The din of the market* increases upon me; and that, with frequent interruptions, has, I find, made me fay fome things twice over; and, I fuppose, forget fome others I intended to fay. It has, however, one good effect, as it obliges me to come to the relief of your patience with Your humble fervant, B. FRANKLIN. * [Hungerford-market, near Craven-ftreet, where Dr. Franklin ufually refided when in London. E.] Experiments Experiments, Obfervations, and Facts, tending to Jupport the opinion of the utility of long pointed rods, for fecuring buildings from damage by ftrokes of lightning . EXPERIMENT I. THE prime conductor of an electric machine, A. B. being fupported about 10 inches above the table by a wax-ftand, and under it erected a pointed wire 7 inches high and of an inch thick, tapering to a fharp point, and communicating with the table; When the point (being uppermoft) is covered by the end of a finger, the conductor may be full charged, and the electrometer c*, will rife to the height indicating a full charge: But the moment the point is uncovered, the ball of the electrometer drops, fhewing the prime conductor to be inftantly difcharged and nearly emptied of its electricity.-Turn the wire its blunt end upwards, (which reprefents an unpointed bar,). and no fuch effect follows, the electrometer remaining at its ufual height when the prime conductor is charged. Obfervation. What quantity of lightning, a high pointed rod. well communicating with the earth may be ex Read at the committee appointed to confider the erecting conductors to fecure the magazines at Purfleet. Aug. 27, 1772. + [See the plate. E.] Mr. Henley's. pected On pected to discharge from the clouds filently in a hort time, is yet unknown; but I have reason from a particular fact to think it may at fome times be very great.-In Philadelphia I had fuch a rod fixed to the top of my chimney, and extending about nine feet above it. From the foot of this rod, a wire (the thickness of a goofe quill) came through a covered glass tube in the roof, and down through the well of the ftair-cafe; the lower end connected with the iron fpear of a pump. the ftair-cafe oppofite to my chamber-door, the wire was divided; the ends feparated about fix inches, a little bell on each end; [and] between the bells a little brass ball fufpended by a filk thread, to play between and ftrike the bells when clouds paffed with electricity in them. After having frequently drawn fparks and charged bottles from the bell of the upper wire, I was one night waked by loud cracks on the stair-cafe. Starting up and opening the door, I perceived that the brass ball, instead of vibrating as ufual between the bells, was repelled and kept at a distance from both; while the fire paffed fometimes in very large quick cracks from bell to bell; and fometimes in a continued denfe white ftream, feemingly as large as my finger, whereby the whole ftaircafe was enlightened as with funshine, so that one might fee to pick up a pin *. And from the • Mr. De Romas faw ftill greater quantities of lightning brought down by the wire of his kite. He had explofions from it, the noise "of which greatly refembled that of thunder, and were heard (from "without) into the heart of the city, notwithstanding the various "noifes there.-The fire feen at the instant of the explosion had the "shape |