obvious, that square paving-bricks of a proper dimension and equal, will stretch themselves over half of those conduit-bricks, quite round; very aptly taking in the half of 4 bricks. And so they cover the whole floor. These must be laid too with good cement to keep the steam in, and thus you finish the floor of a room, handsom and useful. The heat of a furnace or chimney properly plac'd, is by this means drawn in an equable manner quite thro' the whole floor of the room, and may be convey'd upwards too by the sides of the room. Whence the air of the room is kept in what degree of warmth we please. The lines drawn upon the bricks are made with a tooth'd bit of wood, for no other purpose than to roughen the surface, that the mortar may take the better hold, and confine the steam. These bricks are found in innumerable Roman citys, towns and villa's in Britain. My Lord Hertford has of them, among his antiquities, found at Froxfield in his neighborhood.
For exercise, I must recommend it with the greatest earnestness. All podagrics must have a very particular regard to be constant therein and practise it dayly. All the antients, the easterns, the Greeks, Romans, &c. set apart a certain quantity of time every day, as regularly for exercise as for
