POPULAR MISCELLANY. 



287 



tions in solar radiation by the operation of 

 the same causes that produce sun-spots do 

 beyond doubt occur ; and the sudden blazing 

 out of new stars, like that in Auriga, are 

 facts which suggest almost unlimited possi- 

 bilities of the rejuvenescence of suns. It 

 may well be that the Glacial period is a phe- 

 nomenon attendant upon the decrepitude of 

 the sun, and the first of a series whose second 

 term may be nearer at hand than geologists 

 or laymen have previously suspected. 



Depth of the Atmosphere. — Calculations 

 based on the observation of the refraction of 

 light have caused it to be supposed that the 

 air becomes so rare at the height of about 

 sixty miles that that distance may be re- 

 garded as the limit to its sensible extent ; 

 but other calculations, made during the pres- 

 ent century, of the distance from the earth 

 at which meteors ignite, indicate that the at- 

 mosphere extends to upward of a hundred 

 miles. The question is thus presented, says 

 M. Forster, in a paper on the subject, whether 

 the incandescence of these meteors is caused 

 by the resistance of an earthly atmosphere — 

 that is, of oxygen and nitrogen moving with 

 the earth — or is developed in an interstellar 

 atmosphere. The fact that the aurora bore- 

 alis reaches heights of about four hundred 

 miles tells in favor of the latter hypothesis. 

 The orbits of some comets and the satellites 

 of Jupiter are subject to changes which can 

 be explained only by the action of a resisting 

 medium, and it would be desirable to deter- 

 mine from solar analysis whether the me- 

 dium in which the aurora exhibits itself is 

 differently composed from our atmosphere, 

 either of gases emanating from the sun or 

 those produced by the explosion of meteoric 

 bodies. The luminous clouds, of which Mr. 

 0. Jesse has made a special study, are ob- 

 jects of great importance in the study of the 

 circulation of the upper atmospheric strata. 



Cyrus W. Field.— Mr. Cyrus W. Field, 

 who died at his summer home near this city, 

 July 12th, will be best remembered for his 

 agency in the laying of the Atlantic cables, 

 by which methods of communication and of 

 transacting business between this country and 

 Europe have been revolutionized. Without 

 him they would not have been put in operation 

 for many years later than they were, if at all. 



Mr. Field was born in Stockbridge, Mass., in 

 1819, began his business life as a clerk in A. 

 T. Stewart's store at one dollar a week, and at 

 the end of his term of apprenticeship set up in 

 business for himself as a junk-dealer and pa- 

 per-maker. He became interested in sub- 

 marine telegraphy in 1853, and induced a 

 few capitalists to join with him in the Atlan- 

 tic telegraph enterprise. After thirteen years 

 of effort, fifty journeys across the Atlantic, 

 and many failures, the lines were established, 

 and Mr. Field received the honors that were 

 his due. Several years afterward, Mr. Field 

 engaged in the enterprise of building the 

 elevated railroads in New York city, and ma- 

 terially contributed by his energy to their 

 speedy completion. 



National Characteristics in Science.— In 



his address before the Physical Section of 

 the British Association Prof. Arthur Schus- 

 ter spoke of the peculiarities possessed by 

 each nation which make it better fitted than 

 its neighbors to do some particular part of 

 the work on which the progress of science 

 depends. No country, for instance, has ri- 

 valed France in the domain of accurate meas- 

 urement, with which the names of Regnault 

 and Amagat are associated, and the Interna- 

 tional Bureau of Weights and Measures has 

 its fitting home in Paris. The best work of 

 the German universities seems to consist in 

 the following up of some theory to its logi- 

 cal conclusions and submitting it to the test 

 of experiment. The speaker doubted whether 

 the efforts to transplant the research work of 

 German universities into England will prove 

 successful. Does it not seem well to let each 

 country take that share of work for which 

 the natural growth of its character and its 

 educational establishment best adapt it ? As 

 far as the work of the Physical Section is 

 concerned, the strongest domain of English 

 students has been that of mathematical phys- 

 ics. Look at the work done in Great Britain 

 during the last two centuries — the work not 

 only in physics, but in astronomy, chemistry, 

 and biology. 



Cause of the Bursting of Peat-hogs. — 



The curious phenomena of the swelling and 

 bursting of peat-bogs have been studied 

 by Herr Klinge. They generally occur after 

 heavy rains, and are preceded by detonations 



