The use of paving brick is now mainly a question of freight. The weight of 1,000 pavers is so large, from four to six tons, that a long haul greatly increases their cost. The use of brick is, therefore, largely confined within a moderate radius of where suitable clays occur. Thus, New England, with its great wealth and dense population, has used comparatively little brick on account of the excessive freight, while local macadam is usually good and cheap. The state of Ohio, on the contrary, with its great abundance of suitable clays, has scarcely a town of 500 that has not at least paved its main street with brick. Vitrified brick is now exclusively employed in many of the larger cities for sewers, for which its exceptional hardness pre-eminently adapts it, while its use is steadily growing among our more advanced architects for the exterior of buildings, for under skillful handling it lends itself readily to picturesque effects which not only do not fade, but remain clean-a feature that is so rare in any other building material in our western cities. Very recently a careful comparison was made in Indianapolis (see CLAY-WORKER August, 1909) of all the various paving materials to find the one most suitable for a speedway for automobiles. After elaborate tests, in which no expense was spared, it was found that vitrified brick was the best. The decision is too recent to have the great influence that it at least prognosticates for the industry. For, with the very rapid growth in the use of the automobile and its increase in power, the enormous mileage of macadamized roads that this popular machine has developed will largely give way to brick, for the modern automobile is found to rapidly wear and heavily cut into even well maintained macadam roads. The writer takes this opportunity to express his thanks and appreciation to the many engineers who favored him with local data and their personal experience. St. Louis, Oct. 11, 1909. H. A. WHEELER. HISTORY OF PAVING BRICK. Brick for street paving has been in use for more than a century in Holland, where the absence of natural paving material developed a very durable quality of paving brick by mixing the fine river silt or mud with sand. The village of Moor, on the river Yssel, is especially famous for the excellence of its brick and the magnitude of its paving brick industry. To a much less extent and for a shorter period, they have been used in northern England, especially in Staffordshire and Leeds; under the name of "blue brick" and "terro-metallic ware," where their application is restricted more to stables, chemical works and similar places where a non-absorbent brick is desired. When the clay is not readily fusible, slag, mill cinder, or chalk dust is added in English practice to secure the fluxing or vitrification that is so essential in this class of brick, Paving brick was first used in the United States at Charleston, W. Va., in 1870, a town of 12,000, where a small section was laid as an experiment. This proving satisfactory, a block of one of their principal streets was paved in 1873, in grading for which it was necessary to take up the small section laid in 1870. This is still in use, although laid on a poor foundation of boards, and while the street has been repeatedly torn up for laying pipe, etc., it is still in fair condition after thirty-five years' service. A sample of this brick kindly sent by the city engineer, Mr. W. A. Hogue, shows it to be a side-cut, repressed, hard burned building brick of high density, Development Development in the United or 2.48, and it absorbs 4.5 per cent on soaking twenty-four hours. Bloomington, Ill., a town of 26,000, laid an inferior paving brick in 1875, on one of their principal streets that lasted twenty years before it was replaced by a high grade shale paver. A sample courteously forwarded by Mr. W. P. Butler, the city engineer, shows that it was made from a very poor glacial clay by the "slop" process (or from a very soft mud) by hand and was not repressed. It shows an absorption of 4.33 per cent after twenty-four hours immersion, it had a density of 2.11, which is very low, and it showed a wear of 1 to 11⁄2 inches. St. Louis put down three trial lots of brick paving in 1880, one of which was the result of experiments dating back to 1873, the Sattler brick. They all proved failures, from being either too soft or too brittle, although they were laid on a poor foundation. Another lot of the Sattler brick was tried in 1881 that was successful, but the maker was unable to furnish a uniform, reliable brick, as he used a fireclay that was too refractory, besides having other manufacturing difficulties. These failures made such a bad impression on the city authorities, although made in the infancy of the industry and before any first-class pavers had been produced in this country, that no further effort was made to use brick until 1895. Since then brick has not only become very popular, but today is used almost exclusively on the residential and semi-business streets and alleys. Wheeling, W. Va., put down an impure fireclay paving brick in 1883 that was so successful as to make this one of the important pioneers of the paving brick industry, from the confidence it inspired; some of these brick are still in use, although most of them were renewed after twenty years. Decatur, Ill., also put down a vitrified brick this same year that was made from a glacial clay, which is still in use after twenty-six years' service. Galesburg, Ill., the nestor of the shale brick industry, laid the first shale paver in 1884, on their principal street, where it is still doing excellent service. The year 1885 witnessed the first substantial increase in the use of vitrified brick, as during that year it was laid at Columbus, Zanesville and Steubenville, Ohio, and Peoria, Ill. Since then its use has steadily forged ahead, although at first the progress was slow. As the accumulated experience of brick pavements in actual use grew more favorable and more voluminous it developed confidence in the new material. Finally the ability to secure a strictly first-class, durable, low maintenance pavement at a moderate cost appealed so strongly to cities of the second class and large towns that a regular boom developed by 1895. There were over 175 plants devoted to vitrified brick, some of which had outputs as high as 50,000,000 to 100,000,000 brick annually and with plant investments as large as $500,000 to $1,000,000. The expanding markets and high prices that resulted from the boom enticed many small plants to abandon the building brick trade and enter the paving brick market, especially if shale was available, as at first too many thought that any shale would answer. Many of those plants were inadequately equipped to produce a good grade of vitrified brick, while others used a clay from which it was impossible to make a tough paver. Still others crowded their plants and shipped out as No. 1 pavers anything that was harder than a salmon brick and not warped beyond recognition. When the boom subsided it had the wholesome result of putting many such plants out of business; others went back to their former legitimate business, while others were ab Growth. Misconception of the Term. sorbed by the larger plants, where the clay had proven satisfactory. By 1894 vitrified brick had so favorably impressed the city engineers that in a canvass of the new pavements specified that year in thirty-two leading cities, 44 per cent of the new work was to be vitrified brick, 32 per cent macadam, and 24 per cent asphalt. This was certainly a very flattering lead over its two great rivals, and especially over macadam, its much cheaper competitor. While the very large cities, with their characteristic conservatism, were slower in adopting brick, most of them have since used it, if within reasonable freight haulage, for the alleys, for the residence streets and for the semi-business streets. A few efforts have been made to lay it on the downtown, heavy traffic streets, where granite or similar tough stone is usually employed, as it is so much less noisy and smoother than stone blocks.* While it has not the durability of the granite, its compensating advantages are regarded by many as sufficient to justify its occasional renewal, especially as the first cost is usually about half. The railroad engineers have shown the highest confidence in the ability of vitrified brick to successfully resist the heaviest traffic, as it has been most extensively used by them for paving freight yards where the teaming is usually of the heaviest nature. They usually draw specifications, however, that admit only the highest grade of brick or block. DEFINITION OF THE TERM VITRIFIED BRICK. *A noteworthy example of vitrified brick under very heavy traffic is the block on LaSalle street, opposite the court house, in the heart of Chicago, which was laid with Purington brick in 1894, of the standard or small size; after fifteen years' service, this pavement is still in fair condition. |