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PUBLIC RECORD OFFICE
Reference:→
6
C.O. 882
PUBLIC RECORD OFFICE, LONDON
ALLY, WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
53
Figs. 3 and 4 show the method of fitting a bath and a scullery sink. The waste pipe are fully from the bath passes at once through the wall of the house and discharges above the dangers to open head of a down pipe, which again delivers above the grating of a trapped gully. In his
badly like manner the waste pipe from the sink discharges above the gully. The trap beneath arranged the sink is rather a luxury than a necessity. Its chief use is to prevent the entrance of herolossta a draught of cold air,
nexion
the cond.
25. By the intelligent application of the principles of disconnexion and ventilation, Ventilation coupled with complete freedom from deposit in the house drains, which may be secured and discon by good workmanship, the inhabitants of any house may make themselves practically render independent as to the interior of the dwelling, of the condition of the public sewer. interior That is to say, the entrance of sewer gas from sewer, drain, or even cesspool, may be dwelling rendered impossible. It need hardly be said that these arrangements do not obviate the depend pollution of the air by sewer gas in the street, but they cannot fail to diminish the of public quantity generated by discharging the effluent before putrification has commenced.
Closets or latrines should always have one, preferably three, outside walls. In hospitals they should be placed in a projecting tower, separated from the main building or'ward by an ante-room, provided with windows at each side, so as to secure a thorough draught.
To sum up,-
26. The principles ruling the designs of sewers and drains may be thus briefly stated. (1.) Permanent deposit must not take place in any channel (pipe, drain, or sewer). (2.) To prevent permanent deposit the velocity in any given channel must for a certain períod daily at least be not less than that required to remove deposit, call this said velocity the "self-cleansing velocity."
(3.) Therefore the channel must have in inclination not less than that requisite to produce during an appreciable daily period of greatest average discharge the
self-cleansing velocity."
(4.) If the conformation of the ground prevents the construction of a channel with a
fall adequate to produce the "self-cleansing velocity."
Then-A. The natural fall must be increased by pumping.
B. Or "flushing" must be resorted to, an artifice which depends on the fact, that with streams of similar section the greater the sectional areas, leas inclination required to produce a given velocity, or in other words with similar sections and equal inclinations,
than amall.
large streams flow faster tunes of channel being made such as to give the self-cleansing velocity when full the natural flow must be augmented to the extent necessary to fill it, either by collecting and discharging the effluent from some higher district periodically, or sufficient water from some external source must be periodically added to make up the requisite volume.
The choice between these alternatives depends on local circumstances.
The formation of permanent deposit must at any cost be prevented on sanitary grounds.
And it may be safely asserted that, in the vast majority of cases, it will be far cheaper to prevent its formation than to remove it by hand.
18th September 1882.
OSBERT CHADWICK.
sewer.
Summary
of princi
G 3
53
+
I and 4 show the method of fitting a bath and a scullery sink. The waste pipe are fully as
bath passes at once through the wall of the house and discharges above the dangerous to d of a down pipe, which again delivers above the grating of a trapped gully. In health as
badly ner the waste pipe from the sink discharges above the gully. The trap beneath arranged is rather a luxury than a necessity. Its chief use is to prevent the entrance of waterclosets, t of cold air.
nexion
7 the intelligent application of the principles of disconnexion and ventilation, Ventilation with complete freedom from deposit in the house drains, which may be secured and discon
workmanship, the inhabitants of any house may make themselves practically render ent as to the interior of the dwelling, of the condition of the public sewer. interior to say, the entrance of sewer gas from sewer, drain, or even cesspool, may be dwelling impossible. It need hardly be said that these arrangements do not obviate the depende
the cond
BOWOT.
of the air by sewer gas in the street, but they cannot fail to diminish the of public generated by discharging the effluent before putrification has commenced. sor latrines should always have one, preferably three, outside walls. In they should be placed in a projecting tower, separated from the main building by an ante-room, provided with windows at each side, so as to secure a thorough
m up,-
he principles ruling the designs of sewers and drains may be thus briefly stated. 'ermanent deposit must not take place in any channel (pipe, drain, or sewer). fo prevent permanent deposit the velocity in any given channel must for a certain period daily at least be not less than that required to remove deposit, call this said velocity the "self-cleansing velocity."
Therefore the channel must have in inclination not less than that requisite to produce during an appreciable daily period of greatest average discharge the
self-cleansing velocity."
C
f the conformation of the ground prevents the construction of a channel with a
fall adequate to produce the "self-cleansing velocity."
-A. The natural fall must be increased by pumping.
"flushing" must be resorted to, an artifice which depends on the fact, that with of similar section the greater the sectional areas, less inclination required to a given velocity, or in other words with similar sections and equal inclinations, same flow faster than small.
limensions and figures of channel being made such as to give the self-cleansing when full the natural flow must be augmented to the extent necessary to fill it, y collecting and discharging the effluent from some higher district periodically, lent water from some external source must be periodically added to make up the
volume.
hoice between these alternatives depends on local circumstances.
formation of permanent deposit must at any cost be prevented on sanitary
+
t may be safely asserted that, in the vast majority of cases, it will be far cheaper nt its formation than to remove it by hand.
OSBERT CHADWICK. September 1882.
Summary
of princip
G 3
PUBLIC RECORD OFFICE
Reference:→
TPLEICO. 882
RECORD OFFICE, LONDON ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- | COPYRIGHT PHOTOGRAPH-NOT TO
PUBLIC
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