community has been proved eminently practical. The advanced fruit grower now knows that even a heavy freeze such as destroyed millions in fruit, cotton, grain and other growing things can be neutralized so as to insure practically full crops every year. The fruit growers of the Grand River Valley earned their lesson after the loss of millions in successive frost attacks, but they learned it well. The twenty-five hundred carloads of fruit that went out of Mesa County alone last fall testify to the thoroughness with which they operated this gigantic system of crop protection in one of the severest of late springs. It is estimated by government authorities that from $75,000,000 to $100,000,000 has been lost annually to the fruit growers by reason of frost and freezing weather. Careful and methodical orchard heating has saved a large percentage of this in the fruit areas where heating has been generally adopted. The orchard heating committee of the Colorado fruit growers estimates that $4,000,000 was saved to the growers of that state alone in 1909. For as many as five years in succession in many fruit growing communities the crop has been either totally or partially destroyed.

Smudging, or the formation of a dense blanket of smoke over the orchard, had been practiced with varying degrees of success in some parts of Europe. Orchard heating proper, was first used in California, and the original California smudge pot is still successfully used in many orchards. In the spring of 1908 several growers in the Grand Valley of Colorado experimented with the burning of oil in simple pots of the "lard pail" type, with the result that they saved their entire crop on the heated areas and lost it on the unheated tracts. The spring of 1909 saw the adoption of smudge pots in every fruit section of the state, and they reached the experimental stage in several other states. In the spring of 1910 there was not a fruit growing state without them, and many sections of several states were as fully equipped as Colorado.

The thrilling and successful frost fights in Colorado were an inspiring object lesson to the growers. At Canon City they organized and appointed an

orchard heating committee, the first in existence. With an appropriation of $1,000, its members set zealously to work on a series of experiments to determine just what could be accomplished in raising the temperature of entire orchards, and what the cost and the conditions of work would be. For six months they worked with every kind of fuel and all the various devices for producing fires. At the end of this time they unanimously recommended oil as the most practicable fuel owing to the ease and rapidity with which heat could be generated. The experiments of the orchard heating committee had showed that the temperature of an orchard could be raised fourteen degrees with one hundred small oil pots to the acre. The record of that historic spring fight of 1909 fully bore out this conclusion. The last night of April the temperature in the Canon City district fell to seventeen degrees above zero. The orchardists with heaters kept the temperature up to twenty-eight or thirty degrees, which they considered the safety point. the preceding night there was a terrific blizzard. The wind blew a gale and there was a snow fall of over eight inches, weather that made very trying conditions for the free burning of oil. In spite of this unusually severe test, the temperature was kept up to the safety point for over five hours. As an experiment, several acres of the test orchard were left unprotected. On the heated part there was a banner crop, more than 15,000 boxes, while on the several acres not heated, with one hundred ten year old trees in full bearing condition, there was not a box of apples.

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Frost fighting is not an easy job. It is necessary to have a force of men, industrious, careful, and observing to the last degree. And it is no pleasant task to rush out into the still, cold darkness to drudge the better part of the night to save your own or your neighbor's orchard. In the early days of orchard heating, a man was detailed to watch the tested thermometers that were hung in different parts of the orchard and at the farm house some distance away from the fruit trees. If the temperature was not sinking fast, perhaps the rancher went to bed for a brief nap, setting his alarm

clock to wake him at intervals through the night. Nowadays he can go to bed with a feeling of security, leaving the frost alarm thermometer to watch for him. This electric watchman has for its business end in the orchard a specially made thermometer, with a fine platinum wire fused into the mercury at the freezing point or at whatever is considered the danger point. As soon as the mercury sinks below this wire, the circuit is broken and the alarm at the head of the orchard boss' bed rings out its warning. Any interruption of the current causes the bell to ring so that if the apparatus should be out of order it automatically tells on itself.

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But the orchardist is usually forewarned, even before he goes to bed, and makes ready for the fray. Late in the afternoon he notices great fleecy clouds. hurrying from the northwest, chased by a bitter wind which seems to have been intended for January rather than this April night. He goes to the post office for the day's mail and in every window sees the warning of the diligent local government weather forecast: "Freezing temperature tonight." By seven o'clock the government thermometer is at thirty-seven and falling fast. seven-thirty he telephones the weather man and gets the reply: "Bitter cold all over the country; temperature is already down to twenty-seven in many parts of the valley and will drop to twenty degrees on the Western Slope of Colorado tonight." By eight o'clock it has fallen to thirty-two, his alarm begins to ring, and he knows that King Frost with his icy-fingered warriors is marching on the camp. Steam whistles are beginning to shriek all through the Valley to warn the growers of the all-night siege. Farm wagons laden with coal and oil rattle past, giving evidence that the laggards who have been hoping to the last, are beginning to get their heating machinery into action. Already the early ones are firing heavily. Clouds of smoke hang low over the trees, and the little spots of fire beneath punctuate the blackness with rays of hope.

The orchard firemen dash for the trees, a torch in one hand, and a gasoline can to aid in quick lighting in the other. Dashing a few drops of gasoline on the

oil, they apply the torch, and the blaze is at work. The lighting is done as fast. as the men can walk through the orchard, leaving a trail of smoke and fire behind them. In fifteen minutes each man has his tract of orchard transformed into a sea of flame under a cloud of smoke.

Then comes the first period of rest. The men gather in the packing house or barn, for lunch or smoke, making occasional trips to the thermometers to see that the fire is doing its work. By ninethirty the thermometers outside the orchard register twenty-eight, and those in the area of heat show a comfortable thirty-seven. Then the frost fighters know that the battle is half won, for keeping up the temperature is a good deal easier than raising it when it has once reached the limit. The rest is a matter of vigilance. If the heater is of the regulated type, with enough fuel to burn through the night or longer, a few men are left to watch and open the burners wider if a later sudden fall of temperature shows that more fire is needed. If the heaters are of the uniform single burner type, they may need to be refilled when they are nearly burned out, if the frost battalion should come back for another charge. The outside thermometers drop to twenty-four, and those in the orchards stand at thirty, the danger mark of the orchard frost fighter. The heaters are opened wider, or refilled if burning low, and the mercury shoots up to thirty-three. eight degrees of frost has been driven away, and if the oil supply is plentiful, and the labor unflagging, the orchardist may now consider the battle won. When the sun has shed his rays over the trees long enough to make the outside temperature more nearly that of the orchard, the heaters are shut off by merely putting on the covers.

The

Heating in the spring of 1910 was much easier than that of the year before, and proved more conclusively than ever the effectiveness of the fires. The crop in the Colorado fruit area for 1910 averaged about fifty-five per cent. The unheated orchards yielded from twenty to seventy-five per cent of a crop, while the yield of the protected orchards was from ninety-five to a hundred per cent,

so heavy that thinning was necessary in many of them.

Individual testimony to the efficiency of orchard heating in every fruit growing state could be multiplied indefinitely.. Fruit crops valued at $250 to $750 an acre were frequently saved at a cost of seven to ten dollars an acre. A few striking examples are typical of general results. A Colorado grower with fifty heaters to the acre raised the temperature of his forty-acre orchard from eighteen to twenty-eight degrees and produced forty-one carloads of apples.

Another one in the Grand River Valley, who was one of the pioneer orchard heaters, holds some world's records for heavy apple production. He produced this season 4,150 boxes of apples from 2.6 acres, an average of 1,600 boxes an acre, valued at one dollar a box. A block of two-thirds of an acre in this orchard produced at the rate of 2,200 boxes an acre, the largest yield on record. This orchard was carefully pruned, heated, sprayed and thinned and proves

what can be done with care and cultivation. The entire orchard this year gave the largest crop in its history, while adjoining tracts, not heated, got only thirty-five per cent of a crop.

An Iowa grower who had lost several crops from frost, came to the conclusion that he must do something to save his crop or go out of business. By experimenting with the burning of brush, he saved a peach crop of 6,000 bushels, and was induced to go into the heating business in earnest. In his orchard of 900 bearing trees he placed 1,000 of the small single burning oil pots. The temperature was held to thirty-three degrees in the orchard while it was twenty-three outside, and accompanied by the most adverse weather conditions that could be experienced. The wind was blowing so hard that it was difficult to pour oil into the pots. It was snowing heavily, causing the oil to sputter and pop from the pots, wasting a good part of the fuel supply. He fired up nine nights during the season.

He harvested this fall a full

crop of apples, the only one in the state, at a cost of only seven cents a bushel for heating. This figure includes the storage tank, wagons, and all necessary equipment, including labor. With the plant established, his next season's expense will, of course, be much smaller. There is seldom necessity for firing more than two or three nights in a season. A grower in the Rogue River Valley of Oregon, saved ten acres of apples valued at $6,000, at a cost of $6 an acre, where one freeze on May 5 of the previous year had destroyed his entire crop. In a neighboring apple orchard which has yielded as high as $1,000 an acre, a full crop was saved at about the same cost. Many acres of crops in this territory valued at $500 to $1,000 an acre were saved at a total expense for the season's firing of $15 to $20 an acre. There were frequent object lessons of unheated orchards, with the entire crop killed, adjoining heated tracts that had full yields.

One of the most remarkable stories of heater successes comes from Missouri. A 240 acre orchard located in a deep valley had suffered severely from frost every year and had not produced a full crop for fourteen years. Against the advice of all the wise-acres, two brothers from Kansas City bought it, and it, and equipped it with 5,000 heaters of the controlled or graduated fire type. With thirty-five or forty pots to the acre, the firing was done for four nights at the time the apples were in bloom. They harvested a crop of 15,000 barrels, valued at $45,000, and it was the only crop in that fruit growing territory. The net profit on each acre approximated $200. This valley is an excellent fruit growing country, but on account of regular frost damage for many years the industry has almost died. Land has depreciated in value till good orchard tracts are often sold at $40 to $100 an acre. The successful experience of this one orchard will revive a whole fruit growing community.

Modern orchard warming is the effective combination of smudging and actual heating. The principle of air drainage underlies successful frost fighting. Cold air settles, and hot air rises. Heating warms the air; smudg

ing prevents the warmed air from rising, and keeps out the cold currents from above. Frost injury is greatest where there is poor air drainage and the radiation is consequently uninterrupted by clouds or moisture. This is why fruit growers located in valleys had much harder fights against the common enemy in the early history of smudging than their neighbors on higher ground. The cold air settled in the valleys and chilled the life out of their fruit for many years before they discovered the

reason.

The definite system of building a multitude of small fires and actually heating "all outdoors" was a long time developing, but when once the idea was born its growth was like a forest fire. When it finally seemed inevitable that the fruit grower must build a fire big enough to heat his orchard, naturally the first fuel thought of was wood, as a result of the burning of smudging materials. It is still successfully used in some sections of the West where cord wood is cheap. The labor of handling it, however, and of keeping the fires going, with the added uncertainty of getting quick enough action to get ahead of the frost, has militated against the general use of wood for large orchards and for all sections of the country. The sticks of cord wood are usually piled along the sides. of the orchard at odd times during the winter months when little else could be done. One Oregon grower saved seven acres of Bartlett pears two years in succession by burning old fence rails. Fires of about six pieces of good cord-wood last four or five hours. Constant attention is necessary, for the sticks must be moved forward into the crater of the flame to keep the fire going. With wood plentiful and labor cheap, the cost of maintaining forty fires on an acre may be as low as two to four dollars a night.

Coal was the second fuel to be used, and is still employed with success in the little coal furnaces on stilts or the conical, perforated coal pails. Here again, however, difficulty of firing and handling the coal operate against its use in severe weather. Where the supply is plentiful, and prices low, where the orchard is small and labor easy to get, coal makes a very successful heat if amazing zeal is

used in handling it. It has certain advantages that appeal to many users, in spite of the trouble of handling it. Next to wood it is the commonest and best known fuel, and every one understands its action in combustion. It requires less expensive storage equipment, and the cost of the first outfit is less than for an oil burning plant. The little sheet iron coal furnaces hold about twentyfive or thirty pounds of coal and will burn four to six hours. The cost of heating an acre with about sixty furnaces of this description will average five or six dollars, including labor, interest on the cost of the pots and about 250 pounds of coal.

The little outdoor oil stove has come to be recognized as the dreadnaught of all heaters when it comes to making fires easily and quickly with a minimum of labor and the greatest economy of material. The oil pots can be lighted as fast as a man can walk through the orchard, can be regulated to burn any length of time or any quantity of fuel and at any strength demanded by the weather. When the necessity of fire is past, they can be extinguished and the rest of the fuel saved.

The development of the machinery of orchard heating has been an amazing industrial growth. It has sprung within three years from nothing to an industry employing a score of firms that supply fruit growers with upwards of a million

heaters a year. The manufacturers estimate that some two million are now in use, and the next few years will see millions more installed. The value of the heaters now in use is estimated at $300,000. The two leading factories alone have put out in the neighborhood of a million. One of them has a capacity of 10,000 a day and has turned out a half million heaters. There are now some two thousand orchards equipped with these small furnaces. It must be understood that these figures represent an industry that is but in its infancy. When orchard heating has been as generally adopted as spraying they will be many times multiplied.

The first cost of installing an oil heating plant is higher than for a coal or wood outfit, but the results in time saved and efficiency gained have made it the most popular fuel. Oil can be obtained in quantity at prices ranging from four to six and a half cents a gallon, and it makes a quick, strong and easily controlled heat. One man can care for from three to five acres of orchard for four or five hours and this is about as long as it will be necessary to burn under ordinary frost conditions. The prices of the oil heaters range from twelve cents for a simple "lard pail" type to forty-five cents for one of the controlled fire area type, holding thr gallons and burning at full capacity for ten or twelve hours, or even longer if