The Three Secretaries H7 



"Times morning, noon, and night, or morning and night. 

 Most important observations : i. Barometer. 2. Face of the 

 sky. 3. Direction and force of the wind. The rise of the 

 barometer will precede a fall." 



Under May 19, is the following entry : 



"Wrote to Judge McLean to give me an account of his 

 obs. on thunderstorms. Thunder storms come from the 

 west at Washington on the opposite side of the river divide, 

 one part down, the other to Baltimore. Prepare circulars 

 relative to storms of this kind." 



The "Instructions for Meteorological Observers" were writ- 

 ten by his own hand. The instruments for distribution were 

 tested by him, and that magnificent corps of observers whose 

 contributions, covering a period of thirty years, constitute 

 a considerable portion of the foundation of meteorological 

 science, was kept together by his personal labor in corre- 

 spondence. 



His original study was not limited, however, to electricity 

 or to physics. He entered every field into which human 

 thought may enter. 



He was, perhaps, the first to work out a theory of the cor- 

 relation of physical, chemical, and vital forces. This was in 

 1844. His conclusions were essentially as follows: 1 



"They who are disposed to continue the speculation . . . 

 may extend the generalization so as to reduce all mechanical 

 motion on the surface of the earth to a source from without. 

 Thus . . . the mechanical power exerted by animals is due 

 to the passage of organized matter in the body from an un- 

 stable to a stable equilibrium [or, as it were,] (from the combus- 



1- Proceedings of the American Philosophical page 215; The London, Edinburgh, and 

 Society, 1844, Volume iv, page 127; Amer- Dublin Philosophical Magazine, 1845, Vol- 

 ican Journal of Science, 1845, Volume XLVIII, ume xxvi, page 541. 



