[2] When playing at Oxford, Cobham, with his wife, was engaged by Sampson Penley for the theatre in Tottenham Street, where he appeared with much success as the eponymous Marmion in a dramatisation by William Oxberry of Scott's poem.
William Hazlitt, however, who was present on the occasion, declares his Richard to have been 'a vile one,' a caricature of Kean, and continues : He raved, whined, grinned, stared, stamped, and rolled his eyes with incredible velocity, and all in the right place according to his cue, but in so extravagant and disjointed a manner, and with such a total want of common sense, decorum, or conception of the character as to be perfectly ridiculous.
[2] In 1817, Cobham appeared at the Crow Street Theatre, Dublin, as Sir Giles Overreach, playing afterwards Macbeth, and Richard.
He was in Dublin in 1821–2, a member of the Hawkins Street stock company, dividing with James Prescott Warde the principal characters of tragedy.
After Warde dropped out, he played, in the memorable engagement of Kean in July 1822, Richmond, Iago, Edgar in Lear, and the Ghost in Hamlet.
[2] Early in his career Cobham played at Woolwich, at the Navy Tavern, Glenalvon to the Young Norval of Kean.
[2] Cobham had some resemblance in appearance and stature to Kean, being dark, with flexible features, and about five feet five inches in height.
[2] It is there also said that 'the modern stage affords few efforts of genius superior to his acting in the last scene of "Thirty Years of a Gambler's Life."'