376 BOARD OF AGRICULTURE. [Pub. Doc. 



Both glazed and unglazed tile are offered in our markets. The latter, 

 if well burned and of good workmanship, should make excellent 

 drains, but glazing is likely to improve the tile in two directions. It 

 makes the surface over which the water must move smoother, so that 

 friction is reduced, thus giving greater capacity for carrying water for 

 a given size, and the tile must prove somewhat more durable. 



Special Forms of Tiles for Particular Uses. 



There are a number of special forms of tiles for different uses. Among 

 the more important are curves, enlarging tiles and junction or branch 

 tiles. 



Curves. 



In ordinary land-drainage operations these are seldom necessary, 

 but if for any reason the Une of the drain must make relatively sharp 

 turns, the work is more secure if the turn is made by the use of a curve 

 of suitable character. It is a matter of some difficulty to make turns 

 in lines of drains with straight tiles, and at the same time make the 

 joints between abutting tiles sufficiently close to effectively exclude 

 sand and silt. 



Enlarging Tiles. 



The enlarging tile is one that tapers, and such tiles are used when 

 on any given line of drain a change is made from a smaller to a larger 

 size. 



Junction or Branch Tiles. 



Such tiles are useful in making connections between lateral or branch 

 drains and a main drain. Both Y and T branches are manufactured. 

 The former are in most cases to be preferred. In order to procure 

 when ordering the kind of Y needed the figure designating the diameter 

 of the main drain should be placed first and connected by the sign of 

 multiplication with the figure indicating the diameter of the lateral or 

 branch tile which is to be united with the drain. For example, if a 

 2-inch branch is to be connected with a 4-inch main drain the order 

 should read "1 Y, 4 X 2." 



Collars. 



Manufacturers of round tiles usually offer short sections for use at 

 the junctions under the name of collars. Collars are usually about 

 2 or 3 inches long. The collar needed in any case is a short section of 

 tile just large enough to allow the insertion of the abutting ends of the 

 tiles which are being laid. Such collars somewhat increase the security 

 of the drain, as they reduce the chances that the tiles will get out of 

 alignment. Their use, however, greatly increases the cost, and they 

 are not ordinarily required. 



