Report on the sanitary condition of Singapore / by W.J. Simpson.

  • William Simpson
Date:
1907
Catalogue details

Licence: Public Domain Mark

Credit: Report on the sanitary condition of Singapore / by W.J. Simpson. Source: Wellcome Collection.

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    The following filters have been taken out in recent years :— Years. No. of Filter. .Reason for taking out. 1900 Nos. 7 and 8 Repairs to Floors 1901 • •• ... ... ... 1902 ... ... ... ... 1903 No. 4 Cleansing 1904 ^ 1905 / No. 6 Repairs to Floor 24. “ Is the new sand, both coarse and fine, and also the granite always washed before being laid down or renewed in the filter P ” Yes, the whole of the materials for the beds are always washed before being laid down. 25. “ What is done with the dirty sand that cannot he washed, if any ? Is it sold ? ” See No. 17. It is sometimes sold for road-making and similar purposes. It is chiefly used for filling on the Race Course. 26. “ What is the method of washing the sand ? ” The sand is placed in hoppers, and stirred about with wooden paddles while clean water under pressure enters at the bottom of the hopper and passes up through the sand carrying the impurities with it. The dirty water and washings overflow from the hopper into an open drain beneath. This is continued until the overflowing water runs clear, when the sand is clean. 27. “ Percentage of filtered and unfiltered water consumed ? ” See tabular statement attached. 28. “ Thickness of sand at start and stop ? ” In filters 1 to 3 the maximum thickness of sand at starting is 37 inches, and in the remainder 24 inches. At stopping for renewal the minimum allowable is 12 inches, and the minimum thickness that is usually worked to is 15 inches. See also No. 16. 29. “ Average rate of filtration per annum and per mensem ? ” See tabular statement attached. N.B.—The calculations in the Tables are believed to be accurate, but they have only been checked once, by a Draftsman. R. PEIRCE, 12-12-06.
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