When he arrived at manhood, he obtained employment as porter to a drysalter and paper-maker at Norwich; he was next made a journeyman, with increased wages. He then, through his master, got an appointment in the Excise, in a district near London; and his master also gave him a letter of introduction to a sugar-baker in the metropolis. After a tedious journey by waggon, he reached London, with only eight shillings in his pocket. There was some delay and expense before he could act as an exciseman, and his immediate necessities compelled him to take the situation of porter to the sugar-baker. He then became a journeyman, and by his parsimonious habits saved money enough to pay the preliminary expenses, and was enabled to assume the office to which he had so long aspired. He was then appointed to inspect a paper-mill at Tottenham, where he closely watched a new process in paper-making. During Cooke's official visits to this mill the owner died, and his widow resolved to carry on the business with the aid of a foreman. Cooke had noted here many infractions of the law, which, designedly or otherwise, were daily taking place; and having summed up the penalties incurred thereby, which he set off against the value of the concern, he privately informed the widow that he had complained of these malpractices, and told her that if the fines were levied, they would amount to double the value of the property she possessed, and reduce her to want and imprisonment. This he followed up by an overture of marriage, and assured the lady that he only knew of the frauds of her establishment. The widow consented to become his wife when the appointed days of mourning for her first husband had expired. To this Cooke agreed, but lest she might prove fickle, he required of her a promise in writing. On his marriage, Cooke became possessed of her property, which was considerable, together with the lease of the mills at Tottenham.