Tiles and Tile-Laying.—After allowing for breakage, it will take about 16 tiles and 16 collars to lay a rod in length of drain. The cost of these will, of course, be very much affected by the considerations of the nearness of the tile-kiln and the cost of transportation. They should, in no ordinary case, cost, delivered on the ground, more than $8 per thousand for 1-1/4-inch tiles, and $4 per thousand for the collars, making a total of $12 for both, equal to about 19 cents per rod. The laying of the tiles, may be set down at 2 cents per rod,—based on a skilled man laying 100 rods daily, and receiving $2 per day.
Covering and filling will probably cost 10 cents per rod, (if the scraper, Fig. 39, can be successfully used for the rough filling, the cost will be reduced considerably below this.)
The four items of the cost of making one rod of lateral drain are as follows:
| Digging the ditches | - - - .43 |
| Grading | - - - .06 |
| Tiles and laying | - - - .21 |
| Covering and filling | - - - .10 |
| - - -.80 cts. |
If the drains are placed at intervals of 40 feet, there are required 64 rods to the acre,—this at 80 cents per rod will make the cost per acre,—for the above items,—$51.20.
How much should be allowed for main drains, outlets, and silt-basins, it is impossible to say, as, on irregular ground, no two fields will require the same amount of this sort of work. On very even land, where the whole surface, for hundreds of acres, slopes gradually in one or two directions, the outlay for mains need not be more than two per cent. of the cost of the laterals. This would allow laterals of a uniform length of 800 feet to discharge into the main line, at intervals of 40 feet, if we do not consider the trifling extra cost of the larger tiles. On less regular ground, the cost of mains will often be considerably more than two per cent. of the cost of the laterals; but in some instances the increase of main lines will be fully compensated for by the reduction in the length of the laterals, which, owing to rocks, hills too steep to need drains at regular intervals, and porous, (gravelly,) streaks in the land, cannot be profitably made to occupy the whole area so thoroughly.[22]
Probably 7-1/2 per cent. of the cost of the laterals for mains, outlets, and silt-basins will be a fair average allowance.
This will bring the total cost of the work to about $60 per acre, made up as follows:
Cost of the finished drains per acre - - - $51.20
7-1/2 per cent. added for mains, etc. - - - 3.83