olG EEroRT OP THE Depautmext of Entomology ok the 



ESTIMATING CONTENTS OF BOX FUMIGATORS. 



The cubic contents of rectangular boxes are easily computed. 

 To estimate the contents of a hexagonal fumigator, multiply the 

 width of one side by one-quarter of the shortest diameter, and 

 this product by the number of sides and by the height; this will 

 give the cubic contents. 



COMPARISON OF VARIOUS FUMIGATORS. 



Tents. — The principal advantages of tents for orchard fumiga- 

 tion are that they require less chemicals and have less waste 

 space than any other form of covering, and that they can be 

 easily folded for storing or for transportation from one place to 

 another. Their objectionable features lie in the facts that the 

 space enclosed by them cannot be accurately estimated; that 

 this space and the amount of chemicals must be determined for 

 each tree; and that they rest directly upon the tree and are liable 

 not only to break the branches but to rub off many of the buds. 

 Furthermore, they are apt to be torn by the broken branches, 

 which, with constant abrasion in folding, causes them to leak. 

 The result is that there is no certainty as to the thoroughness of 

 the work done. When made over 30 feet in diameter they not 

 only require a derrick for handling, but increase rapidly in cost. 

 In addition, an expert is required where tents are used, to esti- 

 mate contents. 



Box fiimUjators. — Box fumigators^ whether folding, opened by 

 removal of one side or lifted bodily over a tree, have the advan- 

 tage of constant dimensions, hence the amount of chemicals for 

 charging can be accurately estimated and need be determined 

 but once for all. They have the further advantage of not rest- 

 ing upon the tree, thus they rarely break the branches or rub 

 buds from them; they are not as apt to be torn, therefore give 

 more uniform results and last longer; they have the disadvan- 

 tage of requiring more chemicals than do tents, they are more 

 unwieldy to handle, store or move from one orchard to another. 



'This does not iuclude Johusou's " Emory fumigator.' 



