A.W. Moore's Manx Worthies (p. 121) mentions James Kewley, the inventor and patentee in 1817. I found another patent in 1816 for thermometers.It gave James's address as James Kewley of Aldersgate Street i the City of Landon, Gentleman.
I have also found a James Kewley listed in Commercial Directories in the East End of London in the 1830's. Address 57 and a half Gloucester Street, Commercial Road, occupation "Manufacturer of hot-air apparatus" and "hot-house warmer"
A bit later the Manx Sun announces [28 June 1848] the death at Chelsea of consumption aged 42 the beloved wife of Mr. James Kewley, another maybe unconnected reference
Manx Sun 7 April 1855 Died at Marylebone, London in his brother's house Thomas Kewley aged 18 youngest so of the late William Kewley