A 4-foot ditch, in most soils, need be only 20 inches wide at the surface, and 4 inches at the bottom. This gives a mean width of 12 inches, and requires the removal of nearly 2-1/2 cubic yards of earth for each rod of ditch; but an increase to a mean width of 16 inches, (which day workmen will usually reach, while piece workmen almost never will,) requires the removal of 3-1/4 cubic yards to the rod. As the increased width is usually below the middle of the drain, the extra earth will all have to be raised from 2 to 4 feet, and the extra 3/4 yards will cost as much as a full yard taken evenly from the whole side, from top to bottom. In clay soils, free from stones or "hard pan," but so stiff as to require considerable picking, ordinary workmen, after a little practice, will be able to dig 3-1/2 rods of ditch per day, to an average depth of 3.80,—leaving from 2 to 3 inches of the bottom of 4-foot ditches to be finished by the graders. This makes the cost of digging about 43 cents per rod. In loamy soil the cost will be a little less than this, and in very hard ground, a little more. In sandy and peaty soils, the cost will not be more than 30 cents. Probably 43 cents would be a fair average for soils requiring drainage, throughout the country. This is about 17 cents for each yard of earth removed. In soft ground, the caving in of the banks will require a much greater mean width than 12 inches to be thrown out, and, if the accident could not have been prevented by ordinary care on the part of the workman, (using the bracing boards shown in Fig. 28,) he should receive extra pay for the extra work. In passing around large stones it may also be necessary to increase the width. The following table will facilitate the calculations for such extra work: CUBIC YARDS OF EXCAVATION IN DITCHES OF VARIOUS WIDTH. _Length of 12 _Inches 18 _Inches 24 _Inches 30 _Inches 36 _Inches Ditch._ Wide._ Wide._ Wide._ Wide._ Wide._ Yds. Feet. Yds. Feet. Yds. Feet. Yds. Feet. Yds. Feet. 1 Yard. 0 12 0 18 0 24 1 3 1 9 1 Rod. 2 12 3 18 4 24 6 3 7 9 Men will, in most soils, work best in couples,—one shovelling out the earth, and working forward, and the other, (moving backward,) loosening the earth with a spade or foot-pick, (Fig. 41.) In stony land, the men should be required to keep their work well closed up,—excavating to the full depth as they go. Then, if they strike a stone too large to be taken out within the terms of their contract, they can skip a sufficient distance to pass it, and the digging of the omitted part may be done by a faithful day workman. This will usually be cheaper and more satisfactory than to pay the contractors for extra work. [Illustration: Fig. 41 - FOOT PICK.] Fig. 41 - FOOT PICK.