322 



Mr. Hinds on Climate in connexion 



years, and comprehend an extensive range of the Atlantic and 

 Pacific Oceans, with numerous ports and harbours on their 

 coasts. On running the eye over the column containing the 

 weight of vapour, it is not a little surprising to see the regu- 

 larity with which the amount of the atmospheric moisture in- 

 creases on approaching the equator. From the high latitudes 

 of both hemispheres the same occurs, nor can we perceive that 

 the trades make any notable difference. The value of this table 

 over the manufacture of the closet is immense ; here we have a 

 set of results such as they really were at a certain period of the 

 year, and in every probability conducted with such a regard to 

 correctness that implicit confidence can be placed in them. 

 Such numerous details induce us to draw comparisons between 

 the circumstances of humidity in the two oceans, and one at 

 the equator will be among the most interesting. 



Temp. Dew-point. Grains. 



Atlantic, June 79°*6 73° 9*8560 



Pacific, May 80*24 79 10*9945 



„ April 79 75 9*8550 



The two first are from Captain Beechey, and are his means 

 for 5° north of the equator; the latter I observed myself with- 

 in a few miles of the equator some ten years afterwards. As it 

 was not unlikely that further comparisons might show me 

 some practical results of the influence of the seasons, I se- 

 lected another parallel, but only for the reasons that it was 

 frequently traversed, and that it approached closely the lati- 

 tude of England. Like the former, they are a set of means for 

 a series of 5° in the North Pacific Ocean between 50° and 55°. 

 The similarity in the months and the difference in the sea- 

 sons are marked. 



Temp. Dew-point. Grains. 



1826 July 47-10 47*4 4*1933 

 „ October 44*9 40*7 2*4131 



1827 July 49*12 48*1 4*0161 

 „ October 40*36 35* 2*7697 



The atmosphere over such a surface as the ocean may rea- 

 sonably be considered as having more aqueous vapour in 

 solution than will be found elsewhere in the same latitude, 

 and on this account the observations for any particular spot 

 may be regarded as nearly the excess for that season of the 

 year. The humidity of the air over the ocean being so great, 

 every wind which blows from it towards the land carries with 

 it a quantity of vapour ; and wherever sea-breezes blow over 

 elevated land, this is rendered visible ; for the atmosphere, 

 previously clear and transparent, becomes on its accession 

 obscured with light clouds, and the surface of the high land 



