166 BuivivETiN 86 



as a basis for comparison. The first contract was for two miles of 

 the McCracken pipe. The price for making and curing the 16-inch 

 pipe was 8 cents per foot, and the price for laying was 5 cents per 

 foot. The second contract was for 6500 feet of hand-tamped pipe 

 and included opening the trench and backfilling, the earth cover 

 above the pipe to be at least 12 inches. The price for the 16-inch 

 size was 22^/4 cents per foot. The price bid for the making and 

 curing alone was 12 cents. In the other sizes there was a little more 

 economy in the machine-made pipe in the smaller sizes, a little less 

 economy in the larger sizes. Both contracts proved to be profitable 

 for the contractors. 



Another bid received was for hand-made pipe for the whole sys- 

 tem, and was from a very reliable pipe maker. His bid for 16-inch 

 pipe, for making and laying but no trenching, was 20 cents per foot. 



List prices of hand-tamped pipe in southern Arizona vary from 

 25 to 40 cents per foot for 12-inch pipe and from 40 to 50 cents for 

 16-inch pipe, these prices being at the pipe yard. List prices are 

 usually intended to apply for small quantities ; discounts can be 

 given on large contracts. 



The unit prices for the pipe at Glendale could not be learned. 

 The unit prices for the pipe laid in the trench were as follows : 

 14-inch pipe, $0.90 per lineal foot of trench 

 15- " " 1.14 " " " " 

 18- " " 1.40 " " " " 



The contractor's bid included prices also for 8 and 10-inch pipe, 

 55 and 62 cents per foot, respectively, but no pipe of those sizes was 

 laid. 



The item of cement in Table XXIV constitutes about two-thirds 

 of the cost of the pipe. The price per barrel as stated, $3.45, is 50 

 percent higher than the price one year ago. Since no cement is 

 made in xA.rizona, the price is relatively high. There are many lo- 

 calities where cement pipe can be produced much more cheaply, on 

 account of the lower cost of cement. 



The cost of pipe laying consists of the labor and the cement, sand, 

 and water distributed along the ditch. According to the data on 

 page 107, the labor cost varies from 2 cents a foot for 12-inch pipe to 

 4 cents a foot for 20-inch pipe. The cost of the mortar materials 

 will be about an equal amount, and a contractor must charge an ad- 

 ditional sum for taking the responsibility for obtaining a strong and 

 durable pipe line. 



The cost of trenching depends upon the depth of the trench and 

 the nature of the material. For deep trenches and for hardpan, a 



