No. 144.] 79 



in case of a leak. Another precaution is taken for the easy re- 

 moval of the foundation, by placing opposite to every house, over 

 the connecting point of the lateral with the service water pipe, 

 cast iron boxes filled with concrete, having, for the facility of lift- 

 ing them out, two wrought iron ringbolts set equi-distant through 

 them. Nine years of experience has proved that every leak has 

 been discovered through these means over the exact place where 

 such leak has occurred, which could not have been the case had 

 th« foundation been of concrete unbroken in its bond from curb 

 to curb. The foundation being thus perfected, a superstiucture 

 of rectangular blocks of trap rock (not granite), from three to 

 seven inches in width, from five to fourteen inches in length, and 

 of a uniform depth of four or six inches, is then to be laid there- 

 on, at a right angle with the line of the street if it is a great public 

 thoroughfare; although this mode of laying the blocks will not 

 last as long as when laid diagonally, still the advantages for the 

 sure-footedness of horses more than counterbalances the lack of 

 economy ; but the extravagance of this mode of laying has yet to 

 be proved, for by cutting the blocks four inches in depth, instead 

 of eight, as are row used, the blocks will be full on every joint ; 

 therefore, when the first surface has been rounded up by wear, 

 they can be reversed, the base forming, at a cost of not more than 

 twenty cents per yard, as good a pavement as the first ; that being 

 worn a'.vay, the sides, and finally the ends, maybe made of equal 

 value as a travelling surface, making from one set of blocks six 

 separate and distinct pavements. This may be considered as the 

 best, most durable, and consequently most economical pavement 

 that can be adopted for the service or use of a crowded thorough- 

 fare. 



For lateral streets, where no such continual and heavy travel 

 occurs, the concrete foundation may be dispensed with ; it would 

 be an unnecessary expense, as the blocks, cut full at every joint, 

 and six inches of uniform depth, could be made subject to the 

 same change of surface as before mentioned, with the undoubted 

 certainty of lasting much longer. 



