SMALL SAWMILLS, THEIR EQUIPMENT, ETC. 51 
small operation. Medium-sized logs can be decked a couple of tiers 
high in spiked skids quite easily, thereby saving the expense of a 
decking team and teamster. 
If you are hauling on a snow or ice road, keep the space in front 
of the skidways on which the sled stands free from bark and chips. 
Figure on loading the heaviest logs on the bottom of the tier. If the 
sawyers leave any knots on the logs, trim them off close to the bole 
and see that the binding chains or toggles are grabbed on the un- 
loading side. If the sawyers have left a " chip " on the bottom of 
the cut, set the " Samson " (which should be higher than the log) 
on the near side, drop the swamp hook over the far side of the log, 
and fasten in the dog. Make the swamp-hook chain or logging chain 
fast with a half hitch around the top of the " Samson," and hitch 
the team to the chain. One pull from the team usually breaks the 
chip or turns the log over so that the teamster can reach it with his 
ax. If the teamster is not equipped with a swamp hook and does not 
understand how to use a " Samson," he can take a " roll " on the log 
with his log chain, with the draft down low on the side of the log 
opposite his team, and if the log is not too heavy and the chip too 
large, can lift the log far enough with his team to enable him to cut 
the chip with his ax and roll the log on to the dray. 
The jackknife dray has a roller in front set on gudgeons in the 
nose of the runners. A stout bunk armed with spikes connects the 
runners. If the dray strikes any obstruction it will "jackknife" or 
partially fold, hence the name. 
SCALING. 
There are many rules for the measurement of saw logs. None of 
them, however, is mathematically exact, simply because a saw log 
is not a mathematical figure. Also, the unit of sawed lumber is 
144 square inches, or a piece of board 12 inches square and 1 inch 
thick. Any rule purporting to give the actual amount of board 
feet which a log of a given diameter will saw out is, therefore, only 
an approximation. 
The Decimal C rule is the one adopted by the Forest Service for 
scaling Government timber. This rule is made by dropping the 
unit figures of the Scribner rule and accepting the nearest tens as 
correct values. The contents of logs as given by the Scribner rule 
were found by drawing diagrams outlining the smaller end sections 
of logs and computing the board feet in the boards that could be* 
sawed from them. 
The Doyle rule, which is extensively used., is based on the follow- 
ing formula : Deduct 4 inches from the diameter of the log, square 
one-fourth of the remainder, and multiply by the length of the log 
in feet. This gives the approximate contents in board feet. Another 
