ART OF BUILDING. 



bricks should be applied gradually, till it attains its great- 

 est height, because a sudden application would cause the 

 bricks to break as they are bad conductors of heat. 



Bricks are of several kinds, as rnarls, stocks, and place. 

 The finest marls are called Jirsts, and are used for arches; 

 the next best are called seconds, and are used for fronts. 

 Stocks are similar to seconds, and are used for the same 

 purposes. Place- bricks, samel or salmon, are such as 

 were on the outside of the kiln, and arc not thoroughly 

 burned, consequently are pale and soft. There are also 

 burrs or clinkers, which are such as were too violently 

 burned. 



There is another division of bricks founded upon a 

 difference in the manufacture, viz. pressed and impressed, 

 or common bricks. 



Pressed bricks are such as after being partially dried, 

 are subjected to mechanical pressure, and then are 

 burned, which increases their density und beauty. 



The use of bricks in constructing buildings is of the 

 highest antiquity. The Jirsl bricks made by man were 

 rude masses of clay, hardened in the sun ; afterwards, 

 they were regularly shaped. The tower of Babel or 

 Belus, was built of sun-dried bricks. The ruins of Babylon 

 are of the same material. The ruins of a pyramid near 

 Grand Cairo in Egypt, erected by Asychis, is of unburnt 

 bricks. The ancient Greeks and Romans used the 

 same material in their edifices the walls of the 

 temple of Jupiter and Hercules the palace of Croesus 

 at Sardis, &c. Augustus (wasted that he found Rome 

 of brick and left it of marble. The Roman bricks were 

 square and triangular, the last being just half of a square 

 one cut, diagonally, and formed the outsides of the walls, 

 the square ones being laid diagonally across the thickness 

 of the wall. 



Mortar. Mortar is made of quicklime and sand, each 

 of which we shall describe. 



Lime is the soul of masonry, and is the principal sub- 

 stance used for joining stones and bricks together in the 

 construction of masonry. 



Quicklime is obtained by the calcination of limestone, 

 the heat driving off the water and carbonic acid. 

 Limestone is generally contaminated with alumina 



