Henry Slater
Henry Slater, bookseller, publisher, stationer, and book binder; at the Golden Key on the corner of Clare Court, Drury Lane; and at the Printing Office in Hind Court, opposite Water Lane in Fleet Street.
A Dictionary of the Printers and Booksellers who were at work in England, Scotland and Ireland from 1726 to 1775, by Henry Plomer et al. (1932)
SLATER (HENRY), bookseller and publisher in London, Golden Key, the corner of Clare Court in Drury Lane, 1749–55. His name is found in the Poll Book for the City and Liberties of Westminster in 1749 as living in Clare Court. In 1750 he published A Genuine Account of Earthquakes, especially that at Oxford. He may be identical with the previously mentioned Slater, junior. [Ed. note: these are not in fact identical.]
Notes & Queries "London Booksellers Series" (1931–2)
SLATER, H. He had a bookselling business in Close [Clare] Court, Drury Lane, in 1750.
—Frederick T. Wood, 10 October 1931