DRAINAGE METHODS FOR COUNTY ROADS. 
21 
together 1 part cement, 2 parts sand, and sufficient water to give the grout a 
consistency about equal to that of ordinary cream. When the joints are grouted, 
the bedding sand should not extend above the center of any stone ; because, if 
it does, the grout is very likely to crack and spall out. 
This type of construction will give a gutter practically as strong 
as the road surface and may consequently ba used in juxtaposition to 
COBBLESTONE GUTTER 
D=|jr Cross-section is segment of a circle. 
Use cobblestone 4" to 6" 
Sand bedding about 2" thick 
Fig. 4. 
it. If there is little probability that traffic will use a gutter, naturally 
such heavy construction is not necessary. There are cases when ade- 
quate gutters may be built on a thin course of cinders with a sand 
bedding course. If the soil be not noticeably poor, 4 inches of cinders 
or gravel will be adequate. In some cases, on unusually favorable 
soils, such as sands or sandy loams, it may be possible to build im- 
mediately on the soil in place or with nothing more than the sand 
bedding course added. 
CONCRETE GUTTER 
ROAD WAY 
D=g Cross-section is segment of a circle. 
1-2:4 concrete about 6" thick 
Foundation of gravel, broken stone, or good quality earth. 
Fig. 5. 
Figure 4 shows a typical cross section for a cobble gutter, and 
Plate I is a photograph showing a completed gutter which was con- 
structed in accordance with the foregoing directions and which is 
now giving satisfactory service. Sand was used for filling the joints 
in this gutter. 
CONCRETE GUTTERS. 
There are two types of concrete gutters in general use. One has 
a curved cross section, as shown in figure 5, and the other is essen- 
