INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



485 



The writer is indebted to Mr. R. S. Vaile for the information on 

 shrinkage and cost of work. 



Marking. — Because of the shrinkage it is preferable to mark the. 

 tents after dipping. 



The usual practice, as determined by Dr. A. W. Morrill, consists in 

 making three, one and a half or two-inch parallel lines across the 

 tent three feet apart. Three lines are made in preference to one. 



jTjg 4S4. — Apparatus for dipping tents in tannin to prevent 

 mildew. (After Woglum, U. S. Dept. Agric.) 



so that when the tent is put over the tree one of these lines will be 

 sure to pass over the center. The measurements over the tree are 

 ascertained by numbering each foot across the tent, beginning in 

 the middle, and numbering each way, as shown in Fig. 482. The 

 first four numbers are omitted because they are seldom if ever needed. 

 The cost of marking and stenciling the numbers averages aboul seventy- 

 five cents a tent. 



Number for Outfit.— The ordinary fumigating outfit consists of from 

 thirty to forty tents, a number which five men are eapable of throw- 



