225 



Unio Daricnsis. Testa oblonga, subinflata, incequilatorali, postico pcrangu- 

 lata, ad latcra planulata, valvulis subcrassis, natibus prominulis; epidermide 

 luteo-fusca; dcntibus cardinalibus compressis; latejalibus longissimis lamclla- 

 tisque ; margarita alba. Hah. Near Darion, Georgia. ./. //. Couper, Esq. 



Jinodonta Dnnlapiana. Tesl.1. elliptic;), inflatti, subcylindracca, transverse 

 vittata; valvulis tenuibus ; nalibus prominulis, undulatis ; epidermide nitida, 

 luteola, obsolete radiatii; margarita alba ot iridescente. IJab. South Caro- 

 lina. — Mis. Dunlap. 



Dr. Hare laid on the table some copies of an essay published 

 in Silliman's Journal for July, entitled "Additional Objections 

 to Redfield's Theory of Storms," for the use of such members 

 as might take an interest in meteorological discussions. 



In addition to the errors previously enumerated as existing in the 

 opinions and allegations, advanced in favour of that hypothesis, he 

 had, in the essay now submitted, adverted to the following : — 



Attributing winds to the rotary or orbitual motion of the earth, 

 when by those forces no corresponding currents are produced in the 

 ocean. 



Alleging that, by a conflict with an island, or concentration by 

 cliffs, a trade wind could be so accelerated and deflected, as to whirl 

 with the fury of a hurricane. 



Supposing that, if a whirlwind could be so induced, it could endure 

 and could even receive an accession of force from a conflict with 

 extraneous bodies; when, owing to the centrifugal force consequent 

 to the gyration, the momentum must be rapidly communicated to the 

 surrounding fluid, and thus be dissipated in a quantity of matter, in- 

 creasing with the square of the distance from the centre. 



The inconsistency of the characteristics of whirlwind storms, as 

 made out by certain alleged " reliable facts and observations" of 

 Mr. Redfield; such storms being represented as heaping up the air 

 on the border of the centrifugal force, while, at the same time, carry- 

 ing it, and other bodies, towards the centre, to be discharged at "one 

 extremity of the axis of rotation.'''' 



The contradiction in representing the barometric column as sink- 

 ing when first exposed to the advanced portion of a whirlwind, and 

 rising when under the rear portion ; when it is admitted that, by the 

 centrifugal force, an aerial accumulation must take place on all sides 

 towards the border. 



The inconsistency of representing the diameter of the most violent 

 zone in storms, as usually much exceeding a hundred miles, the 

 storm advancing twenty -seven miles per hour ; and yet that an ob- 



