George Marsh in his diary (Page 21 & 66) mentions John Clevland who was Secretary to the Admiralty in the mid 1700s.

In 1745 John Clevland was Clerk of the Acts on the Navy Board.  Later on he became the MP for Sandwich, an Admiralty-controlled borough.  In 1751 he was appointed as the first Secretary of the Admiralty.  He was a cousin of Henry John Phillips Towry.

(George Marsh)  (Diary of George Marsh)