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Answer.-When the duplex pump is started from rest, the low pressure piston always makes the first stroke, moving from the lower end of its cylinder to the upper. If the tappet rod should be broken in the low pressure side, the slide valve on this side, which controls the admission of steam to, and exhaust of steam from, the high pressure side, would not be moved; hence, the high pressure piston would remain at rest in the lower end of its cylinder, and also, because of its not moving the slide valve under it, which controls the admission of steam to, and exhaust of steam from, the low pressure side, the low pressure piston would not be moved down, and, therefore, this piston would stop at the upper end of its stroke, and remain at rest.

If it is the tappet rod in the high pressure side that is broken, then, after the low pressure piston has completed its upstroke, the high pressure pisto will make its up-stroke, but as it will not move its slide valve, no steam will be admitted to the upper end of the low pressure cylinder and the low pressure piston can not make its return stroke.

Hence, it makes no difference on which side the tappet rod may be broken, the low pressure piston will always stop after making the up-stroke and will always be found in the upper end of its cylinder; the high pressure piston will be found in the upper or lower end of its cylinder, depending upon which side has the broken tappet rod.

sure side that is broken; and if the pump stops, the high pressure piston remaining at the top of its cylinder, it is the tappet rod in the high pressure cylinder that is broken.

From the above, it will be seen that if the pump stops on account of a broken tappet rod, the high pressure piston remaining in the lower end of its cylinder, it will be the tappet rod in the low pres

Therefore, when the duplex pump stops, the quickest and surest way to determine which cylinder the trouble is in is to remove the oil cup from the high pressure air cylinder head and look into the cylinder to see whether the high pressure piston is at the top or at the bottom of the cylinder.

Before removing the oil cup, however, it should be known that steam is being the pump governor is not restricting the admitted properly to the pump, and that supply. This may be easily determined by opening the drain cock in the steam head and observing the quantity of steam and the force with which it issues, that escapes from it.

If a piece of wire about the length of the air cylinder be handy, that will go through the opening in the oil cup cock, then the oil cup need not be removed, as by opening the plug cock and inserting the wire through the oil cup the location of the air piston may be determined.

The above method of determining which tappet rod is broken holds good whether the pump has just been started and stops, or stops after working some time, and applies to a loose tappet plate as well as to a broken tappet rod.

133. Diaphragm Leaking in Duplex Governor. -"When engines are equipped with the duplex governor, if the diaphragm valve leaks in either pressure top, will it not have the same effect upon the working of the pump governor as if there was but one pressure top on it, having a leaky diaphragm air valve in it?"-J. E. D.

Answer. With the duplex governor, whether used with the "single" or the "double pressure method," if one of the diaphragm air valves leaks it will permit air to flow down upon the governor piston the same as though there was only a single pressure top upon the governor, and the air that leaks in upon the governor piston, if more than the small vent port in the governor piston chamber can relieve, will have a tendency to form a pressure in the governor piston chamber that will force the piston together with the steam valve part way down, throttling the steam somewhat and tending to make the governor less sensitive to variations in train pipe pressure; and will, therefore, have the same effect upon the pump as though it were a leaky diaphragm valve in a single top governor.

134. Test to Determine Which Diaphragm Air Valve is Leaking in the Duplex Governor.-"How should I test to find out which diaphragm air valve is leaking in the duplex governor?"-J. E. D.

Answer. If either or both diaphragm air valves leak, there will be a continuous blow at the small vent port from the chamber above the governor piston, to the atmosphere. To determine in which pressure top the diaphragm is leaking it will be necessary to take into consideration the way in which the duplex governor is piped. If it is piped for the "single pressure method," as already illustrated and described in the January, 1902, number of the Firemen's Magazine, stop the pump, close the cut-out cock under the brake valve, place the handle of the valve in emergency position and note if the blow continues at the vent port in the governor body. If the blow ceases, it is an indication that the trouble is with the diaphragm in the train pipe pressure top, but if it continues it indicates that the diaphragm valve in the main reservoir pressure top is at fault.

If the diaphragm valve in the main reservoir pressure top is leaking, it is possible that this test might not indicate for a certainty that the diaphragm air valve in the train pipe pressure top was not leaking also; but it is rarely that both leak at the same time. However, after the diaphragm air valve in the reservoir pressure top has been made tight, a continuance of the blow of air at the vent port, after pressure was restored in the train pipe pressure top, would indicate that the diaphragm in the train pipe pressure top is leaking.

If the duplex governor is piped for the "double pressure method," illustrated in the January, 1902, number of the Firemen's Magazine, that is, with branch pipes leading one to each pressure top with a single connection to the brake valve at the usual point in front of the excess pressure valve, and a stop cock in the branch pipe leading to the low pressure governor top, to test for leaky diaphragm air valves, close the stop cock in the branch pipe leading to the low pressure top. If the blow ceases at the vent port, it indicates that the diaphragm air valve in the low pressure top is leaking; if it does not cease, it indicates that the diaphragm air valve in the high pressure top is leaking.

Answer.-Yes; the potash should be hot and the pump should be run slowly, so that the liquid may have time to pass through the various valves without causing the pump to pound.

135. Hot Potash for Duplex Pump.-"Can a hot solution of potash and lye be worked through the duplex pump for purposes of cleaning?"-E. K.

At the same time that the pump is being cleaned with the potash, the discharge pipe should be disconnected from the main reservoir, if the latter is located on the engine; or, if it is located on the tender, the hose couplings for the discharge pipe between the engine and tender should be parted, and the hose in that portion of the discharge pipe connected to the pump should be removed in order to prevent the discharged potash from coming in contact with the rubber. Potash and lye are bad for leather and rubber.

Locomotive Running and Repairs.

Answers by W. G. Wallace.

63. Engine Rating.-"If a 19x26-inch tenwheel engine is rated to pull 1,000 tons over a division, how much should an 18x 26-inch engine be able to pull over the same division? It will be understood that both engines are the same in every particular except the difference in the diameter of the cylinders."-J. C.

Answer-As J. C. has neglected to state the boiler pressure and the diameter of the driving wheels, we will assume that the wheels are sixty inches, including tire, and that the boiler pressure is 190 pounds. Taking 85 per cent. of the boiler pressure as the effective cylinder pressure and using the formula, we will work method used for both engines and obtain out an example which will illustrate the

the tractive power of each.

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25.26 pounds power used per ton. Then it is clear that the 18-inch engine, with 22,674 pounds tractive force, should pull as many tons as 25.26 is contained in 22,674, which equals 898 tons, or the rating for the 18-inch engine. The 18-inch engine would have the advantage on ac

count of having a greater heating surface to her cylinder volume and in service. would stay hot easier and stand harder hitting in taking a run for a hill. The above would be a fair comparable rating in the absence of a practical test.

Railway Club Proceedings

ing the season of river navigation. The natural route from "Camp 1" is along the east side of the river, which for some little distance has hugged the east wall of the valley; but a wagon road, operated as a toll road, occupied the only available ground for such a purpose for a distance of about three miles, with a price set upon its right of possession which forced the railroad to cross the river at this point, recrossing again as soon as it could be done without interfering with the toll road. Our railroad, now some five miles from tide-water, with no opportunity thus far to make any material progress skyward, lost no further time in that direction, but soon got above and beyond any further danger of conflict with the toll road. Good progress was now being made, with every indication that the summit would be reached before winter set in, when a stampede to the Atlin gold fields set in, which in three days carried with it more than a thousand men off the grade, and virtually put a stop to everything. It was well into the winter before men could be had and active work resumed. Notwithstanding this exasperating delay, the track reached the summit of the well-named White Pass on 'ebruary 18, 1899, having pushed its way through the ruggedest kind of mountain work in our heaviest snow district, this task including the building of thirty-seven bridges, the material for which was in most cases snaked up the mountainside by man power. The fight for a railroad over this pass being thrown into the winter months, furnished a continuous performance for an army of snow shovelers. View No. 3 will give some idea of the magnitude of this undertaking. The lone figure in this picture is standing at one of the storm-swept points in the path made by our rotary plow, which last winter accomplished the task of keeping this mountain open to daily traffic, without a skip, in spite of the fact that, every winter since this road has been in operation,

A Railroad in the Far North.

MR. J. R. VAN CLEVE: The head of Lynn Canal, the extreme northern limit of what is known as "The Inland Passage," is the logical starting point for this rail connection. It is as near the head of navigation of the Upper Yukon as salt water can take one. All that could be desired in the way of a deep and sheltered harbor marks the entrance to the Skagway Valley, the key to the best route through the mountain range which separates the head waters of the Yukon from tide water, known as the White Pass. Several surveys were made before sufficient distance was found for a feasible grade; but when a survey was finally made which demonstrated that twenty miles could be had to make this climb of 2,940 feet, on a maximum grade of 3.9 per cent., little time was lost in financing the undertaking and getting to work. The grading outfit reached Skagway May 27, 1898, and, as a sort of initiation fee, paid $500 for the privilege of pitching camp on the only spot suitable for such a purpose, title to the ground not entering into this transaction. Skagway has so far found room for itself in an acute-angled triangle, whose base, some 3,000 feet in length, is the water-front at the foot of this valley; one side, the east wall of the valley; the remaining side, the Skagway River, which, as a last act, cuts this much-chopped-up little valley in two on the bias. The altitude of this triangle is a mile and a half, and this first camp was pitched at its apex. Our present shops are located on the site of this first camp. The view which I have marked No. 1 probably gives as good an idea of the town as could be had from one view-point. It shows but a corner of the wharf over which virtually all business is now done, and back of which the railroad has freight tracks. No. 2 shows about half of this wharf, and gives a very good idea of its appearance dur

work along Lake Bennett would be the
last piece of grade ready for the track,
an engine, together with a few flats and
enough material for a start at track lay-
ing, was put over the lake before the
freeze up.
Work on the grade north of
Caribou Crossing, at the foot of the lake,
was begun the latter part of August, and,
together with the work along the lake
shore, was pushed with vigor all winter.
The balance of the material for the track
north of Caribou, together with another
engine and flats, was taken over the lake
the following spring, and on July 8th
these forty-two miles were open for traf-
fic. During the seven weeks' wait for the
track along the lake shore, the lake was
used as a connecting link, and freight be-
gan moving into White Horse, the name
given to the town created by this new con-
dition of things, and situated at the foot
of the rapids from which it takes its
name, the rapids which mark the first
break in the navigable waters of the Yu-
kon above Dawson. On July 29, 1900,
the final connection was made at Caribou
Crossing, with ceremonies befitting the
driving of the last spike, and through rail
service between tide water and the head
of unbroken navigation of the Upper Yu-
kon was at last a fact.

The work north of Caribou was com paratively light. What might be called the spectacular feature of this part of the work was the draining of Lewis Lake. The locating engineer conceived the idea of lowering the level of the lake about five feet, to give a better line and to make the work lighter along its shore. It was found that a ditch connecting Lewis with a couple of small lakes about a quarter of a mile away would accomplish this, these small lakes in turn having the Watson River to take care of their surplus. A ditch ten feet wide was decided upon, and, while this was being dug, the question was raised as to the length of time it would take the lake to find its new level. One engineer set the time at three months, and pronounced the ditch too small. The engineer in charge, however, thought it safe to leave something to the action of the water, and decided that a larger ditch would be a needless expense. Subsequent events more than bore him out in this view of the matter, for the nature of the material through which the ditch was dug proved so yielding that this little stream soon became a raging torrent, and the bottom proceeded to drop out of that lake with a celerity fairly dazzling. When the rush was over, such a

It being apparent that the heavy rock change was found to have been wrought in

the outside papers have brought us word that the "White Pass and Yukon Route" is hopelessly buried in snow and abandoned for the winter, the depths under which reports have us buried ranging from fifty to 200 feet.

While the item of snow is before us, it might be well to state that our snowbucking outfit consists of a standardgauge rotary, with its trucks closed in to our three-foot gauge, and two of our heaviest engines to keep it up to its work. This outfit makes daily trips over our mountain district through the winter months, and a duplicate outfit is held here in reserve. Aside from an occasional trip by the rotary to the foot of Lake Bennett, flangers and pilot plows on our road engines take care of the snow north of Bennett, as the station at the head of the lake is called, for, strange as it may seem, the farther north we go, the less snow we encounter. On account of the great amount of water used by the rotary in heavy snow, as compared with that used by its pushers, the injector piping on the engines assigned to rotary service has been so arranged that their injectors can put water either into their own boilers or into the tender ahead. This arrangement permits the rotary to work as long as there is water in the outfit, which arrangement has in many cases cut out a stop for water by the snow-melting process, which in some of our storms might easily mean a tie up. **

But, to get back to construction work: The completion of the track to Lake Bennett marked the end of another chapter of trying delays, including a laborers' strike. In spite of these delays, no opportunity to push the work at every point was overlooked, a large portion of the work on the Canadian side also being done in the winter. Although track laying north of White Pass Summit was not begun until June 21st, Lake Bennett was reached July 6th, these twenty-one miles of track being laid in sixteen days, in addition to three miles of grading, part of which was rock work. It is hardly necessary to add that every minute of those sixteen nightless days was improved. The train which put the track into Bennett returned to Skagway on the same day, with over a ton and a half or gold dust and 200 passengers glad of a chance to ride on flat cars over the pass, which recalled to the minds of many of them hardships and tests of endurance they had no desire to experience again.

**

the topography of the neighborhood that a revision of the map, as well as of the plans of the locating engineer, became the next logical order of business. The new level of the water impounded in the pockets of the lake's former bottom was found to be eighty-one feet below the old level of the lake. No. 5 is a corner of the lake's old bed crossed by the road, and gives a fair idea of the work accomplished by the digging of that little ditch. If a train were to be caught on the bridge to be seen in this picture by a sudden res

and sent up here for erection. But little time was lost, however, in getting together the necessary tools and organizing a force sufficient to take care of our running work and to keep up with the demand for freight equipment, which included flat, box, stock and refrigerator cars and coal dumps. With the exception of our baggage cars and an official car, we have so far looked to the outside for our passenger equipment. But our aim has been to make ourselves as independent of the outside world as we consistently could,

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toration of the water of the lake, it would be entirely submerged. The awe which this act of the "Boston man" inspired in the Indians would have been no more profound had he reversed the current of the Yukon and turned its waters into Lynn Canal.

While construction work was being carried on, the question of equipment was, of course, bei given attention. The engines for this work were picked up where they could be had the quickest, for there was no dallying between the decision to build and getting to work, and waiting for engines to be built was out of the question. A score of flats were also picked up at second hand, and, while a start was being made toward a shop, a few of the first freight cars were framed in Seattle

the wisdom, not to say necessity, of which can readily be seen when it is borne in mind that a thousand miles of water separate us from any possible market. To this end we have included in our modest plant a brass and iron foundry, which provides us with everything in that line entering into the construction of freight cars and into car and locomotive repairs, as well as into the repairs of the fleet of lake and river boats which constitute a part of this route to Dawson and to the Atlin district. With high mountains close at hand on every side to further shorten our all too short winter days, the question of light became an important one. Electricity was decided upon as the best and most reliable substitute for daylight, and,

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