312 



Mr. Hinds on Climate in connexion 



have been anticipated, since the power of the sun's rays over 

 the temperature advances inversely to the mean heat. In 

 low latitudes, and with a high annual mean, the difference is 

 less than in high latitudes where the annual mean is low. In 

 Mr. Daniel's Essays some observations on this subject are 

 given which clearly prove this ; and further, it appears, by 

 some synchronous observations, that in the month of June, 

 when the sun's rays were 47° above the air at Bahia, they 

 were 65° in England. Connecting these with the polar re- 

 gions, it was found that in the month of March, when in 

 England the power of radiation was 49°, at Melville Island it 

 was 55°. As none of the details given show any regular pro- 

 gression through different parallels, I obtained the materials 

 for the following table ; the observations were chiefly taken 

 at sea, but always on board ship, where local influences are 

 less numerous than on shore, and far more uniform. 



Latitude. 



Sun's 

 Altitude. 



Temp, of 

 Shade. 



Sun's 

 Rays. 



Difference. 



State of the Weather. 



o / 





o 





o 





26 



77 30 



80-5 



120-5 



40 



Atmosphere clear and fine. 



5 56 



69 4 



80-5 



111 



30-5 



Clear and fine : a fresh breeze. 



8 8 



66 29 



80-5 



107 



26-5 



Cloudless : a moderate breeze. 



13 



61 5 



78 



104 



26 



Clear : a fresh breeze. 



17 47 



55 44 



75-5 



109-5 



34 



Clear : a light breeze. 



20 59 



51 10 



75 



102 



27 



Clear : a light breeze. 



21 34 



48 53 



74-5 



107 



32-5 



Clear and fine : a calm. 



33 9 



48 10 



70 



112 



42 



Clear: a light breeze. 



44 27 



68 41 



66 



US 



52 



Light fleecy clouds : a calm. 



46 19 





66 



108 



42 



Clear : a moderate breeze. 



46 19 





77 



119 



42 



Clear: nearly calm. 



In pursuance of the established fact, that many causes of 

 climate are affected very similarly on elevation as in increa- 

 sing the latitude, experiments were next made to ascertain 

 the laws of radiation in the former. By those of Major Sa- 

 bine, at a height of 4000 feet in the island of Jamaica, the 

 force of radiation was 57°, being a much greater intensity 

 than was observed at the level of the sea. Saussure observed 

 that the power of the sun's rays was greater in elevated sta- 

 tions on the Alps than on the plains below. He at that time 

 could not possibly appreciate the value that meteorologists 

 would, at some subsequent period, place on such data ; they 

 were then but a fragment of the mass of irregular information 

 which great and industrious minds are always accumulating, 

 and which at some future day find an appropriation, whilst they 

 also become an answer to the sceptic who is continually ex- 

 claiming " qui bono}" at every addition to our knowledge. 



