Abstracts of Technical Articles by Bell System Authors 



Lodgepole Pine Poles — Full Length Treatment Under Pressure — Butt 

 Treatment in Open Tanks} C. H. Amadon. Lodgepole pine ("Pinus 

 contorta") forms extensive forests in Colorado, Wyoming, Idaho and 

 Western Montana. The timber has been used widely for mine props, 

 railway ties and telephone and telegraph poles by the various industries 

 in the general region in which it grows. Like most of the pines, 

 lodgepole pine in its natural state is classed as a non-durable wood in 

 contact with the soil, and where a relatively long service life is desired the 

 timber has been treated with creosote or some other wood preservative. 



Lodgepole pine poles are exceptionally straight, free from knots of 

 objectionable size, fairly soft and when well seasoned weigh about 30 

 lb. per cu. ft. 



The purpose of this paper is to present information on the behavior, 

 under actual service conditions, of lodgepole pine poles that had been 

 pressure-treated in closed cylinders or butt-treated in open tanks, and 

 to describe the development of a process for the pressure treatment of 

 lodgepole pine poles to meet specific penetration and low retention 

 specification. 



Sound Measurement Objectives and Sound Level Meter Performance.'^ 

 J. M. Barstow. The standardization of sound level meters is shown 

 to have improved conditions in the field of sound measurement, al- 

 though several characteristics thought to be desirable in visual indi- 

 cating sound measuring devices are not fully realized in instruments 

 conforming to the present standards. The extent to which certain 

 sound measurement objectives have been realized in present sound 

 level meters is discussed. Further work will undoubtedly be necessary 

 before some of these objectives may be more completely realized. 

 Present indications are that sound level meter limitations in regard to 

 the approximation of sound jury loudness levels will be difficult to 

 remove and at the same time retain reasonable apparatus simplicity. 

 Some consideration is given to possible courses of action in regard to 

 such limitations. 



Coordination of Power and Communication Circuits for Low- Frequency 

 Induction."^ J. O'r. Coleman and H. M. Trueblood. Where power 



^ Proc. Anier. Wood-Preservers' Assoc, 1940. 

 2 Jour. Acous. Soc. Amer., July 1940. 

 ^Electrical Engineering, July 1940. 



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