In 1870, Prof. E. J. Smedt, a Belgian chem ist, laid the first sheet asphalt pavement in this country, in Newark, N. J. Prior to this date coal tar had been used as the cementing mate rial, but with little satisfaction. In 1876 Con gress appointed a commission, consisting. of Gens. Horatio G. Wright and Quincey A. Gilmore, of the corps of engineers, and Edward Clark, architect of the capitol, to select the best pavement for Pennsylvania Avenue in Wash ington. Forty-one proposals for stone, macad am, tar and asphalt pavements were received. The commission selected two and decided to use Neuchatel rock asphalt and De Smedt's artificial Trinidad mixture, in the proportion of two to three. The artificial Trinidad mixture has been most satisfactory. When it was de cided, in 1889, to repave Pennsylvania Avenue in Washington, the entire avenue was relaid with it, and the Neuchatel was discarded.
Trinidad Pitch Lake has furnished over 85 per cent of the asphalt used in the United States. The liquid asphalt passing through clay saturates it or carries it in suspension and becomes a brown, earthy, non-viscous substance, chemically composed as follows: Bitumen 47 per cent Infusorial earth 28 per cent Water 25 pet cent The water is evaporated in refining and th residue (approximately one-third clay and two thirds hard asphalt) regains some of its vis cosity and requires the admixture of some flux or softening agent to give it the proper con sistency for paving operations. Samples taken at 100 and 150 feet deep at the centre of Pitc Lake do not differ in composition from those taken on the surface near the shore, showing the homogeneousness of the entire mass. The surface is in constant motion, and gradually lowers as the asphalt is removed. Refined as phalt is shipped from Trinidad to Mexico, South America and other foreign countries; but, owing to the very high duty on refined asphalt coming into the United States, it is cheaper to refine here.
In 1892 the New York and Bermudez Com the h pany began the importation of a very pure and hard asphalt from a deposit in the state of Bermudez, Venezuela. The Bermudez Asphalt Lake, covering an area of about 1,000 acres, lies about 20 miles from the Gulf of Paria, in a straight line. There are many springs of soft asphalt or maltha, the largest being about seven acres in area Outside of the springs, where new material is constantly exuding, the surface of the lake is covered with vegetation and trees, which must first be cut off to reach the asphalt. The quality of the asphalt varies from maltha or liquid asphalt exuding from the springs, to a hard glance pitch. The crude Bermudez asphalt contains on an average about 31 per cent of water, which is present as a mixture and not as an emulsion, and about 66 per cent of bitumen. This asphalt is softer and
more brittle than Trinidad, but possesses all essential cementitious qualities. In 1912 exten sive deposits of asphalt were discovered in Leyte, Philippine Islands, by a ranger of the Insular Bureau of Forestry. The products of these deposits are now being used in paving the streets of Manila and are also being exported to other points in the Orient by a strongly capitalized corporation.
As early as 1879 asphalt found in southern California was laid at an intersection on Mar ket Street, San Francisco, which is the heaviest traveled street in that city. In 1884 the late Jesse Warren reported on these California asphalts, the only indications of which were slight surface exudations of liquid asphalt and large banks of bituminous sandstone (sand sat urated with asphalt). In 1895 the Alcatraz Company successfully laid two streets in New York city and acquired a high standing for the California product which was subsequently con trolled by the Asphalt Company of America. It has been laid in many eastern cities under the trade name of cAlcatraz,p gStandard,"Ven tura,p etc., and has been uniformly successful when refined, mixed and laid intelligently by men experienced in handling asphalt in all its stages. Shortly after the organization of the Asphalt Company of America beds of very pure, high grade, liquid asphalt were discovered in southern California. This being a nearly pure, viscous bitumen, it does not require a softening agent or flux, nor the admixture of other bituminous material to make it of the proper consistency for paving.
Asphalt deposits have been found in many widely separated areas in the United States, but commercial production is limited to a few localities in six States, whose output for 1916 is shown in the following tables: Short tone Value California 18.135 Kentucky and Texas 37,777 132.984 Oklahoma 15.431 112,555 Utah and Colorado.. 27.'34 60.60 Total 98.477 $933,381 Within the past few years manufactured or oil asphalt has become an increasingly import ant part of the industry in the United States and in several countries of Europe. In the United States it is manufactured from certain grades of crude petroleum found in Colorado, Louisiana, Oklahoma, Kansas and Illinois. In 1907 the output of this artificial product for the first time exceeded the combined output of the natural varieties by a margin of over 52,000 short tons. Of late years Mexican oil has proved a strong competitor with our domestic materials, the asphalt product of such oils in 1916 amounting to 572,387 short tons, valued at $6,018,851.