in a press at this temperature and each block is subjected to a pressure of 120 tons. After leaving the press the blocks are gradually cooled in a water-bath, and are then ready for use.

In the earlier years of the industry blocks were made 4 × 5 × 12 inches. A depth of 5 inches, however, was considered to be unnecessary, and the present practice makes them of the same dimensions as above, except that the depth is 4 and 3 inches, the blocks weighing 13 and 18 lbs. respectively. These blocks are carried to the street and laid upon a base of either gravel, broken stone, or concrete, as the case may be.

The blocks are laid in practically the same manner as are bricks, the joints being filled with fine sand. The advocates of this system claim the advantage of uniformity in manufacture; that the materials are always mixed in exactly the same proportions and at the same temperatures; that the blocks are made under cover and are not subject to any differences on account of changes in the weather; also that, as the blocks are manufactured at one central plant, they can be used in cities of small size without the expense of the location of portable plants. These arguments are good, but, as all the material must be first transported to the plant and then the blocks carried to the place where they are to be used, the cost of this double transportation in some localities prevents them from competing successfully from an economical standpoint with the sheet asphalt. Wherever used, asphalt blocks have given satisfaction. It is claimed that they can be laid successfully on much steeper grades than sheet asphalt, and that, on account of their being so very solid and compact, they do not require as thick a concrete base as the sheet asphalt. On January 1, 1900, there had been laid in this country 1,655,532 yards of this class of pavement. Quite an amount also has been laid in South America, and some in Europe.

The cost of asphalt-block pavement varies with location of city, depth of blocks, character of foundation, etc.

For 4-inch blocks laid on natural-cement concrete 4 inches thick the price will range from $2.40 to $2.70 per square yard, and

for 3-inch blocks about 25 cents less.

Another form of asphalt blocks is sometimes used in which the broken stone is replaced by granulated cork. Such blocks were laid

on Fifth Avenue, New York, between Thirty-fourth and Thirtysixth streets, in strips ten feet wide, adjacent to the curb. The grade on these two blocks being somewhat steeper than the remainder of the avenue, it was deemed best to provide a better foothold for horses in slippery weather than the ordinary asphalt. The blocks are 2 × 43 × 9 inches and were set flatwise. This pavement was laid in the fall of 1897, and in the spring of 1900 was in very good condition. It cost $5.25 per square yard, exclusive of foundation, under a fifteen year guarantee.

Although very desirable for driveways and bridges, cork blocks can never be very generally used on account of their excessive

cost.

CHAPTER IX.

BRICK PAVEMENTS.

BRICK pavements have been used in Holland since the teenth century. In the seventeenth century the roads from Hague to the Scheveningen were paved with brick. These by were 73 inches long, 2 inches wide, and 4 inches deep. Holla having no natural material of its own suitable for pavements, fortunate in being able to make bricks out of the silt and depoof the river, which have been very successful in pavements. So stone has been used in the larger cities, most of it having be brought from Sweden. Amsterdam and Rotterdam at the prese: time use brick quite extensively, the former city having now abou 181,500 square yards. The life of the brick pavement there is sai to be on an average of from ten to twenty years. In Amsterdan it is generally used on one side for ten years, when the bricks are turned, after which they will last about four years, making a total life of fourteen years. The foundation is usually a bed of sand from 8 to 12 inches deep.

It is said that Japan has had brick pavements for more than one hundred years, and one authority gives the dimensions of the brick as 7 inches long, 4 inches deep, and 14 inches thick. Inquiry made of the authorities in Yokohama elicited the following reply:

"I have to say that the brick pavements in use in Osaka since very ancient times are composed of broken roofing-tiles set on end, usually obtained from débris of houses after conflagration. Heavy traffic quickly destroys these pavements."

England has never used brick to any great extent in pavements; but in Staffordshire so-called blue brick, described in detail in a previous chapter, are said to have been in use for about fifty years.

In the United States the first brick pavement was laid in

CHAPTER IX.

BRICK PAVEMENTS.

BRICK pavements have been used in Holland since the thirteenth century. In the seventeenth century the roads from the Hague to the Scheveningen were paved with brick. These brick were 73 inches long, 2 inches wide, and 4 inches deep. Holland, having no natural material of its own suitable for pavements, was fortunate in being able to make bricks out of the silt and deposits of the river, which have been very successful in pavements. Some stone has been used in the larger cities, most of it having been brought from Sweden. Amsterdam and Rotterdam at the present time use brick quite extensively, the former city having now about 181,500 square yards. The life of the brick pavement there is said to be on an average of from ten to twenty years. In Amsterdam it is generally used on one side for ten years, when the bricks are turned, after which they will last about four years, making a total life of fourteen years. The foundation is usually a bed of sand from 8 to 12 inches deep.

It is said that Japan has had brick pavements for more than one hundred years, and one authority gives the dimensions of the brick as 7 inches long, 4 inches deep, and 14 inches thick. Inquiry made of the authorities in Yokohama elicited the following reply:

"I have to say that the brick pavements in use in Osaka since very ancient times are composed of broken roofing-tiles set on end, usually obtained from débris of houses after conflagration. Heavy traffic quickly destroys these pavements."

England has never used brick to any great extent in pavements; but in Staffordshire so-called blue brick, described in detail in a previous chapter, are said to have been in use for about fifty years.

In the United States the first brick pavement was laid in