them to ionise 

 a large volume of air. For this purpose the arrange- 

 ment last described is particularly convenient. It is 

 only necessary to solder a long straight wire upon the 

 lower end of 6 and to fix g by m'eans of a rubber 

 stopper into the neck of an oil' can. The leak then 

 measured is due to the ionisation produced throughout 

 the volume of the can. The sensitiveness, though 

 greater than before, is not increased in the ratio of 

 the volumes, as would otherwise be the case, owing 

 to the increased capacity produced by the additional 

 wire. This arrangement is especially useful for 

 examining the induced activity which may conveniently 

 be deposited on the wire. 



.A still more sensitive type of electroscope was re- 

 cently invented by Mr. C. T. R. Wilson. It does not, 

 however, appear to be an instrument which can be 

 safely recommended to the inexperienced, so that it 

 scarcely comes within the scope of this article. It is 

 described in the Cambridge Phil. Soc. Proc, vol. xii. 

 p. _ 135, and may be bought from the Cambridge 

 Scientific Instrument Company. Much further in- 

 formation about electroscopes and electrometers for 

 radio-active work will also be found in Prof. Ruther- 

 ford's book on radio-activity, chapter iii. 



O. W. R1CH.4RDSON. 



GEOLOGICAL SURVEY OF CANADA. 

 T^HE Geological Survey of Canada, which was 

 *■ established in 1842 under the direction of Mr. 

 (afterwards Sir) William E. Lxagan, commenced its 

 labours with isooL, which was voted by the Provincial 

 Legislature. The sum seems to have been granted 

 without any clear idea of the length of time which the 

 survey would take, but apparently it was expected to 

 last about two years. 



In the winter of 1844-5 the amount was expended, 

 and Logan was more than 800^ out of pocket. 

 Eventually provision was made for the continuance 

 of the survey for five years with an annual grant of 

 2000/. Notwithstanding many difficulties and dis- 

 appointments vigorous progress was made in the field 

 work and office work, and this has been continued 

 for upwards of sixty years under the successive 

 directors, Selwyn, George Dawson, until now, when 

 the survey, under Dr. Robert Bell, is provided for 

 better than at any previous time. Thus the total votes 

 for the present financial year amount to 22,800/. for 

 general purposes, and to about Sooo/. for the salaries 

 of permanent officers. 



We gather from the last summary report by Dr. 

 Bell that while the Canadian Geological Survey, like 

 that of the United States, has been engaged in 

 palaeontological, zoological, botanical, ethnological, 

 and archaeological investigations, by far the largest 

 proportion of the work has been of an economic and 

 practical character. Thus the justification for the in- 

 creased support given to the survey is amply supplied 

 by the investigations which have been carried on with 

 the view of aiding the development of the mineral re- 

 sources of the country. Up to the end of 1903 the 

 publications of the survey included about 350 maps, of 

 which too relate especially to mining districts ; and 

 about 250 reports and bulletins, amongst which nearlv 

 100 are exclusively economic. During the four 



NO. 1838, VOL. 71] 



years of Dr. Bell's directorship, the field parties have 

 been increased, and during the past year they have 

 worked in many interesting districts, from the Yukon 

 and British Columbia in the west to \ew Brunswick 

 and Nova Scotia in the east, and from southern 

 Ontario and Quebec to Lancaster Sound in the Arctic 

 regions. Their researches have had reference to gold, 

 silver, lead, copper, graphite, corundum and mineral 

 pigments; to coal, peat, petroleum and natural gas;, 

 to various building and ornamental stones, clays and 

 cement ingredients. Hitherto unknown sections of the 

 country have been explored and surveyed, and observ- 

 ations have been made on the timber, soils, and water 

 supply, as well as on the general natural history. 



The palaeontological work of the survey has been 

 carried on by the veteran palaeontologist Dr. J. F. 

 Whiteaves, aided in the department ot vertebrates by 

 Mr. Lawrence M. Lambe. In the " Contributions tO' 

 Canadian Palaeontology " (vol. iii.), recently issued by 

 the survey, Mr. Lambe has described some remains of 

 the carnivorous dinosaur Dryptosauriis iiicrassatus 

 (Cope), from the Edmonton series of Alberta, in the 

 North-West Territory. The strata belong to the 

 Lower Laramie (Cretaceous) formation. The import- 

 ance of a more intimate knowledge of the fauna of the 

 Edmonton series is apparent when it is borne in mind 

 that the beds of this series in Alberta constitute the 

 principal coal-bearing horizon of the district. 



Dr. Bell himself has been partly occupied, in con- 

 junction with other leading geologists in Canada and 

 the United States, in investigating the crystalline rocks 

 in Upper Michigan, in \Msconsin and ^iinnesota, and 

 in the Rainy River, Thunder Bay, and other districts 

 of Ontario, with the view of settling disputed ques- 

 tions. The controversies on these rocks have long 

 been occupying attention without any definite result. 

 A few years ago Dr. Bell urged upon the International 

 Committee of Geologists the desirability of forming a 

 small central committee, the members of which should 

 go to the ground together and look at the facts. This 

 was carried out, and as a result the members have 

 come to an almost complete agreement on all the vexed 

 points. The standing committee consists of Dr. Bell 

 and Dr. F. D. Adams (professor of geology in McGill 

 Universit}') for Canada, and Dr. C. W. Hayes (chief 

 geologist of the U.S. Geological Survey) and Prof. 

 C. R. Van Hise (president of the State LIniversity of 

 Wisconsin) for the United States. By invitation there 

 were also associated with them Prof. Leith (of the 

 University of Wisconsin), Dr. Lane (State geologist 

 of Michigan), Prof. Seaman (professor of geology in 

 the College of Mines at Houghton, Michigan), Messrs 

 Sebenius and Merriam (geologists of the Iron Ranges), 

 and Prof. W. G. Miller (provincial geologist of 

 Ontario). It is anticipated that the joint report will 

 shortly be published. 



RECENT EXPLORATION IN THE MENTONE 

 CA VES. 



PROF. M.\RCELL1N BOULE has recently been 

 studving the deposits in the well known caves of 

 the Rochers rouges (Baousse-rouss^ of local patois) 

 near Mentone, and read a paper on his results before 

 the Soci^t6 g^logique de France in the early part of 

 last year, which is published in the society's Bulletin 

 (No. i). Since the original discovery by M. Rivifere 

 of a human skeleton in one of these caves, the question 

 of the age of their deposits has been debated with 

 much warmth, but without any satisfactory result. In 

 recent vears the caves have been carefully and system- 

 aticallv explored under the direction of the Prince of 

 .Monaco, with the result that a great number of fossils 

 have been obtained. Prof. Boule's researches were 



