creased 50 per cent. The average production per well, of today, has gradually fallen from that of the gusher period to 30 barrels in 1919. This means that a large number of wells are approaching the marginal production below which it will not be profitable to pump them, unless the price advances. The average rate at which the production of California wells declines is fairly well established for the first few years of their life. The following table gives the average production of California oil wells by years of life in percentages of production of the first year.

Obviously, as the fields grow older, and the gushers become only a recollection, the wells become more crowded, the gas pressure goes down, and initial production of the new wells drilled becomes less and less year by year, a continuously expanding drilling program must be carried out to keep up a constant supply. If, on top of that, the demand increases, conditions are still more strained for the old law of supply and demand. The future price trend would, of course, be checked in its upward career, by the development of new oil fields within reasonable shipping distances. While no one can predict positively that new oil fields will not be developed, it is highly improbable that the production of any such fields, on the Pacific Coast, will be sufficient materially to lower the California price. Freight rates from the mid-continent fields prohibit importation from that source, even if mid-continent prices were lower than our own. Mexican oil is still further out of reach on account of freight rates by any route. The only other source in sight is Colombia and Venezuela, but the probable tanker rate of a dollar or more for the 3000-mi. haul will prevent this source from ever giving us cheap oil, even if the price at the source is not held high, as it undoubtedly will be by East-coast demands and by the large volume of shipping through the Canal which will in future utilize oil fuel for propulsion.

A NECESSARY DEVELOPMENT

The point we wish to make from the above data is that power development, as in the ordinary steam station, at an average

efficiency of 185 to 200 kw-hr. per barrel, will cost for fuel alone at least one cent per kw-hr. with fuel prices of $1.85 upwards. This figure, added to other steam operating costs and all fixed charges, makes the total cost of power so developed much higher than that of hydro-electric power, even at present high costs of money and construction. This being the case for steam-turbine plants of reasonably fair to good efficiencies, it is much more true of the steam locomotive with its wasteful boiler and non-condensing reciprocating engine.

In other words, the cost of the fuel oil alone used in the steam locomotives in California and neighboring states, based on its value at the market (amounting to approximately $50,000,000 per annum which will increase year by year until this fuel can with difficulty be obtained at all) will in time compel the steam railroads to seek other methods of operation, chief and most promising of which is electrical. Disregarding all other reasons and arguments for electrification, the cost of fuel is going to force it.

Coal is, of course, a possible substitute. On a thermal-unitcost basis, Utah coal is now on a par with oil on the Sierra grades. Much as the dyed-in-the-wool steam railroad man mistrusts electrification, we believe he would have a greater dislike for the use of coal where he has been accustomed to oil, on account of its inconvenience in firing large furnaces. Pulverization offers a possible means of overcoming these difficulties but involves many complications over the use of oil.

In view of the inability of the power companies to meet their present commercial demands, and the apparently insuperable financial program involved in meeting future demands, a large railroad load cannot be anticipated with any great degree of satisfaction. The solution, however, is obvious namely, a railroad power rate which will finance the necessary development. The hope for the situation seems, then, to be in the electrification of the steam railroads, and thus the conservation of fuel oil which will retrieve the depleting of the stocks now on hand will be brought about. The entire matter is of the utmost concern and its varying characteristics from month to month will be followed by the public and particularly by the steam power plant engineer with the keenest interest.

CHAPTER XVIII

THE SAFE OPERATION OF STEAM BOILERS

Many fatal accidents both to life and property have happened due to foolhardy methods in design and operation of the steam boiler. This early became so apparent that rigid governmental inspection of boiler operation was insisted upon. To aid in systematic inspection the Department of Commerce and Labor at Washington has issued general rules and regulations for such supervision under Form 801 entitled Steamboat Inspection Service. Many insurance companies have, too, put into force rigid rules of inspection to safeguard their interests in assuming risks. The most complete publication on the subject, however, is to be found in the recently published report of the Boiler Code Committee of the American Society of Mechanical Engineers, entitled: "Rules for the Construction of Stationary Boilers and for Allowable Working Pressure." These rules have been adopted by law in a number of States, including California where they have been incorporated in the Safety Orders of the State Accident Commission.

In the discussion taken up in this chapter only fundamentals will be considered. The thorough mastering of these fundamentals will, however, enable the reader to understandingly read the deeper discussions alluded to above.

The Inspection Tests Involved. The testing of the water and steam gages, the checking of fittings and appliances, and the trying out of the safety valves and other accessories constitute, of course, important details of boiler inspection. The most important feature, however, is to ascertain by computation the maximum allowable working pressure that may be safely put upon the boiler. After this maximum allowable pressure is ascertained the boiler is subjected to a hydrostatic pressure test by filling the boiler completely with water and then pumping enough additional water into it to raise the pressure to the desired point. This apparatus is held under proper control and the total pressure put upon the boiler is one and one-half times the maximum allowable working pressure.

Thus if the maximum allowable working pressure on a boiler is 160 lbs. per sq. in. above the atmosphere, the test pressure to be applied should be 240 lb. per sq. in.

Many carefully compiled instructions have from time to time. been issued by various boiler makers, inspectors, and others interested in economic and safe operation. The instructions compiled by J. B. Warner chief inspector of the San Francisco

FIG. 76. An inspector's testing and proving outfit.

Here is a typical outfit for boiler and power plant inspectors. It consists of a standard test gage, a screw test pump, a gage hand puller, a hand set and other useful conveniences.

department of the Hartford Steam Boiler Inspection and Insurance Company are especially good, and largely the ideas appearing in the following lines come from this source:

Preliminary Precautions.-Whenever going on duty in the boiler room, find out, first of all, where the water level is in the boilers. Never lower nor replenish the fires until this is done.

Make sure that the gage glass and gage cocks, and all the connections thereto, are free and in good working order. Do not rely upon the glass altogether, but use the gage cocks also, and try them all, several times a day.

Before starting up the fires, open each door about the setting and look carefully for leaks. If leaks are discovered, either then or at any other time, they should be located and repaired; but cool the boiler off first. If leaking occurs at the fore and aft joints, the inspecting company should be notified at once. This is important, whether the attendant considers the leakage serious or not; and it is especially important when the boiler has a single bottom sheet, or is of the two-sheet type.

After the maximum allowable working steam pressure for the boiler has been computed, the boiler is then submitted to a hydrostatic test of one and one-half times this allowable pressure. The above apparatus is especially adapted for those having frequent occasion to make hydrostatic tests of boilers.

When a boiler has been emptied of water, do not fill it again until it has become cold.

In preparing to get up steam after the boiler has been out of service, be sure that the manhole and hand-hole joints are tight. Do not use gaskets that are thin and hard.

Vent the boiler in some way, first, to permit the escape of air. Then fill the boiler to the proper level, open the dampers, and start the fires. Start them early so as to have the pressure up the required hour, without forcing.

Ventilate the setting thoroughly before lighting the fire. Never turn on the fuel supply when starting up without first