THE BOULEVARDS. 



133 



and for lining tanks and ponds, and about half an inch for 

 the ground line of brickwork to prevent the damp from 

 rising. An asphalted surface admits of easy repair. By 

 placing hot mastic on the places requiring it, the faulty- 

 part may be cut away and the edges cut square^ when the 

 hot material will be found to adhere to them if they are 

 perfectly free from damp or moisture. 



The great secret,, then^ in obtaining a perfect layer of 

 asphalte paving, dry, hard, elastic, warm, and durable, is 

 first to employ only the natural material, such as that from 

 Pyrimont-Seyssel ; and secondly, to provide a firm, dry sub- 

 stratum of concrete for it to rest upon. For pavements, 

 terraces, &c., nothing can be better. It is always warm 

 and elastic to the tread ; there are no joints to encourage 

 the accumulation of filth or the growth of weeds; and in 

 case of rain it dries in a few minutes. As laid down by 

 the Seyssel Asphalte Company, its durability is immense. 

 The whole of the quadrangle in Trafalgar-square has been 

 laid with asphalte since 1863, and yet there is no sign 

 of wear upon it, in spite of the enormous traffic. The 

 terrace at Bridgewater House is also an excellent specimen. 

 If the reader desires to see a really bad example, he has 

 only to examine the pavements of some of the metropolitan 

 stations of the Midland Railway to see what badly-laid 

 asphalte made of improper materials is capable of be- 

 coming, in the course of even a few months. 



For roadways and carriage drives asphalte does not seem 

 so applicable. In dry weather it is all well enough^ but 

 after rain, more especially if there is any mud about^ it 

 becomes disagreeably slippery both for horses and foot pas- 

 sengers. For laying between the courses of brickwork to 

 prevent the damp from rising, it is unequalled, a layer, even 

 only one quarter of an inch thick, keeping all damp down 

 most effectually. It is especially fitted for this purpose in 

 the case of boat houses built by the sides of rivers or lakes. 

 For ornamental ponds and banks it is also excellent^ but it 

 should be roughened for, say, a foot in depth, so as to hold 

 sufiicient soil or mud to grow water plants and weeds, and 

 so entirely conceal its existence. As to its cost, in England 



