Sir William Cubitt FRS (bapt. 9 October 1785 – 13 October 1861) was an eminent English civil engineer and millwright. Born in Norfolk, England, he was employed in many of the great engineering undertakings of his time. He invented a type of windmill sail and the prison treadwheel, and was employed as chief engineer, at Ransomes of Ipswich, before moving to London. He worked on canals, docks, and railways, including the South Eastern Railway and the Great Northern Railway. He was the chief engineer of Crystal Palace erected at Hyde Park in 1851. He was president of the Institution of Civil Engineers between 1850 and 1851. Early life Cubitt was born in Dilham, Norfolk, the son of Joseph Cubitt of Bacton Wood, a miller, and Hannah Lubbock. He attended the village school. His father moved to Southrepps, and William at an early age was employed in the mill, but in 1800 was apprenticed to James Lyon, a cabinet-maker at Stalham, from whom he parted after four years. At Bacton Wood Mills he again worked with his father in 1804, and also constructed a machine for splitting hides. He then joined an agricultural machine maker named Cook, at Swanton, where they constructed horse threshing machines and other implements. Engineer and inventor Cubitt became known for the accuracy and finish of his patterns for the iron castings of machines. Self-regulating windmill sails were invented and patented by him in 1807, at which period he settled at Horning, Norfolk, in business as a millwright. He in 1812 sought and obtained an engagement in the works of Messrs. Ransome of Ipswich, where he soon became the chief engineer. For nine years he held this situation, and then became a partner in the firm, a position which he held until he moved to London in 1826. Already Cubitt was concerned with the employment of criminals; and for the purpose of using their labour he invented the treadmill, with the object, for example, of grinding corn, and not at first contemplating the use of the machine as a means of punishment. This invention was brought out about 1818, and was immediately adopted in the major gaols of the United Kingdom. From 1814 Cubitt had been acting as a civil engineer, and after his move to London he was fully engaged in important works. He was extensively employed in canal engineering, and the Oxford canal and the