630 Obstructions in Draining-Tilcs. 



deposit. I have, however, seen the mischievous effects of the 

 latter in boggy grounds drained by the Duke of Portland. The 

 drains were constantly choked by the deposit, called by the 

 workmen the red ochre. I have inquired of Mr. Tebbett, the 

 head-drainer of the Duke of Portland, whether he has found any 

 remedy for this evil — an evil of a serious magnitude, occurring 

 as it does in drains of from 8 to 12 feet deep, the reopening of 

 which from the surface causes a very heavy expense. Mr. 

 Tebbett says, in answer, that the only remedy with which he is 

 acquainted is to flush the drains witli fresh water, by applying it 

 from a shaft built at the head of the drains. He finds this ochreous 

 deposit occurs generally in drains made in boggy land, upon sand- 

 rock, and not far from running water. When first made these 

 drains require flushing every five or six weeks ; after a time the 

 deposit becomes less, and a larger period may be allowed between 

 the times of flushing. If an air-trap would correct the evil, it 

 could in most cases be easilv made, and would be a valuable 

 improvement. 



J. Evelyn Denison. 



END OF VOL. XVI I. 



LONDO^J : PRINTED BT W. CLOWES AND SONS, STAMFORD STREET, 

 AND CHABING CROSS. 



