178 LOGGING 
two horses can haul from 2500 to 4000 feet. On unfavorable 
grades the capacity of four horses may be from 2000 to 3000 
board feet, and of two horses from 1250 to 1500 feet. 
The number of daily trips made by teams for given distances 
is influenced by the weight and condition of the animals, the 
character of the road and the time required to load and unload 
the sleds. Horses tire on long hauls with heavy loads, conse- 
quently more timber can be hauled with lighter loads because 
of the greater speed possible. Horses cannot travel more than 
24 miles daily for long periods, and this should be cut down to 
20 miles when possible. The number of round-trips for a given 
length of haul is approximately as follows : 
6-mile haul 2 round-trips 
5-mile haul 2 round-trips 
4-mile haul 2-3 round-trips 
3-mile haul 3 round-trips 
2-raile haul 4-5 round-trips 
1-mile haul 6-8 round-trips 
^- to f-mile haul 10-12 round-trips 
Log Haulers. — As early as 1885 the attention of loggers was 
directed to the problem of introducing some form of mechani- 
cal traction to replace horses on long sled hauls, but it was some 
years before a satisfactory machine was placed on the market. 
In 1889, Geo. T. Glover placed four log haulers on operations 
in Michigan. These were probably the first machines used for 
this purpose and, although they were not a success, they were 
the forerunners of the more recent ones that have proved to 
be of great value. 
The first successful steam log hauler was patented by 0. A. 
Lombard of Waterville, Maine, who adopted the general principles 
of the driving gear on geared locomotives, substituting for driving 
wheels a special form of heavy traction device. 
The hauler has a locomotive-type boiler mounted on a heavy 
reinforced channel-iron frame, which also supports the cab and 
coal tender at the rear. The machine is supported in front on 
a narrow tread sled, which is so constructed that it may be run 
either forward or backward. A pilot, who sits on the front of 
the machine, steers the hauler by means of a hand wheel which 
turns the sled. 
The weight of the machine rests chiefly upon two special trac- 
