dry weather flow of the sewage proper from populations
numbering from 1,000 to 10,000, and is prepared after deducting
all water which may be present in the sewers resulting from the
infiltration of subsoil water through leaky joints in the
pipes, and from defective water supply fittings as ascertained
from the night gaugings. Larger towns have not been included in
the table because the hourly rates of flow are generally
complicated by the discharge of the trade wastes previously
referred to, which must be the subject of special investigation
in each case.


[TABLE NO. 4.

APPROXIMATE HOURLY VARIATION IN THE FLOW OF SEWAGE.
Percentage of Total Flow Passing Off in each Hour.

-----------+------------------------------------------------
| Population.
Hour. +-----+-----+-----+-----+-----+-----+-----+------
|1,000|2,000|3,000|4,000|5,000|6,000|8,000|10,000
-----------+-----+-----+-----+-----+-----+-----+-----+------
Midnight | 1.0 | 1.0 | 1.2 | 1.3 | 1.5 | 1.5 | 1.8 | 2.0
1.0 a.m. | 0.7 | 0.7 | 0.7 | 0.8 | 0.8 | 1.0 | 1.0 | 1.0
2.0 " | nil | nil | nil | nil | 0.2 | 0.2 | 0.3 | 0.5
3.0 " | nil | nil | nil | nil | nil | nil | nil | 0.2
4.0 " | nil | nil | nil | nil | nil | nil | nil | nil
5.0 " | nil | nil | nil | nil | nil | nil | nil | 0.2
6.0 " | 0.2 | 0.2 | 0.3 | 0.5 | 0.6 | 0.5 | 0.7 | 0.8
7.0 " | 0.5 | 0.5 | 1.0 | 1.5 | 1.6 | 1.7 | 2.0 | 2.5