100 



Bullet IN 86 



CURING 



Curing the tile requires that it be kept wet until the mortar has 

 not only set but has hardened. Seven to ten days is the usual time 

 for curing but two weeks is preferable. A water supply under 

 pressure is desirable, and several automatic sprinklers should be 

 provided. It is awkward and difficult to keep the pipe wet with 

 hand sprinklers or with water that has to be handled with a pail, as 



Pig. 17.— Yaqui Indians tr-mpingr 15-inch cement pipe at Flowing Wells ranch. 



(From Bulletin 55.) 



from a ditch. An occasional wetting is not enough ; the pipe must 

 be kept wet. 



For at least twenty-four hours and preferably forty-eight, the 

 pipe should be protected from the sun. Any cheap shed covering is 



