The Gentleman's Magazine was an important and influential monthly magazine in the 18th and 19th Centuries; it began in 1731, ceased regular publication in 1907, and shut down completely in 1922.
The August, 1855, edition carried a substantial obituary for John Black (d. June 15, 1855) , notable for being the long-time editor of the London newspaper The Morning Chronicle. "Notable" because the Morning Chronicle was, per its Wiki entry, the first steady employer of Charles Dickens (hired by Black) and of the noted essayist William Hazlitt; it was also the first newspaper to employ a salaried female journalist.
Of relevance to Newfie-dom is this remark about Black:
In his walks, Mr. Black's constant attendant at one time was a large Newfoundland dog named Cato, whom he used to tug along from book-stall to book-stall, or run with to and fro from Blackheath and London at all hours of the night. (211)