The Public Gardens and Parks of Paris. 105 



platform two iron bars of the same thickness as the asphalte is to 

 be, equally distanced from each other, and the asphalte is brought in 

 a very warm state, but thick enough to require some slight exer- 

 tion of the operator to make it level. This operation dons, a small 

 quantity of fine gravel must be spread upon the asphalte when hot, 

 and slightly beaten down to penetrate in it. This gives a greater 

 resistance and solidity to the footway, and insures its lasting for a 

 very long time. 



The roads before spoken of are made of the powdered asphalte. 

 The surface of the roadway must be beaten down very hard, and 

 covered at a thickness of about three inches with leton, well beaten 

 down and dry. If the dryness is very necessary in the making of 

 a pavement, this condition is of a greater importance for the road, 

 as, if the powder were spread on a wet surface, the steam caused by 

 the heat would produce a great quantity of little fissures, the elasti- 

 city would be destroyed, and the road would be useless after a few 

 months use. The luton well dried, the powder (hot) must b^ 

 spread about three inches thick ; and then proceed with the bsat- 

 ing. The sides must be done first, and pressed down with a rec- 

 tangular iron pestle eight or nine inches in length and two or two 

 and a half inches in width. When the sides are done, proceed 

 with the middle. The pestles used in beating are made of cast- 

 iron, and circular, with about eight inches diameter. The pestles 

 of either form are heated and used quite hot, so as to compress tha 

 asphalte into a hard smooth mass. When the crust of asphalte is 

 brought to the thickness required, and is sufficiently smoothed and 

 beaten hard, they spread with a sieve a little quantity of very fine 

 powder to fill all the unevenness, and again smooth the whole with 

 a flat piece of hot iron. The compression is completed by the roll- 

 ing of two cast-iron rollers, one of 4000 Ib. weight and the other of 

 3000 Ib. Sometimes three of these rollers are employed, and the 

 intermediate one is about from 1500 to 1600 Ib. weight. This 

 rolling is not always necessary, and in many cases the beating 

 down with pestles is sufficient. The roads thus made, completely 

 noiseless and lasting a long time, have been adopted with the 



