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Page:Popular Science Monthly Volume 89.djvu/570

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556

��Popular Science MoniliJij

��Sampling the Drinks for an Entire Large City

���Cincinnati's water is tested three times a day. If it is not pure this man makes it so

IN llic employ of the good city of Cin- cinnati is a (loiij;;ht\' kniyht of the sack who attcntls to the sanii)liiiii of the water which, after all, i'ornis llu- basic <!rink of the city.

The water to he taken internally by Cincinnati is tested at least three limes a day, in ortlinary times, and oftener in seasons f)f high water and the like.

Regulation tests are made for imih alkalinity and turbidity. After llu- analysis has been made there is dumped into the water sufticient (|iiaiilit\' of iron to form ferric-hydroxide (a ji'lU-likc

��substance), which settles out whatever there may be of impurity remaining.

That is to say, the water taken from the Ohio River by Cincinnati is first led into settling-basins, where sixty to sixty-five per cent, of the mud is re- moved by simple sedimentation. The water is then run to the filtration plants, where the sulphate of iron solution and the lime-water are added. These chem- icals react and yield the ferric-hydroxide, which is insoluble in water. As a result, the greater portion of all remaining im- purity settles in the coagulating basins, as they are called. By this process per- haps thirty per cent of the original amount of mud and the like is removed.

The remaining five per cent to ten per cent deposited is then filtered out by the sand-filter and the water is then ready to drink.

What Is the Leaning Tower of Pisa Compared with This?

A CHURCH in a litde Connecticut town has become a famous land- mark in the state as a result of a severe storm. A few years ago the spire was blown off and in falling made a half turn and dived through the roof, driving its point through the shingles. There it has remained ever since, and as the photograph shows, it presents a decided- ly "misplaced" appearance.

���Tlie spire was blo«ii off the steeple and its sharp end pierced the roof and stuck

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