226 Royal Society :■ 



Fig. 1 



annexed diagram, which is copied from an actual 

 occurrence ou December 2, 1861. The appearance 

 is that of a centre of calms whence currents flow 

 in radial lines, rapidly curving to the right and 

 forming a sort of " anticyclone." 



Dove's law of gyration is so fertile in result, that 

 it accounts for the same direct rotation of a cold Scale 1000 milea . 

 wind by a wholly different process. As an antithesis to his theory 

 of cyclones being due to an equatorial current pressing against 

 quiescent air, he adds (Law of Storms), with a view of illustra- 

 ting his position, and not of meeting cases that practically occur, 

 polar cyclones, "if they exist," would have a direct rotation. 

 It is not necessary to allude further to his well-known theory — it is 

 sufficient to show that two separate causes cooperate in producing a 

 rotation or curvature of currents such as I have described. I have 

 not the slightest doubt that a strong curvature of atmospheric cur- 

 rents to the right does frequently exist, owing to the descent of cold 

 air from above ; for in lately charting the weather of Europe thrice 

 daily during a month, I found it more or less present on from fifty 

 to sixty occasions. Its existence is consonant to what we should 

 expect. It is hardly possible to conceive masses of air rotating in a 

 retrograde sense in close proximity, as cyclonogists suppose, without 

 an intermediate area of direct rotation, which would, to use a mechani- 

 cal simile, be in gear with both of them, and make the movements of 

 the entire system correlative and harmonious. 



The result I have thus far arrived at, and which I should look for 

 hereafter, is that whenever the barometer shows circumscribed areas 

 of marked elevation and depression at distances not exceeding 1500 

 miles apart, a line drawn from j^~ 2. 



the locus of highest to that of 

 lowest barometer would be cut A ^ 



by parallel wind-currents at an ' /^ __^ . X 



angle of about 45°, in the way * / ^ ^x t| i 



ghown in the diagram. a ^ s~\ *^\ \ \ \ ' r ~^S 



I doubt if it be of advantage \ (J \ \ \\^ £>)} 

 to investigate the changes of "*- \ ^-Z^Z^if 



wind produced by a system of j/ N> ^~ ' 



indraught and dispersion passing High barom< Low barom< 



over any locality, because the (dispersion). (indraught). 



barometrical sections vary so rapidly as to make the incoming portion 

 unsymmetrical with that which has already passed over. 



"On the Immunity enjoyed by the Stomach from being digested 

 by its own Secretion during Life." By Frederick W. Pavy, M:D. 



January 15. — Major-General Sabine, President, in the Chair. 



The following communications were read : — 



" Notes of Researches on the Poly- Ammonias. —No. XXII. Se- 

 condary Products formed in the Manufacture of Aniline." By A. 

 W. HoYmann, LL.D., F.R.S. 



