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Discussion. ~l~~p~~~i d~~~The PRESIDENT proposed a vote of thanks to the Author, who he regretted could not be present, as he had returned to India. ~I I~. Beresford Mr. J. S. BERESFORD renmrked that the Paper dealt with a very interesting subject, though the mechanical portion of the scheme was not entirely new. He was disappointed t o find that no particulars had been given as to how far the object in view-reducing the ground-water level-had been attained. It was over 21 years since he retired from the position of Chief Engineer of the Irrigation Department of the Punjab, and conditions at Amritsar had changed in that time. During his service in India he had to deal with the question of reducing the water-level in ground that had been waterlogged by percolation from the Ganges and other canals, and it had proved a very difficult question. It 'was thought at one time that i t was only necessary to dig open drains 3 or 4 feet deep a t intervals of 150 to 200 feet to take the water out of the subsoil. The drains were deepened at considerable expense, while the object which it was desired to attain was not accomplished. The same difficulty had been experienced in Egypt in recent years, where i t was found necessary to make the drains very close and deep if they were to be effective.The invention of an effective strong strainer for tube-wells, strong yet with fineness to TiT of an inch was a very important matter, because for a long time they had been endeavouring to construct masonry wells in sandy districts in India in which there were no beds of clay, but failed. No cultivator mould spend a large sum of money in sinking a well unless time was a bed of clay l0 feet or 15 feet thick at a reasonable depth. He sank his wcll, which might be 6, 8 or 10 feet in diameter, down t o the clay, and then he considered he was within reach of the true spring mater. It was the same water as above, but it had the advantage of a thick bed of clay over it, through which he bored a holc of 3 or 4 inches diameter (Pig. 7, p. 83). When the water was first drawn, the sand calne out freely, but the bed of clay formed a rocf which allowed a large regulating cavity t o be formed underneath, the water percolating into the cavity at a rate which did not wash out the sand. That was known as a permanent well. Endeavours were made to sink wells in places in which no beds of clay existed, and to embody filters in the wells, but that system had not been a complete success. He Downloaded by [] on [12/09/16].

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