details of this are obscure. There is also evidence that the complex housed a pipe boring machine, whereby straight elm trees were bored out for pump dales. These could be up to long and were fitted through the decks of a vessel to pump seawater to the deck. There was a machine for making treenails—long wooden dowels used for fixing wooden parts of a ship together. Blocks The Royal Navy used large numbers of blocks, which were all hand-made by contractors. Their quality was not consistent, the supply problematic and they were expensive. A typical ship of the line needed about 1000 blocks of different sizes, and in the course of the year the Navy required over 100,000. Bentham had devised some machines for making blocks, but did not develop them and details of how they worked are now obscure. In 1802 Marc Isambard Brunel proposed to the Admiralty a system of making blocks using machinery he had patented. Bentham appreciated the superiority of Brunel's system and in August 1802 he was authorised by the Admiralty to proceed. There were three series of block-making machines, each designed to make a range of block sizes. They were laid out to allow a production line, so each stage of the work progressed to the next in a natural flow. The yard between the two wood mill buildings was walled-off and roofed to form a new workshop to house the block-making machines. The first set, for medium blocks, was installed in January 1803, the second set for smaller blocks in May 1803, and the third set for large blocks in March 1805. There were numerous changes of layout and some modification of the plant until in September 1807 the plant was felt able to fulfil all the needs of the Navy: 130,000 blocks were produced in 1808. The block-making processes using the machines The machines were of 22 types and totalled 45. They were driven by two steam engines. The machines included circular saws, pin turning machines and morticing machines. With these machines 10 men could produce as many blocks as 110 skilled craftsmen. A pulley-block has four parts: the shell, the sheave, the pin for locating the latter in the shell and a metal bush, or coak, inserted into the sheave to save wear between it and the pin. Blocks can vary in size and in the number of sheaves. The process