8o Forestry Quarterly. 



directly behind the boring spindles and so timed to the machine 

 feed that when the tie moves to the proper position, the dies ad- 

 vance and leave their deep-sunken impression in both ends of the 

 tie. 



After the ties have been machined and loaded directly upon 

 tram cars, they are transported to the drying ovens. The time 

 required in the ovens to complete the drying of railroad ties which 

 have undergone the several preceding steps is about from eighteen 

 to thirty hours, or an average of twenty- four hours. 



The transfer from the drying ovens is quickly made by means 

 of a transfer table and no appreciable amount of heat is lost while 

 making the shift from said ovens to the impregnating retorts. It 

 has been popularly supposed that in operations on a large scale it 

 would involve considerable expense to move the ties from the 

 steaming cylinders to the drying yards and from the drying yards 

 to the drying ovens, and from the drying ovens to the impreg- 

 nating retorts, and thereby increase the cost of handling. This 

 is incorrect. On the contrary, by means of the transfer table and 

 the locomotive crane, the cost of handling ties and lumber may be 

 actually reduced in most cases. 



Green timber fresh from the saw can be treated as readily as 

 older stock; sometimes apparently more readily, so that prelimi- 

 nary air seasoning may be dispensed with; therefore this system 

 of steaming and drying ties or lumber may be employed with or 

 without a treating plant adjunct. 



After the timbers have remained in the ovens a sufficient length 

 of time thoroughly to dry and warm them, the trams are 

 drawn out onto a transfer table and immediately run into the 

 impregnating cylinders for chemical treatment. The length of 

 the said cylinders corresponds with that of the drying oven and is 

 capable of holding twelve tram loads of eight-foot ties, each tram 

 carrying between forty-five and fifty ties, or approximately five 

 hundred and sixty ties per charge. 



The duration of the diverse phases of one complete operation 

 occupying four hours is as follows : 



(i) Charging the cyHnder with ties, 15 minutes 



(2) Producing vacuum to 14 inches, 45 



(3) Filling cylinder with chemical, 15 



(4) Continuation of filling with pressure pump,.. 90 



