Current Literature. 79 



plants, they are transferred by hand from standard gauge cars to 

 narrow gauge tram cars, which are placed alongside of the former. 

 The tram cars after being loaded are run on tracks into the steam- 

 ing cylinder. The cylinders are provided with a heavy cast steel 

 door adapted to slide up and down and close hermetically. It 

 is operated by an electric hoist and can be lowered or raised in 

 the space of one minute. The ties or timbers, in whatever form, 

 are then subjected to live steam for a period varying from thirty 

 minutes to four hours, depending upon the character and con- 

 dition, such as thickness of pieces, density of the wood, proportion 

 of heartwood and sapwood, species of wood, moisture condition 

 and the like, and at steam pressure of about fifteen pounds per 

 square inch. In most cases possibly fifteen to twenty pounds 

 should be the maximum. 



Next in order is to evaporate the condensed steam or moisture 

 from the ties or timbers. This is accomplished by stacking in a 

 yard for air seasoning. 



The ties should be piled in such manner that the air will have 

 free access to all surfaces, and a good way to stack ties for sea- 

 soning is to pile them by what is known as one by eight and run- 

 ning the stacks fourteen to sixteen feet high, which can easily be 

 done with a locomotive crane. 



Ties which have been given a preliminary steaming dry rapidly, 

 and the average time required to evaporate the moisture from 

 them to put them in condition for treatment is about three 

 months, depending upon the character of the wood and climatic 

 conditions. Ordinarily it requires from nine to twelve months in 

 the open air for hardwood ties to season sufficiently for treatment. 



When the ties have sufficiently seasoned and are ready for 

 treatment, they are taken from stacks, passed through an adzing 

 and boring machine and loaded directly on tram cars to be trans- 

 ported to the ovens for the completion of the drying and thence 

 to the impregnating cylinder for treatment with preservatives. 



It is essential to know the date when the ties were treated. 

 Some railroads affix galvanized dating nails. This method is 

 expensive and unsatisfactory. Instead of using dating nails a 

 pneumatic branding device, consisting of two opposite cylinders 

 with pistons, provided with dies for stamping dates, or any other 

 information, and controlled by automatic air valves, may be placed 



