Engineering reminiscences contributed to "Power" and "American machinist"

by Charles T. Porter

Our engine work was finally, as a last resort, done by Mr. Watts on new lathes, made for customers and used for a month or two before they were sent out. Not only in England, but on the Continent and in America, the Whitworth Works were regarded as the perfect machine-shop. I remember a visit I had at the Paris Exposition from Mr. Elwell, of the firm of Varrell, Elwell & Poulot, proprietors of the largest mechanical establishment in Paris. After expressing his unbounded admiration of the running of the engine, he said, “I warrant your fly-wheel runs true.” After observing it critically, he exclaimed, “Ah, they do those things at Whitworth’s!”

The fact was Mr. Whitworth had cursed the British nation with the solid conical lathe-spindle bearing, a perfect bearing for ordinary-sized lathes and a most captivating thing—when new. These hardened steel cones, in hardened steel seats, ran in the most charming manner. But they wore more loose in the main bearing every day they ran, and there were no means for taking up the wear. It came on insensibly, and no one paid any attention to it. The cream of the joke was that people were so fascinated with this bearing that at that time no other could be sold in England, except for very large lathes. All toolmakers had to make it. I remember afterwards that Mr. Freeland, our best American toolmaker, who, as I have already mentioned, went to England and worked for some years as a journeyman in the Whitworth Works for the purpose of learning everything there that he could, did not bring back to America the conical bearing.

The firm of Smith & Coventry were the first to fit their lathes with the means for taking up this wear, which took place only in the main bearing, where both the force of the cut and the weight of the piece were received. They made the conical seat for the back end of the spindle adjustable in the headstock and secured it by a thin nut on each end. This then could be moved backward sufficiently to let the forward cone up to its seat. This made it possible to use the solid bearing, but it involved this error, that after this adjustment the axis of the spindle did not coincide with the line connecting the lathe centers; but the two lines formed an angle with each other, which grew more decided every time the wear was taken up. This, however, was infinitely better than not to take up the wear at all.

At that time the Whitworth Works were divided into four departments. These were screwing machinery, gauges, guns and machine tools. The first three of these were locked. I never entered either of them. The latter also, like most works in England, was closed to outsiders. No customer could see his work in progress. This department was without a head or a drawing-office. It seemed to be running it on its traditions. I once said to Mr. Hoyle, “There must at some time have been here mechanical intelligence of the highest order, but where is it?” They had occasionally an order for something out of their ancient styles, and their attempts to fill such orders were always ruinous. The following is a fair illustration. They had an order for a radial drill to be back-geared and strong enough to bore an 8-inch hole. Mr. Widdowson had the pattern for the upright fitted with the necessary brackets, and thought it was such a good thing that he would make two. The first one finished was tried in the shop, and all the gears in the arm were stripped. He woke up to the fact that he had forgotten to strengthen the transmitting parts, and moreover that the construction would not admit anything stronger. There was nothing to be done but to decline the order, chip off the brackets, and make these into single-speed drills. This I saw being done.

Mr. Widdowson told me the following amusing story. The London Times had heard of the wonderful performance of Mr. Hoe’s multiple-cylinder press, and concluded to have one of them of the largest size, ten cylinders. But, of course, Mr. Hoe did not know how to make his own presses. His work would do well enough for ignorant Americans, but not for an English Journal. The press must be made in England in the world-renowned Whitworth Works.

Mr. Hoe sent over one of his experts to give them the information they might need, but they would not let him in the shop. Mr. Hulse told him they had the drawings and specifications and that was all they needed. When the press was finished they set it up in the shop and attempted to run it. The instant it started every tape ran off its pulleys, and an investigation showed that not a spindle or shaft was parallel with any other. They had no idea of the method that must be employed to ensure this universal alignment. After enormous labor they got these so that they were encouraged to make another trial, when after a few revolutions every spindle stuck fast in its bearings.

Mr. Whitworth, absorbed in his artillery and spending most of his time in London, of course had no knowledge of how things were going on in his shop, of the utter want of ordinary intelligence.

I formed a scheme for an application of Mr. Whitworth’s system of end measurement to the production of an ideally perfect dividing-wheel. In this system Mr. Whitworth employed what he termed “the gravity piece.” This was a small steel plate about ¹⁄₈ of an inch in thickness, the opposite sides of which were parallel and had the most perfectly true and smooth surfaces that could be produced by scraping. The ends of the piece to be tested were perfectly squared, by a method which I will not stop here to describe, and were finished in the same manner. The gravity piece was held fast between two such surfaces. None of the pieces were permitted to be touched by hand while an observation was being made. If now one of these pieces were loosened the millionth of an inch, the gravity piece would slide slowly down. If loosened two millionths of an inch, the gravity piece would descend twice as fast, and so on. I made a design for the application of this system to the correction of the dividing-wheel, so that a difference of pitch of one millionth of an inch could be shown and removed, the gravity piece being made to descend at the same rate of motion to whatever tooth it might be applied. I thought Mr. Whitworth would be interested in this novel and important application of his method, and I showed it to him. This was the encouraging and patronizing reply I received: “You had better inform yourself, sir, about what already exists. You will find a perfect dividing-wheel in my shop. What do you want better than that?” This wheel had divided my governor gear patterns, but spindles wabbling loose in their holes accounted for most of their defects.

The above recital is sufficient to show the conditions by which I found myself surrounded and the kind of man I had to deal with.

It may be supposed that when my agreement with Mr. Whitworth was concluded, the disappointment I had experienced on the stoppage of Ormerod, Grierson & Co. was quite relieved. But that does not express it. In fact, my revulsion of feeling could hardly be described. I believed that I had met a piece of good fortune that was unparalleled. I had got into the most famous machine-shop in the world, a shop in which in years gone by had been originated almost everything then regarded as most essential in machine construction. No one had ever before introduced anything into that shop. Its business, in its various departments, was confined to the manufacture of Mr. Whitworth’s own creations. I should never have dreamed of such a thing as getting into it. That I was there, and had been received so cordially, bewildered me. I could scarcely believe it.