material must be obtained, having regard to expansion and contraction. The same material used for the bricks, &c., worked into a paste, must be employed for the joints. The design for a furnace on the principle shown at Fig. 10 must be prepared with constant regard to expansion and contraction in heating and cooling. Should this warning be disregarded, fractures will result. It will be seen, upon reference to the plans, that the block of flues and air spaces is left quite free, to allow of any expansion, the connection with the smoke-shaft being by means of an iron flue-pipe, which, being provided in considerable length before passing through the party-wall of laconicum and stokery, by its flexible nature permits any slight movement in a vertical direction. If an "expansion" joint were provided, there would be a sufficient length of iron pipe if it passed direct from the junction with the heating apparatus into the stokery. So much of the iron flue as is in the laconicum must be coated with asbestos or some composition, or the heating will not be wholly by firebrick. The junction of iron flue and heating apparatus is shown by a cast-iron cap sliding over a projecting rim of fireclay, moulded into the last quarry cover, similar to the way in which cast-iron mouthpieces are fitted to retorts. This heating apparatus is shown visible in the laconicum, but if thought desirable it could be screened by a wall of glazed bricks--9 in. and miss 4-1/2 in. The 4-1/2 by 3 in. holes can be arranged in diamond patterns. This screen wall, however, cuts off a large quantity of radiant heat. The first flue past the actual furnace--shown with ordinary dead-plate, raking fire-bars, ashpit, fire-door, and ashpit door for regulating draught--has walls 4-1/2 in. thick; above, smaller bricks, 3 in. wide; but in a larger apparatus, 9 in. and 4-1/2 in. respectively would be required. The quarries between flues and air spaces are 24 in. by 24 in. by 3 in., with rebated joints. Larger covers would be more liable to crack at any provocation. In addition to heating by means of furnaces, steam-heating may be employed, if found, as in many cases it would be, convenient and economical. The chief disadvantage of this method of heating Turkish baths, is the constant danger, however slight, of bursting a pipe in the heating coil, which, by immediately filling the highly-heated atmosphere with vapour, might prove most disastrous to the occupants of the hot rooms, who would be seriously scalded. Nevertheless, the principle has been largely employed in the heating of the most recent Turkish baths in Germany.