=Evolution in Lamps.=--The story of lamps from Herodotus down to 1830, Mr. Henry C. Mercer says, in an instructive study on Light and Light Making in the contributions of the Bucks County (Pa.) Historical Society, is not one of development. In principle and form they remain the same, whether as the tin cylindrical or boat-shaped cups on candlestick pedestals and the round tin cups with hemispherical lids, or the lidless cups resting on wooden stands such as were recently rescued by the author from the garret rubbish of old Bucks County. And before Herodotus, as we follow the lamp back into the tombs of the Old World, we find the boat-shaped form of earthenware preceding the boat-shaped form of iron and possibly even that of bronze. The chalk-cup lamp found by Canon Greenwell in the neolithic flint mines at Grimes Graves, England, perhaps the oldest wick-floating lamp in the world, is not essentially different from the oyster shell filled with lard and provided with wicks that may be found among Virginia negroes to-day. The Egyptian, Grecian, Phoenician, and Roman lamps, as they have been found in the tombs and as we see them in the museums, are not unlike the lard lamps that were most in use early in the nineteenth century. Then crude grease gave way to sperm oil and lard oil, with especial adaptations of the lamps that made them more convenient and improved the light; and burning fluids that were convenient and clean and gave a brilliant light, but were dangerous; and kerosene, with other improvements in the lamps and refinements in the oil that enabled it to give the most perfect artificial light yet found and to keep up the fight for quality with gas and electricity--all these having come in within the life-time of men still among us. Besides the old lamps, our ancestors had candles, molded when the price of tin, the material for the molds, did not forbid the luxury, and before them tallow dips; a suspended wick was dipped into a pot of hot tallow, on a cold day, and the operation was repeated till layer after layer of grease hardened, and the candle was thick enough. These candles were, however, troublesome in hot weather, on account of their propensity to yield to the temperature and fall over. "Who shall say, however, that candle-dipping is older than molding, when we know ... that they molded candles in County Galway, Ireland, in late years by punching holes in peat and pouring in tallow on the down-hung wick of twisted flax fiber?" The Irish had, too, as had the negroes, the rush light, a greased rush set in a hole in a wooden block serving as a candlestick; or rushes joined in a triple twist which flies apart when lighted, increasing the blaze. From this Mr. Mercer passes to forms of candlesticks and torches and cressets and methods of producing fire, whither we can not follow him, for the multitude of details he notices, which will not bear abstracting.