120 ANNUAL OF SCIENTIFIC DISCOVERY. 



The stop employed Avas a small one (0*3 inch), and the definition of 

 the developed picture was extremely sharp. Again : the appearance 

 could not be caused by smoke coming from the chimneys, because 

 that would hardly have been luminous ; not y^- of the whole chim- 

 neys could have had fires below them, and either smoke or rarefied 

 air would have drifted with the wind, which was blowing sensibly at 

 the time, whilst the dark rays went upward straight as arrows. 

 Again : that the chimneys as chimneys, had nothing to do with it, 

 was shown by a similar brush or ray appearing at the top of a certain 

 little ventilator in the roof of one of the houses shown, and not ou 

 of the parts emitting air, but from the ornamental spike at the top. 



This circumstance convinced me at the time that the phenomenon 

 was an electrical one, invisible to the eye, but abundantly visible or 

 sensible to the photographic camera, and the occasion was perfectly 

 agreeable thereto ; for it was at the conclusion of a week of unusually 

 hot, calm weather, and the sky had that morning become clouded with 

 forms of clouds eminently electrical. Happily the thunder-storm did 

 not break in this neighborhood, being waited away elsewhere ; but 

 had it broken here, the photograph tells exactly where the lightning 

 was preparing to come down ; and there is one tall iron chimney in 

 the view, with the strongest ray of the whole above it, showing that 

 that would certainly have been struck in preference to its neighbors, 

 and, if unprovided with metal communication to the earth and Avater, 

 would infallibly have caused mischief to the house to which it is 

 attached. 



I have sent a second plate, taken six days afterward, when east 

 wind and rain had disposed of all the electricity that had been brew- 

 ing in the air ; and it Avill be seen that, although it is the same vieAv, 

 taken Avith the same camera, and with the same sort of tannin dry 

 plate, there are no electrical brushes, or black rays, surmounting the 

 chimney pots. 



ELECTRICITY FOR LIGHTING GAS. 



Messrs. Cornelius & Baker of Philadelphia, have recently patented 

 and introduced a very beautiful method of lighting gas by means of fric- 

 tional electricity, arranged for use with a bracket, two portable lighters, and 

 a table light, all being simple in arrangement and readily kept in order. 



These instruments are constructed upon the principle of the eiectro- 

 phorus. 



The electric bracket is arranged Avith a brass cup in the form of a 

 vase, resting upon the bracket, Avith a connecting piece of hard rubber. 

 This cup is lined Avith lamb-skin covered with silk, and contains the hard 

 rubber electric piece, Avhich corresponds in form to the inside of the cup. 

 A coiled wire connects the cup Avith a wire attached to the burner, and 

 terminating just above the burner. 



In order to light the gis. the stop is turned, the hard rubber piece 

 lifted partly from the cup, thus liberating the spark and lighting the gas. 



The Portable Lighter consists of the same vase or cup, Avith the addi- 

 tion of a non-conducting handle. When the brass cup is lifted from the 

 electric piece, and held to the conducting Avire of the burner, the gas is 

 immediatelv lighted. 



* cj 



Another portable instrument called Double Air-Tight Electrojihorus, 



