4. The extreme dryness and heat of the climate in some of the eastern countries, rendered the application of fire dispensable; and there are structures of unburnt bricks still remaining, which were built two or three thousand years ago. Bricks both sun-dried and burned, were used by the Greeks and the Romans. 5. The walls of Babylon, some of the ancient structures of Egypt and Persia, the walls of Athens, the rotunda of the Pantheon, the temple of Peace, and the Thermæ, or baths, at Rome, were all built of brick. The most common bricks among the Romans were seventeen inches long and eleven broad; a size, certainly, far preferable, as regards appearance, to those of modern manufacture. 6. In the United States, a great proportion of the edifices, particularly in the cities and towns, are constructed of bricks, which are usually manufactured in the vicinity of the place where they are to be used. The common clay, of which they are made, consists of a mixture of argillaceous earth and sand, with a little oxyde of iron, which causes them to turn red in burning. The material for bricks is dug up, and thrown into a large heap, late in the fall or in the winter, and exposed to the influence of the frost until spring. 7. The operation of making bricks is conducted very systematically; and, although every part of the work seems to be very simple, it requires considerable dexterity to perform it properly and to the best advantage. The workmen, in the yards about Philadelphia, are divided into _gangs_ consisting of three men and a boy. The first is called the _temperer_, who tempers the material with water and mixes it with a spade; the second is called the _wheeler_, who conveys it on a barrow to a table, where it is formed in moulds by the _moulder_, whence it is carried to the _floor_ by the boy, who is denominated the _off-bearer_. 8. The bricks are suffered to remain on the floor a day or two, or until they have become dry enough to be handled with safety. They are then removed and piled into a _hack_, under cover, in such a manner that the air may circulate freely between them. It is the business of the whole gang to remove the bricks from the floor, and also to place them in the kiln to be burned. In both cases, each one has his due proportion of labor to perform. 9. The day's work of a gang, when the weather is favorable, is to make and pile in the hack a tale of bricks, which consists of 2332, or an even 2000. The former number is called a _long tale_, and the latter, a _short tale_. Considerable skill and much care are required in burning the bricks in a proper manner; too much fire would cause them to vitrify, and too little would leave them soft, and unfit for atmospheric exposure.