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It consisted in the employment of a knife-edged hardened steel instrument, so arranged as to be set at any required angle, and its edge caused to penetrate the surface of a cylindrical bar of soft steel or brass. This bar being revolved under the incisive action of the angularly placed knife-edged instrument, it thus received a continuous spiral groove cut into its surface. It was then in the condition of a rudimentary screw; the pitch, or interval between the threads, being determined by the greater or less angle of obliquity at which the knife-edged instrument was set with respect to the axis of the cylindrical bars revolving under its incisive action.

The spiral groove, thus generated, was deepened to the required extent by a suitable and pointed hard steel tool firmly held in the jaws of an adjustable slide made for the purpose, as part and parcel of the bed of the machine. In the case of square-threaded screws being required, a square-pointed tool was employed in place of the V or angle-threaded tool. And in order to generate or produce right hand or left hand screws, all that was necessary was to set the knife-edged instrument to a right or left hand inclination in respect to the axis of the cylindrical bar at the outset of the operation.

This beautiful and truly original contrivance became, in the hands of its inventor, the parent of a vast progeny of perfect screws, whose descendants, whether legitimate or not, are to be found in every workshop throughout the world, wherever first-class machinery is constructed. The production of perfect screws was one of Maudslay's highest ambitions and his principal technical achievement. It was a type of his invaluable faculty of solving the most difficult problems by the most direct and simple methods.

It was by the same method that he produced the Guide screw. His screw-cutting lathe was moved by combination wheels, and by its means he could, by the one Guide screw, obtain screws of every variety of pitch and diameter. As an illustration of its complete accuracy I may mention that by its means a screw of five feet in length and two inches in diameter was cut with fifty threads to the inch; the Nut to fit on to it being twelve inches long, and containing six hundred threads! This screw was principally used for dividing scales for astronomical and other metrical purposes of the highest class. By its means divisions were produced with such minuteness that they could only be made visual by a microscope.

This screw was sent for exhibition to the Society of Arts. It is still preserved with the utmost care at the Lambeth Works amongst the many admirable specimens of Henry Maudslay's inventive genius and delicate handiwork. Every skilled mechanic must thoroughly enjoy the sight of it, especially when he knows that it was not produced by an exceptional tool, but by the machine that was daily employed in the ordinary work of the factory.

I must not, however, omit to say that I took an early opportunity of presenting Brougham's letter of introduction to Faraday at the Royal Institution. I was received most cordially by that noble-minded man, whose face beamed with goodness and kindness. After some pleasant conversation he said he would call upon me at Maudslay's, whom he knew very well. Not long after Faraday called, and found me working beside Maudslay in his beautiful little workshop. A vice had been fitted up for me at the bench where he himself daily worked. Faraday expressed himself as delighted to find me in so enviable a position. He congratulated me on my special good fortune in having the inestimable advantage of being associated as assistant workman with one of the greatest mechanical engineers of the day.

Mr. Maudslay offered to conduct Faraday through his workshops, and I was permitted to accompany them. I was much impressed with the intelligent conversation of Faraday, as well as with the quickness he exhibited in appreciating not only the general excellence of the design and execution of the works in progress, but his capacity for entering into the technical details of the composite tools and machinery which he saw during his progress through the place. This most pleasant and memorable meeting with the great philosopher initiated a friendship which I had the good fortune to continue until the close of his life.

It was, of course, an immense advantage for me to be so intimately associated with Mr. Maudslay in carrying on his experimental work. I was not, however, his apprentice, but his assistant workman. It was necessary, therefore, in his opinion, that I should receive some remuneration for my services. Accordingly, at the conclusion of my first week in his service, he desired me to go to his chief cashier and arrange with him for receiving whatever amount of weekly wages I might consider satisfactory. I went to the counting-house and had an interview with Mr. Young the cashier, a most worthy man* [footnote... I may mention that he was brother to Dr. Thomas Young, the celebrated natural philosopher. ...] Knowing as I did the great advantages of my situation, and having a very modest notion of my own worthiness to occupy it, I said, in answer to Mr. Young's question as to the amount of wages I desired, that "if he did not think ten shillings a week too much I could do well enough with that." "Very well" said he,"let it be so" And he handed me over half a sovereign!

I had determined, after I obtained a situation, not to cost my father another shilling. I knew how many calls he had upon him, at a time when he had his own numerous household to maintain. I therefore resolved, now that I had begun life on my own resources, to maintain myself, and to help him rather than be helped any longer. Thus the first half-sovereign I received from Mr. Young was a great event in my life. It was the first wages, as such, that I had ever received. I well remember the high satisfaction I felt as I carried it home to my lodgings; and all the more so as I was quite certain that I could, by strict economy and good management, contrive to make this weekly sum of ten shillings meet all my current expenses.

I had already saved the sum of #20, which I placed in the bank as a deposit account. It was the residue of the sale of some of my model steam-engines at Edinburgh. My readers will remember that I brought with me a model steam-engine to show to Mr. Maudslay as a specimen of my handiwork. It had gained for me the situation that I desired, and I was now willing to dispose of it. I found a purchaser in Mr. Watkins, optician at Charing Cross, who supplied such apparatus to lecturers at Mechanics' Institutions. He gave me #35 for the model, and I added the sum to my deposit account. This little fund was quite sufficient to meet any expenses beyond those of a current weekly nature.

[Image] My cooking stove* [footnote... I have this handy apparatus by me still; and to prove its possession of its full original efficiency I recently set it in action after its rest of fifty years, and found that it yielded results quite equal to my grateful remembrance of its past services. ...]

But I was resolved that my wages alone should maintain me in food and lodging. I therefore directed my attention to economical living. I found that a moderate dinner at an eating-house would cost move than I could afford to spend. In order to keep within my weekly income I bought the raw materials and cooked them in my own way and to my own taste. I set to and made a drawing of a very simple, compact, and handy cooking apparatus. I took the drawing to a tinsmith near at hand, and in two days I had it in full operation. The apparatus cost ten shillings, including the lamp. As it contributed in no small degree to enable me to carry out my resolution, and as it may serve as a lesson to others who have an earnest desire to live economically, I think it may be useful to give a drawing and a description of my cooking stove. The cooking or meat pan rested on the upper rim of the external cylindrical case, and was easily removable in order to be placed handy for service. The requisite heat was supplied by an oil lamp with three small single wicks, though I found that one wick was enough. I put the meat in the pot, with the other comestibles, at nine o'clock in the morning. It simmered away all day, until half-past six in the evening, when I came home with a healthy appetite to enjoy my dinner. I well remember the first day that I set the apparatus to work. I ran to my lodging, at about four P.M., to see how it was going on. When I lifted the cover it was simmering beautifully, and such a savoury gusto came forth that I was almost tempted to fall to and discuss the contents. But the time had not yet come, and I ran back to my work.

The meat I generally cooked in it was leg of beef, with sliced potato, bits of onion chopped down, and a modicum of white pepper and salt, With just enough of water to cover "the elements." When stewed slowly the meat became very tender; and the whole yielded a capital dish, such as a very Soyer might envy. It was partaken of with a zest that, no doubt, was a very important element in its savouriness. The whole cost of this capital dinner was about 4 1/2d. I sometimes varied the meat with rice boiled with a few raisins and a pennyworth of milk. My breakfast and tea, with bread, cost me about fourpence each. My lodgings cost 3s. 6d. a week. A little multiplication will satisfy any one how it was that I contrived to live economically and comfortably on my ten shillings a week. In the following year my wages were raised to fifteen shillings a week, and then I began to take butter to my bread.

To return to my employment under Mr. Maudslay. One of the first jobs that I undertook was in assisting him to make a beautiful small model of a pair of 200 horsepower marine steam-engines. The engines were then in course of construction in the factory. They were considered a bold advance on the marine engines then in use, not only in regard to their great power, but in carrying out many specialities in their details and general structure. Mr. Maudslay had embodied so much of his thought in the design that he desired to have an exact model of them placed in his library, so as to keep a visible record of his ideas constantly before him. In fact, these engines might be regarded as the culmination of his constructive abilities.

In preparing the model it was necessary that everything should be made in exact conformity with the original. There were about three hundred minute bolts and nuts to be reduced to the proportional size. I esteemed it a great compliment to be entrusted with their execution. They were all to be made of cast-steel, and the nuts had to be cut to exact hexagonal form. Many of them had collars. To produce them by the use of the file in the ordinary mode would not only have been difficult and tedious, but in some cases practically impossible.

[Image] Collar-nut cutting machine.

To get rid of the difficulty I suggested to Mr. Maudslay a contrivance of my own by means of which the most rigid exactness in size as well as form could be given to these hexagonal nuts. He readily granted his permission. I constructed a special apparatus, consisting of a hard steel circular cutter to act as a circular file. When brought into operation in the production of these minute six-sided collared nuts, held firm in the spindle of a small dividing plate and attached to the slide-rest, each side was brought in succession under the action of the circular file or cutter with the most exact precision in regard to the division of the six sides. The result was absolutely perfect as respects the exactness of the six equal sides of the hexagonal nut, as well as their precise position in regard to the collar that was of one solid piece with it. There was no great amount of ingenuity required in contriving this special tool, or in adapting it to the slide-rest of the lathe, to whose spindle end the file or cutter /\ was fixed. But the result was so satisfactory, both as regards the accuracy and rapidity of execution in comparison with the usual process of hand filing, that Mr. Maudslay was greatly pleased with the arrangement as well as with my zeal in contriving and executing this clever little tool. An enlarged edition of this collar-nut cutting machine was soon after introduced into the factory.

[Image] Arrangement of the machine

It was one of the specialities that I adopted in my own workshop when I commenced business for myself, and it was eagerly adopted by mechanical engineers, whom we abundantly supplied with this special machine. It was an inestimable advantage to me to be so intimately associated with this Great Mechanic. He was so invariably kind, pleasant, and congenial. He communicated an infinite number of what he humorously called "Wrinkles" which afterwards proved of great use to me. My working hours usually terminated at six in the evening. But as many of the departments of the factory were often in full operation during busy times until eight o'clock, I went through them to observe the work while in progress. On these occasions I often met "the guvnor, as the workmen called Mr. Maudslay. He was going his round of inspection, and when there was any special work in hand he would call me up to him to and explain point in connection with it that was worthy of particular notice. I found this valuable privilege most instructive, as I obtained from the cheif mechanic himself a full insight into the methods, means, and processes by which the skilful workman advanced the various classes of work. I was also permitted to take notes and make rapid sketches of any object that specially interested me. The entire establishment thus became to me a school of practical engineering of the most instructive kind.

Mr. Maudslay took pleasure in showing me the right system and method of treating all manner of materials employed in mechanical structures. He showed how they might be made to obey your will, by changing them into the desired forms with the least expenditure of time and labour. This in fact is the true philosophy of construction. When clear ideas have been acquired upon the subject, after careful observation and practice, the comparative ease and certainty with which complete mastery over the most obdurate materials is obtained, opens up the most direct road to the attainment of commercial as well as of professional success.

To be permitted to stand by and observe the systematic way in which Mr. Maudslay would first mark or line out his work, and the masterly manner in which he would deal with his materials, and cause them to assume the desired forms, was a treat beyond all expression. Every stroke of the hammer, chisel, or file, told as an effective step towards the intended result. It was a never-to-be-forgotten practical lesson in workmanship, in the most exalted sense of the term. In conformity with his often repeated maxim, "that there is a right way and a wrong way of doing everything," he took the shortest and most direct cuts to accomplish his objects. He illustrated this by telling me, in his own humorous style, " When you want to go from London to Greenwich, don't go round by Inverness." Another of his droll sayings was that he "considered no man a thorough mechanic unless he could cut a plank with a gimlet, and bore a hole with a saw!"