Written by a frustrated Lt. General Sir Henry Clinton during the Revolutionary War in 1777, this beautifully crafted Masked Letter is a perfect example of early coded correspondence. The letter reads perfectly well on its own, however only when you place a mask over the paper does the true meaning appear. Incredibly clever, and surprisingly successful as both the letter and mask were sent to the recipient (in this case John Burgoyne) along different routes. Below is the original letter, a picture of the mask itself, and the letter when read using the mask.

Original Article