An early indication of his abilities came in 1825 when he was instructed by opponents of the proposed Liverpool and Manchester Railway, principally the directors of the Bridgewater and Leeds and Liverpool Canals, as their counsel in the committee stage of the private bill needed to establish the railway. Alderson was to cross-examine George Stephenson on his designs for the railway and the surveys on which they were based. Alderson proved an able advocate and Stephenson a poor witness. Stephenson later confessed, "I was not long in the witness box before I began to wish for a hole to creep out at." Largely owing to Alderson's devastating closing speech, the bill was lost, the railway was delayed for several years and Stephenson's early reputation badly damaged.