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crete, wood, asphalt, oils, and clay puddle. A good lining should fulfill the 

 following requirements: it should be water tight, prevent the growth of 

 weeds, stop burrowing animals, be strong and durable, and preferably not 

 affected by the tramping of cattle. From investigations made by the writer 

 in 1906 and from more recent experience as regards the efficiency of the 

 different types of linings, the following results can be anticipated: 



1st. A good oil lining constructed with heavy asphalt road oil applied" 

 on the ditch sides and bed at the rate of about 3 gallons per square yard, 

 will stop 50 to 60 per cent, of the seepage. 



2nd. A well constructed clay puddle lining is as efficient as a good 

 oil lining. 



3rd,- A thin cement mortar lining about 1 inch thick, made of one part 

 cement to four of sand, will prevent 75 per cent, of the seepage. 



4th. A first-class concrete lining, 3 inches thick, made of one part of 

 cement to two of sand and four of gravel, will stop 95 per cent, of the 

 seepage. 



5th. A wooden lining when new is as efficient as a concrete lining, but 

 after two or three years, repairs and maintenance will become an important 

 item and by the end of eight or ten years, it will necessitate complete 

 renewal. 



The cost of an oil lining where oil can be bought at California prices 

 (about 2 cents a gallon) is about % cent per square foot. Cement mortar 

 lining 1 inch thick costs about 3 to 4 cents per square foot. Cement con- 

 crete 2 inches thick costs about 6 cents and 3 inches thick about 8 cents a 

 square foot. These prices do not include the trimming and preparation of 

 the ditch before the lining is put on, which would add from % to 1 * cents 

 per square foot. The cost of a clay lining depends greatly on the nearness 

 of the canal to suitable clay. If clay is close at hand, it can be hauled and 

 spread on the canal, then either tramped in by cattle or worked in by drag- 

 ging over it, at a cost of less than 1 cent per square foot, but there are 

 localities where the writer has seen enough money spent on clay linings to 

 pay for a good concrete lining. Wooden lining has been used in very few 

 cases and the cost of such a lining built of 2 inch lumber nailed on sills and 

 side yokes will not be less than that of a 2 inch concrete lining and not 

 nearly as durable. 



The disadvantages of the cheaper linings are the following: An oil lin- 

 ing stops only a part of the seepage losses, and while it will resist erosion 

 well, it probably will not prevent the growth of weeds for more than one 

 season unless a high velocity is used, and it will not stop the activities of 

 burrowing animals. Another serious objection is that suitable oil would 

 be hard to obtain in British Columbia at a reasonable cost. Oil linings have 

 not been sufficiently tested to determine their durability. 



Clay puddle will not prevent the burrowing of animals, and weeds grow 

 rapidly, especially since the velocity of the water must be small in order to 

 prevent the eroding or washing of the lining. 



A concrete lining has none of the above disadvantages and it meets the 

 requirements of a good lining better than any other material. The only 

 objection is its higher first cost. This, however, can be partly balanced, 

 especially on side hill work, where a new canal is to be constructed, by using, 

 a higher velocity and a smaller cross section, thus decreasing the cost of 

 excavation. Where an old canal must have its capacity enlarged, this may 

 be done either by lining the canal which will gfve a higher velocity because 



