Through sand, gravel, calcined ores, &c.
Through wire gauges, hair gauge, &c.
Reversible filters, such as the “Thames,” &c., are made self-cleansing by reversing the flow for a short time through a waste pipe, thus washing out the deposit.
[2603]. Filtering cone, formed of wire cloth inside a pipe.
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LONDON: PRINTED BY WILLIAM CLOWES AND sons, LIMITED.
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