"C'est là, Monsieur, ce qu'il y a de plus important, car j'aurais bien d'autres particularités à vous communiquer; mais ma lettre, devenue d'une excessive longueur, m'avertit de finir. Je me réserve de mettre au jour la dernière (quoiquelle ne soit qu'un jeu d'enfant) lorsque je me serai assuré de la réussite par l'expérience que je me propose d'en faire et que je ne negligerai pas."
In English this would read: "Such, Sir, are the more important points which I have to communicate, and to which many others might be added, were it not for the excessive length of this letter, which warns me that it is time to bring it to a close. I will, however, give publicity to the last one of all (though it is only a child's plaything) as soon as I shall have assured myself of its success by an experiment which I have devised and which I shall not fail to make."
The words in brackets—"though it is only a child's plaything"—are all important, for it is on them and on them alone that the claim for priority has been put forth and maintained. It will be seen that the word kite (cerf-volant), does not occur in the letter, so that there can be no absolute certainty as to the nature of the jeu d'enfant which the author had in mind, though it is very likely that the kite was meant. In his Mémoire sur les moyens de se garantir de la foudre dans les maisons, he says, after describing some experiments that he had made with pointed rods: "Néanmoins toujours plein du désir d'augmenter le volume du feu électricque, il fallut chercher le moyen pour y parvenir. En conséquence, je me plongeai dans de nouvelles méditations. Enfin une demi-heure après, tout au plus, le cerf-volant des enfants se présenta tout à coup à mon esprit, et il me tardait de la mettre à l'épreuve. Par malheur, je n'en avais pas le temps." In English: "Being anxious to augment the quantity of electric fire, I began to think of some means to effect my purpose, and soon became quite absorbed with the subject. Not more than half an hour elapsed before the idea of the kite suddenly occurred to me, and I longed for an opportunity to try it; but unfortunately I had not sufficient leisure at the time." The work in which this passage occurs was published at Bordeaux in 1776, shortly after the death of the author. De Romas always maintained that he did not borrow the idea of the kite from any one, but that it occurred to him while pursuing his experiments with pointed conductors.
It must be admitted that de Romas could not have been acquainted with Franklin's performance of June, 1752, when he sent to the Bordeaux Academy his letter of July 12th, of the same year, for we cannot suppose that in an age of sailing vessels such news would cross the Atlantic and reach an obscure provincial town in the southwest of France in the space of a month. On the other hand, it is equally improbable that a vague allusion to the electrical use of a kite made at Nérac on July 12th, by a man entirely unknown to fame as was de Romas, should be talked of on the banks of the Schuylkill before October 19th, the date of Franklin's memorable letter to Collinson. Moreover, the "jeu d'enfant" allusion as well as the very use of the kite by de Romas failed so completely to attract the attention of scientific men of his own country that he frequently and bitterly complained down to the end of his life, in 1776, of their persistent neglect of his claims to recognition.
From all this, we conclude:
(a) That Franklin's "lightning kite" is not a myth, the experiment having been made by him in June, 1752, and fully described by him in a memorable letter written to Peter Collinson, of London, dated October 19th of the same year:
(b) That de Romas independently had the idea of using a kite for electrical purposes as early as July 12th, 1752; but that he did not carry out his idea until May 14th, 1753; and, furthermore, that he did not succeed in getting any electrical manifestations until June 7th, 1753, his success then being due, at least in part, to the clever idea which he had of entwining the cord with a fine copper wire. Therefore, suum cuique.
In conclusion, we would say that the cardinal and enduring achievements of Franklin are:
(1) His rejection of the two-fluid theory of electricity and substitution of the one-fluid theory; (2) his coinage of the appropriate terms positive and negative, to denote an excess or a deficit of the common electric fluid; (3) his explanation of the Leyden jar, and, notably, his recognition of the paramount role played by the glass or dielectric; (4) his experimental demonstration of the identity of lightning and electricity; and (5) his invention of the lightning conductor for the protection of life and property, together with his clear statement of its preventive and protective functions.
If Franklin was well acquainted with electrical phenomena, it is safe to say that his knowledge of human nature was wider and deeper still. This appears continually in his Autobiography, in his political writings, in business transactions and diplomatic relations.