The First American: The Life and Times of Benjamin Franklin

by H.W. Brands

Summer brought thunderstorms and the opportunity to test both his theory and his experimental design. A promising storm blew up one afternoon, with thunderheads rising high. Franklin and son launched their kite; it soared toward the base of the cloud. But nothing happened. The key gave no indication of absorbing an electrical charge. Franklin could not understand where he had miscalculated. Joseph Priestley, to whom Franklin related the afternoon’s events, described what happened next: At length, just as he was beginning to despair of his contrivance, he observed some loose threads of the hempen string to stand erect, and to avoid one another, just as if they had been suspended on a common conductor. Struck with this promising appearance, he immediately presented his knuckle to the key, and (let the reader judge of the exquisite pleasure he must have felt at that moment) the discovery was complete. He perceived a very evident electric spark. Others succeeded, even before the string was wet, so as to put the matter past all dispute, and when the rain had wet the string, he collected electric fire very copiously.