LINE OP DIRECTION. 53 



unless the upper wheel pass over a stone, or the lower 

 wheel sink into a rut. The centre of gravity of a large 

 load may be nearly ascertained by measuring with a 

 rod ; and it may sometimes happen that by measuring 

 the sideling slope of a road, all of which may be done 

 in a few minutes, a teamster may save himself from a 

 comfortless upsetting, and perhaps heavy loss. Again, 

 a load may be temporarily placed so much toward one 

 side, while passing a sideling road, as to tlu'ow the line 

 of direction considerably more up liill than usual, and 

 save the load, which may be adjusted again as soon 

 as the dangerous point is passed. This principle also 

 shows the reason why it is safer to place only light 

 bundles of merchandise on the top of a stage-coach, 

 while all heavier articles are to be down near the 

 wheels ; and. why a sleigh will be less likely to upset 

 in a snow-drift, if all the passengers will sit or lie on 

 the bottom. Wlien it becomes necessary to build very 

 large loads of hay, straw, wool, or other light sub- 

 stances, the " reach," or the long connecting-bar of the 

 wagon, must be made longer, so as to increase the 

 length of the load ; for, by doubling the length, two 

 tons may be piled upon the wagon with as much secu- 

 rity from oversetting as one ton only on a short wagon. 

 Fig. 24. Fig. 25. Where, however, a high 



load can not be avoided, 

 great care must be taken 

 to have it evenly placed. 

 vp;_^ip wi^i'^^j- ^ f^j. instance, the load 

 of hay represented by 



Centre of gravity of an even and one-sided Figure 24 be skillfully 



'""'' bunt, the line of direc- 



