284 



RECENT PUBEICATIONS. 



THE OPEN-TANK METHOD FOR THE TREATMENT OF TIMBER. 



A marked' saving in three directions — cost of equipment, of 

 materials and labor, and of transportation — is being effected by 

 the introduction of what is known as the ''open-tank" method of 

 treating timber. The general practice of preserving timber has 

 hitherto been retarded by the heavy cost of closed retorts and 

 other complicaied equipment ordinarily used and the need of 

 experienced men to operate them. Not until the kinds of timbc-r 

 long used and considered almost indispensable for certain pur- 

 poses grew scarce and rose alarmingly in price did wood users 

 consider seriously the possibility of consuming less wood by mak- 

 ing it last longer. 



As a rule preserving plants have been located at lumber centers, 

 where a large business might be expected, and it has often been 

 necessary to pay transportation charges to and from the treating 

 plant on timber needed for local uses, such as for ties, posts and 

 poles. The equipment of the open-tank method, which consists of 

 an open tank, capable of withstanding heat and either equipped 

 with steam coils or so arranged that fire can be placed imderneatli, 

 is so simple and comparatively so cheap that it is within reach 

 of the smaller companies, contractors and farmers. The fact 

 that it is portable gives it a distinctive value, since it can be taken, 

 if necessary, into the heart of the forest, and even into the moun- 

 tains. 



One of the chief advantages of the open-tank process is that it 

 can be effectively applied to parts of timbers which are especially 

 subject to rapid decay, such as the butts of fence posts and tele- 

 phone poles, without wasting preservatives on other parts. It Is 

 also especially adapted to the treatment of mine props, small 

 dimension timbers, cross-ties, piling, and shingles, and timbers in 

 small sizes of loblolly pine, black and tupelo gum, western yellow 

 pine, and lodgepole pine, and similar kinds of wood. Fairly good 

 results have been obtained in the treatment of arborvit?e, chest- 

 nut, and red oak, but the experiments thus far do not warrant 

 the application of the method to the treatment of piling and ties 

 made of these woods. 



The open-tank treatment is being rapidly developed, and while 

 it ordinarily does not secure so deep a penetration of the chem'- 

 cals as the retorts it is sufficiently thorough to protect timber 



