TI NOTES BY THE EDITOR 



disturbances, is due to the gradual retardation of the earth's 

 rotation. 



According to Mr. Grove, in his Inaugural Address to the British 

 Association for 1866, from which we quote largely, there are some 

 objections, though not insuperable, against the theory of Mayer, 

 thivt the licat of the sun is caused by friction or percussion of me- 

 teorites falUng upon it ; but these cosmical bodies have not been 

 ascertained to impinge upon the sun in a definite direction from 

 their gradually lessening orbits. And M. Faye, who has recently 

 investigated the pi-oper motions of the sun-spots, has pointed out 

 many objections to this theory, and attril)utes them to some gen- 

 eral action arising from the internal mass of the sun. 



Assuming the undulatory theory to be true, and that light 

 must lose something as light, in its progress from distant luminous 

 bodies, it becomes an interesting question what becomes of the 

 enormous force of light lost, and heat radiated into space, which 

 do not apparently return in the same forms. Force cannot be an- 

 nihilated; its modes of action in this case are only changed. 

 Tliis is one of the most interesting problems of celestial dynamics, 

 which we wait for some Newton to solve. 



The doctrine of the correlation of forces is steadily gaining 

 ground. Many points of great practical importance are connected 

 with this subject, as whether we can produce heat by the expen- 

 diture of other forces than those locked ujj in our coal-beds and 

 forests ; whether we can absorb and store up fur future use, by 

 chemical or mechanical means, the rays of the sun now wasted 

 for human purposes in the desert and the tropics. 



The researches of Prof. T3-ndall on radiant heat, and the dis- 

 coveries of Graham on the increased potential energy of atmos- 

 pheric air when passed through films of caoutchouc, it becoming 

 richer in oxygen by losing half its nitrogen, are interesting as 

 indications of means for storing up force. The magneto-electric 

 machine of Mr. Wilde, and the electrical machine of Mr. Holz, 

 show how mechanical may be advantageously converted into 

 electrical force. The greatest practical conversion of force is ex- 

 emplified in the fact that the chemical action of a little salt water 

 upon a few pieces of zinc, as shoTvna in the Atlantic cable, has 

 bound the two hemispheres together by electrical action. 



The remarkable results of spectrum analysis, from the labors of 

 Kirchhoff, Bunsen, Huggins, and Miller, have thrown a flood of 

 light upon the structure of the heavenly bodies. These conclu- 

 sions wiU be found under the Head of " Celestial Chemistry." 



