Page:Popular Science Monthly Volume 81.djvu/187

Rh A sheet asphalt pavement was laid in 1879 of Trinidad asphalt, on Vermont Avenue in Washington, between H and I Streets. This pavement is still in existence, and during that period has cost only in the neighborhood of ten cents a square yard, for maintenance for the entire period. It is apparently good to-day for ten or fifteen years more. This street is one of very moderate travel, delivery wagons and pleasure vehicles, and being very broad, over 100 feet, this is well distributed The pavement is typical of what Trinidad asphalt will do under such conditions for a long period of time.

Another striking piece of Trinidad sheet asphalt pavement is that on Fifth Avenue in New York, between 10th and 59th Streets. This was laid under the personal direction of the writer in 1896 and 1897, and has

withstood the very heavy travel which Fifth Avenue carried in a most satisfactory way for fifteen years, the number of vehicles passing any one point, when the travel is the greatest, being at the rate of as high as 14,000 in ten hours. No other smooth surface pavement in any country has withstood the conditions existing on Fifth Avenue with an equally satisfactory result.

The third type of Trinidad sheet asphalt pavement is that found on the Victoria-Thames Embankment in London, the first portion of which was put down by the writer in 1906, upon old macadam and a course of Trinidad asphalt concrete. Much the larger portion of the embankment has since that time been paved with this same form of construction, other forms having been removed in the meantime as unsatisfactory and replaced by it. The surface of the Embankment is rarely dry from November to April, and it carries the very large traffic which