NINTH ANNUAL YEAR BOOK— PART XII 
733 
This table is prepared from figures given in surveyor's tables of F. 
Hodgmann, and credited to catalog of Bennett Sewer Pipe Co.,T]iere are, 
however, tables prepared which give reference to acres rather than gallons, 
and I believe they are better for the ordinary farmer than the above. 
When you Imow the slope of the drain and acres of untillable land to be 
accommodated you can be reasonably safe in relying on these tables, I 
will give a table here adapted from the tables of Wells and Carpenter, 
and published in Hodgmann's Manual of Surveying: 
Table showing capacity in acres of drain of different sizes and slopes: 
OrEN DITCH, SIDE SLOPE 1 TO 1. 
Slope 
.05 
.08 
.12 
.15 
3 ft. bottom. 
"■ 
aa. 
1,600 
2,000 
2,600 
3,500 
4,000 
4,000 ' 
6,000 
8,000 
10,000 
15,000 
4 ft. bottom. 
3d. ! ed, 
6 ft. bottom. 
3d. j 6d. 
i 
10 ft. bottom. 
6d. 
3d. 
2,000 
2,300 
3,200 
4,000 
4,600 
5.000 
6,500 
9,000 
12,000 
16,000 
3,000 
3,500 
4,500 
5,500 
6,200 
8,000 
10,000 
12,000 
16,000 
20,000 
4,000 
5,000 
7,000 
8,500 
9,500 
12,000 
15,000 
21,000 
25,000 
30,000 
TILE. 
Slope 
4 inch. 
6 inch. 
8 inch. 
10 inch. 
13 inch. 
.05 






6 
7 
7 
8 
10 




13 
15 
17 
IS 
20 
23 
27 


21 
24 
28 
30 
34 
38 
43 
48 
56 

30a. 
37 
42 
48 
54 
60 
65 
74 
84 
97 
40 a. 
47 
56 
65 
74 
81 
90 
107 
117 
132 
15 1 
.07 
.10 _ . 
.12 _-. 
.16 
.20 - 
.25 
.33 
.40 
..50 - 
.65 
For instance, if you have an untillable slough of ten acres with forty 
acres of ordinary tillable land draining into it, and find that you can make 
a drain with a slope of only five hundredths, you will learn from the 
table that nothing smaller than a 12-inch tile can be used, and that will 
be good for forty acres or its equivalent in wet land. You have ten acres 
of slough and forty acres of dry land, equal to ten acres more, or twenty 
acres of drainage, and your 12-inch tile will do in like manner; if your 
slope is seven hundredths a 10-inch tile will do. If it is ten hundredths, 
8-inch will do; if it is forty-hundredths, a 6-inch will do. 
Third — How can a uniform slope be secured? The line should be 
carefully laid out, and a stake set at the end of every hundred feet, and 
the depth of cut computed at every stake. A cord or wire should be 
stretched tightly eight feet above the required bottom, as shown in the 
following cut. A light measure eight feet long should be used on every 
foot when cutting the bottom of the trench. A line of targets will answer 
the same purpose, but are not as accurate or handy as a line. It is 
