A COVER FOB n M l«. \ l l»».\ ,,i..\ ERA CORS. 
i) < 
tent. It is attache*! to the generator by iiinges of stout copper wire 
Becured by a key bolt passing through the handle. The cover is 
raised by a slight pressure of the thumb od a projecting piece which 
ie curved in such a manner that the cover will remain in an upright 
position when so required. When the generator is emptied of its 
contents, t ho cover swings clear by its own weight. A glance at the 
illustration will satisfy the practical I'ninigator that it is adapted to 
all the requirements of rapid work in the dark, while its use has 
demonstrated that it is simple, strong, and durable. It is \<t\ 
possible that if the copper cover were lined with a thin covering 
o[ Lead its durability 
would be increased. 
A common result of 
the use of heavy do- 
sages o( line fragments 
of cyanid is the burn- 
ing and ultimate drop- 
ping of many of the 
Leaves directly above 1 
the generator in the 
pathway of the rapidly 
rising gas. This result 
is usually spoken of as 
the "chimney " effect. 
The generator cover 
eliminates this " chim- 
ney' ' burning. 
A second and highly 
important point is the 
effect of open gener- fig. 20.-7,1 
a tors on the tent. 
The outer part, or skirt, as it is sometimes called, of fumigating 
tents is constantly being perforated with small holes, even when 
used by the most careful of workers. We have noticed this effect 
to some extent in our own outfit, which we believe to be as carefully 
handled as any fumigation outfit could be. These holes are known 
to be acid burns. A few simple tests have demonstrated conclu- 
sively that many of these acid holes are due to acid carried along 
with the escaping gas and reaching that part of the tent nearest 
the generator. By placing large pieces of canvas in the path of gas 
escaping from open generators in which dosages similar to those 
often used in field work are employed, it was found that drops of 
acid reached the canvas a- high as 5 feet from the ground. The 
writer has frequently seen generating vessels placed not more than 
2 feet inside the tent. At such a distance one can readily see that 
d top for protecting cyanid in the field. 
(Original.) 
