PROTECTION AGAINST LIGHTNING, 67^ 



pared with small," the light and sound called forth when glass rods 

 were rubbed were of the same nature as lightning and thunder. 

 Franklin, from the time when the electrical experiments came under 

 his notice, enthusiastically adopted this view. In a letter written to a 

 friend in 1749, he very clearly expressed his reasons for this belief. 

 In this communication he insisted upon the facts that the electric 

 spark gives light like lightning ; that the luminous discharge follows 

 a similar crooked track ; that this discharge is swift in its motion, is 

 conducted by metals, is accompanied by an explosion when it escapes, 

 rends bodies that it passes through, destroys animal life, melts metals, 

 sets fire to inflammable substances, and causes a smell of sulphur — all 

 of which attributes seemed to him to point to the identity of the phe- 

 nomena. He also observed that the electric discharge was attracted 

 by points, and stated that he was bent upon ascertaining whether light- 

 ning had not the same tendency. In the autumn of the following year 

 he wrote to Mr. CoUinsou to say that he had satisfied himself in this 

 particular ; that he was entirely convinced of the identity of the so. 

 called electricity with lightning ; that he believed the damage done by 

 lightning descending from the clouds to the earth might be altogether 

 prevented by placing iron rods, with sharp points, upon the summits 

 of buildings ; that he intended to test experimentally the soundness 

 of his belief in that matter ; and that he hoped other persons would 

 assist him in his labors by following his example. This was virtually 

 the definite forecast of the conductor which Franklin attached to his 

 house in 1752. 



In the mean time the suggestion that buildings might be protected 

 from lightning by the use of iron rods with sharp points was incident- 

 ally communicated by Mr. Collinson to the editor of the " Gentleman's 

 Magazine" in London, who, at once perceiving the practical impor- 

 tance of the hint, offered to print an account of Franklin's views in the 

 form of a pamphlet. This offer was accepted, and, in the month of 

 May, 1751, a pamphlet was published in London, entitled " New Ex- 

 periments and Observations on Electricity made at Philadelphia, in 

 America, by Benjamin Franklin." The pamphlet was not very warm- 

 ly received in England, but it was enthusiastically welcomed and ap- 

 preciated in France. Count de Buffon had it translated into French, 

 and the translation appeared in Paris within four months of the publi- 

 cation of the original pamphlet in England. It was soon afterward 

 translated into German, Italian, and Latin. The attention of scientific 

 men in Paris was quickly drawn to the method of defense proposed by 

 Franklin, and M. Dalibard, a man of some wealth, undertook to erect 

 the apparatus at his country residence at Marly-la- Yille, some eighteen 

 miles from Paris. The situation of the hoijse was considered to be 

 eminently favorable for the purpose, as the building stood some four 

 hundred feet above the sea. A lofty wooden scaffold, supporting an 

 iron rod an inch in diameter and eighty feet long, was erected in the 



