Brickwork. Brick in common use has far greater resistance to fire than has stone and is for that reason, if for no other, better adapted for use in the construction of" warehouses, common buildings, chimneys, and for many other purposes in building and engineering work.

Brick is used more than any other building material, except wood, though it appears that concrete sometime will take first place. For a better grade of work face brick is used, but while it is much finer in appearance, it does not stand fire, being speedily destroyed if exposed to a great heat. It is made in innumerable designs, and in a great variety of colors, and is principally used for the face walls of buildings, and for decorative purposes in the interiors of large rooms, armories, libraries, etc., where the effect of a brick wall is appropriate.

Fig. 10. - Inside Open Drain.

Fire brick should be used where great heat is to be resisted.

A good brick for general use should give a clear, ringing sound if struck with a hammer, and if soaked for twelve hours should not absorb more than 10 per cent of its weight in water. In laying brick the joints should be level and plumb, and not more than 5/16" thick. Upon the best work, it is the custom to make a shove joint, that is, the brick is bedded in mortar, and shoved against the one next to it, thus filling the vertical joint; upon common work, the brick simply is bedded, and the plumb joints partly filled with the cleanings from the outside of the wall and with mortar from the bedding of the next course.

Mortar for brick laying should be mixed in the proportions of one of lime to three of sand, though this will vary according to the strength of the lime.

In building thick walls, piers, etc., grouting is sometimes done; this consists in laying the outside walls in mortar or cement, the inside being filled with "bats" or pieces of brick, and in pouring in after every second or third layer a thin mixture of mortar or cement over the inside courses. If the bricks are thoroughly wet before laying, and if the work is done well, satisfactory results may be obtained, though otherwise this method is worthless.

Bricks should be sorted for colors in fine work, and the poorer colors and quality used where they will be less conspicuous. Decorative effects are often obtained by laying the different colors in surface design.

If bricks are laid in very dry weather, they should be thoroughly wet before laying, for if laid dry, they absorb the moisture of the mortar before it has time to set.

It is not wise to lay brick in very cold weather, for if the mortar freezes the work will be worthless. It is sometimes necessary to lay brick in winter, in which case everything should be heated, and the walls should be kept covered, to hold the heat as long as possible, so that the mortar may set before it freezes. This is sometimes satisfactory, but the result is always doubtful.