CONCRETE LINING FOR IRRIGATION CANALS. 61 
(10) Where conditions are adapted to its use, the type of joint 
shown in figure 3, i, possesses some advantages over those previously 
discussed. This is merely the carpenter's shiplap or half- timber 
joint applied to concrete. It provides for all the expansion necessary 
without weakening the lining by too wide a joint space. It also 
permits a certain amount of " creeping" in the section without mis- 
placement and furnishes an excellent opportunity to secure a water- 
tight joint by the use of an elastic material like asphalt. 
(11) In adapting the shiplap joint to thin concrete finings a greater 
thickness of fining is used at each joint. The sections shown in j, I:, I, 
and m, figure 3, represent this modification showing two joints and 
methods of construction, as designed by A. F. Parker for the lining 
of the Davis and Uinta Counties Canal in Utah. 
CONSTRUCTION METHODS AND COST. 
In submitting the following data an effort has been made to show 
as fully as possible what constitutes current practice throughout the 
West in the fining of old and new canals. The lack of space prevents 
taking up many of these features in detail, but it has been the aim to 
select representative work in the various localities and to point out 
not only the good features of such work but to call attention to 
doubtful practices in order to assist the engineer in the design and 
execution of similar construction elsewhere. 
PATTERSON LAND & WATER CO., PATTERSON, CAL. 
About three years ago a series of pumping plants was installed to 
raise water from the San Joaquin River to irrigate a tract of 14,000 
acres, comprising the bulk of what is locally known as the Patterson 
ranch. To prevent the loss of water by seepage the canals of this 
system were fined with a 3-inch layer of concrete and finished with a 
1-inch plaster coat. 
The main canal at the river end (PL II, fig. 1) lias a bottom 
width of 7 feet, a vertical depth of 5^ feet, side slopes of 1^ to 1, and 
a capacity of about 110 second-feet. Its capacity is reduced at 
various points along its length, and at a distance of 2h miles from 
the intake the bottom width is 4^ feet. 
After the excavation of each division the main canal was filled 
with water and allowed to soak for from 6 to 9 days. It was then 
trimmed and fined in 12 foot sections. The gasoline-driven concrete 
mixer had a capacity of 75 cubic yards per day, which provided 
material to fine 300 linear feet. The position of this mixer when 
operated and the methods employed in elevating the material and 
delivering the concrete are shown in Plate II, figure 2. The concrete 
used was a mixture of 1 part cement to 6 or 6^ parts of sand and 
gravel. The plaster coat was proportioned 1 : 2 cement and river sand. 
