For more than twenty years W. J. Greenstreet was scientific correspondent of the evening Westminster Gazette, and he was one of the first to bring scientific developments regularly under the purview of a newspaper. His work consisted in writing articles on any discovery or research of special importance, contributing a regular fortnightly article on current science, and reviewing scientific books and periodicals. He read widely, English, American and foreign books and scientific records of all sorts, to equip himself for this work, and, whenever possible, gave it a practical application.