they show many of the principles of the machines actually installed bear little resemblance to the final designs. The machines submitted by Brunel to the Admiralty for evaluation are now in the National Maritime Museum. Once the contract with the Admiralty had been placed Bentham engaged Henry Maudslay to make them, and it is clear the final designs had considerable input from Bentham, Maudslay, Simon Goodrich, (mechanician to the Navy board) as well as Brunel himself. Due to Bentham's absence in Russia, it was Goodrich who actually brought the block mills into full production. Brunel's payment was based on the saving the Navy made with the new system. These machines were almost entirely hand made, the only machine tools used being lathes to machine circular parts, and drilling machines for boring small holes. At that time there were no milling, planing or shaping machines, and all flat surfaces were made by hand chipping, filing and scraping. There is evidence that the grinding of flats was also done to get near-precision finishes. Each nut was made to fit its matching bolt and were numbered to ensure they were replaced correctly. This was before the days of interchangeability, of course. The materials used were cast and wrought iron, brass and gun metal. The use of metal throughout their construction greatly improved their rigidity and accuracy which became the standard for later machine tool manufacture. Publicity These machines and the block mills attracted an enormous amount of interest from the time of their erection, ranging from Admiral Lord Nelson on the morning of the day he embarked from Portsmouth for the Battle of Trafalgar on 1805, to the Princess Victoria at the age of 12, as part of her education. Even during the time of the Napoleonic Wars, until 1815 there was a stream of foreign dignitaries and military men wishing to learn. The machines were fully described and illustrated in the Edinburgh Encyclopædia (1811), Rees's Cyclopædia, (1812), the supplement to the 4th edition of Encyclopædia Britannica (1817) and the Encyclopædia Metropolitana. Later encyclopaedias such as Tomlinson's Encyclopaedia and the Penny Cyclopaedia derived their accounts from these earlier publications. These accounts concentrated almost entirely on the blockmaking machinery, and ignored the saw-milling side of the mills, and in consequence modern commentators have not discussed this aspect of the Block Mills. The sawmills were important since Brunel was enabled to develop his ideas which