Abstracts of Technical Articles by Bell System Authors 



Poles and Pole Treatment.^ Reginald H. Colley. Studies made of 

 pole use and drainage on the southern pine forest have brought out that if 

 the demand for poles 35-feet and longer were to continue at the present rate, 

 a situation would soon develop in which these poles would be at a premium. 

 It would seem wise to use as many circumference classes as possible and to 

 broaden the use of poles of other species whenever it is practicable to do so. 

 Successful full length treatment of red pine, lodgepole pine, western cedar 

 and Douglas fir poles will help to broaden this use. 



There has been a definite trend toward greater mechanization in pole 

 production. Machine shaving smooths the pole surface and accelerates 

 drying. Poles with square cut roofs and slab gains are all-purpose poles, 

 one design taking the place of four. New types of preservative treatment — 

 greensalt, creosote-petroleum-pentachlorphenol and salt-creosote — are of 

 promise and must be considered, when current restrictions are removed, in 

 those cases where clean poles are mandatory. 



Interesting breaking test data are reported which show that the modulus 

 of rupture of pole top sections average 90 per cent of the modulus of the 

 poles as a whole, and that pole tops are sufficiently strong to meet their 

 specified class breaking loads. This is of considerable importance where 

 poles are guyed. 



Current groundline treatment methods, it is pointed out, should be applied 

 to untreated poles in line that are worth saving at the time of inspection, as 

 a part of the regular inspection procedure. 



Hearing, the Determining Factor for High-Fidelity Transmission.- Harvey 

 Fletcher. This paper gives the requirements for ideal systems for the 

 transmission of speech and music. These requirements are based on: 1. 

 Measurements of the threshold and frequency limits of the hearing of more 

 than 500,000 people at the New York and San Francisco World's Fairs; 

 2. measurements of the discomfort level of sound; 3. measurements of room 

 noise in a wide variety of locations; and 4. measurements of the frequency 

 limits and the maximum and minimum levels of speech, orchestral music, 

 and various instruments of the orchestra. 



From this information and from judgment tests it is concluded that 

 substantially complete fidelity in the transmission of orchestral music is 



^ Elec'l. Engg., Transactions Section, September 1942. 

 2Proc. /. i?. £., June 1942. 



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