ON SEISMOLOGICAL INVESTIGATIONS. bil 
VIII. The Experiment at the Ridgeway Fault. 
: Mr. Horace Darwin informs the Committee that he visited Upway in 
March last, when he took out most of the apparatus and put new 
in its place. This seems to be working well, and if it continues to do so 
_he hopes to furnish a detailed report on the relative movements of the 
_ two sides of the fault next year. 
Underground Temperature.—Twenty-third Report of the Committee, 
consisting of Professor J. D. Everett (Chairman and Secretary), 
Lord Kenvin, Sir ARCHIBALD GEIKIE, Professors Hpwarp HULL, 
A. S. Herscne., and G. A. Lesour, Messrs. A. B. WYNNE, 
W. GatLoway, JoserH Dickinson, G. F. Deacon, E. WETHERED, 
and A. Straan, Professors Micuiz Smita and H. L. CALLENDAR, 
Mr. B. H. Brouas, and Professor Harotp B. Dixon, appointed for 
the purpose of investigating the Rate of Increase of Underground 
Temperature downwards in various Localities of Dry Land and 
under Water. (Drawn up by the Secretary.) 
In response to a pressing request from the Secretary for further informa- 
tion respecting the Calumet and Hecla mine, Professor Agassiz, in the 
spring of 1903, had all the observations (covering a period of ten years) 
tabulated and sent with sketches to Professor T. C. Chamberlin, head of 
the Geological Department of the University of Chicago, who undertook 
tosuperintend their examination. In February 1904 Professor Chamberlin 
wrote the Secretary to the effect that he had only been able to prepare a 
preliminary report of a tentative kind, and that the material must have 
‘more critical study before going into print. Subsequent information 
unofficially communicated renders it probable that the rate deduced will 
be between 1° in 120 feet and 1° in 130 feet. 
_ The report of the Australian Association for the Advancement of 
Science for 1902 contains, at p. 309, an account, by Henry C. Jenkins 
(Government Metallurgist, Victoria), of observations of underground 
temperature in deep gold mines. 
_ At the North Garden Gully mine, Bendigo, 99°-1 was found at 
3,000 feet ; and at New Chum Railway mine, Bendigo, 107°-0 was found 
at 3,645 feet. The mean surface temperature inferred from observations 
at 182 feet and 247 feet in neighbouring shallow shafts is 61°-4; which 
gives the rate as 1° F. for 80 feet at both these mines. 
Electric-resistance platinum thermometers were used. Also slow- 
acting thermometers in which fine flannel is wrapped three times round 
the bulb, and the thermometer, with cork supports, then inclosed in a 
sealed glass tube. 
A nearly identical rate was obtained in some preliminary observations 
_ which were taken in less favourable circumstances in a 1,700-foot heading 
at South German mine, Maldon, and at the depth of 2,080 feet in the 
Band and Albion mine, Ballarat. The rate 1° in 80 feet is exactly the 
same as that found by Professor David in a bore, 2,733 feet deep, near 
Port Jackson.! 
A shaft 1,000 metres deep, recently sunk at the collieries of Ronchamp 
_ (Haute Saéne) in East France, is described in a series of four articles, by 
! See Report for 1895. 
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