In continental Europe and Canada, extra precaution is necessitated by the rigorous climate. In S. Russia, the plan shown in Fig. 46 is sometimes used. The beets are disposed completely below the surface of the soil, in a trench dug with sharply sloping sides. At about 15 in. from the bottom, is an openwork floor of reeds, on which the beets are piled to within a few inches of the level of the exterior soil. On the top, and following the apex of the heap, is laid a triangular ridge-piece _a_, for the purpose of facilitating evaporation. The whole is covered with a layer _b_ of straw and fine earth, the thickness of which is varied according to the indications of the thermometer _c_ placed in the center of the mass. Between the floor of the trench and the openwork floor is a space _d_, communicating with two vertical channels leading to the outer air, thus providing ventilation. The outlets of the channels can be opened and closed at will. The Russians also often employ regular cellars, as shown in Fig. 47. The structure consists of two stories, covered with a bed of earth, each furnished with a floor of hurdles or open planking, on which the beets are piled to the depth of about one yard. Lateral passages facilitate ventilation, and openings in the roof permit the heated air to escape. The cost of erecting these cellars is heavy, but there is great saving of labor in storing the beets, as it suffices to simply pile them up on the floors. Moreover, the arrangement permits the examination of the contents beyond the indications of a thermometer; and enables any portion to be removed, even during snowy weather. [Illustration: FIG. 47.--Storage Cellar for Beets.] =Alcohol from Beets.= Beets contain 85 per cent. of water, and about 10 per cent. of cane sugar, the remainder being woody fibre and albumen; cane sugar not being in itself fermentible,--as is grape sugar,--it has to be converted into "inverted sugar" by a ferment as yeast. Either the sugar beets may be mashed or the molasses which remains from the manufacture of beet sugar (as described in Chapter X). The conversion of the sugar into alcohol is effected in several different ways, of which the following are the principal: By rasping the roots and submitting them to pressure, and fermenting the expressed juice. By maceration with water and heat. By direct distillation of the roots. The first two methods are the best as by them the woody fibre of the plant which is non-fermentible is separated from the fermentible juice. In both the first and second processes the beets must first be entirely cleaned of adhering dirt, trash and clods of earth, and then rasped, pulped or sliced by certain machinery. =Cleaning.= Care must be taken in this operation that the beets shall be freed from small stones and adhering hard lumps of earth which would otherwise get into the rasping machinery to the damage and stoppage of the mechanism.