J30 New Method of maling Cement fir Terraces, ^c. 



add pebbles fomewhat larger than tbofc employed in the pre- 

 ceding cement, and increafe the dofe of lime in proportion : 

 ■the cement nuift then be beaten with clubs like thofe ui'ed for 

 fmoothing the walks in the neighbourhood of Paris. Tt is 

 then to be left to dry for a month, after which the furface of 

 it mult be moiltened with milk of lime; and the bricks are 

 to bo placed with good lime and fand. 



It is iwt neceflary that thcfc bricks ftiould be ground. I 

 have obferved that, by cutting, their ftrength is Icffened, as 

 it deflroys their upper half-vitrified furface: nothing then 

 remains below but an earthy furface, which is foon pene- 

 trated by moifture, and which is eafily deftroyed by froft. 

 Care mud be taken to fill up the joints with good mortar, 

 which mu.c be prelled in and fmoothed by the trowel, and 

 then pitched. 



Terraces conftruftecl in this manner fuffer the water for 

 fome time to filter through them in fmall quantity. This 

 water charged with calcareous particles ftops up the pores of 

 the cement; no more filtration takes place; and terraces o[ 

 this kind have the greateft folidity, and are exceedingly cheap. 

 This cement may be employed with advantage for the interior 

 of apartments ; it alfo may fupply the place of pavements of 

 cut bricks, and cofts two-thirds lefs. 



It muft be fpread over a pavement of rough bricks, or 

 bricks picked with an inftrument, to the thicknefs of an inch 

 or nine lines. The pebbles may be omitted, and their place 

 fupplied by fragments of tiles and iron fcales coarfely pound- 

 ed : it is tlicn to be prcfled dovi'n and fmoothed with flat 

 ftones, but before it is painted it muft be fuifered to dry for 

 a month. It is painted and waxed in the fame manner as 

 brick pavement. 



Such are the details of the cement T have emploved, and 

 which has been attended \\\\.h. complete fuccefs. But I fhall 

 here repeat, that the dofes muft be varied according to the 

 p-reater or lefs purity of the lime and of the oth^^r matter^ 

 emploved; and the application of pitch is merely to prevent 

 the infiltration of water, and the dcfiruftion of the cement 

 by froft. 



XXI. A 



