EARTH, SAND-CLAY, AND GRAVEL ROADS. 61 
drag to compact readily after it is moved, but not sufficiently wet for 
traffic following the drag to produce mud. . 
The principal factor in successfully operating a properly con- 
structed road drag, provided the condition of the road is favorable, 
is skill on the part of the operator. Such skill can be obtained only 
by intelligent experience, and no rules can be laid down which would 
enable an inexperienced operator to produce first-class results. 
Under ordinary circumstances the position of the hitching link on 
the draw chain should be such that the runners will make an angle of 
60° to 75° with the center line of the road, or, in other words, a skew 
angle of from 15° to 30°. But when dragging immediately over the 
ruts, or down the center of the road after the sides have been 
dragged, it may be found advantageous to place the hitching link at 
the center of the chain and run the drag without skew. An intelli- 
gent operator will learn quickly to adjust such details as this, as well 
as to shift his weight while riding upon the drag in order to make it 
cut where cutting is desirable, and deposit material where material 
is needed. 
MAKING REPAIRS. 
If roads of such types as have been discussed are to be maintained 
properly, they must frequently receive other attention than mere 
dragging. The side ditches should be kept open and free from vege- 
tation, the cross drains and culverts maintained in proper condition, 
and worn places in the surface repaired as fast as they develop. 
The material used in repairing the surface should be the same as 
that composing the surface and should be put on in such quantity 
and manner that after it is compacted the surface will be uniform 
and continuous. Much time and labor can be saved by making re- 
pairs as soon as needed, because when a bad place once develops in a 
road it generally will spread very rapidly until proper steps are taken 
to correct it. 
COST OF MAINTENANCE. 
There are not sufficient cost data ' available at present to warrant 
aiiy very definite statements as to the cost of maintenance, but when 
roads can be maintained largely by use of the drag, as usually is the 
case with the simpler types of construction, the cost ordinarily is very 
small. Accurate data kept by a representative of the Office of Public 
Roads for road maintenance in Bennington County, Vt., during 
1912 and 1913 showed that under favorable conditions a road could 
be dragged at the rate of about 1 mile per hour. This was where 
the road was comparatively well shaped and only one trip in each 
direction was necessary. Where more trips of the drag were re- 
