230 BOARD OF AGRICULTURE. 



especially in what is now France ; the others are named from their 

 inventors, two distinguished modern road-builders of England. 

 In the Scottish Highlands alone Mr. Telford built some 800 miles 

 of his road. It was over such roads as were built by Telford and 

 • Macadam that the driver of the renowned English coach, before 

 the advent of the railway car, was able to make his one hundred 

 miles and count it only a fair day's work. It was in the transpor- 

 ■ tation of travelers over such roads, that the Aldgate widow, with 

 her too horses constantly employed, and her 1400 beds in hotels 

 along the way, achieved fame and fortune, demonstrating the 

 ability of woman to manage successfully a vast and intricate busi- 

 ness. 



Ill making the concrete road covering, a layer of perfectly 

 slaked lime, about six inches thick, is first provided ; before this 

 hardens a layer of pebbles, some three inches thick, is added, and, 

 in due season, another similar layer of pebbles. Broken stone is 

 much better ; but, with the help of the lime in binding, natural 

 pebbles and a certain amount of perfectly clean sand may be 

 successfully used. Travel soon compacts the whole into one solid 

 mass. This road should fiad favor along the coast, where lime 

 can be so readily obtained and wave-screened pebbles abound. 

 In many localities it would prove a cheap road. 



In making a macadamized road covering broken stone is em- 

 ployed, for smooth pebbles, when thus used, will not bind. It is 

 important that the pieces of stone be nearly cubical. All splinters 

 are rejected. The rule is that the weight of the largest pieces 

 should not exceed six ounces ; for the smaller the fragments the 

 more quickly they will bind. Yet the opposite extreme must be 

 avoided ; for, if the pieces of stone are very small, they will be 

 sooner worn to dust. The tougher the stone the better ; it may 

 be broken finer, and so bind quicker, while it will wear longer. 

 Of this broken stone, there is first put upon the road-bed a layer 

 some three or four inches thick ; after this layer has become par- 

 tially compacted by travel or by the pressure of heavy rollers, a 

 second similar layer is added, and sometimes a third, until the 

 stone covering acquires a depth of seven to ten inches. In a 

 short time, indeed very speedily, if rolled, this broken stone, with 

 its many sharp angles, becomes thoroughly compacted and water- 

 proof. 



The telfordized covering differs from the macadamized in this 

 important particular : The road-bed is first paved with wedge- 



