300 DEVELOPMENT OF WATERING PLACES 



water and so afford an outlet for the overflow. Piping with a 

 diameter of i| to 2 inches is best. No pipe less than i inch in 

 diameter should be used, as there is always danger of its becoming 

 clogged. If there is more or less travel over the ground, the 

 pipe should be located underground; otherwise it is not neces- 

 sary to bury or in any way cover it. 



Kinds of Troughs. — The particular type and construction of 

 the trough will be determined largely by the character of the 

 surroundings. In deciding on the trough to be constructed the 

 matter of permanency and cost should be kept in mind. 



Log Troughs. — The troughs most commonly met with over 

 woodland ranges are hewn out of logs. The availability of the 

 material and the low cost of construction, as well as the slight 

 need of repair and the ease of renewal, account largely for the 

 popularity of the log trough. The average cost of log troughs 

 18 to 20 feet long, made from yellow pine or Douglas fir, is about 

 $8. The cost will vary according to the skill and energy of the 

 workman, but on the average it will amount to from 20 to 30 

 cents per cubic foot of opening. Expense in the construction 

 of log troughs may be held down if burning out the material is 

 combined with the process of hewing with the axe. Yellow 

 pine is harder to hew than some other woods, but it burns out 

 well. Such materials as spruce, aspen, yellow pine, lodgepole 

 pine, Douglas fir, and grand fir are hewn into troughs. 



Other Wooden Troughs. — Next to the log trough the plank 

 trough is the most common. This type of trough is objection- 

 able because it is short-lived and is difficult to keep tight. Ma- 

 terial lighter than 2-inch planks should never be used. Usu- 

 ally plank troughs are rectangular in shape, common dimensions 

 being 12 feet long, 2 feet wide, and 2 feet deep. A trough of 

 this size, built of 2-inch material and properly supported, costs 

 about $10. 



Wooden troughs should always be thoroughly painted both 

 inside and outside, as this tends to prevent leakage and greatly 

 increases the life of the trough. Wood containing knots should 

 be avoided as far as possible. If knots occur, they should be 

 heavily painted or tarred, and both sides should be carefully 

 covered with tin. 



