American Scientific Association, 291 



meteorological observation; by it, electrical phenomena and the 

 formation of clouds could be observed. The reason why the Eng- 

 lish meteorologists had failed to make any satisfactory observations, 

 was because they lived on the western side of a great continent, 

 with no opportunity to make observations west of them, while we 

 lived on the eastern side of a great continent, with telegraph lines 

 extending inland thousands of miles. The formation of hail, 

 thunder gusts, tornadoes, and other phenomena, were explained in 

 a clear manner, which was listened to with intense interest and 

 frequent applause. 



He gave an account of the method of observation pursued each day 

 at the Smithsonian Institute. They have a map of the United States 

 hung upon a board, with pins stuck through it at the points where 

 the observers of the institute are stationed. The Institute has 

 daily reports by telegraph from many of these points. Each morn- 

 ing an assistant hangs a cord on the pins to indicate the state of the 

 weather — black if raining, green if snowing, brown if cloudy, and 

 white if fair. All storms travel east, and thus they are enabled to 

 predict with great certainty the condition of the weather twelve 

 hours in advance. 



Meteorology as connected with agriculture, was then considered. 

 It was shown that the fertility of the soil of the United States was 

 owing to the currents from the Mexican Gulf and the Pacific ; and 

 it was shown that the climate of the 100th meridian must forever 

 be unfruitful, unless trees should be planted, which might modify 

 it somewhat. 



CORRELATION OF PHYSICAL AND CHEMICAL FORCES. 



Professor Joseph Le Conte, of South Carolina, read one of the 

 ablest papers of the session on the above subject. The fact that 

 matter is constantly changing its form, and is also indestructable, it 

 universally admitted. Both these axioms hold good with regard to 

 force. " The same absolute of force exists in the universe at all times 

 and forever. The mutual convertibility of the various forms of force, 

 is called the correlation of forces; and the unvariability of the 

 absolute amount in the midst of changes shows the conservation of 

 force." 



There are four planes of material existence, which may be re- 

 garded as being raised one above another. The first and lowest is 

 the plane of elementary existence, the second the plane of chemical 

 compounds or mineral kingdom, the third the plane of vegetable 



