tion or other control very difficult. They embrace the variety of fruits that are sought by travelers for curiosities "to bring home to the folks," and the danger from this source is extremely grave. A single fruit dropped upon the dock at San Francisco could liberate enough maggots to menace, or even possibly destroy, our fruit industry, as they could find hiding place in the crevices of the wood where they would quickly develop into adults and begin their work of destruction. For the reason that even during inspection at the docks it might be possible for the insects to be liberated, it was considered desirable to remedy the defect in the quarantine law providing for the examination of baggage and consignments of fruit in port. The right of search, therefore, was extended to the three-mile limit, thus making it possible to destroy all infested fruit before it could reach the mainland. In June, 1911, the quarantine became effective against all fruits imported from the islands, except the banana and the pineapple, which appear to be immune. Because of the ignorance of the general public regarding the terrible risk involved and the perversity of some tourists who like to show that they are "smarter than the inspector," attempts are made to slip through a few specimens and occasional consignments of affected fruit are received, which are at once destroyed. Even the wild native. grasses which are used as packing materials about shipments of bananas and pineapples are now barred, as many of the wild grasses used for that purpose grow in infested districts and are likely

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to contain the insect in the pupa state. Excelsior and clean rice straw are the packing used at present.

It is now proposed to place a horticultural inspector at Honolulu to keep the infested fruit from the ships bound to San Francisco or even from the docks where these ships for San Francisco are loaded.

Another method of combating the pest in the islands is the installation of an oil-burning garbage crematory, in which the affected fruit is destroyed.

Measures are also being taken to provide protection for consignments of Hawaiian fruit brought into California by railroad from states farther north and also from the still remoter district of British Columbia.

Speaking of the dollars and cents involved in combating imported pests, the following statement from the Monthly Bulletin of the California State Commission of Horticulture contains a figure which is startling to the average taxpayer:

"When we stop and consider that fifty per cent of all our injurious pests are from foreign countries, and that this fifty per cent includes such insects as the Hessian Fly, Codlin Moth, San Jose Scale, Gipsy and Brown-tail Moths, Cottony, Cushion-Scale, Cotton Boll-weevil, the Alfalfa Weevil, and many other important pests, and that the annual cost for fighting injurious insects in the United States reaches $1,000,000,000, we might get some idea of the value of keeping out those pests which are now knocking at our very doors."

M

UCH more poetical, and infinitely more beautiful than the old-fashioned, prosaic "ditch" irrigation is a revolutionary system of applying water to orange groves which is now being worked out in the Porterville orange district in California, in which the orchardist actually "makes it rain" at will, with every indication that the result will be nearly, if not quite, as beneficial to growing and fruiting trees as the gentle moisture which falls from the clouds during the California rainy season.

Described in a sentence this system,

which has been installed by Robert Baird at Winterhaven, in the Porterville foothills, consists of a series of nicely graduated, galvanized iron water pipes, carried above the tops of the orange trees, there being upon these pipes, at intervals of a few feet, specially constructed sprinkling nozzles through which the water is forced under pressure. Consistent experimenting was necessary to arrive at the proper distance apart for the main pipe lines, the distance between the sprinklers and other details, but as the system was finally installed, water is uniformly distributed over the entire orchard, with

the identical effect that would be secured

from a gentle rain.

Advantages of this system to the orange grower are manifold. The best orange land is that which lies upon sidehill or gently sloping land, and under the old-fashioned system, of leading water through ditches plowed between the rows of trees, the oranges at the bottom of the hill received heavy irrigation at the expense of those planted on higher land. With the "artificial rainfall" system, the distribution of the water is absolutely uniform.

One of the heavy items of expense in the installation of the old system was in levelling the land, for ditch irrigation can only be carried on in orchards where water will flow readily and at least with a semblance of uniformity. If the land is level enough for the installation of the new system, it is level enough to carry water under the pressure needed to produce the best results with the sprinklers.

It is in the matter of frost protection, however, that the rainfall system is particularly valuable, and of particular value to the grower of the late or Valencia variety of orange. Occasionally even in the sheltered side-hills where oranges reach their greatest perfection, a frost will settle on the trees. It would be a very light frost indeed for those states in which the inhabitants are accustomed to several feet of snow during the winter months, but even a light frost, if it remains for a few hours on an orange about ready to pick, means the difference. between a perfect fruit and one of indifferent flavor and texture. It may be that the orchards will escape a frost for several years, but there is no guarantee that any rainy season will not be characterized by a slight freeze. To guard against these frosts the general system in use is that of using scores of smudge pots, in which crude fuel oil is burned, and by means of which the orchard is enveloped in a thick, black smoke. This is effective, but unsatisfactory in many ways.

When frost threatens in the Winterhaven orchard, if it ever does, the pumps will be set to work, the valves opened and the orchard will be enveloped in a fine. mist, in a veritable blanket of water the

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temperature of which in the irrigating well of this particular orchard is about seventy degrees, Fahrenheit. No frost that has ever been known in California would cause even the slightest damage against such opposition.

Mr. Baird's first idea of this system came through careful observance of his orchard and the development of the fruit. He noticed that when the rainy season set in especially early and when a brisk shower soaked the orchard just at the time when the vivid-green orange was turning to a bright golden color, the fruit matured from ten days to fifteen days earlier than in those seasons when the orchard was dependent upon ditch irrigation. This set him to experimenting with single trees. He was soon convinced that there is some subtle effect upon the vigor of the tree when it is thoroughly wet, probably upon the same general principle as the invigorating feeling when a tired man takes a bath. any rate the early rains produce the early fruit, and now the Winterhaven orchard is so equipped that the early rains can be controlled at the will of the owner of these fruit lands.

At

As the Winterhaven plant has been installed, ten acres is covered in a single unit. The orchard contains about 120 acres of orange trees, and twelve units will therefore be used in irrigating the entire orchard. One man can handle each unit easily, making a very appreciable saving in labor cost, as three or four men are needed to keep water running through ten acres of ditches.

There are no patents on this system of water distribution as it has been put to use in the Porterville orchards, and anyone can install it with such tools as the average rancher handles every day. All that is needed is a line of stand-pipes running centrally through the orchard, as feeders from which to run the pipes carrying the sprinklers. Each sprinkler line is provided with a sliding valve and a handle by which the sprinklers are set at a varying angle, so that the orchard may be covered uniformly, or it would be possible for an ingenious orchardist. to equip his system with a small motor, with clockwork attachment by which this work could be done automatically.

THE LITTLE INSTRUMENT

HEN the last tile is laid on the roof of a big city building and the first elevator begins to run; when

W

the steam is turned into

the radiators and the first tenant sits in his office chair; when the dynamos begin to turn in the basement and the first water is pumped into the tanks on the lofty top-when the first life of the big hive begins, in fact, there also begins a series of subtle, hidden changes, covered away from the eye by brick and plaster and stucco, that are not unlike the changes that begin in the human body with its first contact with life.

Even a sky-scraper can wear out. Even a sky-scraper may have disease. Every wind that blows against its towering sides, every sunbeam that gilds its windows, every person who enters its doors, every shadow that touches its walls, is in a sense its enemy, as a myriad of germs are enemies of the man who built it. And like its builder, too, if it is sick and improperly cared for, it may suffer disaster.

Steel expands with heat exactly as dried apples swell in water. The difference is in degree. If you could wet one side of a strip of dried apple and leave the other dry, the strip would curl up with the wet side out, because the wet side would grow longer than the dry side. If you heat one side of a steel beam and leave the

other side cold, the beam has the same tendency to bend toward the cold side, because the heated side grows longer. If you heat a sheet of paper, it will curl away from the heat-for the same reason. So, when the sun shines on one side of the steel girder in a building, even through its coating of brick or concrete, that girder begins to move. The movement may be very slight indeed, but it is very mighty, and if things are not adjusted to take care of that motion, there will be trouble in the surrounding and depending parts. When frost follows sun, the girder reverses its movement and will make further trouble. After a few weeks or months or years of these squirmings and twistings and wrigglings

think of a steel girder wriggling!the damage done may become so serious as to threaten the life of the tenant in his chair.

When a dozen people stand together on an office floor or an elevator takes twenty men and women and messengerboys up to the twentieth floor, there is a gathering or a shifting of weight that materially affects the hidden girder again. When the steam rises hot in the radiators or the water climbs to the overflow in the tanks or the dynamos in the base

ment reach the peak of the load, each has its effect. Gradually the girder changes about till it becomes warped from its original

shape. Perhaps the man who designed it for its work made a little miscalculation of the exact manner in which all the influences were going to affect it. If so, it acts a little differently from the way in which he expected it to act. It changes. Sometimes it changes to the dangerpoint-sometimes past that point.

The great difficulty engineers have always had in treating sick buildings is in diagnosing the case in hand. A doctor can put his clinical thermometer in your mouth and read your temperature upon its gauge. He can finger your pulse and judge of conditions hidden from his eyes, by the beat of your heart. He can take your blood-pressure and tell you what to do and what not to do to be out of danger. But there has never been a way till recently of feeling the sky-scraper's pulse -or the pulse of any other structure of steel and brick and stone and concrete. Now there is a way. A man named J. E. Howard, who is an engineer-physicist in the bureau of standards at Washing