72 
Observations, tyc. 
[March, 
always commenced from the top downwards : and as the whole cannot be done at 
once, the edges of the first portions are bevelled or sloped, and made rough, on 
leaving off work, by which means the new cement applied next day is made to 
adhere. 
47. When the surface of a wall is to be stuccoed with cement, or the inside of a 
tank lined, or the outside of a casemated roof coated with it, before the usual 
mass of earth is applied, the joints of the brick work must be raked out, and if 
the surface be dirty, it must be well cleaned, and it should be wetted before the 
cement is applied. 
48. Cement in itself is porous, and will imbibe water, unless it be well worked 
up, and pressed in by the trowel, and the surface made quite smooth, which will 
render it sufficiently water-tight either for tanks or casemates, as has been proved 
by the efficient state of the great reservoir on the western heights of Dover, and 
by the dry state of a part of the casemates in Chatham lines, which since they 
have been coated with cement, have been used as powder magazines, although 
before this precaustion was taken, the upper story of those casmates was so damp 
as to be uninhabitable. 
49. Some persons doubt, whether cement, that has completely set, will receive 
a second coat of the same material. I believe that it is best to avoid this arrange- 
ment, if possible. Sometimes, however, it may become absolutely necessary, as 
was the case in respect to two small tanks, one executed at Dover the other at 
Chatham, neither of which, after being lined with cement of the usual thickness, 
would hold water. In both cases, a second coat of cement was applied either of 
a better quality or with greater care, which proved effectual. In applying a second 
coat of cement, under the above circumstances, I would recommend that the first 
coat should previously be roughed by a light pole pick. 
I T Very C ° at , ing ° f pUre ccment must be carefully protected from the sun, 
wh.ch has a tendency to cause the surface of it to crack, in the course of a few 
ays, after it has been applied. This precaution is unnecessary in respect to ce- 
ment stucco, of which sand is a component part * respect to 
terraces ‘ ° f “ k for flat roofs or flat 
tenaces or e, v aults. One instance has come to my knowledge where it has failed ■ 
dedde — * 
the Yorkshire cement rather lighter. Whc’n used ITefot 
to be coloured, to make them resemble stone. erefore, 
Cement Fronts. 
o3. It is understood, that different 
ing the cement fronts of buildings and that th ^ ^ ° lfferent wasbes for cover ” 
secret. The article common to airis wh^w keeptb - own mistum 
they add copperas to take off the dead white Tnd -ive^t^ qU1Ck bme ’ to which 
resembling stone ; and with the water thev us, mil brownish colour, more 
grounds, and sometimes of alum. The ’drv W a 7 ““ * proportion of beer 
mixed with tallow. Sometimes also cement fT , ^ SOmetimes previously 
Pound, under an idea, that it will cause the J 18 USed &S Part ° f the C ° m ‘ 
yellow ochre have also been observed amcLl^ ^ SCt ' L&mp bIack and sprUC8 
last mentioned substances are probably intl^d to v ’t ^ ^ ^ 
a resemblance of stone of different tint s . f d he C ° loUr > and t0 produce 
the joints, & c . of stone work. Somcf ° r §T6at pains is often taken to imitate 
resemblance to that of stone, is appliedhTthp" 6 * colour > hav mg a general 
whole surface. The latter method, as 
