174 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



each other, as do those of ponderable gases. The ether atoms 

 within the mass of a good conductor of electricity move more 

 easily than within a poor conductor. The mechanical action 

 of the ether of one body upon that of another constitutes the 

 phenomena of electricity ; and thus, by Edlund's theory, is 

 all reduced to not very complicated questions of mechanics. 

 A body is said to be charged with positive electricity when 

 it contains more than its normal quantity of ether. The gal- 

 vanic current consists in the transportation of ether from one 

 point to another in the circuit. By the mathematical de- 

 velopment of these simple propositions, to which he adds the 

 principle that is not very generally entertained in works on 

 mechanics, but which he deems axiomatic ^.e., that "every 

 thing that occurs in nature demands an interval of time, no 

 matter how short" Edlund endeavors to account satisfac- 

 torily for the fundamental phenomena of electricity. Aim. 

 Chim. et Phys. ,1873. 



SECULAR MAGNETIC VARIATION IN NEW YORK. 



The recent annual report of the State Geologist of Kew 

 Jersey, Professor G. H. Cook, gives some interesting particu- 

 lars of the history and establishment of the boundary-line 

 between New York and New Jersey. This boundary is an 

 artificial line marked out by stone monuments set np at each 

 mile of the distance from the Hudson River, and continuini^ 

 forty-eight miles in a northwest direction. It was establish- 

 ed in 1773 and 1774, and at that time the mao-netic bearino- 

 of the line was N. 54 40' W. Professor Cook justly urges 

 the importance of re-establishing the broken monnments, and 

 of determining the 2)resent magnetic bearing of the whole 

 line. 



INTENSITY OF THE FRAUNHOFER LINES. 



The number and lengtli of the lines given in the spectra 

 of metallic vapors being dependent upon the density of this 

 vapor, only the longest lines remain visible when the vapor 

 is rarefied. Lockyer has recently made the important dis- 

 covery that the lines which are reversed in the solar spectrum 

 are, without exception, the longest lines observed in the spec- 

 tra of the corresponding element. Since, therefore, the very 

 few zinc and aluminium lines visible in the solar spectrum 



