SCIENTIFIC WRITINGS. 413 



disturbance of the indifferent equilibrium of the at- 

 mosphere, had convinced me, that in meteorology the 

 requirements of mechanical equilibrium and the prin- 

 ciple of the conservation of energy had not hitherto 

 received proper attention. Recent meteorology, in its 

 endeavour to deduce all the phenomena of atmospheric 

 motion from its extensive material of observation, has 

 too much lost sight of the causes of these movements. 

 Scientists were generally content to be able to refer 

 the aerial movements to the observed maxima and 

 minima of the pressure of the air and its movements, 

 and were satisfied with pointing to local influences of 

 temperature and the earth's rotation in explanation of 

 the causes of theses maxima and minima. In my paper 

 "On the conservation of energy in the earth's aerial 

 ocean" I have set up and defended the principle, that 

 every motion of the air is exclusively to be ascribed 

 to the unequal heating of the air by the sun's rays, 

 and that the earth's rotation can produce no new 

 motion of the air, but only change the direction of 

 the motion produced by solar influence. One direct 

 consequence of this principle is, that the sum of the 

 vis viva stored up in the rotation of the aerial ocean 

 on the earth's axis must unalterably be that, which 

 this ocean would have, if no meridional motion of air 

 were produced by solar influence, and the air every- 

 where had the rotatory velocity of that part of the 

 surface, on which it rests. In consequence of the 

 accelerating equatorial ascent of the overheated air, 

 streaming to the equator in the trade -winds, a back 



