112 GEOR&E HERBERT STOCKBRIDGE 



ing the note book entry in November, 1749, were letters of 

 Collinson, enlarging upon the idea and suggesting ways of 

 carrying it out. The correspondence shows that the notion 

 was gradually approaching the moment of fructification. 

 Notably in a letter of July 29, 1750, Franklin gave the com- 

 plete details of a plan for making the test. He says : 



'To determine the question whether the clouds that 

 contain lightning are electrified or not, I would propose an 

 experiment to be tried where it can be done conveniently. 

 On the top of some high tower or steeple, place a kind of 

 sentry box, big enough to contain a man and an electrical 

 stand. From the middle of the stand let an iron rod rise 

 and pass bending out of the door, and then upright twenty 

 or thirty feet, pointed very sharp at the end. If the electrical 

 stand be kept clean and dry, a man standing on it, when such 

 clouds are passing low, might be electrified and afford sparks, 

 the rod drawing fire to him from a cloud. If any danger to 

 the man should be apprehended (though I think there would 

 be none), let him stand on the floor of his box and now and 

 then bring near to the rod the loop of a wire that has one end 

 fastened to the leads, he holding it by a wax handle; so the 

 sparkS; if the rod is electrified, will strike from the rod to 

 the wire and not affect him." 



The French publication of Franklin's letters led to the 

 curious result that his suggested plan was first tried in France, 

 and not in America. Both Monsieur d'Alibard, at Marly, 

 and Monsieur de Lor, at Paris, preceded Franklin in carry- 

 ing out the experiment which owed its suggestion to him, 

 but with a generosity not always shown in similar circum- 

 stances. Monsieur d'Alibard admitted that he only carried 

 out Franklin's proposition, and French writers generally 

 have not attempted to obscure Franklin's part in the results. 

 The mode of procedure of both the French experimenters 

 was, indeed, so similar to that suggested by Franklin, that 

 it would have been hard to make a denial of their indebt- 

 edness to him appear credible. The report of the Abbe 

 Mazeas to the Royal Society, already quoted, related to the 

 Paris and Marly trials, yet he mentions them as the 'Thil- 

 adelphian experiments." 



