introduced locomotives. During the survey of the S&DR George had been persuaded, mainly by the Scottish engineer Robert Bald, that Robert would benefit from a university education. George could have afforded to send his son to a full degree course at Cambridge but agreed to a short academic year as he wished that Robert should not become a gentleman but should work for his living. Robert first helped William James to survey the route of the Liverpool and Manchester Railway and then attended classes at Edinburgh University between October 1822 and April 1823. On 23 May 1823, a second S&DR Act received Assent with the Stephensons' deviations from the original route and permission for the use of "loco-motives or moveable engines". In June 1823 the Stephensons and Pease opened Robert Stephenson and Company at Forth Street in Newcastle to build these locomotives, Pease lending Robert £500 so he could buy his share. As George was busy supervising the building of the railway, Robert was placed in charge of the works with a salary of £200 per annum. Robert also surveyed the route and designed the Hagger Leases branch, which was planned to serve the collieries at Butterknowle and Copley Bent. A new Act was required for the line, and Robert stayed in London for five weeks while the bill passed through its parliamentary process, Assent being given in May 1824. The S&DR ordered two steam locomotives and two stationary engines from Robert Stephenson & Co. on 16 September 1824, and the railway opened on 27 September 1825. Colombian mines On 18 June 1824, Stephenson sailed on the Sir William Congreve from Liverpool for South America with a contract for three years. At that time Colombia and Venezuela had not been independent of Spain for long, and they were both part of the same republic, Gran Colombia. The area's natural resources were attracting some British investors, including the Colombian Mining Association which had been formed to reopen gold and silver mines worked by the Spanish in colonial times. A Robert Stephenson & Co. partner, Thomas Richardson, was a promoter. Robert Stephenson & Co. received orders for steam engines from the company, and Richardson suggested to Stephenson that he go to South America. To prepare for the trip, Stephenson took Spanish lessons, visited mines in Cornwall, and consulted a doctor, who advised that such a change of climate would be beneficial to