36 FORESTRY AND IRRIGATION January 



had been steamed without the subse- in a liquid condition. Consequently, 



quent application of zinc chlorid. The comparison between seasoned timber 



same statement may be made of timber and creosoted timber will always result 



treated with an S^ per cent, solution to the disadvantage of the latter as far 



of zinc chlorid. It may be that subse- as its strength is concerned. In the 



quently the crystallization of the zinc case of creosoted wood, it also remains 



chlorid will weaken the wood fiber, to determine what changes in the wood 



This remains to be determined. fiber take place through lapse of time 



The effect of the creosote appears to in the presence of creosote oil. 

 be the same as that of an equal amount It is expected that a bulletin will be 

 of water in weakening the fiber. That issued upon the results of these inves- 

 is to say, the strength of creosoted tim- tigations when the tests are completed, 

 ber is that of green timber. The dif- This bulletin will also contain the re- 

 ference is that while green timber suits of the investigations to determine 

 gains strength upon seasoning, the the best 'methods of preserving wood 

 creosote oil remains in the wood, and, so that the maximum impregnation 

 it appears from analysis of a pile thir- may be obtained with the least expen- 

 ty-five years old, that the oil remains diture of oil per cubic foot of timber. 



TREATING TELEGRAPH POLES 



Two Great Corporations Very Desirous of Dis- 

 covering a Means to Effect a Large Economy 



the last two years the Bureau pole, but only so far as the conditions 

 of Forestry has been co-opera- exist which promote the growth of 

 ting with the American Telephone and wood-destroying fungi. A few inch- 

 Telegraph Company and recently with es below the ground there is lack of 

 the Postal Telegraph-Cable Company the necessary oxygen and heat, while 

 also, in an experimental study to in- at about the same distance above 

 crease the durability of telegraph and ground the requisite moisture fails, 

 telephone poles. The interest in this The exact time at which decay begins 

 matter taken by these corporations its work depends upon the climate, the 

 promises an important forest economy character of the soil, and similar con- 

 through the possibility of using much ditions. In a hot, moist climate it or- 

 smaller trees than are now cut for dinarily sets in with great rapidity, 

 poles. This means a new market for But at best, in a very few years after 

 these smaller trees and liberating the the pole is set the struggle has corn- 

 larger ones for other uses. menced. The decay soon girdles the 

 The length of service of a telegraph pole and gradually eats into it deeper 

 or telephone pole is determined in a and deeper until it is so weakened that 

 section of the pole not more than a it breaks under the weight of its equip- 

 foot or a foot and a half long. In a ment. 



standing pole this section extends The strain upon the pole from wind 

 about six or eight inches above and be- pressure and the weight of its cross- 

 low the top of the ground. This is the arms and wires is calculated for the 

 universal point of attack upon the life ground line. When the diameter of 

 of the pole, arid is called its breaking this ground line is constantly de- 

 point. Decay is the arch-enemy of creased, the strength of the pole is pro- 

 these poles. It sets in at the ground portionately reduced, and it becomes 

 1 ine and reaches both up and down the only a question of time when the pole 



