Several years ago I placed some barrels of early Ohio potatoes in the Kansas City cold storage warehouses from March till July. They were kept in a temperature of 38 degrees, and came out crisp and very little sprouted. The plan of this structure was very simple: a three-story brick building so lined with matched lumber and tarred paper as to make three air-spaces around the wall. In the top story was a great bulk of ice, which was freely accessible to the air that, when cooled, passed through ducts to the different "cool rooms." The results were satisfactory, but the system seemed too expensive for potatoes. I have wondered whether it was necessary for potatoes to be kept as cold as 38 degrees. Would not a current of air passing through pipes showered with well water keep them cold enough? Wine vaults, I believe, are sometimes cooled by air currents forced through a cold water spray. If the air blast of well water temperature would be sufficient, the apparatus for producing it would be comparatively inexpensive--or at least much cheaper than those plans of cold storage where ice is stored in quantity over the cool room. However, any process that could be devised would probably be unprofitable to the small cropper, and the larger the business done, the less the cost per bushel. If it should be found that individual operators could not reach such an improvement on a profitable scale, why could not several of them pool their issues sufficiently to build, jointly, a potato elevator? There are at least 50,000 bushels of potatoes held in store by farmers within three miles of where I live. It seems to me there would be many advantages and economies in having that large stock under one roof, one insurance, one management; on a side track where they could be loaded in any weather or state of the roads, besides the great item that the temperature could be controlled, by artificial means, in one large building much cheaper than in several small ones. EDWIN TAYLOR. Edwardsville, Kans. * * * * * [KNOWLEDGE.] A FIVEFOLD COMET. The figure illustrating this article is taken from _L'Astronomie_, and represents the remarkable southern comet of January, 1887, as drawn on successive days by Mr. Finlay, of Cape Town. The comet was first seen by a farmer and a fisherman of Blauwberg, near Cape Town, on the night of January 18-19. The same night it was seen at the Cordoba Observatory by M. Thome. On the next Mr. Todd discovered it independently at the Adelaide Observatory, and watched it till the 27th. On the 22d Mr. Finlay detected the comet, and was able to watch it till the 29th. At Rio de Janeiro M. Cruls observed it from the 23d to the 25th; and at Windsor, New South Wales, Mr. Tebbutt observed the comet on the 28th and 30th. Moonlight interfered with further observations.