-1859] WRITINGS OF JOSEPH HENRY. 293 



to protract on a chart the relative position and direction of 

 the prostrated trees and the lines described by bodies which 

 had been moved by the force of the wind. Mr. Chappel- 

 smith, of New Harmon}', Indiana, has furnished the Smith- 

 sonian Institution with an account of a tornado and a map 

 of its path, on which are delineated, from actual survey, the 

 position and direction of several thousand trees. Professor 

 Loomis has also minutely described the effects of a number 

 of tornadoes, and has besides investigated with much care 

 and extended research the phenomena of several large storms- 

 He was the first to adopt the system of preparing a series of 

 maps illustrating the phases of the storm at different periods. 



The laborious observations of the lamented Mr. Redfield, 

 particularly in regard to the hurricanes of the Atlantic Ocean, 

 have intimately connected his name with the history of 

 meteorology, while the theoretical expositions which have so 

 long occupied the attention of Mr. Espy have done admirable 

 service to the cause of the same branch of knowledge. 



The controversial papers of Dr. Hare, bearing evidence of 

 his great logical powers, served to give precision to the views 

 of those engaged in these investigations, and thus to elimi- 

 nate error as well as to advance the truth. In speaking of 

 those who have given interesting expositions of the general 

 facts of the meteorology of North America, we ought not to 

 omit mentioning Mr. Robert Russell, of Scotland, who visited 

 this countr\^ a few years ago, and who has since published 

 a work on the agricultural resources of the United States 

 and its meteorology, which is alike characterized by accu- 

 racy and sagacity of observation as well as by candor and 

 justness of opinion. 



The facts v/hich have been gathered from the researches 

 of those we have mentioned, as well as from other sources, 

 ought to be sufficient to furnish an induction of the prin- 

 ciples on which these phenomena depend; and although no 

 theory at a given time in the history of a progressive science 

 can be considered as perfect, yet we believe the general prin- 

 ciples on which the disturbances we have mentioned depend 

 have been successfully developed by Mr. Espy ; and though 



