Up to now the water from the river has been pumped into the settling tanks where it is allowed to lie quiescent until the heavier particles in suspension have dropped to the bottom of the tank.
In order to obtain a larger output from the existing tanks the Waterworks Ca. propose to pass the water contin ously through the tanks, which will always be kept full, and the necessary velocity will be obtained by constructing baffle walls, As the water comes up in its true Huangpu colour through the river pump deliveries a minute dose of alum is added by automatic feed machine An intimate mixture is obtained by pas the water rapidly through a we hamied chamber, whence it flows through the settling tank proper.
Through the Filters The alteration of these "intermittent ranks is vow well in hand, and to the lay mind there seems to he a conside able amount of remorselczs destruction going on, From these settling tanks water is pumped to the filters. Hitherto, the fillers have been what is techni ally known as "slow sand" but owing to the necessity for extension of this portion of the plant and the high cost of land, it has been decided to construct what are technically known as "rapid filters" which will deal with water 20 times as fast as the older slow sand type. The construction of a battery of eight filters, with a total output of 26,000,000 gallons per day, has already been commenced, and where a.month ago was a sheet of water—two old filters having been scripped to make place for the new, ones—is now a forest of steel rods, The filters, which are being constructed of reinforced conerete, will be entirely are largely modelled on modern practice and contain ations, one of the most me teresting being a new hydraulic valve, the power for operating which is obtai d from the water passing through the valve itself.
To Shanghai It is now that one comes to the new machinery ordered to provide for the nereasing needs of the community. To most people machinery, especially that of a very heavy calibre, is fascinating, and that in the waterworks from its size ix doubly so, A waterworks one gineer seldom dreams of talking in terms of castings for his machinery of Jess than many tons, and he is justified in doing so on account of the millions of gallons of water for which he is responsible day after day. When ona sees the size of the machines he handles and their solidity it is realized that what he says is nothing more than a plain statement of fact, He deals with & type of machinery which 21 hours a day a round, and naturally his engine la which must be of the most train, w Engine The eight main pamp= ing en, in the pumping station, but there ave entirely eclipse ed in' size and power by the new machine where parts recently arrive from Gicat Briiain, The heavi-
Gat existing i contain is no less than 24 tons, this being the low pressure sunder, its dimensions being ¢9-in, diameter by 5-ft, stroke, The cranke shaft, over 30 ft. in length, weighs 14 tons, and the flywheels, cast in two pivees, are 20 ft, in diameter and weigh 20 tons. Each of the piston rods—from the high, medium and low pressure cylinders—actuates a pump, and these are designed to give a capacity of over 14 million gallons a day.
All the work of assembling this engine has been done by the staff of the Waterworks Ca. and it is not difficult to appreciate the engineering skill involved when certain additional facts are noted. To start with, foundations 27 ft. deep had to be constructed, and then overhead, resting on the walls of the engine house, a travelling crane had to be placed into position; each beam of this alone weighs 5 tons.
Simultaneously with the erection of this engine, a network of delivery pipes, air vessels and valves are being laid in cavernous excavation between tha pumping station and the road. The drawing showing the arrangement of these pipes resembles the chart, showing the interior of the human body, so beloved of the Chinese dispensary, Tue GO-INCH PIPE LEADING PROM THE INTAKE TO THE sHORB
Text read from the printed page and cleaned; old type leaves the occasional error.