In February 1671 he discovered Taylor 's theorem (not published by Taylor until 1715), and the theorem is contained in a letter sent to Collins on 15 February 1671.
Noong Pebrero 1671 siya natuklasan Taylor 's teorama (hindi nai-publish sa pamamagitan ng Taylor hanggang 1715), at ang teorama ay nakapaloob sa isang sulat na ipinadala sa Collins sa 15 Pebrero 1671.