APPROXIMATING DIMENSIONS AND CUBIC CONTENTS. 39 



In undertaking the fumigation of a large grove the citrus growers 

 should avoid underestimating the liindrance to the work through winds 

 and rains. Fortunately during the season for fumigating in Florida 

 there is comparatively little rainfall in ordinary years. In the central 

 section of Florida wdnds at night ^\^ll ordinarily interfere very Httle, but 

 in sections near the coast interference from this source may be more 

 frequent. From the middle of December until the middle of Febru- 

 ary it is well to make allowance for an average of two nights each week 

 when fumigation work \vill have to be suspended. 



In finnigating seedling trees 30 feet or more in height one could 

 expect to fumigate from 300 to 400 trees a week with an outfit of 8 or 10 

 tents. In fumigating trees from 15 to 20 feet high with an outfit of 20 

 tents one could expect to fumigate from 800 to 1,000 trees a week. In 

 the cases of both the large and the small trees these estimates can fre- 

 quently be exceeded when conditions are favorable, but as the period 

 for fumigating is so limited it is advisable to avoid underestimating 

 the time required to complete the fumigation of a grove. In plan- 

 ning for the necessary equipment it is safe to calculate that with one 

 tent for each 100 trees the work of fumigation can be completed in 

 between ten and fourteen nights' work. In many cases it is neces- 

 sary to have two complete outfits at work in the same grove when 

 the work is started late in the season and there is danger of new 

 growth appearing on the trees before one outfit could finish the 

 grove. 



METHODS OF COMPUTING APPROXIMATE DIMENSIONS AND 

 CUBIC CONTENTS. 



The dosage recommended in the table given in the appendix is based 

 upon detailed records of 100 trees fumigated by the writer and his 

 assistants during January and February, 1907. Heretofore tables of 

 this kind have been based on the height and diameter of the trees, 

 with the exception of one prepared by Prof. C. W. Woodworth, who 

 first recommended a dosage system based on the dimensions of the 

 tented trees. The two dimensions of practical importance are the 

 circumference and the distance over the top from ground to ground. 

 The method for obtaining these dimensions has been described. In 

 Professor Woodworth's table of dosage referred to above, the amount 

 of cyanid was directly proportional to the cubic contents. The table 

 of dosage here recommended is based upon actual experience and is, 

 as far as known to the writer, the first to take into consideration the 

 effect of leakage. Tented trees are alwa^^s more or less irregular and 

 any attempt to calculate the volume of the space inclosed can give 

 only approximate figures. A cylinder surmounted by a hemisphere 

 is the regular figure that is nearest to the form of a tented tree. The 

 leakage surface of a flat octagonal tent covering a tree obviously is not 



