595 



[Chase. 



newspaper articles by S. S. observers, and in reports of the Chief Signal 

 Officer. Prof. Loomis is, perhaps, somewhat unconsciously biased by a 

 still lurking prejudice in favor of Redfield's views, which disposes him to 

 trace all rainfalls to "a cyclonic movement of the winds about the rain 

 area." As soon as the rain begins to fall, there must undoubtedly be a 

 local cyclonism, as I stated (loc. cit., 7); but a careful study of weather- 

 maps, especially in winter storms and in cases of failing forecasts, satis- 

 fies me that the origin of storms is as much anticyclonic as cyclonic. 

 The frequent instances of snows in a "high" area, with simultaneous 

 rains in a "low" area, are very instructive. Ferrel's researches show 

 that cyclonism and anticyclonism must be companions. It is, therefore, 

 hardly right to regard either as peculiarly storm-breeding. The vera 

 causa is a blending of moist and cold currents. When the precipitation 

 begins in a high area, the initial currents are anticyclonic ; when in a low 

 area, cyclonic. Ferrel's middle-latitude ridge of high barometer also ex- 

 plains the anticyclonism of our Southern States, to which Loomis refers. 



368. " Central Forces and the Conservation of Energy." 



Mr. Walter R. Browne {PliU. Mag., Jan. 1883), confirms some of the 

 views of central force which hj^ve guided my own researches, and which 

 are embodied in Taylor's retiring address (Note 366). He shows that 

 the conservation of energy requires, and results from the equation 



f^ "^ F dx = C Y dx; 



•J a >} a -^h 



in which two particles, A and B, are alternately receding and approaching 

 between the distances a and « -j- & ; and that F can only be a function of ?• ; 

 "in other words, the force with which A acts upon B always tends 

 towards A, and varies, if it varies at all, according to the distance from A 

 only. But this is the definition of a centml force." He also refers to his 

 paper "On Action atadistance" {Phys. Soc, 1881;PMl.. Mag., Dec, 1880), 

 in which he showed that it is "impossible to explain certain elementary 

 facts of physics without the hypothesis of action at a distance. ' ' He de- 

 duces from the kinetic theory of gases, the conclusion that the collision 

 " occasions the instantaneous development of a strictly infinite force. " In 

 1876, I showed that "if the theory of Boscovich were true, at the centre, 

 where p = 0, v would be infinite" (Proc. Amer. Phil. Soc, xvi, 304). 

 These conclusions, as well as Laplace's doctrine of the instantaneous action 

 of gravity {op. cit. p. 302), are inexplicable by any hypothesis which does 

 not either recognize spiritual activity or spiritualize its definition of matter. 



369. Mean Molecular Excursions. 

 In discussing the kinetic interpretation of the law of gases, Taylor cites 

 {Address p. 17) the application of the calculus of probabilities, by which 

 Clausius inferred "that of the whole number ■ f free molecular excur- 

 sions in a given time (in any large enclosure), those having less than the 

 mean length will be 0.6321, or nearly double the number of those having 



PROC. AMER. PHILOS. SOC. XX. 113. 3w. PRINTED MARCH 19, 1883. 



