The site chosen, the next question is the arrangement of the buildings. It is very doubtful, where ground is not inordinately expensive, whether it is wise to erect drying-sheds over the pits. In case of fire, very serious damage is done to liquor and leather by the heat and burning timber. If the turret form of drier be decided on, strong foundations are required, and the ground-floor or basement is occupied with heating apparatus; and, on the other hand, the tan-house may be easily and cheaply covered with slated roofs, with sections of glass, to the north, if possible, like a weaving-shed, through which sufficient light for convenient work and cleanliness is admitted. The direct rays of the sun should be avoided, but in the writer's opinion the balance of advantage is largely in favour of a liberal supply of light. Iron roofs are unsuitable, since the moisture condenses on, and rusts them; and particles of oxide fall into the liquors, and cause iron-stains. Good ventilation along the ridge of the roof should be provided, wherever there is any steam or hot liquor used; or the condensed moisture soon leads to decay. As regards the general plan of the buildings, much depends on local circumstances; but as far as possible, they must be so arranged that the hides and leather work straight forward from one department to another with as little wheeling or carrying as possible; that the buildings where power is used be near to the engine, so as to avoid long transmissions, which are very wasteful of power; and that the different buildings be so isolated as to diminish the risk of the whole being destroyed in case of fire. As regards the first of these conditions, if the various soaks, limes, bates, and handlers are well arranged, it is hardly necessary to do more than draw the goods from one pit into the next throughout the whole of the process. To, and from the layers, the goods must generally be carried or wheeled. In the sheds, if it be a sole-leather tannery, the butts should first come into turrets or open sheds for the rough drying; then into a room sheltered from draughts to temper for striking. The striking machines or beams should be in an adjoining room, or immediately below; then a small shed-space for drying before rolling; next the roller room; and then the warm stove for drying off. If two of these can be provided to be used alternately, it will allow the goods to be aired off without taking down, and they may then be immediately handed or lowered into the warehouse, without fear of over-drying, which is sometimes difficult to avoid where leather must be taken direct out of the hot drying-room.