By the age of 27 he had his own business in London in the Strand where he became acknowledged as the most skilful designer of mathematical, astronomical, surveying and navigational instruments in the 18th century.
Sa edad na 27 niya ang kanyang sariling negosyo sa London sa Strand na kung saan siya ay naging kumilala na ang pinaka-sanay-disenyo ng matematika, astronomya, pagtilingin at navigational instrumento sa ang 18th siglo.