Isle Of Man. (Prisoner Of War Mail). 1915. Registered 'Prisoner of War' envelope addressed to Devon bearing SG 157, 1d scarlet and SG 368, 2d orange tied by Peel date stamp '7th Ja 15' with 'R/Peel' registration label and oval 'Aliens Detention Camp/Knockaloe, I.O.M. in blue on face routed via Liverpool with Sidmouth arrival on reverse. Herman Heiser was interned early in the war first in the short lived Stratford Camp and then Deepcut and Frimley Camps before being transferred to Knockaloe Camp. Scarce item of registered mail.