intellect. His quaint remarks on my first visit to his workshop, and on subsequent occasions, proved to me invaluable guides to "right thinking" in regard to all matters connected with mechanical structure.

Mr. Maudslay seemed at once to take me into his confidence. He treated me in the most kindly manner -- not as a workman or an apprentice, but as a friend. I was an anxious listener to everything that he said; and it gave him pleasure to observe that I understood and valued his conversation. The greatest treat of all was in store for me. He showed me his exquisite collection of taps and dies and screw-tackle, which he had made with the utmost care for his own service. They rested in a succession of drawers near to the bench where he worked. There was a place for every one, and every one was in its place. There was a look of tidiness about the collection which was very characteristic of the man. Order was one of the rules which he rigidly observed, and he endeavoured to enforce it upon all who were in his employment.

He proceeded to dilate upon the importance of the uniformity of screws. Some may call it an improvement, but it might almost be called a revolution in mechanical engineering which Mr. Maudslay introduced. Before his time no system had been followed in proportioning the number of threads of screws to their diameter. Every bolt and nut was thus a speciality in itself, and neither possessed nor admitted of any community with its neighbours. To such an extent had this practice been carried that all bolts and their corresponding nuts had to be specially marked as belonging to each other. Any intermixture that occurred between them led to endless trouble and expense, as well as inefficiency and confusion, -- especially when parts of complex machines had to be taken to pieces for repairs.

None but those who lived in the comparatively early days of machine manufacture can form an adequate idea of the annoyance, delay, and cost of this utter want of system, or can appreciate the vast services rendered to mechanical engineering by Mr. Maudslay, who was the first to introduce the practical measures necessary for its remedy. In his system of screw-cutting machinery, and in his taps and dies, and screw- tackle generally, he set the example, and in fact laid the foundation, of all that has since been done in this most essential branch of machine construction. Those who have had the good fortune to work under him, and have experienced the benefits of his practice, have eagerly and ably followed him; and thus his admirable system has become established throughout the entire mechanical world.

Mr. Maudslay kept me with him for about three hours, initiating me into his system. It was with the greatest delight that I listened to his wise instruction. The sight of his excellent tools, which he showed me one by one, filled me with an almost painful feeling of earnest hope that I might be able in any degree to practically express how thankful I was to be admitted to so invaluable a privilege as to be in close communication with this great master in all that was most perfect in practical mechanics.

When he concluded his exposition, he told me in the most kindly manner that it would be well for me to take advantage of my father's presence in London to obtain some general knowledge of the metropolis, to see the most remarkable buildings, and to obtain an introduction to some of my father's friends. He gave me a week for this purpose, and said he should be glad to see me at his workshop on the following Monday week.

It singularly happened that on the first day my father went out with me, he encountered an old friend. He had first known him at Mr. Miller's of Dalswinton, when the first steamboat was tried, and afterwards at Edinburgh while he was walking the courts as an advocate, or writing articles for the Edinburgh Review. This was no other than Henry Brougham. He was descending the steps leading into St. James's Park, from the place where the Duke of York's monument now stands. Brougham immediately recognised my father. There was a hearty shaking of hands, and many inquiries on either side. "And what brings you to London now?" asked Brougham. My father told him that it was about his son here, who had obtained an important position at Maudslay's the engineer.

"If I can do anything for you," said Brougham, addressing me, "let me know. It will afford me much pleasure to give you introductions to men of science in London." I ventured to say that "Of all the men of science