OF FARM TIMBERS 



can be of assistance in supplying both the lumber and the 

 preservative. A further source of help and information 

 should be the State Agricultural College, experimental work 

 having been done in several states, and several bulletins 

 issued. 



PRESERVATIVES. 



The essentials of a good wood preservative are that it 

 shall kill the low forms of plant growth, known as fungi, 

 which cause the decay of wood; remain liquid at ordinary 

 temperatures, and penetrate at least the outer surface of 

 the wood; be permanent to the extent that enough remains 

 to give continuous protection; and be safe to handle and 

 use, there being no necessity for using anything poisonous 

 nor explosive. In addition to the essential characteristics 

 of the preservative itself, it should be of reasonable cost. 



Coal Tar Creosote is the best preservative known for 

 treating farm timbers. It prevents decay and is lasting in 

 its results, because it combines in a large measure the es- 

 sentials of the ideal preservative. There is some loss by 

 evaporation of the lighter less valuable portions, but creo- 

 sote is practically insoluble in water, remains liquid at ordi- 

 nary temperatures, and satisfactorily penetrates most kinds 

 of wood. It is comparatively cheap and safe to use under 

 nearly all conditions. Where the odor would be objection- 

 able exposure to the air for a time will render it less notice- 

 able. Creosoted surfaces should not be painted, nor is it 

 necessary because the oil itself gives a rich dark brown color 

 to the wood, and in most situations where used painting is 

 not needed. 



Such excellent results have been obtained from the 

 proper application of creosote that for many years it has 

 been widely recognized as the standard preservative for 

 general use. Although used to the extent of over 125 million 

 gallons a year, its application to farm timbers has been lim- 

 ited because it has not always been available in retail quan- 

 tities. Furthermore, the commercial creosote used for the 

 pressure treatment of railroad ties and large timbers is not 

 always best for brush and open tank treatment. Whenever 

 possible what is known as a high boiling, high gravity creo- 

 sote should be purchased for farm timbers. This simply 

 means a special oil or one corresponding to the highest grade 

 crude creosote, which is heavy and has a low percentage of 

 parts which evaporate at low temperature. 



Five 



