260 MPLMORIAL OF JOSEPH HENRY. 



legislators, to impress them with the great need — as well as the 

 practical policy of prosecuting the subject by governmental 

 ■ resources. No one at that day seemed so fully awake both to the 

 importance and to the methods of prosecuting such inquiry: and 

 no one more effectually advanced both by direct and by indirect 

 exertions the wide-spread interest in this study, than he. 



In 1839, while at Princeton, he in conjunction with his friend 

 Professor Bache, induced the American Philosophical Society 

 officially to memorialize the National Government to establish 

 stations for magnetic and meteorological observations : a movement 

 which was partly successful, though not to the extent desired. On 

 the subject of international systems of observation and register, he 

 justly remarks at a later date: "In order that the science of 

 meteorology may be founded on reliable data, and attain that rank 

 which its importance demands, it is necessary that extended systems 

 of co-operation should be established. In regard to climate, no 

 part of the world is isolated: that of the smallest island in the 

 Pacific, is governed by the general currents of the air and the 

 waters of the ocean. To fully understand therefore the causes 

 which influence the climate of any one country, or any one place, 

 it will be necessary to study the conditions, as to heat, moisture, and 

 the movements of the air, of all others. It is evident also that as 

 far as possible, one method should be adopted, and that instruments 

 affording; the same indications under the same conditions should be 

 employed. - - - A general plan of this kind, for observing 

 the meteorological and magnetical changes, more extensively than 

 had ever before been projected, was digested by the British Asso- 

 ciation in 1838, in which the principal Governments of Europe 

 were induced to take an active part; and had that of the United 

 States, and those of South America, joined in the enterprise, a series 

 of watch-towers of nature would have been distributed over every 

 part of the earth. - - - Though the Government of the 

 United States took no part with the other nations of the earth, in 

 the great system before described, yet it has established and sup- 

 ported for a number of years a partial system of observation at the 

 different military posts of the army."* 



* Agricultural Meport of Commissioner of Patents, for 1855. pp. 367, 368. 



