The leading thought on this subject is that art has made greater strides in the United States within the past twenty years than for the century preceding. Twenty years ago there was comparatively no art public at all. There were not a quarter part as many foreign pictures here as to-day; there were not a fourth part as many American artists. The department of American water colors has been substantially created within ten years. The facilities for art education have been quadrupled within the same period, and the wealthy who form galleries have multiplied in like proportion. American progress in science and mechanism, though so great, falls short of American progress in taste and American productivity in the fine arts. PHILIP QUILIBET. SCIENTIFIC MISCELLANY. PROTECTION FROM LIGHTNING. Prof. Clerk Maxwell says that the ordinary lightning rod is a great mistake. It acts to discharge electricity from the clouds at all possible opportunities, but these discharges are smaller than would occur without the rod. The true method is to encase the building in a network of rods, when it will take its charge quietly like a Leyden jar. Taking the case of a powder mill, it would be sufficient to surround it with a conducting material, to sheathe its roof, walls, and ground-floor with thick sheet copper, and then no electrical effect could occur within it on account of any thunderstorm outside. There would be no need of any earth connection. We might even place a layer of asphalte between the copper floor and the ground, so as to insulate the building. If the mill were then struck with lightning, it would remain charged for some time, and a person standing on the ground outside and touching the wall might receive a shock, but no electrical effect would be perceived inside, even on the most delicate electrometer.