Letter from WSC [First Lord of the Admiralty] to the Commander-in-Chief, Grand Fleet [Admiral Sir John Jellicoe] on the need to rest the fleets and flotillas to conserve strength, and stressing the great importance of capturing the island of Borkum [Germany] to provide an overseas base for British submarines. WSC also comments on using "priceless information" [intercepted and decoded German naval signals; these comments were deleted before the letter was sent]. [Hand-written copy, with typed transcript].