For twenty years Franklin continued to work at electricity, devoting most of his leisure to his beloved study. The great practical value of the lightning-rod, at one time in the early part of this century somewhat exaggerated, as a perfect protection against harm by lightning, just as electricity was at one time heralded as a panacea for all bodily ailments, has of late years been questioned, but the consensus of scientific opinion still attributes much merit to the device, and the extent of Franklin's services to science in the matter cannot be called into doubt. Others have claimed his discoveries. The Abbé Nolet, of France, has been credited as being the first to note the similarity between electricity and lightning; and M. Romas, of Nerac, France, is said to have used a kite with a copper wire wound around the string, to attract electricity from clouds, some time before Franklin made his experiment. But posterity has ignored these claimants, and Franklin had the happiness of escaping bitter contentions with rivals. In fact, there could hardly have been a quarrel with a man who claimed nothing, who mentioned with honor everybody's achievements but his own, and who recorded his most brilliant observations in the plural, as though he were but one of a band of investigating Philadelphians. Passing now, to Franklin's connection with the use of oil to still dangerous waves, I had occasion recently to note that Lieutenant W.H. Beehler, of the United States Navy, in writing upon the matter, quotes Franklin's explanation of why oil works so beneficently as the accepted theory. Franklin was greatly interested, when at sea, in studying the matter. Any phenomenon that puzzled him was fit subject for investigation. Let us see how he went about the inquiry. "In 1757," he wrote, "being at sea in a fleet of ninety-six sail bound against Louisburg, I observed the wakes of two of the ships to be remarkably smooth, while all the others were ruffled by the wind which blew fresh. Being puzzled with the differing appearance, I at last pointed it out to our captain and asked him the meaning of it. 'The cooks,' says he, 'have, I suppose, been just emptying their greasy water through the scuppers, which has greased the sides of those ships a little;' and this answer he gave me with an air of some little contempt, as to a person ignorant of what everybody else knew. In my own mind I at first slighted his solution, though I was not able to think of another; but recollecting what I had formerly read in Pliny, I resolved to make some experiment of the effect of oil on water, when I should have opportunity. Afterwards, being again at sea in 1762, I first observed the wonderful quietness of oil on agitated water, in the swinging glass lamp I made to hang up in the cabin, as described in my printed papers. This I was continually looking at and considering, as an appearance to me inexplicable. An old sea captain, then a passenger with me, thought