unnecessarily great amount of creosote, while other poles may be badly 

 undertreated. Furthermore, the process is time-consuming. 



Efforts have been made to devise a 'method of treating the lower 

 section of poles with the use of hydraulic pressure, thus shortening the time 

 required and insuring a better penetration of creosote. The most practic- 

 able method is one that was patented some time between the years 1860 

 and 1870. (Patent office records for this period are not available to the 

 writer, so the exact date can not be cited.) This method makes use of a 

 vertical cylindrical retort, slightly longer than the longest pole to be 

 treated. The retort is mounted in a pit with the upper end at the ground 

 level. The poles are placed in the retort and a sufficient amount of creo- 

 sote is introduced to bring the level of the creosote to a point somewhat 

 above the upper limit of the section to be treated. A heavy door at the 

 upper end of the retort is then tightly bolted shut, and compressed air is 

 pumped into the space within the retort above the level of the creosote. 

 The hydraulic pressure thus developed forces the creosote into the section 

 of the pole that is immersed. If it is desired to give the whole pole a light 

 treatment after the butt section has been heavily treated, the compressed 

 air is released and the retort is filled with creosote. Pressure is then 

 applied for a short time. The creosote is then removed and the treated 

 poles are withdrawn from the retort. 



In the method just described, excellent results can be obtained. Rela- 

 tively expensive equipment is however required, and the writer knows of 

 only one plant where this system is in use, though with certain modifica- 

 tions. Several years ago John T. Logan, of Texarkana, Texas, patented 

 an apparatus (U. S. Patent 956,382) for the pressure treatment of the 

 butt sections of poles. Logan's patent covers the idea of a retort mounted 

 on heavy trunnions at its middle section, so that it can be filled with poles 

 while in a horizontal position and then swung into a vertical position. 

 While in a horizontal position, it can be used for the treatment of any 

 material just as an ordinary creosoting retort. Mr. Logan erected and is 

 using a retort of this description. 



While the process described above enables the creosoting plant 

 operator to inject the creosote into the wood with greater rapidity and 

 makes possible the butt treatment of poles by so-called "empty cell" pro- 

 cesses, it has the same defects as the open tank process in that creosote 

 is wasted in end penetration and uneven penetration of the sap wood. 

 There is no assurance that the section of the pole at the ground line will 

 receive the necessary penetration of creosote. 



A new era in the treatment of poles seems to have begun with the 

 recent development of what is known as the "perforation process." The 

 fact that the penetration of creosote into wood can be effectively and 

 cheaply localized by making small perforations at frequent intervals into 

 the surface of the wood has lately occasioned much interest. This is 

 however not a new principle. In the early nineties the J. M. Colman 

 Company, of Seattle, Washington, made use of this idea in the creosoting 

 of piling for the Colman Dock, which was then in the process of erection. 

 The sections of the piling that were to be in the water and exposed to the 

 attacks of teredoes were perforated by driving small spikes into the wood 

 to a depth of about one-half inch, and withdrawing them. The sections 

 below the mud line and above the water line were left unperforated. Very 

 excellent results were secured, but the cost of perforating, which was all 

 done by hand was excessive ,and the process was not continued. 



In 1911, three Austrians, Kolossvary, Haltenberger and Berdenich, 

 patented a method of perforating (U. S. Patent 1,012,207) in which rotating 

 needles are forced into the section of the pole at the ground line, thus 

 making it possible to treat this section of the pole much more heavily 

 than the rest of the section immersed in the creosote, when such perforated 

 poles are treated by the open tank process. This machine is rather compli- 

 cated and it would seem to be expensive to operate. The writer knows of 



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