210 FORESTRY AND TIMBER 



Antiseptic preservatives. — Tlie best antiseptics for shingle treat- 

 ment are creosote and other derivatives of coal tar. Painting the 

 roof with these oils is a rather satisfactory method of treatment, 

 since the coal-tar derivatives penetrate the shingles better than 

 ordinary i)aint and do not leave ridg(;s below the base of the shingles. 

 At least two coats should be applied. Dipping the individual 

 shingles gives good results. The best results, however, are obtained 

 by heating and cooling the wood in the preservative, as described 

 for the treatment of fence posts. 



Suggestions for community action (Willis). 



It is often difficult for a farmer efficiently to treat his own material 

 with preservatives. This, however, does not indicate that the work 

 should be neglected. Rather it points to some different means of 

 securing the desired result. 



There are two practical methods of doing this. One is for some 

 individual to undertake the work for the neighborhood. A small 

 wood-preserving plant could be profitably operated in connection 

 with a threshing outfit, a feed mill, or sawmill. The other plan is 

 for several farmers to cooperate in establishing and operating the 

 plant. As an indication of the success which should attend such an 

 undertaking, the cooperative creameries of various sections of the 

 country may be cited. 



Board Measure 



Board measure is designed primarily for the measurement of sawed 

 lumber. The unit is the board foot, which is a board one inch thick 

 and one foot square, so that with inch boards the content in board 

 measure is the same as the number of square feet of surface ; with 

 lumber of other thicknesses the content is expressed in terms of inch 

 boards. 



Lumber is always .sold on a basis of 1000 feet board measure, the 

 abbreviation for wliich is B.M., and for thousand is M. Thus, 500 

 feet B.M., costing $18 per thousand, would be S9; 100 feet B.M., 

 $1.80; 10 feet B.M., 18 cents. 



At $10 per M., B.M., lumber costs l^ per square foot ; at $12, 1.2<^ 

 square foot ; at $14, 1.4^ ; at $15, 11^- ; at $17, 1.7^ ; at $20, 2^ square 



