50 AN AUSTRALIAN STUDY OF AMERICAN FORESTRY. 
Aerial tramways are used on steep slopes where other forms of transport 
are not practicable. 
Timber slides and chutes are very often employed down slopes. On the 
Pacific Coast, chutes are built at the terminus of a skid or pole road where 
the logs are dumped into a stream. 
Traction engines are used for transporting logs where the amount to be 
hauled is not great enough to warrant the laying down of a railroad, where 
the grades are unfavourable for the use of animal power, or where timber 
of large size and weight is to be handled. 
A novel engine is the Holt caterpillar gasoline tractor, which has a tread 
chain traction device in place of back wheels. It is suitable for use on soft 
sandy, roads, weighs eight tons, and can carry 18,000 feet of green lumber over 
12 per cent. to 14 per cent. grades at 24 to 5 miles an hour. It uses 2-4 
gallons of kerosene or gasoline per hour, and carries a fuel tank of 70 gallons 
and sufficient water for four or five days’ running. 
This traction seems to solve the problem of timber exploitation in the 
Pilliga Forest, New South Wales, where the stand is too light for railroad 
construction, the distance too great for bullock haulage, and the roads too 
soft and the water too scarce for the ordinary traction engine. 
An average lumber camp has a crew of about sixty men, and employs 
about thirty horses. 
Some of the modern camps are quite elaborate. One of them—the Cherry 
Valley Camp—provides spring beds, hot and cold baths, laundries, and 
electrically lit libraries and reading rooms for the crew. 
The aim of this camp betterment scheme is to hold the workers interested 
and content, and to maintain a permanent crew at a maximum standard of 
efficiency, and so secure the biggest possible cut. 
The modern American sawmill is one of the most remarkable examples of _ 
American engineering efficiency. 
Location alongside permanent and plentiful water is essential, largely with 
the object of water storage for the logs in the mill pond. 
The railroad track where it is parallel to the edge of the mill pond is 
laid at an angle which sets the outer rail 12 to 15 inches above the inner 
rail. The trucks thus are tilted to one side, and when the car stakes are 
removed, most of the logs roll out into the pond. 
I visited the Bonner mill of 700 h.p. in Montana, situated 25 miles from 
the logging area. Sawing was proceeding at the rate of 750,000 superficial 
feet sawn output daily, and there was stored in the Blackfoot River beside 
the mill a four months’ supply of logs! They were piled up in a water area 
extending beyond sight and then almost obscured the surface. 
Americans excel in method. Their enterprises are planned carefully. 
They have a passion for detail and efficiency. 
Nowhere is this exemplified better than in the running of a large sawmill. 
From the mill to the log pond extends a chute carrying a great hauling 
chain studded with “dogs.” Log drivers on the logs in the water push them 
against the chute. They are seized automatically by the “dogs” and lifted 
one after another, in a seemingly endless row, up the chute into the mill, 
streams of hot water spraying them clean as they go. The logs are sawn with 
the bork still on. At the top of the chute the log-scaler measures them with 
the simple and effective Scribner Decimal “C” scale stick, digs out any stones, 
