Nasmyth retired from business in 1856, bought an estate in Kent, and spent the remainder of his life in travel and in his studies in astronomy. He was deeply interested in this study from boyhood. Before he was twenty he had built an excellent 6-inch reflecting telescope, and it was he who aroused Maudslay’s interest in the subject. He had a 10-inch telescope at Patricroft and a large one at Hammersfield. He began his study of the moon in 1842, and received a medal for his work at the Exhibition of 1851. His book, “The Moon, Considered as a Planet, a World, and a Satellite,” published in 1874, in conjunction with James Carpenter, the result of his thirty-two years of work, is authoritative today. Nasmyth died in 1890 at the age of eighty-two. He was much more than a splendid mechanic. His personal charm and quality of mind can best be appreciated by reading his own story. This chapter will have served its purpose if it induces the reader to read the autobiography from which we have quoted so freely. CHAPTER IX WHITWORTH The work of the earlier generation of English tool builders may be said to have culminated in that of Sir Joseph Whitworth. For a man of his commanding influence, the information in regard to his life is singularly meager. He left no account of himself as Nasmyth and William Fairbairn did; no biography of him was written by his contemporaries, and the various memoirs which appeared at the time of his death are short and incomplete. He was born at Stockport in 1803. His father was a minister and schoolmaster. At fourteen he was placed in the office of his uncle, a cotton spinner in Derbyshire, to learn the business. But commercial work did not appeal to him. He slighted the office as much as possible and delved into every nook and corner of the manufacturing and mechanical departments of the establishment. In a few years he had mastered the construction of every machine in the place and acquired the deep-seated conviction that _all_ the machinery about him was imperfect. He ran away to Manchester to escape a routine business life, and found work with Creighton & Company, as a working mechanic. He married in 1825, and shortly afterward went to work with Maudslay & Field in London. Maudslay soon placed him next to John Hampson, a Yorkshireman, who was his best workman. While there, Whitworth developed his method of making accurate plane surfaces by _hand scraping_ them, three at a time. On leaving Maudslay, Whitworth worked for Holtzapffel, and later for Clement. He returned to Manchester in 1833, rented a room with power, and hung out a sign, “Joseph Whitworth, Tool Maker from London.” Here he began his improvements in machine tools--the lathe, planer, drilling, slotting and shaping machines. He improved Nasmyth’s shaper, adding the quick-return motion, which has been known ever since as the Whitworth quick-return motion. His tools became the standard of the world, and in the London Exhibition of 1851