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Rh be concealed as long as possible, and unknowing visitors continue to go down as into a trap. "Not long ago," again says the "Lancet," "family after family went down to one of our [English] largest seaside towns, to be infected with scarlet fever, the existence of which at the place was carefully concealed." The dangers arising from imperfect sanitary arrangements at these resorts and in the lodging-houses have been much discussed of late, but the agitation ought to be kept up without intermission till they are all remedied. The question of drainage, which is a difficult one anywhere, is no less difficult at seaside resorts than at other places. The most natural measure is to carry the sewage to the nearest and most convenient spot at which it can pass into the sea, and this is often the place where visitors and loungers will be most exposed to its emanations. The case is still worse on lakes, for there the slowly moving water becomes charged with sewage; and cases of illness have been known to arise from boating in the neighborhood of the discharge-pipes. Many physicians have had experience with diseases arising from filth that have been contracted at the seaside, and cases of typhoid fever originating in such places have been noticed in England as well as in the United States. That sickness is not more general is doubtless due to the fact that visitors spend so much time in the open air. If they lived there as they do at home, they would, perhaps, find many of these places the reverse of "health resorts."

Rhythmic and Colored Lights for Lighthouses.—Sir William Thomson urges a threefold reform in the British lighthouse system, viz.: "A greater quickening of nearly all revolving lights; the application of a group of dot-dash eclipses to every fixed light; and the abolition of color as a distinction of lighthouse-lights, except for showing dangers and channels and ports by red and white and green sectors." He observes that, in revolving lights of which the period is ten seconds or less and the time of extinction seven seconds or less, the place of the light is not practically lost in the short intervals of darkness, the eye sweeping deliberately along the horizon to "pick up the light, passes over less than the breadth of its own field of view in the period of the light, and thus picks it up almost as surely and quickly as if it were a fixed light. Compass-bearings may also be taken with these quick-revolving lights almost as easily and accurately as if the light were continuous. The distinction by color alone ought to be prohibited for all lighthouse-lights, on account of its liability to confusion with ships' and steamers' side-lights. In place of color, Sir William would distinguish every fixed light by a rapid group of two or three dot-dash eclipses, the shorter, or dot, of about half a second duration, and the dash three times as long as the dot, with intervals of light of about half a second between the eclipses of the group, and of five or six seconds between the groups, so that in no case should the period be more than ten or twelve seconds. The Holywood Bank Light, Belfast Lough, until 1874 was inclosed in a red-glass lantern, was only visible for five miles, and was constantly liable to be taken for a sailing vessel's port-side light. In 187-1 the red glass was removed, and the light was marked by a dot, dot, dash (. . —, or letter U of the Morse flashing alphabet), repeated every ten or twelve seconds, and has been so ever since. It is now recognized with certainty as soon as seen in ordinary weather from the mouth of the Lough, ten miles off, and has proved most serviceable as a leading light for ships bound for Belfast or entering the Lough. Sir William Thomson's objection to colored lights is corroborated by Mr. J. P. Thompson, who relates, in a letter published in "Nature," how he narrowly escaped shipwreck off the Cornish coast by inability to perceive the red flashes of the "Wolf" light, which seemed to have been neutralized by the fog, or from the daze caused by the phosphorescence of the sea.

A Singular Root-Growth.—A correspondent of "Die Natur" describes a singular form of growth of fibrous roots, which he and his associates observed in opening one of the ancient-burial places, called cromlechs, at a town in the province of Posen, Prussia. Along with other objects usually found in such burial-places, they noticed several urns, filled with ashes, calcined bones, and sand, and all closed with a cover shaped