Mr. Redfield's Explanation of his Map. 17 



If we ascribe the electricity of steam to its condensation, 

 the circumstances under which that condensation takes place 

 are likewise of great influence. The smallest jet of high- 

 pressure steam developes more free electricity than 100 times 

 greater quantity of low-pressure steam; — another condition 

 under which electricity is produced from a jet of steam, seems 

 therefore to be its rapid expansio7i when issuing from the 

 boiler ; or probably, as I have suggested on a former occasion, 

 the quantity of caloric becoming latent during the expansion 

 of high-pressure steam, has some I'elation to the quantity of 

 electricity being set free. Even electricity in thunder-storms 

 seems to be ascribable partially to the rapid currents of air 

 whirling towards the centre of the clouds, as caloric is ab- 

 sorbed whilst the thunder-clouds are charging themselves. 



V. Explanation of a Map, sJwwing the Direction of the fFind 

 at Nootif as observed at various Places, iji the Storm of De- 

 cember 15, 1839. By W. C. Redfield, Esq. 



T^HE arrows on the map, Plate I. denote, approximately, 

 the direction of wind at noon at the several places of obser- 

 vation. The concentric lines, drawn at intervals of thirty miles, 

 were added, not as precisely indicating the true course of the 

 wind, but in order to afford better means of comparison for 

 the several observations. 



The assumed axis of the gale, at this time, should pro- 

 bably have been placed more to the westward, on a line with 

 the position of the Morrison and Cape Cod Bay, at which 

 points the gale was then blowing wilh great violence in op- 

 posite directions. The Morrison was from China, bound to 

 New York, and I have reason to believe that her position may 

 be safely relied on. The ship, as I am informed, was lying 

 to at noon with bare poles, and had taken the western side of 

 the gale suddenly at 7 A.M. This gale was severely felt in most 

 of the region comprised in this map, excepting its north- 

 western and extreme northern portion, and excepting also 

 the light winds which were found near the axis of the gale in 

 the vicinity of Buzzard's Bay, &c. in the afternoon and even- 

 ing. A very heavy fall of snow accompanied the gale in the 

 states of Connecticut, Rhode Island, Massachusetts, New 

 Hampshire and Maine, also in parts of the states of New 

 York and Vermont. Some snow also fell in the western and 

 northern parts of New York and Vermont, but attended with 

 moderate winds, chiefly from the north and north-west. 



Abhicvialions — N.H. New Hampshire. — Me. Maine. — Ms. Massacliii- 

 ietts. — R.I. Rhode Island, State. — Ct. Connecticut. — L.I.Lonj; Island. — 

 N.Y. New York, State. — N.J. New Jersey. Note. My observations on 

 the 1.5th P.M. iiavc on a former occasion been erroneously printed N.W. 

 by W. ;/-^a<ZN.W. byN. 



Phil, Mag, S. 3. Vol. lb. No. 1 H-. Jati, 18H. C 



