404 METEOROLOGICAL COREESPONDENCE, 



termining the great currents of the atmosphere. The resultant winds of the 

 valley of the Hudson, as determined by the surface wind, are north and. south, 

 while the resultant wind of the whole State has a westerly direction. Still we 

 would not dispense with the use of the wind vane. There are many places 

 where its indications are strictly correct, when it is placed at a proper elevation ; 

 and at almost any place of which the topographer is well known an approxi- 

 mation to the true direction may be deduced from the directions indicated by the 

 vane. Moreover, the vane serves to give the direction of the changes of the 

 wind, an important element in the theory of the phenomena of storms ; and even 

 the indication which it affords of the lower surface winds is of value in perfect- 

 ing our knowledge of the influence of moderate inequalities of the surface on the 

 direction of currents of air and the distribution of temperature. 



In the records of the motion of the clouds care must be taken to state whether 

 they are the upper or lower. 



From J. Baltzell, Tallahassee, Florida. 



September 16, 1857. 



The regular wind on the Atlantic coast of Florida, from which is derived the 

 health and comfort of the inhabitants in the summer, is a southeasterly one from 

 the sea, filled with moisture, evidently having saline particles, and stimulating in 

 its effects. The wind at this place, which produces a like effect in- the summer, 

 giving us life, health, animation, and comfort, is the southwest, which comes from 

 tlie gulf of Mexico, about twenty miles distant ; I think it is not as stimulating, 

 or as highly charged with saline particles, as that on the Atlantic coast. With 

 us the east wind is dry, parching, and uncomfortable, prevailing not longer than 

 a week at a time, and, if for a month or more, sickness is sure to follow, with 

 extreme lassitude, depression, and nervous uneasiness. On the Atlantic coast 

 as I Avas informed in a recent visit, the northeasterly winds produce these results. 



I think it will be found that the injurious effects of our east wind are not de- 

 pendent upon the flat lands between this and Georgia. In general, the pine 

 woods of this region are dry, Avith no water upon them, and they are generally 

 regarded as very healthful ; occasionally there are wet seasons, in which the low 

 lands are for a short time covered AA'ith water. 



I cannot give you information as to the prevailing direction of thunder storms, 

 but will bear it in mind, and if I can obtain anything of value, will communicate 

 it to you. 



Remarks. — The east wind, which reaches Tallahassee from the Atlantic, 

 passes over the whole of that portion of Florida lying between the city and the 

 ocean ; a distance ten times greater than that traversed by the current from the 

 gulf. This is sufficient to explain the greater heat and dryness of the air. The 

 same amount of radiation from the sun raises the temperature of the land much 

 more than it does that of the water ; the specific heat of the latter being about 

 six times greater than that of the former. 



From L. F. Ward, Medina, Ohio. 



October 5, 1857. 



I broke the tube of a standard barometer, and in trying to replace it, and pre- 

 paiing to do so, I wiped out the tube carefully with a wooden rod and cotton 

 wool, and laid it by until I could prepare the mercury. Soon after laying it 

 down it began to break up into sections, and some of those sections to split 



