47 



APPENDIX No. 3. 



Extract from a communication from Professor Espy on the subject of 



Meteorology . 



My dear sir: I am much pleased to learn from your letter that the Re- 

 gents of the Smithsonian Institution would probably make an appropria- 

 tion for the purpose of establishing a series of observations " to solve, if 

 possible, the problem of American storms." I am of opinion that no sub- 

 ject of science is more worthy of the attention of the institution; and in 

 answer to your request that I should furnish you with suggestions on the 

 subject, I refer you, in the first place, to my work entitled " Philosophy 

 of Storms," from page 77 to page 172, for a full development of the plan 

 adopted twelve years ago of investigating the phases of storms, by the joint 

 committee of the American Philosophical Society and the Franklin Insti- 

 tute, of the State of Pennsylvania. 



The plan then suggested, and in part carried out, was adopted in the 

 investigation of the phases of storms during the five years in which I was 

 in the service of the government. In my '' circular to the friends of 

 science," in which I invited all persons in the United States keeping 

 journals of the weather to send them to the office of the Surgeon General, 

 Washington, I announced my intention to lay down on skeleton maps of 

 the United States, by appropriate symbols, all the most important phases 

 of great storms which might come within the range of our simultaneous 

 observations ; and thus it was hoped we should be able to determine the 

 shajje and size of all storms; whether they are round or oblong; and if ob- 

 long, whether they move sideforemost or endforeniost , or obliquely; and to 

 ascertain their velocity and direction in all the different seasons of the 

 year; the course of the wind in and beyond the borders of the storm; the 

 fluctuacion of the barometer and change of temperature which generally 

 accompany storms, and the extent to which their influence is felt beyond 

 their borders. 



Having obtained observations from a wide extended correspondence, I 

 laid down the phases of the storms on maps, as presented in my first re- 

 port, and I have continued the same plan in my second report, now ready 

 to be printed. In the investigation of the materials of the second report, 

 comprising the observations of three years and three-quarters, I have dis- 

 covered no facts contradictory to the generalizations deduced from the 

 winter storms of three months embraced in the second report. I consider 

 it of the highest interest, by an extended series of observations, which I 

 hope the Smithsonian Institution will cause to be made over a much wider 



