12 BULLETIN 272, U. S. DEPAKTME1TT OF AGRICULTURE. 



The trees are girdled several months in advance of logging. The pull 

 boat, as finally developed, with its stationary engine mounted on a 

 float or barge, skids the cypress over the soft surface for distances up 

 to 2,000 feet or more on either side of the canal or bayou. The dredge 

 boat, working just in advance of the pull boat in digging canals in the 

 swamp soils, gave access to the cypress where natural channels were 

 lacking. The advent of railroad swamp logging with the overhead 

 cableway skidder was the principal factor in opening up vast regions 

 of cypress previously considered inaccessible because not sufficiently 

 inundated. The fight skidding engine, mounted on runners and 

 pulling itself over the flat pine woods along the margin of swamps and 

 known as a "snaker," has been a valuable accessory, especially in the 

 Atlantic coastal region. 



In the overhead-skidder method the logs are brought in by a car- 

 riage or "bicycle" traveling over a powerful cable suspended between 

 the "head tree" and "tail tree," usually 600 feet apart (PL I). In 

 the heavier types, such as the duplex-spar skidder, the total distance 

 covered is 2,000 feet in the two opposite directions from the skidder 

 engine, which rests temporarily on piles driven beside the railroad 

 track. The logs are pulled up to the main cableway for distances of 

 as much as 100 feet on either side. Thus a strip 2,000 feet by 200 feet 

 wide, or approximately 9 acres, is covered at each "set." The smaller 

 overhead steam skidder logs at -each "set" successively a dozen or 

 more strips 600 feet long extending outward as radii from the engine 

 at the center, covering an area of about 26 acres. 



The cost of logging is discussed on page 15 in connection with the 

 total cost of lumber production. 



GIRDLING. 



It is the general practice to girdle or "belt" cypress trees from 6 

 months to a year in advance of logging. The result is that about 95 

 per cent of the logs will float instead of 10 to 20 per cent. This 

 reduction in the number of "sinkers" is a matter of the greatest sig- 

 nificance in cheap water logging and pond storage at the mill. Large 

 operators, having considerable amounts of the more valuable hard- 

 woods in mixture, generally use dry log yards instead of log ponds at 

 their mills. In this case the cypress is not girdled. 



Under direction of a foreman, girdling crews composed of 2 to 6 

 men each girdle the trees for a price per tree, usually from 6 to 9 cents, 

 determined in advance by the general size and density of the timber. 

 In order to secure early drying it is necessary in girdling to cut 

 through the sapwood to the heart. 



Among operators much variation prevails in respect to the season 

 of the year chosen for girdling and the length of time before cutting. 

 The majority prefer to girdle in the fall because the trees' activities 



