cover 1901 (11 May) envelope to Lt. Heathcote Roberts, No. 3 Native General Hospital in Tientsin, bearing B.R.A. 5c. black surcharge tied by violet Tientsin cancel, uncancelled German P.O. in China 5pf. and showing, on reverse, Base Office C and F.P.O. 4 (Type 54) datestamps