282 TIMBER 



" The temperature of the creosote when injected into the 

 timber is to be not less than 120 Fahr. and the pressure 

 is to be not less than 150 Ibs. per square inch." 



In the case of planking or sleepers, a parcel of say a 

 dozen or more, dependent upon the total quantity to be 

 placed in the tank, is weighed before and after creosoting, 

 and the amount of creosote injected into this parcel is 

 taken as the standard for the amount of creosote which 

 has been injected into the tankful of timber. 1 



It is generally stated that not more than 10 Ibs. of creo- 

 sote per cubic foot will be paid for in pitch pine, and 12 

 Ibs. per cubic foot for Baltic planking and railway sleepers, 

 as this is considered sufficient protection for timber in 

 Great Britain, even against the sea worm, but in the neigh- 

 bourhood of the Gulf of Mexico and other parts of the 

 American coast infested by the teredo as much as 22 to 25 

 Ibs. per cubic foot is recommended, but this is difficult to 

 obtain. Even in America, where the zinc chloride process 

 is almost in general use, creosoting is invariably applied to 

 timber structures in worm infested parts of the coast, as it 

 is the only process of any use in such a situation. Pitch 

 pine timber often requires to be under a pressure of 150 or 

 160 Ibs. per square inch for ten hours to allow of 7 Ibs. of 

 oil per cubic foot being injected ; Baltic timber as a rule 

 does not require such long pressing. 



It must be a very soft class of wood with a great deal of 

 sapwood and well dried which will admit of 22 Ibs. of oil 

 being injected into it, but this is the quantity which the 

 Louisville and Nashville Kailway Company try to get into 

 timber as a protection against the teredo. 



1 See previous remarks about creosoting Oregon Pine. It is now 

 being generally admitted that each species of timber requires different 

 treatment, as what may be very suitable for one species is not suitable 

 for others'. 



