140 THE TARKS AND GAIJDKXS OF PARIS. [Chap. IX. 



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 substratum of concrete for it 

 to rest upon. For pavements, terraces, etc., 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 1868, and yet there is no sign of wear upon it, in spite of 

 the traffic. 



After rain, asphalte (more especially if there is any mud about) 

 becomes disagreeably slippery both for horses and foot-pas- 

 sengers. Therefore it is necessary to keep it thoroughly clean. 

 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 efi'ectually. 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 sufficient soil or mud to grow water-plants and weeds, 

 and so entirely conceal its existence. 



During the last few years the preparation of the asphalte in 

 Paris has been much improved. Some years ago, when a pavement 

 was to be made with bitumen, a great nuisance was experienced 

 by the public during the operation. The mastic was liquefied on 

 the spot, and produced a nasty smell and smoke, disagreeable and 

 injurious ; but now some of these inconveniences have been done 

 away with by a new system, and asphalte is laid down in the 

 most expeditious manner. It is prepared first in out-of-the-way 

 places devoted to the purpose, and the material, ready for use and 

 liquefied, may be transported from these places to any parts of the 

 town without the least inconvenience in a semi-cylindrical boiler, 

 closed by iron doors, and moved about on iron wheels as freely as 

 a common cart. Under the boiler is a fireplace, and the blaze, 



