He travelled to London, where he lodged with John Theophilus Desaguliers and attended his lectures on Newtonian Experimental Philosophy.
He later introduced the subject in the American Colonies and his book An Experimental Course of Mechanical Philosophy, published in Boston in 1726, owed much to Desaguliers.
In London Greenwood met with Thomas Hollis, who wished to endow a chair at Harvard College for him.
[3] This book made the first published statement of the short scale value for billion in the United States, which eventually became the value used in most English-speaking countries.
He was released from service in Charleston, South Carolina, on 22 May 1744 and died from the effects of alcohol on 22 October 1745.