Eldest [?] son of William Southwell.

It is not clear if this is the same John Southwell (i) listed as a music publisher from 1803 to 1806.

In 1804 William drew up a deed of partnership with his brother Nicholas and sons John (ii) and Francis, after which the business was known as 'William Southwell & Co.'. John had already been in partnership with his father 'for some time' by the time this business was established. The partnership was due to last four years but was not dissolved until 1814 (Bozworth, Debenham & Cripps) or 1815 (De Valera, 'Two Eighteenth-Century Musical Instrument Makers'). According to De Valera, the partnership was 'to free himself [William] from the day-to-day pressure of general business and to concentrate purely on the design, development and manufacture of instruments and, in particular [...] the piano, but Bozworth, Debenham & Cripps state that the partnership was to protect Southwell from personal loss in defending his patent in court. After William's death, Nicholas continued the Liverpool business, and John maintained a music shop in Dublin (Bozworth, Debenham & Cripps).

[Dates and addresses differ according to sources: The Dublin Directories give 7 Grafton Street in 1823, 127 Abbey Street from 1832 to 1837 and 37 Abbey Street in 1836, which is probably a misprint for 127 Abbey Street. Teahan gives 34 'Marlboro St.' in 1815, 9 'Marlboro St' in 1822, 54 Exchequer Street in 1824, 65 Exchequer Street in 1830 and 52 Abbey Street in 1844. Hogan gives 34 Marlborough Street from c. 1815 to 1816, 9 Marlborough Street from c. 1822 to 1823, 54 Exchequer Street c. 1824 and 65 Exchequer Street from c. 1825 to 1834. De Valera gives only 127 Abbey Street in 1837. Bozworth, Debenham & Cripps (citing Wilson's Dublin Directory give 34 Marlborough Street from 1815 to 1821 and 9 Marlborough Street in 1822. ]