92 



NA TURE 



[May 24, 1894 



of the lacustrine stations in Switzerland. M. Vouga calculates 

 that the layer of mud that overlies the bronze bed to the 

 thickness of aSout o'i2n. has required 3000 years for its 

 accumulation, that the deposition of the bronze bed itself 

 occupied one or more centuries, a layer of lacustrine mud 

 between the bronze bed and the stone bed (0I2m. thick) took 

 another 3000 years to accumulate, and that the stone bed 

 probably took twice as long in its formation as the bronze bed 

 did. The stations have been suddenly abandoned, with all the 

 personal property of the inhabitants, several times, and com- 

 pletely deserted : once by the men of the pure stone age— the 

 stone of the country ; a second time perhaps, but very probably, 

 by other men who possessed nephrite and jade implements, axes 

 and polished hammers, and articles of copper ; lastly, by the 

 men of the bronze age. No satisfactory explanation of these 

 facts has yet been offered, but perhaps the frequent change 

 of level of the lake waters may be to some extent responsible 

 for tbem. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, .-\pril 26. — " On the Specific Heats of 

 Gases at Constant Volume. Part II. Carbon Dioxide." 

 By Dr. J. July, F.R.S. 



In the former experiments on this gas, recorded in 

 the first part of this research,' the highest absolute density 

 at which the specific heat was determined was 00378. 

 In the present observations the determinations of specific 

 heat have been carried to densities at which the substance 

 was partly in the liquid state at the lower limit of 

 temperature of the experiments. Observations dealing 

 with true specific heat, uncomplicated by the presence 

 o' thermal effects due to the presence of liquid, are limited by 

 the density o"l444. .\t this density the mean specific heal 

 over the range, 12° C. to 100° C, is o'2035. 



These observations, combined with those contained in Part I. 

 (loc. eil.), afford a well define! line, which rises slowly at the 

 higher densities, turning away from the axis of density. 



According to an empirical equation to this line, the specific 

 he\t of carbon dioxide at constant volume is given in terms of 

 its variation with density p, as follows : 



Cv = o'i650 + o'2I25p + o'3400/>" 



"On the Specific Heats of Gases at Constant Volume. 

 Part III. Tne Specific Heat of Carbon Dioxide as a Function 

 of Temperature." By Dr. J. Joly, PM<..S. 



In order to investigate the question of the variation of the 

 specific heat of carbon dioxide with temperature, a steam 

 calorimeter was constructed having double walls of thin brass, 

 between which the vapour of a liquid boiling under atmospheric 

 pressure could be circulated. The vessels used in the experi- 

 ments were hung in the closed inner chamber. Into this chamber 

 steam could be admitted after the temperature had become 

 Btaiionary and the same as that of the jacketting vapour. In 

 this way the iniiial temperature could be varied. 



Expe'imenis at various densities and over four intervals of 

 temperature were carried out. The densities chosen were 

 00456 : o-o8oo; 01 240 ; o'iSoo, and 01973. The intervals 

 of temperature over which the gas at each density was investi- 

 gated were: air temperature to 100° ; 35" C. (boiling point of 

 ether) to 100 ; 56' (t)oiling point of acetone) to 100 , and 78° 

 (boiling puint of ethyl alcohol) to 100°. 



The results are plotted on 5 equi-density lines, in which the 

 precipitation due to the calorific capacity oi the gas between /,, 

 and 100' is plotted against the initial temperature /j in each 

 case. If the specific heal is invariable these are right lines. 

 This proves lo be lensibly the case for the lines p = 0'o^^6 

 and p=:o 0800 ; those of lowest density. 



Tne nc«t line, o' 124, is nearly rectilinear over the higher 

 range*, but pursued in the dirfclMii of decreasing temperature 

 it ri»cs markedly, thui indicating that the specific heat at constant 

 ▼olume fall* in value with increasing temperature. The line 

 p = o'l8oo and the one close above 11, p = oi973, show this 

 variation very markedly. Their variation below the critical 

 temperature i« complicated by the presence of liquid. 



' "On the Sptcific H».il»'.f Omm al Conilanl Vo'u ne," Pan I. Fkil. 

 T'niiii. vol. cUxxii. 1891 pp 7J-117. 



NO. 1282, VOL. 50] 



The following empirical equation expresses the line p=0"l24 

 calcul.ated into a line of variation of specific heat with tem- 

 perature : — 



Cv = a (too—/) ~b (100—/)- +<■ (too—/)', 



where / is the initial temperature of the experiment in centi- 

 grade degrees ; 



= 0' 19020000, 



b= -o 00006750, 



<- = OOOOOOlS2. 



Geological Society, May 9. — Dr. Henry Woodward, 

 F.R.S., President, in the chair. The following communica- 

 tions were read : — Carrock Fell : a Study in the Variation of 

 Igneous Rock-masses. Part I. The (J.ibbro. By Mr. Alfred 

 Harker. The author opened with an account of the general 

 relations of the intrusive rock-masses of the district, and pro- 

 ceeded to deal more particularly with the gabbro, which forms 

 the earliest intrusion. A petrological description of the Carrock 

 Fell gabbro followed a study of the variations observed in 

 different parts of the mass. The rock becomes progressively 

 more basic from the centre to the margin, passing fiom a quartz- 

 gabbro with as much as 59J per cent, of silica to an ultrabasic 

 type with as little as 32^. The latter in extreme cases contains 

 nearly 25 per cent, of iron-ores, partly tilaniferous. This was 

 compared with the igneous iron-ores described by Vogt in 

 Scandinavia, &c., and the probable physical cause of the 

 remarkable variation in the gabbro was discussed. Other 

 modifications of the gabbro were bricfiy noticed, due on the one 

 hand to metamorphism of the rock by a somewhat later intru- 

 sion of granophyre, on the other hand to the gabbro-magma 

 having enclosed considerable masses of the basic lavas ot the 

 district, which are themselves highly metamorpho^ed. The 

 paper w.is commented upon by Mr. Marr, Prof. Judd, Prof. 

 Cole, and Mr. Rutley. — The Geology of Monte Chaberton, by 

 Mr. \. M. Davies and Dr. J. W. Gregory. The importance 

 of the Chaberton district, as affording a key to the general 

 geology of the Cottians, was explained, and the opinions of 

 previous observers referred to. The mountain was examined 

 from three sides — that of the Grand Vallon ; the approach from 

 Mont Genivre by the Col de Chaberton ; and that of the Clos 

 des Morts Valley. The following are the conclusions arrived 

 at : — ^l) The well-known Chaberton serpentine is intrusive into 

 the calc-schists, and yields fragments to the cargneulcs of the 

 Trias: it is therefore a fre-'J'riassic intrusion. (2) There are 

 on the mountain other (airly basic schistose rocks (quartz- 

 chlorite-schists) which cut the Trias, and arc therefore f>osl- 

 Triassif.i (3) The contorted beds in the Clos des Morts Valley 

 are fossiliferous limestones, and it is from them that the fallen 

 blocks previously recorded were derived. The only recognis- 

 able fossil is Calamofhyllia feniilraU, Reuss, a characteristic 

 coral of the Gosau Beds. In spite, therefore, of the doubts of 

 Kilian and Diener, the opinion expressed by Neumayr as to the 

 existence of Cretaceous rocks in this part of the .\lps is con- 

 firmed. (4) The earth-movements of the mountain are de- 

 scribed : they include ordinary folds, inversions, faults, and an 

 important thrust-plane. (5) It is suggested that in addition lo 

 the two series of intrusive rocks above mentioned as pre- and 

 post-Triassic, a third series of late Cretaceous or Tertiaiy 

 date may be represen ted in the Mont Gci.ivrc and Rocci.ivi 

 masses. — Cone in Cone. How it occurs in the l.)cvonian 

 Series in Pennsylvania, U.S..\., with further details ol 1 

 structure, varieties, &c., by Mr. \V. S. Gresley. The author 

 described cone in-cone structure occurring in the Portage .Shales 

 of Pennsylvania, and gave iletails concerning the nature of the 

 structure as seen in these shales. He criticised the explanation 

 of Mr. J. \ oung as to the origin of the structure, and concurred 

 in a great measure with the views of those who have suggested 

 that the f irma'ion was <lue to pressure acting on concretions. 



Mathematical Society, May 10. — Prof. Greenhill, F. R.S., 

 Vice- President, in the chair. — The following communications 

 were made : On the kinematical discrimination ot Euclidean 

 and non-Kuclidean geometries, by Mr. A. F. 11. Love. The 

 problem of Hclmholt/, to lay down axioms concerning motion, 

 by which the Kuclidean, elliptic, and hyperbolic geometries 

 shall be distinguished from all other imaginable geometries, has 

 bien recently solved by Soplius Lie in the third p.irt of his 

 " Theoric der Transformalions-gruppen " (1S93), and he adds 

 (he remark that the group of the Euclidean motions is distin- 

 guished from the two groups of non Euclidean motions by the 



