State board of Health, 
279 
Whatever difference of opinion may e^tist regarding the size and 
shape of sewers and the manner of their construction, all agree that 
the materials should be such as to prevent the escape, not only of 
the liquid portion of the sewage, but more especially of that sub¬ 
tle, deadly poison — sewer gas. 
Formerly sewers were built much larger than was necessary to 
meet the ordinary requirement, in order to guard against obstruc¬ 
tions. Experience has proven, however, that all unnecessary size, 
above the requirement of capacity, is actual injury, since it greatly 
diminishes the scouring power of the currenl. The smaller the 
drain that will carry the largest flow with which it is likely to be 
charged, the better is the scour, and the more likely it is to be kept 
clean. 
If, through carelessness or otherwise, rubbish, such as broken 
crockery, rags, etc. — which they are not intended to carry — find 
their way into sewers, no amount of increase in size will prevent 
their becoming choked, and decomposition will inevitably go on, 
generating a deadly gas next to impossible to exclude from our 
houses with the system of traps now generally in use. 
“ Drain 23ipes, whatever pattern be chosen, should be bedded in 
proper clay, and have the joints well luted; for if the joints be 
badly made, the liquid drainage will escape, and the sediment which 
is left behind may collect to such an extent as to choke the drain 
altogether. When drain-pipes are laid in cellar bottoms, it is a 
good plan to place them upon a bed of concrete, and cover over 
with a few inches of the same material. Wherever the drain-pipes 
pass through the walls, it is wise to turn a relieving arch over them; 
for, if a settlement should take place in the building, the superim¬ 
posed weight will, in all likelihood, crack the pipes, and cause the 
drain to leak at a most dangerous place, or perhaps break them, and 
cause the greatest annoyance. » 
When drains are laid in new-made ground, unless care be taken 
to ram the earth sufficiently hard round about them — and this is 
next to impossible — the pipes will open at the sockets, and sodden 
the ground in their neighborhood to a dangerous extent. It is best 
in such a case, to rest the pipes upon boards laid upon occasional 
piles, or what is better, upon piers of brick-work. 
It will sometimes happen that drain-pipes are laid in ground 
which may afterwards be penetrated by the roots of trees, shrubs. 
