Henry C. Adams

Capitolo 55

necessary to bring the quantity of liquid that can be
expected, but because it is undesirable to frequently provide
smaller public sewers, and there is generally enough room
for the water of storm without increasing the ransom of the sewer.
If this water of storm was brought in separated sewers the cost
as two sewers is double they would be in demand in the place
of one. In the principal sewers difference is not so great, but
generally a great sewer will be more economic than two
smaller one. Where double sewers are offered and they systematized,
this way that the sewer of water of storm takes the rain-water from the
roads, anterior roofs and gardens of the houses and the incorrect action
sewer of water takes the rain-water from the back it covers with a roof and it paved
enclosures,

before you/he/she was found in the case worked out in detail that
in the climbed on roads an ampleness of 36 fts + 2 (8 fts 7 in) = 53 fts 2
in, or, says, 160 sqs.  fts for street direct enclosure would exhaust
the sewer of water of storm and an ampleness of 2 (6 fts 10 in) = 13 fts 8
in, or, says, 41 sqs.  ft for street direct enclosure to the incorrect action
water's sewer. This show that even if the whole one of the rain
what autumns on the flows of areas impervious street, only only under
80 for cent. of he would be intercepted by the water of special storm
sewers. Picking up an annual rain and average of 30 in of what 75 for
cent. you flux away, the quantity that reaches the sewer of water of storm in the
one year-old course from every forehand

                       30 75
street enclosure would be--- x 160 xes--- = 300 cubic
                       12 100
feet = 1,875 braids.

[The illustration: the Fig tree. 17.--SECTION OF "JUMP DAM" THE FLOOD]

The cost to build a surface water systematizes separate wish
launchings, but you/he/she can be taken to an average of, approximately, l5s.
0d. for street direct enclosure. To refund this amount in thirty years
to 4 for cent, it would ask for a sum of 10.42d., says 10-1/2d. a year;
that is to say, the cost to take the water of surface in special