DISCOURSE OF W. B. TAYLOR. 261 



A large collection of original notes of various meteorological 

 observations, on magnetic variations, on auroras with attempts at 

 ascertaining their extreme height, on violent whirlwinds, on hail- 

 stones, on thunder-storms, and the deportment of lightning-rods, 

 unfortunately never published nor transcribed, were lost (with 

 much other precious scientific material) by fire in 1865. The phe- 

 nomena of thunder-storms were always studied by Henry with 

 great interest and attention. A very severe one which visited 

 Princeton on the evening of July 14, 1841, was minutely described 

 in a communication to the American Philosophical Society, Novem- 

 ber 5th, 1841.* 



On November 3d, 1843, he made a communication to the Society 

 "in regard to the application of Melloni's thermo-electric apparatus 

 to meterological purposes, and explained a modification of the parts 

 connected with the pile, to which he had been led in the course of 

 his researches. He had found the vapors near the horizon, powerful 

 reflectors of heat ; but in the case of a distant thunder-storm, he had 

 found that the cloud was colder than the adjacent blue space." f 



On June 20, 1845, he read a paper before the Society on "a 

 simple method of protecting from lightning, buildings covered 

 with metallic roofs;" urging the importance in such cases of having 

 the vertical rain pipes always in good electrical connection with the 

 earth, since a on the principle of electrical induction, houses thus 

 covered are evidently more liable to be struck than those furnished 

 either with shingle or tile. It is of course necessary to have the 

 metallic roof in good metallic connection with the gutters and 

 pipes; and the latter may conveniently have soldered to the lower 

 end a ribbon of sheet copper two or three inches wide, continuing 

 into the ground surrounded with charcoal and extending out from 

 the house till it terminates in moist ground. J 



* Proceed. Am. Phil. Soc. vol. ii. pp. 111-116. 



t Proceed. Am. Phil. Soc. vol. iv. p. 22. 



J Proceed. Am. Phil. Soc. vol. iv. p. 179. HENRY appears to have been much im- 

 pressed with the conducting value of the tinned sheet-iron pipes commonly used 

 as rain spouts, from observing that amid the strange vagaries of the circuitous 

 path pursued by the lightning (in cases of houses struck by this destructive 

 agent), the rain pipe was not unfrequently selected as part of the route; marks 

 of explosive violence being exhibited at its lower end, and sometimes at its top 

 as well, while the pipe itself was found to be uninjured. 



