June 14, 1888] 



NATURE 



151 



logical views, could scarcely hope to account for this ; 

 but if he will allow the meteorologists to rise with him a 

 few thousand feet above the ground, he will find that the 

 " drift theory," of which he appears to regard himself as 

 the discoverer and sole exponent, has for some years been 

 recognized as one of the chief possible causes of the 

 motion of cyclonic systems. 



Prof. Ferrel, a representative deductive meteorologist, con- 

 siders the motions of the upper and middle currents to be 

 the prim ipal cause of the motion of a cyclone in longitude ; 

 its motion in latitude, which is generally towards the poles, 

 being due to the inherent tendency which a mass of fluid 

 gyrating in the same sense as the hemisphere in which it 

 is situated, has to press towards its pole. 



Prof. Loomis, an equally representative inductive me- 

 teorologist, is more cautious ; but in his latest work, 1 

 while admitting the existence of numerous other physical 

 factors to account for the frequently anomalous move- 

 ments of storm centres — which M. Faye elegantly ignores 



— he agrees in attributing their general directions of 

 translation to the general extrinsic movement of the 

 atmosphere at the time, at some height above the surface, 

 in combination with the intrinsic mechanical principle 

 just mentioned. 



That these are not the sole causes of the motion of 

 cyclones may, however, be freely admitted, and we quite 

 agree with the remark which M. Faye triumphantly 

 quotes in italics from Dr. Sprung's recent " Lehrbuch," on 

 p. 14, viz. that " none of the theories which have been 

 put forward will alone suffice to completely explain the 

 motion of translation of cyclones." 



Many facts, such as the observed direction of the upper 

 clouds over and surrounding a cyclone, the velocities at 

 the surface in different quadrants, the retardation of the 

 barometric minima at mountain stations, and the fre- 

 quently small elevation reached by the entire disturbance 

 (not more than 6500 feet according to Loomis) — which 

 are all entirely overlooked by M. Faye— tally more with 



The Manilla cyclone of October 20, 1882. The arrows denote the direction of the wind ; the circles denote the isobars a', intervals of 5mm. 

 the inclination of the arrows to the isobars was constant all through, and = 62°' 2. 



a species of wave-motion by which the conditions are 

 continually reproduced in a certain direction than with 

 the drift theory, and in any case require other and 

 additional causes for their complete elucidation. 



We therefore entirely dissent from M. Faye's dictum 

 that the failure up to date to discover all the causes of 

 the motion of cyclonic areas is to be considered " an 

 irremediable check to their meteorological theory," and 

 we equally fail to recognize how the drift theory as put 

 forward by him strengthens his case in favour of down- 

 ward motion in tornadoes, or advances our knowledge of 

 cyclone and tornado motion one step beyond the position 

 it has already reached. 



To return to tornadoes. 



Fully armed with his preconceived theory of gyration, 

 due to inequalities in the velocity of the upper currents, 

 causing a downward motion of air along the axis of the 



" Contributions to Meteorology," chap, ii p. 142, revised edition, 1837. 



whirl, and completely disregarding all evidence of upward 

 motion or aspiration, M. Faye devotes the main part of 

 his pamphlet to criticizing in turn the various experiments 

 and opinions of MM. Weyher, Colladon, Lasne, and 

 Schwedoff, with the result that he likes none of them, for 

 the very obvious reason that, while they differ from one 

 another in certain points, they all demand aspiration and 

 upward motion along the axis. 



We have not space to follow all these attacks in detail, 

 but we venture to think that before attempting to strangle 

 all adverse hypotheses it would have been wise if M. 

 Faye had placed his own theory on a substantial basis of 

 either physical and mechanical principles, or experiment, 

 As it is, the sole foundations he appears to rest upon are 

 (1) the analogy of the river eddy, and (2) the fancied 

 absence of all indications of upward aspiration either 

 during or after the passage of a tornado. 



Regarding (1) we need only refer to M. Weyher's 

 experiments, which we recently reviewed in Nature, in 



