Journal of Forestry

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doi: 10.1093/jof/40.3.z5pmid: N/A

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doi: 10.1093/jof/40.3.z1pmid: N/A

doi: 10.1093/jof/40.3.205pmid: N/A

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doi: 10.1093/jof/40.3.205pmid: N/A

Demmon, E. L.

doi: 10.1093/jof/40.3.207pmid: N/A

The United States has always been entirely dependent on foreign sonrces for its supplies of crude rubber. This material is essential for many domestic uses, and is particularly important at this time for national defense purposes. Major uses of rubber have been in the manufacture oftires for automobiles, trucks, and airplanes, but it has many other uses which make it the most nearly indispensable raw material not produced in the United States. For many years United States imports have averaged more than 50 percent of the entire world production of rubber, and reachedalmost 60 percent in 1940. The Office of Production Management in Washington placed rubber under priorities control on July 1, 1941, and cut consumption to a rate of about 600,000 tons annually; the rubber thus saved is going into stock piles for use in the defense program.

Demmon, E. L.

doi: 10.1093/jof/40.3.207pmid: N/A

The United States has always been entirely dependent on foreign sonrces for its supplies of crude rubber. This material is essential for many domestic uses, and is particularly important at this time for national defense purposes. Major uses of rubber have been in the manufacture of tires for automobiles, trucks, and airplanes, but it has many other uses which make it the most nearly indispensable raw material not produced in the United States. For many years United States imports have averaged more than 50 percent of the entire world production of rubber, and reached almost 60 percent in 1940. The Office of Production Management in Washington placed rubber under priorities control on July 1, 1941, and cut consumption to a rate of about 600,000 tons annually; the rubber thus saved is going into stock piles for use in the defense program.

Hasel, A. A.

doi: 10.1093/jof/40.3.211pmid: N/A

To organize cruises so as to steer a desirable middle course between high accuracy at too much cost and little accuracy at low cost is a problem many foresters have to contend with. It can only be done when the cruiser in charge has a real knowledge of the required standard of accuracy and of the variability existing in the timber stand. The study reported in this paper works out estimates of the average accuracy of cruises in California pine stands and ontlines methods whereby the accuracy may be estimated for particular cruises.

Hasel, A. A.

doi: 10.1093/jof/40.3.211pmid: N/A

To organize cruises so as to steer a desirable middle course between high accuracy at too much cost and little accuracy at low cost is a problem many foresters have to contend with. It can only be done when the cruiser in charge has a real knowledge of the required standard of accuracyand of the variability existing in the timber stand. The study reported in this paper works out estimates of the average accuracy of cruises in California pine stands and ontlines methods whereby the accuracy may be estimated for particular cruises.

Torgeson, O. W.

doi: 10.1093/jof/40.3.218pmid: N/A

How long does it take to kiln dry sugar maple? The answer looks simple, but is it? Dry kilns vary from hand controlled natural circulation to latest type with automatic controls of both temperature and humidity. In between are remodeled types. The author lists and discusses seven factors such as proportion of heartwood and sapwood, original and final moisture content, proper temperature, humidity and air velocity, which must be correlated so as to bring about uniform drying conditions and satisfactory kiln dried lumber. A thorough understanding of the relation of these factors is essential not only in designing or remodeling dry kilns, but in their operation.

Torgeson, O. W.

doi: 10.1093/jof/40.3.218pmid: N/A

How long does it take to kiln dry sugar maple? The answer looks simple, but is it? Dry kilns vary from hand controlled natural circulation to latest type with automatic controls of both temperature and humidity. In between are remodeled types. The author lists and discusses seven factorssuch as proportion of heartwood and sapwood, original and final moisture content, proper temperature, humidity and air velocity, which must be correlated so as to bring about uniform drying conditions and satisfactory kiln dried lumber. A thorough understanding of the relation of these factorsis essential not only in designing or remodeling dry kilns, but in their operation.