ARTIFICIAL STONE, OR CONCRETE 



sand, and expensive coloring-matter, as well as ex- 

 pensive cement, are used, would make the cost pro- 

 hibitory. But by " facing" his block, the manufacturer 

 is able to produce, without sacrificing quality, an article 

 at a nominal cost, which has a beautiful appearance, 

 and a dense and impervious surface. 



Sometimes a coating of plaster is laid over the fin- 

 ished cement surface, just as plaster is applied over 

 bricks or inside walls. But such troweled surfaces 

 have a tendency to crack and disintegrate, and are 

 distinctly inferior to faced concrete blocks, when the 

 outer surface is molded at the same time, and is of 

 similar material to the body of the block itself. The 

 mixture for the facing is made at the same time as that 

 for the body. If the bottom of the mold is to repre- 

 sent the face of the block a layer of the facing material 

 is first placed in the mold and the coarser mixture 

 added after. It is a common practice among the 

 manufacturers to make the facing mixture a little 

 dryer than that used in the body; but by capillary 

 attraction the moisture of the block becomes evenly 

 distributed throughout, and the concrete sets into a 

 block quite as homogeneous as if a single mixture 

 were used. 



UTILITY AND BEAUTY 



The advantage of such a block over brick or stone 

 is obvious. A material that can be made into any 

 size or shape, and of any color, which sets into a sub- 

 stance more resistant and enduring than most rock, at 



VOL. IX. 1 3 [ 193 ] 



