678 
PROFESSOR JAMES THOMSON ON THE 
tendency in it as compared to the air above, is caused to reverse what would otherwise 
be its motion towards the Equator, and to take its course towards the Pole instead. 
The next publication to which I have to advert is a second paper by Mr. Ferrel. 
It is entitled “ The Motions of Fluids and Solids, relative to the Earth’s Surface; 
comprising Applications to the Winds and the Currents of the Ocean,”* and is dated 
at its close, “ Cambridge, Mass., February, 1860,” and is noted on its title-page as 
being “ Taken from the First and Second Volumes of the ‘Mathematical Monthly.’” 
In that paper he offered a scheme of atmospheric circulation totally different from 
his previous one of 1856, and entailing a fundamentally altered theory. In fact, he 
Fig-. 5. 
FE RREL- 1 860. 
there abandoned his arrangement of six zonal vortex rings of circulation, three for the 
northern hemisphere and three for the southern, and, instead, he adopted really the 
scheme that had been put forward by me in 1857 with its two great currents of 
primary circulation, one flowing from equatorial to polar regions above, and the other 
flowing as a great return current from polar to equatorial regions below’; together 
with the bottom subordinate current close on the surface of the Earth in middle 
latitudes or middle and higher latitudes, flowing pole-ward on account of the frictional 
retardation by the Earth’s surface of its eastward relative motion and consequent 
diminution of centrifugal tendency. 
* New York, Ivison, Phinney, and Company. London, Tkubnee and Co., 1860. It appears that this 
paper was subsequently republished by the United States Signal Service in ‘ Professional Papers,’ 
No. VIII., with extensive notes giving the mathematical processes in detail by Professor Frank Waldo. 
