certain precautions may well be taken. The walls should be of terra-cotta or brick, and of a good thickness. The inner walls should be taken from the basement up to, and through, the roof, so as to divide the building into as many separate portions as possible. The book stores should be built in a series of rooms rather than in one large room, and all rooms should be separated by double iron doors, or, what is even better, thick doors of oak covered on either side with iron plates, with a space the thickness of the wall between them. The iron or steel girders and ties used in construction should in all cases be covered with terra-cotta or fireclay blocks, to keep the direct action of the flames from them. Due provision must also be made for their expansion under the influence of heat, for if this is not done, it is probable that, in case of fire, the outside walls would be pushed outwards, and the whole structure collapse. One of the many different methods of making concrete floors should be adopted for all floors and ceilings. Wood and felt should not be used in the roof, but iron, and some un-inflammable non-conductor. In large libraries the heating apparatus, refreshment rooms, mess rooms for the staff, engines and boilers for the production of electric light, &c., should be separate and distinct from the main building, and connected with it only by corridors with iron doors. All wood used in construction should be chemically treated, and if dust-blinds are fitted to the bookcases, they should undergo a similar
