Dr Forry on (he CUtnate of the United States. 69 



has, in the wonderful advancement of human knowledge 

 during the current half century, especially as regards the 

 natural sciences, by no means kept pace with the progress 

 of its kindred branches. With us, the barren work of M. 

 Yolney on the climate of the United States, written forty- 

 five years ago, when this French savmit made a flying visit 

 through our country, is still quoted by every writer on this 

 topic. To Baron Humboldt is due the distinguished credit 

 of having first generalized the various meteorological data, 

 which had been accumulated in different parts of the globe ; 

 but so little do philosophers seem to have profited by these 

 deductions, that even one of the latest writers, Mr Charles 

 Lyell, in his " Principles of Geology," when speaking of the 

 mild climate of Europe, says — " But this region, constituting 

 only one-seventh of the whole globe, proved eventually to be 

 (he exception to the general ruleP Now, it will be a leading 

 object of this paper, contrary to the opinion here advanced, 

 to demonstrate the harmony of the laws of climate through- 

 out the globe.* 



The merit of being first to establish, on an extensive scale, 

 a system of meteorological observations, with a view to the 

 elucidation of the climate of the United States, is due to the 

 Medical Bureau of the army ; and these registers date back 

 regularly to the year 1819, when Dr Joseph Lovell was the 

 Surgeon-General. The only instruments used at first were 

 a thermometer and vane ; and to these the observations were 

 long confined, with general notices of the weather. At the 

 present time, however, observations are taken on a more 

 extended scale, comprising the barometer, the thermometer 

 attached and the thermometer detached, the pluviometer, 

 Daniell's hygrometer, the wet bulb, and observations upon 

 the clouds, the clearness of the sky, and the force and direc- 

 tion of the winds.t 



* In presenting the present analj'sis of our various writings on tlie 

 laws of temperature of tlie United States, we have not hesitated, as re- 

 gards the dry details of mere facts, to adopt the language used on pre- 

 vious occasions. 



t The Medical Bureau procured a number of Daniell's hygrometers 

 from London — an instrument characterized by beauty, simplicity, and 



