96 Dr. Hare's Strictures on Dove's Essay 



cases, on account of its blowing obliquely towards or from the 

 equator, the wind would change its position relatively thereto, 

 only with a portion of the speed which is assumed in the cal- 

 culation of Professor Dove, and when the change of position 

 should be in an opposite direction from that which he supposes, 

 would it not cause the storm to whirl in the opposite way ? 



107. Professor Dove in the second paragraph, p. 211, em- 

 ploys the following language: — "As the West India hurricanes 

 originate at the inner boundary of the ti'ade winds, where, at 

 the so-called region of calms, the air ascends and flows over 

 the trade in an opposite direction, it is probable that portions 

 of this upper current, penetrating through the lower one, can 

 give the first occasion of those storms. The high mountains 

 of several of the islands, by offering a mechanical impediment, 

 may be one cause of this effect, as the air flows with redoubled 

 violence between two mountains." 



108. Professor Dove here alleges that the upper current 

 may penetrate the lower, but does not say why it should do so. 

 Wherefore, it may be demanded, should the upper current 

 penetrate through the lower current, and supposing it to do 

 so, why should it be productive of a hurricane? 



109. The Professor goes on to say, "It is evident, that if 

 the above deduction of these phaenomena be the true one, a 

 similar whirlwind must be produced wherever, owing to any 

 other mechanical cause, a current flowing towards a high 

 northern latitude is more southerly on its eastern side than on 

 its western." 



110. It seems as if Professor Dove, no less than Mr. Red- 

 field, falls into the error of making the cause of gyration the 

 only object of inquiry. It is, according to them, sufficient to 

 show that the rotation of the earth, or the reaction of a moun- 

 tain, may give a curvilinear direction to the wind. To ac- 

 count for the wind itself is not in the least necessary ! 



111. Can anything be more inconceivable, than that a cur- 

 rent of air, not previously moving with the force of a hurri- 

 cane, should, by influence of the earth's motion, or a conflict 

 with one or more mountains, be excited into a tempestuous 

 fury? W'hence comes the alleged peculiar violence of the 

 whirling portion of the atmosphere noticed in such storms ? 

 Evidently deflection could not cause any augmentation of force. 

 The velocity of the whirl would be less instead of greater than 

 that of the generating gale, since the centrifugal force conse- 

 quent to rotary motion would be productive of a collision with 

 the surrounding atmosphere, tending to dissipate the momen- 

 tum. This, as I have already observed, could receive no re- 

 inforcement, while the mass actuated by it would increase with 



