Oct. 12, 1882] 



NA TURE 



59i 



mine?, especially where the data are known to be very accurate. 

 Doubling the weights above assigned to Przibraro, St. Gothard, 

 Mont Cenis, Schemnitz, Kentish Tow n, Rosebridge, and Seraing, 

 and - quadrupling that assigned to Sperenberg, no material 

 difference is made in the result. The mean still comes out 1° F. 

 in 64 feet, or more exactly '01566 of a degree per foot. 



This is a slower rate than has been generally assumed, but it 

 has been fairly deduced from the evidence contained in the 

 Committee's Reports ; and there is no reason to throw doubt on 

 the results in the upper portion of the above list more than on 

 those in its lower portion. Any eiror that can reasonably be 

 attributed to the data used in the calculations for the St. 

 Gothard Tunnel and for the numerous deep mines of the East 

 Manchester coalfield, will have only a trifling effect on the rates 

 of increase assigned to these localities. 



To obtain an approximation to the rate at which heat escapes 

 annually from the earth, we will first reduce the above rate of 

 increase '01566 to Centigrade degrees per centimetre of depth. 

 For this purpose we must multiply by '0182, giving "000285. 



To calculate the rate of escape of heat, this must be multiplied 

 by the conductivity. 



The most certain determinations yet made of the conductivity 

 of a portion of the earth's substance are those deduced by Sir 

 William Thomson by an indirect method, involving observations 

 of underground thermometers at three stations at Edinburgh, 

 combined with laboratory measurement of the specific heats and 

 densities of the recks in which the thermometers were planted. 

 The specific heats were determined by Regnault, and the 

 densities by Forbes. Specific heats and densities can be deter- 

 mined wiih great accuracy in the laboratory, but the direct 

 determination of conductivity in the laboratory is exceedingly 

 difficult, it being almost impossible to avoid sources of error 

 which make the conductivity appear less than it really is. 



Prof. Ilerschel, in conjunction with a Committee of the 

 British Association, has made a very extensive and valuable 

 series of direct measurements of the conductivities of a great 

 variety of rocks, and has given additional certainty to his results 

 by selecting as two of the subjects of his experiments the Calton 

 Hill Trap and Craigleith sandstone, to which Sir William 

 Thomson's determinations apply. 



From combining Prof. Herschel's determinations with those 

 of Sir Win. Thomson, '005S is adopted as the mean conduc- 

 tivity of the outer crust of the earth, which, being multiplied by 

 the mean rate of increase, '000285, gives 

 16330 x 10-10 

 as \he flow of heat in a second across a square centimetre. 

 Multiplying by the number of seconds in a year, which is 

 approximately 314 millions, we have 



1633X315 x 10-4= 41 4. 



This, then, is our estimate of the average number of gramme- 

 degrees of heat that escape annually through each square centi- 

 metre of a horizontal section of the earth's substance. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — The lists of Boards of Studies for the first 

 time include the separate Boards of Physics and Chemistry, and 

 of Biology and Geology, as constituted by the new Statutes. 

 The Woodwardian Professor appears in both Boards. The 

 Physiology Professor, not being yet appointed, only appears in 

 brackets ; the same is the case with the Professor of Pathology 

 in the Board of Medical Studies. 



The rew Statute B having been finally approved, determines 

 that in 1883 and 18S4, a sum of between 5cco/. and 6000/. in 

 each year will become available for University purposes from 

 College revenues, subject only to deduction of 40/. by each 

 College for each Professorial Fellowship held at the College. 



The Professors of Physiology, Pathology, and Mental Philo- 

 sophy and Logic are to be appointed in such order as the 

 University may think fit, as soon as sufficient funds can be pro- 

 vided conveniently for the purpose from the common University 

 fund, or from other sources. The Professors of Physiology and 

 of Pathology are not to undertake the private practice of medi- 

 cine or surgery. The stipends are fixed at Soo/. for these two 

 Professors, and 700/. for the Professor of Mental Philosophy. 



The appointment of Readers is similarly dependent on the 

 convenient provision of funds. Thus, until the Council of the 



Senate has published its recommendations, nothing certain can 

 be said as to the objects upon which it will be thought wisest 

 first to expend the new funds accruing. But it must not be 

 forgotten that a considerable amount of the new income will be 

 required to pay the increased stipends of present professors. 



Prof. Liveing will lecture on the General Principles of 

 Chemistry this term, and also take practical classes in spectro- 

 scopic analysis. Prof. Dewar will lecture on Physical Chemitry, 

 and Tutorial lectures will be given in connection with this course 

 by Mr. A. Scott, Prof. Dewar's assistant. Demonstrations in 

 volumetric chemistry will be given by one of the demonstrators. 



Lord Rayleigh will lecture on Electrical Measurements to 

 advanced students ; Mr. Glazebrook will give demonstrations 

 on Electricity and Magnetism, and Mr. Shaw on Heat in the 

 Cavendish Laboratory. Mr. Trotter will give an elementary 

 course on Electricity and Magnetism at Trinity College, and 

 also a course on Optics and Light. 



Mr. Vines will lecture on the Physiology of Plants, at Christ's 

 College, in connection with practical work, and will also give 

 an elementary course at the New Museums, especially for 

 medical students. The Assistant Curator of the Herbarium, 

 Mr. T. H. Corry, B.A., of Caius College, will give a \ series of 

 demonstrations on the natural orders of plants. 



Prof. Stuart will lecture on Mechanism and Applied Me- 

 chanics, and the workshops and drawing office will be opened 

 to pupils on October 13. At Gonville and Caius College one or 

 more Entrance Scholarships of values varying from 40/. to So/, 

 according to merit of candidates, will be awarded in Natural 

 Science by an examination beginning on January 8 next. They 

 are only open to candidates under nineteen years of age on the 

 first day of examination, and are tenable only for one year, after 

 which a foundation scholarship may be awarded. The subjects 

 are Physics, Chemistry, Biology, and Animal Physiology ; two 

 subjects at least are required, Chemistry being essential. Par- 

 ticulars of subjects may be learnt on applicaiion to the Senior 

 Tutor, Rev. A. W. Steel. Scholarships may also be awarded 

 for Mathematics and Natural Science combined. 



The examination for Entrance Scholarships' at Emmanuel Col- 

 lege will commence on January 12. They are tenable in the first 

 instance for two years. The subjects in Natural Science are 

 Chemistry, Physics (including Dynamics and Hydrostatics), 

 Elementary Biology, and Geology and Mineratogy. Car.didates 

 may also obtain scholarships for Mathematics and Natural 

 Science combined. Mr. W. Chawner, the tutor, will supply all 

 information. 



Mr. A. Sedgwick, of Trinity College, Cambridge, will con- 

 duct the classes in Morphology which Prof. Balfour had 

 announced for the present term. 



SCIENTIFIC SERIALS 



The Journal of Anatomy and Physiology (Normal and Patho- 

 logical), vol. xvi. pt. iv., July, 1882, contains : — Observations in 

 comparative myology, by Dr. Hans Gadow. The first section 

 of this interesting paper is devoted to the important subject of a 

 scientific nomenclature for muscles. — On fat embolism, by Drs. 

 R. Saundby and G. Barling (with a plate). — On Micrococcus 

 poisoning, by Dr. Alex. Ogston. — On the action of saline cathar- 

 tics, by Dr. M. Hay (D and E series of experiments).— On a 

 variety of pulmonary lobation and its relation to the thoracic 

 parietes, as illustrated by comparative anatomy and abnomalities 

 in the human subject, by Dr. W. Allen. — Prof. Gegenbaur, 

 critical remarks on Polydactyly as atavism ; translated by Drs. 

 Garson and Gadow. 



The American Nalnralist for August, 1882, contains— On the 

 compass plant, by B. Alvord. — On the development of the tree 

 toad, by M. H. Hinckley. — On some entomostraca of Lake 

 Michigan and adjacent waters, by S. A. Forbes. — Organic 

 physics, by Charles Morris. — The Editor's table. — Recent lite- 



The same for September, 18S2, contains — The methods of 

 microscopical research adopted in the Zoological Station in 

 Naples, by C. O. Whitman.— Notes on the habits of the 

 "Savannah cricket frog," by C. C. Abbott. — On the evolution 

 of forms from the Clinton to the Niagara group, by E. N. S. 

 Ringueberg. — On hypnotism in animals, by Dr. W. Prentiss. 



The Transactions and Proceedings of the New Zealand Institute 

 for 1882, being vol. xiv., edited by Dr. J. Hector, F.R.S., and 

 published at Wellington, May, 1882, have just reached us. They 

 form a royal octavo volume of over 600 pages and 39 plates. 



