CO129-094 - Acting Governor Mercer - 1863 [11-10] — Page 198

in a

system of

sewers, are

the for

forms of

the

of

which they

several classes, the materials

are to be composed, and their relative areas.

64.

form of

The

egg shaped or oval is the

sewer proposed by the Committee,

31.

194

to the action of water. The upper part

should be covered with Concrete, and in no

case should Common Chinese Mortar be

such works

employed for

66.

Dressed

stone cut and well

fitted

would be

the side walls and

may at first

first be

and should be adopted for

adopted for the first and

second classes. There

some difficulty about skilled labor, but

can easily

that can e

65.

not well

be

overcome.

The ordinary Chinese brick is

fitted for heavy works of this

description; but if carefully built, with

really good

mortar, bricks might be

used where rapidity of Construction was an object: but in that case cement should

the lower parts, (inverts and

be used

for sides,) which

are

necessarily most exposed

preferable for

inverts, and the Committee believe would in

the end prove

Classes

more economical for

named

just

Great

the two

care must be taken in their

Construction, with reference to the pressure

to which they may

be liable, and to avoid

deposits in the Sewers themselves, the

fall of

of each individual sewer should be kept uniform throughout as far as practicable.

The areas of the various classes

68

must be based on

the

ate areas of aggregate