PAVING. 53 



bricks ; the straw resting upon the several raised surfaces, 

 allows the urine to be drained from beneath it, and a less 

 amount of material, it is claimed, is necessary, than is often 

 put down upon a slippery pavement, to render the foothold 

 less uncertain. The gutter brick. 

 Fig. 33, is laid in conjunction with ■^^'^• 



this paving ; but the slope given to 

 form the channel should be suffi- 

 cient, with a flat surface between *Jv'"'^T^ ^^--^^^ 

 the excrescences, to form a good 

 open surface gutter, without the 

 deep and narrow groove, which it may be found difficult to 

 keep clean and free, and was objected to so strongly in the old 

 form of cast-iron gutters. This paving has only been lately 

 used ; but in the stables where the author has examined it, 

 the opinion expressed by the grooms of the ease by which it 

 can be kept clean is in its favour. It may be added that it 

 has taken the Silver Medal at the International Inventions 

 Exhibition, and the Gold and Silver Medals at the last two 

 Architectural Exhibitions. Twenty-six will pave i yard. 



Blue Staffordshire paviors, also known as vitrified or metallic Vitrified 

 bricks, are made with one, two, and three transverse V-shaped bricks. 

 grooves, and one longitudinal groove in the centre, thus a brick 

 9 inches by 4J inches is divided into 4, 6, and 8 panels ; they 

 are also made with a single transverse groove across the centre, 

 as shown in Fig. 2, Plate 14, giving two panels to each^ and of 

 sizes varying from that of a clinker to 14 inches by 9 inches by 

 4 inches. The following table (p. 54) gives those in ordinary 

 use, with the number required per superficial yard, and their 

 weights per 1000. 



Clinkers, 6 inches by 2J inches by if inch on the face, are 

 also made in this material, chamfered and plain, and a useful 

 size, 9 inches by 4J inches by 3 inches on the face, with 

 semicircular grooves. 



The bricks of this description, manufactured by Mr. J. 



