of an inch every time the brake releases, until the travel is reduced to the proper amount.

air will enter the adjuster through pipe b and will force the adjuster piston 18, Fig. 28, outward. Spring 23 will then

A. Fig. 26 shows the slack adjuster attached to a passenger brake cylinder. It will be noticed that the end of the lever 5, which is attached direct to the cylinder head when no slack adjuster is used, is in this case fastened to a crosshead in the slack adjuster. If the crosshead moves away from the brake cylinder head the piston travel will be reduced, and if it moves towards the cylinder head the travel will be increased. A threaded rod 4 is attached to this crosshead, which has a nut 1 on its op

the ratchet nut 27. When the brake is released, the air in the adjuster chamber will pass out through pipe b and port a to the atmosphere by the non-pressure head of the brake cylinder. The piston spring 21 in the slack adjuster will then force the piston 16 back, the pawl 22 turning the ratchet nut 27 one-eighth of a turn, there being sixteen teeth in this nut, and the pawl moving over two teeth each time the adjuster operates. This movement of the ratchet nut turning on the threaded rod 4, Fig. 26, will draw this rod toward the casing 3 and will

posite end where it extends through the body of the adjuster. Fig. 26 does not show the extreme left end of this nut, as it is within the casing 3, but it is shown in Fig. 27, this part of the nut being marked 27, and on account of its appearance is known as a ratchet nut, by which name it will be called, the part of this nut marked 1, Fig. 26, being regarded as an extension of it. The extension 1 is of course hollow, the threaded rod projecting into it. In Fig. 27, the pawl 27 is used to turn the ratchet nut when air enters the adjuster at a, pipe b, Fig. 26, being attached to the brake cylinder at a, port a being located a distance from the pressure cylinder head about equal to the running piston travel desired. The operation of this device is as follows:

Whenever the brake piston travel is such as to allow the piston packing leather to pass the small port a, Fig. 26,

move the adjuster crosshead away from the pressure head of the brake cylinder 1-32 of an inch, shortening the piston travel the same amount. As the adjuster piston moves back the pawl 22 will strike the projection, Fig. 27, forcing it upward out of the tooth in the ratchet.

The ratchet nut 27 can be turned either way by a wrench by means of the hollow extension 1, Fig. 26, when it is necessary to let out or take up the slack. At such times the pawl is generally not in contact with the ratchet nut. However, there may be conditions which will prevent the slack adjuster from completing the take up movement, such as excessive brake beam spring resistance, in which case the pawl will not be clear of the ratchet nut, and any attempt to let out the slack will result in breaking the teeth of the nut. Therefore before letting out the slack, always take up the slack slightly by turning the extension

4. At low speed. The pressure of the brake shoes against the wheels tends to prevent them from turning, and when

leaking. Also see if this port is clear, as this will also cause a sluggish working pump. If the governor is apparently all right, open the drain cock connected to

the steam passage on the pump. If steam escapes freely, the trouble is in the pump.

emergency application, will the brakes be applied any quicker or harder than with service applications? How much harder,

A. The air goes to the pump through the air strainer and the upper and lower receiving valves. It leaves the pump through the upper and lower discharge valves.

Q. Is it necessary to have standard pressure to obtain full braking power?

A. Yes, as the brake pipe pressure is reduced the pressure developed in the brake cylinders will also decrease, the auxiliaries and brake cylinders equalizing each time at a lower pressure.

Q. Where does the auxiliary reservoir directly receive its air?

A. From the brake pipe, the air entering the auxiliary through the feed ports in the triple valve.

Q. About how large is the feed port from the brake pipe to the auxiliary reservoir in the triple valve?

4. The size of the feed groove depends on the service and the size of the auxiliary it is to charge. In some they are a half circle of one hundred and twenty-eight one thousandth of an inch in diameter, while in some others they are a half-circle of eighty-six one thousandth and one hundred and seventy-three one thousandth of an inch in diameter.

Q. With quick action triple valves in

4. The brakes will be applied both quicker and harder with an emergency application than with a service application. An emergency application will develop 10 pounds higher brake cylinder pressure than will a service application, this additional pressure coming from the brake pipe.

Q. What precautions would you take in regard to personal safety before doing any work on the brakes, such as adjusting the travel?

A.-Securely block the engine, place reverse lever in center, and open the cylinder cocks. It might also be well to close the steam valve to the lubricator.

Q.-Must brakes be tested on both passenger and freight trains before leaving terminal points?

A. Yes. There is no assurance that the brakes will operate unless tested before starting out.

Q.-At what other time should brakes be tested?

A.-Before starting down heavy grades or when a train is picked up. After a break-in-two or when the brake pipe has been closed or separated, it should be ascertained that the rear brakes can be operated from the engine.

(To be continued.)

AUTHOR'S NOTE. This article is divided into paragraphs, each bearing a number. Review questions at the end bear corresponding numbers, so in reviewing the subject immediate reference may be had to the subject-matter in which the answer may be

found.

Inasmuch as the function of the boiler is to convert water into steam, there has been a great deal of attention paid to the kind of water used, not merely in different boilers, but upon different roads and in different sections of the country. There are regions of bad water area where the sediment or the chemical impurities not only injure the boiler, but impose unsatisfactory conditions generally on the engine operatives. The system of water softening for locomotive use will therefore, it is hoped, be of interest. The subject is interestingly covered in the following digest of points in a discussion before one of the railway clubs, by L. H. Turner, who at the time was superintendent of motive power for the Pittsburg and Erie Railway. There were on that line at the time ten water purifying plants in operation in a distance of 190 miles. A period of eighteen months had elapsed since the introduction of the system and up to the time of the discussion referred to, allowing ample time for extensive observations. The water supply came from six different rivers, no two alike in analysis. The greatest trouble seemed to be acidity, and in some instances this ran as high as thirty-five grains to the gallon, with one-third of this amount free sulphuric acid. Sulphates of lime and magnesia presented the next greatest difficulties, with carbonates of lime and magnesia bringing up the third difficulty. Instead of showing any percentage tables having to do with the saving wrought, there were presented both the desirable and the undesirable features. In this particular part of country the worst water seems to be encountered from the first of August until about the first of November, or until the heavy fall rains commence. During the late summer and early autumn period the water in these rivers

is largely drainage from the coal mines, and locomotives that had been put in service in June, new from the manufacturers, were unfit for use in September. Every tube had to be removed and scraped before there was any service in these locomotives. Before the introduction of the purified water there were some sections along the road where the incrustations were so bad as to absolutely obstruct the circulation in portions of the cylindrical part of the boiler, with fifteen to forty tubes collapsed and worthless, so far as future use was concerned. During the latter part of the year it was common to have the tubes and boilers useless, with the sheets and tubes often eaten out by the acids.

Prior to the adoption of the treated water system it was the custom of the road to have boilers washed out every ten or seven days, but after that, the washout plugs were sometimes not removed for a month and a half. This is not given as good advice to engine operatives and roundhouse forces, because the most experienced men are sometimes the most pronounced in their declaration that frequent washing, even of new boilers, is an essential.

1. The points emphasized in this particular discussion were that, first, the treatment of the water overcame practically all of the acidity, and second, it eliminated the sediment. This system was by no means without its drawbacks, and the ingredients used to soften the water also caused the boilers to foam, necessitating the changing of the water every five days. This feature, it is explained, can be overcome readily by equipping the roundhouses with facilities for hot-water boiler washing, making possible the blowing out of the largest boilers and re-filling them without dumping the fires. The time required to do this does not exceed thirty-five minutes. As to the amount of sediment found in a boiler that has been used forty-five days with treated water, it was about the same as that ordinarily found in a boiler that had been in use a week with the

untreated water. Some of this was nothing more than the scale that had been deposited previous to the adoption of the softened water, which was gradually loosened and dropped down.

2. Another point greatly favoring the treated water was the absence of corrosion on plates and tubes. The equipment required is such that the boiler can be emptied, washed out and refilled without dumping the fires, but it was claimed the time and trouble are fully compensated for in that the boilers are not subjected to intense contraction and expansion, but are kept in better service, and that the result permits of the handling of a heavier tonnage of business with the same engines. The claims of the actual number of miles run to each ton of coal consumed are such as to command attention, in this instance resulting in an increase of 5.7 per cent. in the number of miles run and an increase in the trainload represented by 6.5 per cent. The saving in coal, alone, by way of illustration, was said to pay 5 per cent. on the total cost of the plant.

3. Admitting that the burning out of fireboxes has been one of the perpetual banes of railway experience, Mr. Turner points to the effect on the firebox with a reduction in the mud accumulation, and refers to the great saving in this direction alone. There have been mistakes made in the use of treated water, brought about by an inadequate number of plants. As a result, the pure and the impure water has been mixed, resulting in a greater precipitation of sludge than where either was used alone.

4.

But purified water is not a cure for all locomotive ills. It is simply one of the features that attract railway companies and operatives, and does not answer for carelessness in the handling of engines generally. Its use does not imply immunity from leaking or other troubles. Carelessness in washing and handling locomotives will bring about defects in spite of all the water purity that can be guaranteed. There have been many experiments made by way of compounds for use in boilers, but these have been thrown on the market with no consideration as to the nature of the water supply, its source or its quantity. However, experiments are being conducted with a view to determining more of water treatment efficacy, and although the conditions that exist on different roads call

The

for various methods, it is likely much more is yet to be learned in the near future concerning water treatment. building of larger locomotive boilers, with the attendant increase in water consumption, practically forces this sort of consideration on the attention of those most It is known that treated interested. water has proved of untold value in manufacturing lines. One plant, by way of illustration, had water-tube boilers of an aggregate capacity of 1,500 horsepower. The water, in its natural state, contained 3.9 pounds of scale-forming solids to each 1,000 gallons. The boilers were cleaned every thirty-five days, and there would have been a scale accumulation of 3,200 pounds in this time were the water used untreated. There was, actually, very little scale found, and generally only the thinnest film on the tubes.

5. Prof. C. Kershel Koyl, formerly of Johns Hopkins University, has paid a great deal of attention to the subject of water purification for locomotive boilers and has stated the situation aptly by saying it is not wise to put boiler compounds into the boiler, except that one compound known as pure water; that it is not the cure of boiler ills that should interest railroad men so much as the prevention of these troubles. The fact that there are locomotives in New England that have run a decade or more with practically no boiler repair expense, whereas in portions of the west repairs are required three or four times a year, seems to be worthy of attention. Prof. Koyl, in his view of the subject, is positive about his statement of the advisability of water purity, and suggests experiments calling for the complete equipment of an entire division with water purifying or softening plants. This will give the company and its employes an opportunity to witness the actual differences in boilers on that division and boilers on other divisions of the road. In the figures presented by the Master Mechanics' Association it has been shown that locomotives operating in the poorer water regions in the country have an expense of about $750 more than locomotives running in the clear water sections. Of this total, about $340 is traceable to additional fuel, about $360 to boiler repairs and $50 to additional washing expense. With 20.000 locomotives operating in the bad water regions, this means about $15,000,000 spent annually on useless de