CHAPTER VIII

Sale of Governors. Visit from Mr. Allen. Operation of the Engine Sold to Easton, Amos & Sons. Manufacture of the Indicator. Application on Locomotives.

The governor seemed to please every one. In anticipation of a demand for them, I had shipped a number to London, which met a ready sale. The most appreciative persons as a class were the linen-manufacturers of Belfast. One of them early took a license to sell them there. The first one I sold in London was to my friends Easton, Amos & Sons. As soon as they saw it in operation it struck them as the very thing they needed. In connection with their engineering works they carried on the manufacture of lead pipe by hydraulic pressure. The engine which drove a large section of their machine tools also drove the hydraulic pumps for this manufacture. It was a very trying service. The resistance was very heavy and came on and off the engine instantly. The action of the common governor was not prompt enough to control it, and they had to employ a man handling a disk valve with a very short motion. He had to keep his eye fixed on a column of mercury. When this rose he must open the valve, and when it dropped he must shut it. It had been found that this was a poor reliance for the instantaneous action required. They got a governor from me at once. I received a message from them the next day. The governor would not answer at all; would I come down and see about it? I happened first to meet an old man, foreman of the turners. “What is the matter?” “Matter! The governor won’t work, that’s what’s the matter.” I was rather an impulsive young man and replied, “It will work, or I’ll eat it.” He sharply responded,“If it does work I’ll eat it, and I haven’t a tooth in my head.” Foolish old man! he was more rash than I. I saw at a glance that the governor went through but half its action. There was evidently some resistance in the valve, a common fly-throttle. After they shut down at night I had the valve pulled out, and found that the chamber was larger than the pipe and that the wings of the valve were long and their points caught on the ends of the pipe. The wings of the valve were soon shortened and rebedded in the chamber, and when started again the governor controlled the motion of the engine perfectly, to the great gratification of everybody, and the delight of the boys, who had heard the old man promise to eat it. The valve had been put in for my governor to work, and the fitters had put up a job on me. The old man was not in the secret. So the laugh was on him instead of on me.

Directly after this triumph I received an order from Mr. John Penn for a governor to regulate the engine driving his marine-engine works at Greenwich. This was the first and only engine I ever saw of the grasshopper class, quite common, I learned, in earlier days. The superintendent of his works afterwards told me, laughingly, that he had a large account against me for loss of time; that he had become so fascinated with the governor action that he had stood watching it sometimes for twenty minutes. He knew by the position of the governor every large tool that was running and what it was doing, if light or heavy work, and especially every time a planer was reversed.

One day a gentleman asked me if I thought the governor could regulate his engine. He was a manufacturer of the metal thread used in making gold lace. A bar of silver, 2 inches in diameter and 2 or 3 feet long, was covered with three or four thicknesses of dentists’ gold leaf, and then drawn down to exceedingly fine threads, and the gold surface was never broken. I have often wondered how thick that gold covering finally was. The heavy drawing of the cold bars required a great deal of power, and when they shot out the engine would run away and the fine threads would be broken. No governor nor heavy fly-wheel would help the matter, and they had to do their heavy drawing in the night. My governor maintained the motion absolutely. Not only were the finestthreads not broken by the sudden changes in the heavy drawing, but the occasional breakages that they had been accustomed to nearly ceased.

In this connection I cannot refrain from telling a good story on Mr. Ramsbottom and Mr. Webb, although the incident happened the next year. I received an order for a governor for the engine driving the shops of the London & Northwestern Railway at Crewe. Soon after its shipment there came a line from the office there that the governor was behaving badly and I would have to go and see about it. I found that the engine consisted of a pair of locomotive cylinders set upright on the floor and directly connected above, the cranks at right angles with each other, to the line-shaft, a plan which I have always admired, as a capital way of avoiding belts or gearing. They were running at 120 revolutions per minute, and were connected in the middle of the shaft, which was about 400 feet long. The governor was flying up and down quite wildly. I had never seen such an action before, and was at a loss what to make of it. I saw no fly-wheel, but it did not seem that its absence could account for this irregularity. Indeed, with coupled engines running at this speed, and only trifling changes of load, and a governor requiring no time to act, a fly-wheel seemed superfluous. Pretty soon it came out that the want of fly-wheel could not cause the trouble, for they had two. Where were they? There was one at each end of the shaft, close to the end walls of the building, where wall boxes afforded excellent supports. Fly-wheels at the ends of 2-inch shafts and 200 feet from the engine! I fairly shouted with laughter, told them to take off their fly-wheels, and came home. The fly-wheels were taken off, and there was no further trouble. Well, what should railway engineers, absorbed in locomotive designs and everything pertaining to railroading, be expected to know about fly-wheel inertia and shaft torsion?

About midsummer I had the pleasant surprise of a visit from Mr. Allen, whose gratification at the show I had made was unbounded. We saw much of the exhibition together. Perhaps the most interesting exhibits in the machinery department, to us both, were the working models shown by the marine-engine builders. There were a large number of these, generally not much over one foot in any dimension, but complete to every bolt and nut, superblyfinished, and shown in motion. They had evidently been made regardless of cost. In the progress of engineering science, everything represented by these elegant toys has long since vanished. We were much impressed by a cylinder casting, 120 inches in diameter, shown by Mr. Penn, one of a pair made for a horizontal engine for a British warship, to work steam at 25 pounds pressure. Everything there shown pertaining to steam engineering, except our own engine, was about to disappear forever. How long before that also shall follow?

Soon after Mr. Allen’s return he sent me a drawing of his four-opening equilibrium valve with adjustable pressure-plate. I realized the great value of this most original invention, now so well known, but its adoption required a rescheming of the valve-gear, and that had to be postponed for some years.

In setting up the engine in the works of Easton, Amos & Sons, I had a curious example of English pertinacity. Old Mr. Amos said to me, “Porter, where is your pump?” “The engine has no pump.” “No pump!” “No, sir; we consider a feed-pump as an adjunct to the boiler, never put it on the engine, and generally employ independent feed-pumps which can be adjusted to the proper speed. Besides, a feed-pump could not be run satisfactorily at the speed of this engine.” He heard me through, and then, with a look of utter disgust, exclaimed: “If a man should sell me a musket and tell me it had no stock, lock, or barrel, these were all extra, I should think it just about as sensible.” Nothing would do but that this engine must have a pump. I had intended to cut off the projecting end of the shaft, but Mr. Amos ordered this to be left, and had an eccentric fitted on it, and set a vertical pump on the floor to be driven by this eccentric, at 225 double strokes per minute. Also the feed-pipe had to be over 50 feet long, with three elbows.

Of course, as the boys say, we had a circus. A mechanic had a daily job, mornings, when the engine was not running, securing that pump on its foundation. The trembling and pounding in the feed-pipe were fearful. I suggested an air-chamber. They sent word to me that they had put on an air-chamber, but it did no good. I went to look at it, and found a very small air-chamber in the middle of the length of the pipe, where it seemed to me more likelyto do harm. At my suggestion they got one of suitable size and attached it to the pump outlet, when the noise and trembling mostly disappeared, as well as the disposition of the pump to break loose. It did fairly well after that, and they made it answer, although I do not suppose it ever one quarter filled.

Mr. Amos was the consulting engineer of the Royal Agricultural Society. At this exhibition American reapers made an invasion of England. Mr. Amos set his face against them, and in reply to my question, what objection he made to them, he said, “We prefer to get our grain into the barn, instead of strewing it over the field.” And yet this man, the engineering head of this firm, was the only man in England, so far as I knew, advanced enough to take up the Wolff system of compounding, and who had bought my engine to run at 225 revolutions per minute, which it continued to do with complete satisfaction until some years later, when these works were removed to a location on the Thames, east of London, when I lost sight of them.

During the latter part of the exhibition I learned that the McNaught and the Hopkinson indicators were in common use in England; that one or both of these were to be found in the engine-rooms of most mills and manufacturing establishments, and that if the Richards indicator were properly put on the market there would probably be some demand for it, although at existing engine speeds the indicators in use appeared to be satisfactory. A special field for its employment would doubtless be found, however, in indicating locomotives. I felt sufficiently encouraged to set about the task of standardizing the indicator, and during the winter of 1862-3 made a contract with the firm of Elliott Brothers, the well-known manufacturers of philosophical apparatus and engineering and drawing instruments, to manufacture them according to my plans.

This was my first attempt to organize the manufacture of an instrument of any kind, and I set about it under a deep sense of responsibility for the production of an indicator that should command the confidence of engineers in its invariable truth. I found that the opportunity I had enjoyed for studying the subject had been most important. The daily use of the indicator which I hadbrought to the exhibition was an invaluable preparation for this work.

I decided, first, to increase the multiplication of the piston motion, by means of the lever, from three times to four times, thus reducing by one quarter the movement of the piston required to give the same vertical movement to the pencil, and, second, to increase the cylinder area from one quarter to one half of a square inch. The latter was necessary in order to afford sufficient room for springs of proper size, and correct reliable strength in their connections.

The first problem that presented itself was how to produce cylinders of the exact diameter required, .7979 of an inch, and to make an error in this dimension impossible. This problem I solved in the following manner: At my request Elliott Brothers obtained from the Whitworth Company a hardened steel mandrel about 20 inches in length, ground parallel to this exact size and certified by them. Brass tubes of slightly larger size and carefully cleaned were drawn down on this mandrel. These when pressed off presented a perfect surface and needed only to be sawed up in lengths of about 2 inches for each cylinder. Through the whole history of the manufacture that removed all trouble or concern on this account.

The pistons were made as light as possible, and were turned to a gauge that permitted them to leak a little. The windage was not sufficient to affect their accuracy; a thickness of silk paper on one side would hold the pistons tight; but they had a frictionless action, and the cover of the spring case having two holes opening to the atmosphere, there could be no pressure above the piston except that of the atmosphere.

SPRING-TESTING INSTRUMENT.USED IN THE MANUFACTURE OF THE RICHARDS INDICATOR.Designed by Charles T. Porter.LONGITUDINAL SECTION.SCALE, HALF SIZE.END VIEW

SPRING-TESTING INSTRUMENT.USED IN THE MANUFACTURE OF THE RICHARDS INDICATOR.Designed by Charles T. Porter.LONGITUDINAL SECTION.SCALE, HALF SIZE.

END VIEW

The second problem was to insure the accuracy of the springs. This was more serious than the first one. The brass heads of the springs were provided with three wings instead of two, which mine had. The spring, after being coiled and tempered, was brazed into the grooves in the first two wings, and the third wing was hammered firmly to it. This prevented the stress on the spring from reaching the brazed joints, and these heads never worked loose. One head was made fast at once; the other was left free to be screwed backward or forward until the proper length of the spring was found. To insure freedom from friction, I determined to adjust and test the springs in the open air, quite apart from the instrument. For this purpose I had a stout cast-iron plate made, with a bracket cast on it, in which the slides were held in a vertical groove, and bolted this plate on the bench, where it was carefully leveled. The surface of the plate had been planed, a small hole drilled through it at the proper point, and a corresponding hole was bored through the bench. A seating for the scales also was planed in the bracket, normal to the surface of the block. The spring to be tested, in its heads as above described, was set on the block, and a rod which was a sliding fit in the hole was put up through the bench, block, and spring. This rod had a head at the lower end, and was threaded at the upper end. Under the bench a sealed weight, equal to one half the extreme pressure on the square inch to be indicated by the spring, was placed on the rod.

Between the spring and the scale I employed a lever, representing that used in the indicator, but differing from it in two respects. It was of twice its length, for greater convenience of observation, and it was a lever of the first order, so that the weight acting downward should represent the steam pressure in the indicator acting upward.

The weight was carried by a steel nut screwed on the end of the rod and resting on the upper head of the spring to be tested. This nut carried above it a hardened stirrup, with a sharp inner edge, which intersected the axis of the rod, produced. A delicate steel lever was pivoted to turn about a point at one fifth of the distance from the axis of the rod to the farther side of the scale seat. The upper edge of this lever was a straight line intersecting the axis of its trunnions. The short arm of the lever passed through the stirrup, in which it slid as the spring was compressed, while the long arm swung upward in front of the scale. The latter was graduated on its farther side, and the reading was taken at the point of intersection of the upper edge of the lever with this edge of the scale.

The free head on the spring was turned until the reading showed it to be a trifle too strong. It was then secured, and afterwards brought to the exact strength required by running it rapidly in alathe and rubbing its surface over its entire length with fine emery cloth. This reduced the strength of each coil equally. This was a delicate operation, requiring great care to reduce the strength enough and not too much. A great many springs had to be made, several being generally required, often a full set of ten, with each indicator. This testing apparatus was convenient and reliable, and the workmen became very expert in its use.

The spring when in use was always exposed to steam of atmospheric pressure. At this temperature of 212° we found by careful experiment that all the springs were weakened equally, namely, one pound in forty pounds. So the springs were made to show, when cold, 39 pounds instead of 40 pounds, and in this ratio for all strengths.

This system of manufacture and testing was examined in operation by every engineer who ordered an indicator, the shop on St. Martin’s Lane being very convenient. They generally required that the indicator should be tested by the mercurial column. The Elliotts, being large makers of barometers, had plenty of pure mercury, so this requirement was readily complied with, and the springs were invariably found to be absolutely correct. We never used the mercurial column in manufacturing, but were glad to apply it for the satisfaction of customers.

I employed the following test for friction. The indicator when finished was set on a firm bracket in the shop. The spring was pressed down as far as it could be, and then allowed to return to its position of rest very slowly, the motion at the end becoming almost insensible. Then a fine line was drawn with a sharp-pointed brass wire on metallic paper placed on the drum. The spring was then pulled up as far as possible and allowed to return to its position of rest in the same careful manner. The point must then absolutely retrace this line. No indicator was allowed to go out without satisfying this test. The workmanship was so excellent that they always did so as a matter of course.

Mr. Henry R. Worthington once told me, long after, that on the test of an installation of his pump in Philadelphia, after he had indicated it at both steam and water ends, the examining board asked him to permit them to make a test with their own indicator, which they did the next day. They brought anotherindicator, of Elliott’s make like his own, but the number showed it to have been made some years later. “Would you believe it,” said he, “the diagrams were every one of them absolutely identical with my own!” I replied that the system of manufacture was such that this could not have been otherwise.

Plan of Spring-testing Instrument.

I wish to acknowledge my obligation to Elliott Brothers fortheir cordial co-operation, their excellent system of manufacture, and the intelligent skill of their workmen, by one of whom the swiveling connection of the levers with the piston-rod was devised.

The indicator was improved in other important respects, but I here confine myself to the above, which most directly affected its accuracy. This soon became established in the public confidence. During my stay in England, about five years longer, the sale of indicators averaged some three hundred a year, with but little variation. The Elliotts then told me that they considered the market to have been about supplied, and looked for a considerable falling off in the demand, and had already reduced their orders for material. Eight years after my return I ordered from them two indicators for use in indicating engines exhibited at our Centennial Exhibition at Philadelphia. The indicators had from the first been numbered in the order of their manufacture. These came numbered over 10,000.

The indicators were put on the market in the spring of 1863, and I sought opportunity to apply them on locomotives. In this I had the efficient co-operation of Zerah Colburn, then editor ofThe Engineer. The first application of them was on a locomotive of the London and Southwestern Railway, and our trips, two in number, were from London to Southampton and return. The revelations made by the indicator were far from agreeable to Mr. Beattie, the chief engineer of the line. Mr. Beattie had filled his boilers with tubes ⁷⁄₈ of an inch in diameter. The diagrams showed the pressure of blast necessary to draw the gases through these tubes to average about ten pounds above the atmosphere, the reduction of the nozzles producing this amount of back pressure throughout the stroke. Another revelation was equally disagreeable. The steam showed very wet. We learned that Mr. Beattie surrounded his cylinders with a jacket. This was a large corrugated casting in which the cylinder was inserted as a liner. To keep the cylinder hot theexhaustwas passed through this jacket. Mr. Colburn made both of these features the subjects of editorials inThe Engineer, written in his usual trenchant style. The last one was entitled “Mr. Beattie’s Refrigerators,” and produced a decided sensation.

Our next trips were made on the Great Eastern Road, one from London to Norwich and one from London to Great Yarmouth. On these trips we were accompanied by Mr. W. H. Maw, then head draftsman of the Great Eastern Locomotive Drawing Office, under Mr. Sinclair, the chief engineer, and by Mr. Pendred. These gentlemen were afterwards, respectively, the editors ofEngineeringandThe Engineer.

Diagrams from English Locomotives taken with Richards Indicator.

The diagrams from the Great Eastern engines were, on the whole, the best which were taken by us. On one of these trips I was able to get the accompanying most interesting pair ofdiagrams, which were published by me in the appendix to my treatise on the Indicator. One of them was taken at the speed of 50 revolutions per minute, and the other at the speed of 260 revolutions per minute, running in the same notch with wide-open throttle. The steam pressure was higher at the rapid speed. They afford many subjects of study, and show the perfect action of the indicator as at first turned out, at this great speed. I learned afterwards that the almost entire freedom from vibration at the most rapid speed was due to the gradual manner in which the pressure fellfrom the beginning of the stroke. This fall of pressure before the cut-off I fancy was caused largely by a small steam-pipe.

Our last diagrams were taken from a locomotive on the London and Northwestern, by the same four operators as on the Great Eastern trips. We ran from London to Manchester. On our return trip Mr. Webb joined us at Crewe, and accompanied us to London. I am sorry to say that in one respect the revelation of the indicator here was almost inconceivably bad. Mr. Ramsbottom did not protect his cylinders, but painted these and the steam-chests black, and in this condition sent them rushing through the moist air of England. If the steam cooled by “Mr. Beattie’s refrigerators” was wet, that in Mr. Ramsbottom’s cylinders seemed to be all water. A jet of hot water was always sent up from each of the holes in the cover of the spring case to a height of between one and two feet. We had much trouble to protect ourselves from it, and it nearly always drenched the diagram. I never saw this phenomenon before or since. I have seen the steam blow from the indicator cocks white with water when the indicators were removed. But I never saw water spurt through the spring-case cover, except in this instance. Truly, we said to each other, Mr. Ramsbottom has abundant use for his trough and scoop to keep water in his tanks. It was on this trip that I observed how enormously the motion of a black surface increased the power of the surrounding air to abstract heat from it. While we were running at speed I many times laid my hand on the smoke-box door without experiencing any sensation of warmth. I wondered at this, for I knew that a torrent of fire issuing from the tubes was impinging against the opposite surface of this quarter-inch iron plate. In approaching Rugby Junction I observed that the speed had not slackened very much when I could not touch this door, and when we stopped, although the draft had mostly ceased, I could not come near it for the heat. At the full velocity with which the air blew against this door the capacity of the air to absorb heat evidently exceeded the conducting power of the metal.

W. H. Maw

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