METHOD OF GENERATING THE GAS. 35 



indicating the dose, the circumference in yards (paces), and the difference (that is, 

 the amount the dose must be varied) should the distance around he more or less 

 than the amount indicated for an average tent. 



This suggestion in regard to the marking of tents with the dosage 

 to obviate the use of printed tables seems to the writer to be of con- 

 siderable value under some circumstances. One objection to the use 

 of difYere_ntials in this manner is that the cubic capacity and dosage 

 does not increase in direct proportion to the increase in circumfer- 

 ence with a given distance over the top. To illustrate the method 

 of marking the tents with the dosage, when desired, a tent meas- 

 uring 30 feet over from ground to ground will serve as an example. 

 The table in the appendix shows that for every 5 feet of difference 

 in the measurement of the circumference of a tent measuring 30 feet 

 over the top, the amount of cyanid is increased or decreased one- 

 half ounce, or 0.1 ounce for each foot. With the figure 30 on the tent, 

 we would place the dosage of a tented tree measuring 30 feet in cir- 

 cumference. The dosage called for by the table for a tent of this 

 size (30 by 30) is 9^ ounces. Following this the differential, or 0.1 

 ounce, is placed. The entire directions for obtaining the dosage 

 would read 30 — 9^ — 0.1. A tented tree measuring 30 feet over and 

 38 feet in circumference would require 91 ounces plus 0.8 ounce or, 

 for practical purposes, lOi ounces. If the measurement was 30 feet 

 over and 25 feet in circumference, the dosage would be 9h less 0.5 

 ounce, or 9 ounces. 



When tables are worked out in detail, as they should be where 

 accurate work is desired, reference to them is undoubtedly by far 

 the quickest and safest method under ordinary circumstances. 



METHOD OF GENERATING THE GAS, 



In order to permit of making the measurements of tents and esti- 

 mating the dosage with the care hereafter recommended and with 

 the least possible delay, it is sometimes advisable, in operations on 

 a large scale, that the cyanid be weighed during the day or at other 

 times when it is not advisable to fumigate, or, if done at night, that 

 an additional helper be employed. Such a helper, in addition to 

 weighing the cyanid, might look after the replenishing of the stock 

 of cyanid and acid at the cart as needed and assist in measuring the 

 tents and emptying the generating jars. The cyanid shoidd be 

 weighed up in lots of J, 1, 2, 5, 10, and 20 ounces, put into paper 

 bags of convenient size, and protected from dampness. Wlien the 

 tented trees all measure less than 34 feet over the top from ground 

 to ground, the doses of 20 ounces each will not be required, and 

 when measuring more than this the lots of one-half ounce may be 

 dispensed with. At the cart, drag, or tray these bags of cyanid 

 should be kept in separate boxes, or in separate compartments of a 



