The papers consist of five logs, 1730 to 1742, and an order book, 1747 to 1757.

Administrative / biographical background
Osborn served in the Mediterranean before becoming a lieutenant in 1717. In 1718 He took part in the action off Cape Passaro in the Mediterranean and the following year served in a squadron on the north coast of Africa. His first command was the Squirrel in 1728. In 1734 he commanded the Portland in the Channel and in 1738 the Salisbury in the Mediterranean. He was appointed to the Prince of Orange in 1740, returning to England in the Chichester in 1741, when he moved to the Princess Caroline, Channel, until 1743. Osborn was promoted to rear-admiral in 1747 and in 1748 was appointed Commander-in-Chief, Leeward Islands; in the same year he became a vice-admiral. He was promoted admiral and appointed Commander-in-Chief, Mediterranean, in 1757 but after blockading the French fleet in 1758, he suffered a stroke and saw no more active service. Osborn was Member of Parliament for Bedfordshire, 1758 to 1761.