68 
POPULAR SCIENCE REVIEW. 
The sewage arrives by the lowest or main arterial sewer to 
the pnmping-station. It first flows into the pit x, where is 
seen the Jacob's ladder ” (J) of ascending and descending 
buckets, scooping up the solid refuse at x and emptying it as 
they turn over at N into the receptacles above referred to. The 
grating for preventing solid substances from passing into the 
pumping- chamber is shown at a; and through the grating the 
liquid sewage flows on into the pump-well at C. Ascending 
as the pumps (L L) are worked, the sewage is sent by them 
into a chamber (K), from which it passes on through the 
uppermost sewer (A) into the reservoir (R) . There it remains 
until the gates of the middle line of sewer (D D 1 ) at D are 
opened, when the pent-up sewage falls over the wall (W) of 
the reservoir into the penstock (P) and flows out through 
the middle sewer (D D 1 ) into the Thames. As the upper sewer 
is subjected to pressure by the pumping, it is covered over 
with a considerable thickness of concrete, and the coal stores 
are built over it so that it may have the additional benefit of 
the weight of the fuel to serve also to increase its strength 
and resistance. The brick roof of the reservoir is arched 
over from parallel lines of piers, and provision is made at 
every second arch for ventilation. These arches are now 
being turned; and the manner in which the contractor, 
Mr. Webster, has executed those portions of these outfall 
works which are at present completed, is deserving of the 
highest credit. It is very rare indeed to see bricks laid in such 
a fine and finished manner. We have now given an outline of 
the plans of the great metropolitan drainage systems and some 
general ideas of the works themselves. Into the question of 
the utilization of sewage it is not our province to enter in this 
article. For the present, the course adopted is to get rid of 
the sewage into the river, as far off from the city as possible, 
and for this purpose the plans of Mr. Bazalgette are most 
effective and well-considered ; they possess, too, this merit, 
that they can be adapted to any other system which expe- 
rience may hereafter prove to be worthy of adoption. 
