EARTH, SAND-CLAY, AND GRAVEL ROADS. 
29 
inches up to 12 inches and this better distribution of the material 
in the embankment tends to prevent inequalities from developing 
in the finished road surface. 
Wheeled scrapers (fig. 17) are used to a greater extent in road 
grading than either drag scrapers or wagons. The reason for this 
is that in road work the haul length falls, more frequently than 
otherwise, within the limits for which wheeled scrapers are economi- 
cal. Several different sizes of such scrapers are in ordinary use, but 
the size employed most commonly has an actual load capacity of 
from 11 to 15 cubic feet, according to how heavily the load is heaped. 
Scrapers of this size ordinarily sell for from $35 to $50 f . o. b. factory. 
In operating wheeled scrapers the material is loosened by plowing, 
in the manner already described, and is loaded by the scooping 
action of the scraper. 
Two horses usually 
are sufficient to draw 
the scraper after it is 
loaded, but a second 
team, called a snatch 
team, is hitched in at 
, the front of the tongue 
to assist in loading. 
The snatch team 
should consist of either 
two or three horses, 
according to the char- 
acter of the material, 
and one snatch team 
should serve several 
scrapers. The loading and dumping of the scrapers are done by 
laborers provided for that purpose and not by the drivers. 
A small organization for carrying on grading work with wheeled 
scrapers may be made up about as given below : 
Tools : 
Fig. 17. — Wheeled scraper. 
Force : 
1 foreman. 
6 to 11 drivers. 
1 laborer for plowing. 
2 laborers for loading scrapers. 
2 laborers for dumping and 
spreading. 
1 laborer to trim slopes, etc. 
1 two-horse team for plow. 
4 to 8 two-horse teams for scrap- 
ers. 
1 or 2 two-horse snatch teams. 
Total : 1 foreman, 17 laborers, 11 
teams. 
8 wheeled scrapers (capacity 11 
to 15 cu. ft). 
1 road plow. 
2 picks. 
2 mattocks. 
2 axes. 
3 shovels. 
