Verse

/1 We have followed the course of the effluent from the sedimentation tanks. What happens to the sludge, i.e., the finely divided solid matter ! which has settled to the bottom?

It is pumped to a sludge digestion tank. There are several of these concrete tanks, each of which is 60 feet in diameter, 22 feet deep and holds 60,000 cubic feet. Here anaerobic bacteria act on the solids, liberating methane or marsh gas. No use is made of this gas at

Naburn, although in other places it is used for' eating the tanks, which accelerates the digestion. In Birmingham and many other cities it is used for heating purposes in the city. During the war, it was used at Croydon for driving motor vehicles At one place in Lancashire it is used for heating air to accelerate the drying of hay.

From the digestion tanks, the sludge is conveyed to drying beds.

When dried it has the appearance, smell and texture of loam, and makes a good manure. It is in great demand by local farmers.

Modem purification of sewage is an acceleration of processes which normally occur in nature. It is a long time since we were so impressed by the co-operation between man and nature, in this case for the disposal of something objectionable and its transformation into something useful to man. We spent a most profitable and enjoyable (though cold) afternoon, and wish to thank Mr. Graham heartily for making it so interesting.

THE EXPECTATION

There is strength assembled in the dark, There is strength brooding in the stark Appearance of empty meaning. There is strength forever hidden In all, Strength forcing its own power Into waiting. Strength hidden in the innocence of the mellow, The soft, the unconscious, In the placid scene, in the apparent Inertia. Strength waiting, brooding. calling In the earth. The earth Caresses the seed of strength until the great feast Of understanding.

R. S. Daneff.

37