316 PLANTS AND MAN 



the wooden shingle is best for dwelling use because of its cheap- 

 ness, long life, and attractive appearance. By far the outstanding 

 shingle wood is western red cedar, which is the source of nearly all 

 the shingles made in the United States. Eastern white cedars, 

 redwood and cypress also make very good shingles. 



Western red cedar shingles usually come from large-sized 

 trees which are logged with other species. The cedar logs are 

 sorted from other species in the woods and sent to shingle mills. 

 Here they are sawed into the desired length for shingle bolts, and 

 split to a size suitable for the shingle machine, where they are 

 carried past a very sharp circular saw. This power-driven car- 

 riage has a reciprocal action which provides for a tapered shingle, 

 in both up and down directions at alternating strokes of the 

 machine. Then the shingles are "edged" (that is, the sides are 

 made parallel to one another and at right angles to the ends), 

 sorted, and packed into bundles. 



Split shingles, or shakes, were extensively used during early 

 Colonial times, but today are produced and sold commercially 

 on only a small scale in the far west. They are made principally 

 from sugar pine, redwood, and western red cedar. 



Mine timbers. — Ranking sixth in amount of wood consumed 

 yearly, the annual mine timber output is valued at about 

 $28,000,000. The 6,500 mines in the United States all require 

 timbers for safety of operation. Most of the mine timbers are 

 round, hewed, or split; sawed wood in. the form of timbers, 

 plank, and lumber being much less used. For many years local 

 timber supplies were depended upon as a source of mine timbers, 

 but especially in the important coal and metal mining regions, 

 these supplies have been depleted. As a result it is necessary to 

 haul in desirable woods, or use local inferior species. The kind of 

 wood used varies widely, depending upon proximity of the min- 

 ing center to the various timber producing areas. Thus in the soft 

 coal mines of Illinois and Indiana, hardwoods from the region 

 immediately south, and southern pine from further away, are the 

 woods used. Oak, because of its strength and durability, is the 

 most commonly used of all tree species, making up almost one- 

 half of all mine timbers. In the copper and other metal mines of 



