440 



NA TURE 



[March 7, 1895 



years ; bat the effect of pressure on the temperature of 

 solidification mu-t also be taken into account, and Mr. 

 Clarence King, after a careful scrutiny of all the data 

 given to him for this purpose by Dr. Barus, concludes 

 that without farther experimental data " we have no 

 " warrant for extending the earth's age beyond 24 millions 

 " of years." 



By the solution of the conductivity problem to which I 

 have referred above, with specific heat increasing up to 

 the melting point, as found by Riicker and Roberts- 

 Austen and by Barus, but with the conductivity assumed 

 constant, and by taking into account the auginentation of 

 melting temperature with pressure in a somewhat more 

 complete manner than that adopted by Mr. Clarence 

 King, I am not led to ditier much from his estimate of 

 24 million years. But, until we know something more 

 than we know at present as to the probable diminution, 

 or still conceivably possible augmentation, of thermal 

 conductivity with increasing temperature, it would be 

 quite uninteresting to publish any closer estimate. 



In the latter part of .Mr. Clarence King's paper on the 

 " Age of the Earth " the estimates of the age of the sun's 

 heat by Helmholtz, Newcomb, and myself, are carefully 

 considered, and the following sentences with which the 

 paper is brought to a conclusion will, I am sure, be 

 interesting to readers of N.atlkf. : — " From this point of 

 " view the conclusions of the earlier part of this paper 

 "become of interest. The earth's age, about twenty-four 

 "millions of years, accords with the fifteen or twenty 

 "millions found for the sun. 



" In so far as future investigation shall prove a secular 

 "augmentation of the sun's emission from early to pre- 

 "senttimein conformity with Lane's law, his age may 

 "be lengthened, and further study of terrestrial conduc- 

 "tivity will probably extend that of the earth. 



" Yet the concordance of results between the ages of 

 "sun and earth, certainly strengthens the physical case 

 "and throws the burden of proof upon those who hold 

 " to the vaguely vast age, derived from sedimentary 

 " geology." ' Kelvin. 



NOTES. 

 In addition to Lord Aberdare, the Royal Society has to 

 mourn the loss of two more of its Fellows. Sir Henry Rawlin- 

 son, the distinguished Orientalist, died on Tuesday, in his 

 eighty-fifih year. He was elected into the Society so long ago 

 as 1850. Sir William Savory, who died on Mond.iy, at the age 

 of sixty-nine, was admitted eight years later. 



We have also to announce the death of Dr. IJ. H. Tuke, 

 well known for his works on psychological medicine. 



It is announced in the Britiih Medical jfournal that Dr. 

 .\rmand Ruffer has tendered his resignation of the post of 

 Director of the British Institution of Preventive Medicine. 



When the news of Prof Caylcy's death reached America, 

 American mathematicians were not slow in expres'<ing sym- 

 pathy with their En|{lish brethren. We are informed thit — 

 " In that great American University, the Johns Hopkins, in 

 which, not many year* ago. Prof. Sylvester and I'rof. Cayley, 

 at the same time, gave instruction in advanced mathematics, 

 the death of Prof. Cayley was the occasion of universal 

 mourning, and all was appropriately draped with black." 



It appears from a correspondence between the Board of 

 Trade and the Electric Lighting Committee of the St. 

 Pancras V'cttry, that Major Cardew, the electrical adviser 

 of this department, has discovered, during his investigations 

 into the recent explosions in the street boxes used 

 for electrical supply in St. I'ancras, that a remarkable 



NO, 1323, VOL. 51] 



deposit on some of the insulators contained a considerable 

 quaniily of the metal sodium. The presence of this meta) 

 appears to be so grave a source of danger, and to afford so 

 reasonable an explanation, in connection with the accumulation 

 of escaped co.il gas, of the several explosions which have 

 recently occurred, ihat the Board of Trade intends to in- 

 vestigate the causes of the deposit of this substance with a 

 view to iis prevention, and in this investigation they have 

 asked for the assistance of the Royal Society and of the In- 

 stitution of Electrical Engineers. 



Prof. Charles Stew.\rt will deliver a course of six lec- 

 tures on " The Internal Framework of Plants and Animals," at 

 the Royal College of Surgeons, Lincoln's Inn Fields, on 

 March 11, 13, 15, 18, 20, and 22, at five o'clock. Admissiot> 

 to the lectures can be obtained on presentation of visiting card . 



A CORRESPO.VDEN'T, writing from Brooklyn on February 16, 

 says : — The severity of the weather and depth of snowfall 

 throughout the southern United Slates for the past few days are 

 unparalleled. On ihe 14th inst. ihe temperatuie at Abilene, 

 Texas, was 15°, and in the State of Georgia it ranged about 

 9° lower than in New York city. Yesierdav there w.is snow 

 live inches deep in Atlanta, four inches at Darisn, three inches 

 at Thomasville, and two inches at Savannah, all in Georgia ; 

 two feet at Birmingham, .'Mabama; eight inches at New Orleans, 

 Louisiana ; six inches at Galveston, Texas, with snow falling 

 as far south as Corpus Christi. In many places there h.id never 

 before been snow enough to cover the ground to any me.isurable 

 depth. 



Frost prevailed during the greater part of the past week in 

 nearly all paits of the United Kingdom, and in the northern 

 and midland districts the thermometer in the screen has on 

 several nights fallen as much .as 10 below the freezing point. 

 Snow has fallen over the greater part of the country, and in 

 Scotland the amount has been heavy. The type of weather has 

 been chiefly anti-cyclonic, and an area of low barometer read- 

 ings was for several days situated to the eastward of our islands, 

 so that strong and cold northerly winds were experienced over 

 the entire country. A correspondent at Dundee states that 

 the temperature in that district during the Lost two months 

 was unusually low. The average maximum temperature 

 of January and February was 36° '6, and the average mini- 

 mum, 24°'9, so that the average mean temperature for that 

 vicinity was about 3o'''7. The normal values publi-hed by 

 the Meteorological Council for Leith, a little more to the 

 south, give 39°'5 as the average mean temperature for the two 

 months. 



Prof. M. MOllicr contributed an article to the January 

 number of Globus (Brunswick) on meteorology and the figure 

 of the earth, which contains much useful information upon the 

 subject of atmospheric circulation, and the results of the 

 author's own investigations. He points out very clearly the 

 effects of the earth's rotation and of the polar compression on 

 the motion of the air, and strongly opposes the theory of 

 equatorial and polar currents as propounded by Dove and his 

 adherents. He explains the enormous forces that would be 

 required to transpose a kilogram of air from the pole to the 

 equator, and shows that the motion of a particle closely re- 

 sembles that of a ball which is kept in circular motion on a re- 

 volving plate by a juggler, the rapid rotation of the plate, and 

 of the earth, acting similarly on boih ball and air. and keeping 

 both moving in comparatively small and nearly closed curves. 



Dk. a. Cancani notes the existence of two systems of undu- 

 lations in the Constantinople earthquake of July 10, 1894, one 

 propagated with a velocity of 4 9 km. per second, the other 

 with a velocity of 23 km. per second (Rend, dell' Ace. dii 



