June 3, 1910] 



SCIENCE 



873 



inference is that the mass is fragmentary, per- 

 haps intrinsically magnetized, and also perhaps 

 largely oxidized. 



2. The distribution of the ejected material and 

 the inclinations of the exposed strata around the 

 crater wall show a remarkable symmetry with 

 respect to a nearly north-and-south axis. This 

 symmetry, even in details, appears in holes made 

 by bullets in a suitable mass of compacted powder. 

 The inference is that the crater was formed by 

 a projectile. 



3. The mass ejected is estimated at 330 million 

 tons. The energy used to lift it out of the hole 

 is a negligible fraction of the energy expended. 

 Most of the energy expended was used in crushing 

 the rock. An estimate based on the assumption 

 that the powdered sandstone was heated to 

 2,500° C. would indicate an expenditure of 92.5 X 

 10" ft. tons of energy. Taking everything into 

 account, it seems reasonable to estimate in all an 

 expenditure of 60 X lO'^ ft. tons of energy. 



Taking this for the energy expended, and esti- 

 mating the probable velocity of the meteor as 

 lying between 3 and 48 miles a second, the mass 

 of the meteoric group would lie between 15 mil- 

 lion and 60 thousand tons. 



The size and shape of the crater lead one to 

 estimate a mass larger than this lowest limit; 

 and the final estimate is that the mass is 400 

 thousand tons and that its velocity was from 

 18 to 20 miles a second. 

 The Conversion of the Energy of Carion into 



Electrical Energy by Solution in Iron: Paul 



R. Heyl, Philadelphia. 



It is found that carbon dissolves in molten iron 

 with a liberation of energy, which, by providing 

 a suitable negative element, may be obtained as 

 an electric current. The electromotive force thus 

 developed has not yet been definitely determined, 

 but is probably not more than one or two hun- 

 dredths of a volt. There is no possibility of com- 

 pounding this electromotive force with the accom- 

 panying thermal effect, as the two are opposite 

 in direction. 

 The One-fluid Theory of Electricity: Francis E. 



NiPHEB, St. Louis. 



The author has shown in a former paper that 

 what have been taken for discharges from the 

 positive terminal of an electrical machine are 

 really optical illusions. The positive discharge is 

 really an inflow of the electrical discharge which 

 flows outward from the negative terminal. This 

 is in harmony with the one-fluid theory of Frank- 



lin. With this paper he presents photographic 

 plates showing the discharge from its first stages 

 until the disruptive spark appears. These plates 

 fully confirMi the former conclusion that there is 

 no positive electrical discharge. The discharge 

 comes from the negative terminal and goes to the 

 positive. 



The illusion which has led to the idea of a 

 positive discharge is compared to one which might 

 prevail if Niagara Falls should suddenly recede 

 from Lake Ontario to Lake Erie. It might de- 

 ceive us into the idea that there had been a posi- 

 tive discharge into Lake Erie. 



The Past and Present Status of the Ether: A. G. 



Webstee, Worcester. 



The history of the conception of the luminferous 

 ether was covered from the time of Newton and 

 Huygens to the present. For the last hundred 

 years the belief in the ether as necessary to trans- 

 mit light has been universal. Lord Kelvin de- 

 voted most of his life to establishing its proper- 

 ties. The various mechanical theories were suc- 

 ceeded by Maxwell's successful electromagnetic 

 theory, confirmed twenty years later by the elec- 

 tric wave experiments of Hertz. To explain as- 

 tronomical aberration and the phenomena due to 

 the earth's motion Maxwell's theory was severely 

 strained, and was perfected by Lorentz. The 

 classic experiment of Michelson on the apparent 

 fixity of the ether to the earth in its motion, was 

 explained by Lorentz, though by the violent as- 

 sumption that motion changes the dimensions of 

 bodies, and that the local time of a moving ob- 

 server is difi'erent from that of an observer at 

 rest. From this comes Einstein's principle of 

 relativity, which profoundly modifies our ideas of 

 space and time, and leads many radicals to aban- 

 don the ether. The " ether crisis " is the leading 

 question in physics to-day. 



The Ether Drift: Augustus Trowbbidge, Prince- 

 ton. 



Professor Trowbridge spoke very briefly of the 

 general question of relative motion of matter and 

 the ether, and pointed out that in spite of the 

 experimental work of various investigators we 

 are still in doubt as to whether the earth in its 

 motion through ether-filled space entrains the 

 ether in its motion or not. Next he explained in 

 what respect the experimental method adopted 

 by Professor Mendenhall and himself differed from 

 that of former investigators so as to be free from 

 the objections which have rendered the previous 

 work inconclusive. Lastly a report of progress of 



