22 HYDROCYANIC-ACID GAS FUMIGATION IN CALIFORNIA. 
the end of the poles. When ready to throw a cover, the machine is 
drawn opposite the tree, the arms are lowered until their ends are 
suspended beyond the outer edge of the tree, cables are then let down 
from the end pulleys and run through two series of rings in the tent, 
after which the tent is raised to the end of the derricks. These rings 
are so placed that when the cable is raised about one-third of the tent 
is gathered up in a series of folds. The derricks are then erected 
and the tent cables released, when the tent will fall over the tree. 
This operation is quite rapid as well as less wearing to the trees 
and tents than the use of poles or derricks. Although slower and more 
expensive than the use of poles in covering small trees, it is easily 
superior to derricks in covering large ones, such as seedlings, especially 
where so closely set that the branches interlace. 
SUPPLY CART AND SUPPLY WAGON. 
An apparatus of some sort is required in carrying from tree to tree 
the chemicals necessary in fumigation. The idea of using a two- 
wheeled pushcart originated with the San Bernardino County outfits, 
where this method has been used for several years. Observation of 
its use convinced the writer that in most places the employment of 
a properly equipped handcart is the most practical method available 
for carrying the chemicals. Extended effort has been made to equip 
such a cart in a manner suitable for convenient use in the field. The 
result of this effort is shown in Plate IV, figure 1, the make-up of 
which has been so improved over the original as to resemble it but 
little. As purchased, the cart-bed consists of a plain box fitted with 
a two-shaft handle. This handle is removed, and is replaced by a 
tongue having an enlarged link-shaped iron about a foot long firmly 
attached at the end. This link-shaped handle is very convenient in 
field work. The scales for weighing the chemicals are placed on a 
platform above the center of the box. The ordinary kind having a 
free scoop and using weights is most convenient; 1, 2, 4, 8, and 16 
ounce weights are required. The cyanid is contained in a tin-lined 
box in the rear half of the cart, while the acid and water are placed 
in the front end. A 10-gallon keg firmly attached in a horizontal 
position to the bed of the cart is a very convenient receptacle for the 
water. A galvanized-iron basin, like that shown above the keg, 
having an opening at the bottom fitting into the bung of the keg, 
makes a very satisfactory funnel for filling the latter. The acid may 
be held in an earthenware jar or a lead-lined tank, with cover firmly 
attached to prevent slopping. 
By way of a cover for the earthenware jar, a lead-lined lid (fig. 5) 
which fits tightly within the top has been used. At the center of this 
lid is an opening about 6 inches in diameter, around the circumference 
of which is attached a leaden tube which extends downward several 
