1024 
erable amount of heat and a very dense 
smudge. 
Methods of Lighting 
The methods of lighting the different 
fuels are not difficult. With crude oil 
and distillate a small amount of gasoline 
or kerosene, squirted from an oil can 
onto the surface of the oils, was easily 
ignited by a torch. In most cases the 
torches were home-made affairs, but 
were none the less serviceable. A man 
could easily light the pots as fast as 
he could walk. The cover on the pot 
was quickly thrown off, a few drops of 
kerosene or gasoline spilled on the sur- 
face of the oil and the torch quickly ap- 
plied; this is the work of but a moment, 
and scarcely needed a stop on the part 
of the operator. In order to ignite the 
wood it is necessary to pile it in a par- 
ticular way Fine material is not abso- 
lutely necessary if the wood is dry. A 
kerosene can and a torch are all that is 
needed. A small amount of kerosene 
spilled on the wood, which is piled 
“dove-tail” fashion, and the torch applied 
will easily start it. During the past sea- 
son of frosts some difficulty was experi- 
enced in lighting the wood on account of 
the fact that during the week previous 
there had been a heavy precipitation 
amounting to about 1.27 inches. How- 
ever, this exigency was overcome by us- 
ing kindling and a little more kerosene 
and some crude oil. In using wood the 
particular thing to keep in mind is that 
it should be dry. Frost conditions are 
almost certain to follow a heavy rain, 
and this was particularly true during 
this season. 
Planning the Frost-Fighting Campaign; 
Number of Pots or Fires per Acre 
The work of planning the frost-fight- 
ing campaign really begins the previous 
fall. If crude oil or distillate is the fuel 
to be used the pots must be purchased 
so as to be on the ground not later than 
the last week of March, even though 
frosts do not usually occur before the 
first week of April. The fuel oil is also 
ordered in tank cars of 6,000 to 10,000 
gallons each, and upon delivery is emp- 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
tied into large storage tanks on the 
ranches. These tanks are usually of 
concrete, and are placed upon an eleva- 
tion so that the work of unloading the 
delivery wagons, aS well as the subse- 
quent filling of the tank wagons for de- 
livery to the pots in the orchard, is 
effected by gravity. Pumping crude oil 
is rather an impossible task, or a diffi- 
cult one at best, especially when it is 
cold. Distillate is easier to handle, but 
the gravity method of handling it is 
much quicker and saves a lot of work. 
The method of filling the pots is usually 
by means of a large hose attached to a 
gate valve on the delivery tank. An- 
other method is to use large buckets 
with which to fill the pots. When this 
method is used the hose is dispensed 
with, and only a large gate valve or mo- 
lasses gate is used. Six men working 
eight hours can easily fill 2,000 pots. The 
number of pots to be used per acre will 
vary within wide limits. Large spread- 
ing trees, with the fruit borne not low- 
er than four feet from the ground, may 
easily be protected from the most serious 
freeze we have experienced during the 
past four years by using sixty-five to 
seventy pots per acre. However, it is to 
be understood that the sides or outside 
rows should be reinforced by at least two 
rows of pots. This is especially true of 
the sides of orchards in the direction of 
the prevailing wind. However, it is a 
good plan to reinforce all sides so as to 
meet any emergency. During the 1911 
season sixty-five pots burning slop distil- 
late saved the Potter and Goold pear 
orchard when the temperature outside 
of the orchard registered 20 degrees by a 
tested thermometer. The results in this 
orchard are so clear that there is no mis- 
taking the effectiveness of systematic 
orchard heating. A few pear trees of 
the same variety standing about ten rods 
outside of the heated area lost their en- 
tire crop. 
The number of pots to be used will 
depend upon the geographical position of 
the orchard, its elevation, and the size 
and height of the crop bearing portion 
of the trees. In a young orchard of per- 
