John Southern
John Southern was one of the sons of Thomas Southern of Wensley, near Wirksworth, Derbyshire, and interested in mining affairs in various parts of the country
c.1758 Born
June 1782 Southern, then at the age of 24, started with Boulton and Watt on a three years' agreement, and with them he remained until the end of his life. He seems to have dropped into his place without hesitation or friction of any kind, even Watt makes no complaints of him, and he soon proved a valuable assistant and relieved his chief of a good deal of work.
He improved James Watt's steam indicator by adding a pencil and moving paper for recording the pressure in the cylinder.
1793 Southern married the daughter of Thomas Dobbs of Kings Norton.
1800 Southern was given in additional to his salary a percentage upon all goods produced at the Soho Engine works, or in lieu thereof £600 per annum
1810 he was admitted as a partner in the firm of Boulton and Watt to receive one-sixth of the profits.
1815 August. Died aged 57, 'distinguished as a mathematician and engineer'[1][2]
After his death the firm settled £2,000 on Mrs. Southern and the children.