DRAINAGE. 



125 



interrupted, and set on at an acute angle, so that the force of the 

 stream flowing from the lateral drain adds to the velocity of the 

 current in the main, entirely obviates this difficulty, which was 

 one of the greatest connected with the old style of work, and 

 makes the drainage of land even less uncertain than before. 



Among the minor improvements made by Mr. Boynton, the 

 Bend, (Fig. 51, quarter bend, 

 and Fig. 52, one-eighth bend,) 

 for turning corners in drains, 

 allows the stream to change 



its course gradually and Quarter Bend. 



smoothly, and with much less retarding effect 



angular turn which alone was possible in using straight tiles with 



beveled ends \ the reducing tile. Fig. 53, enables Fig. sj. 



us to change from one size to another in a (■ 



straight drain without making an abrupt edge in 



the bore of the drain ; and the glazed outlet, 



Fig. 54, with a grating to exclude vermin, 



makes an excellent and durable finish at the 



only point at which they first attack the 



work. 



--sW 



One-eighth Bend, 



than with the 



Grated Outlets Glazed. 



LAND DRAINAGE DETAILS OF THE WORK. 



It is never pleasant to confess errors ; but I am convinced, by 

 what I have recently seen, that, in previous writing about drain- 

 age, I have been mistaken on one point. That is, in insisting, 

 as a universal rule, that the whole line should be opened from 

 the upper end of the lateral to the lower end of the main, and 

 that the main should be kept open until the tile-laying and cover- 

 ing should be finished in all its laterals. This is frequently, but 

 not always, true, — perhaps it is not even generally so. 



I have probably directed the laying of over a hundred miles of 

 tile drains, and I have always tried to approach as nearly as pos- 

 sible to the English practice, as I had seen it described. I 

 have bought sets of English draining-tools, and have read in 

 English agricultural books and papers about the way in which 



