With original fitted three-tier mahogany box, the cover set with a plaque inscribed Herbert Blockley & Co. 31629 London.
Such water-resistant "Explorers" watches were mostly commissioned by The Royal Geographic Society for use on expeditions to places where severe climate conditions would be expected, such as the Arctic. The sealed cases protected the movements against humidity and the cold.
Herbert Blockley, associated with J.A. Lund under the firm of Lund & Blockley, was working at Duke Street in London until the 1920s.