A copper diving helmet by C.E. Heinke, mid-Nineteeth century, the hand-beaten non-recessed twelve bolt helmet with three face-plates (one removable), adjustabe sde-v-alve with a futher rblanked- off valve input to right of air intake, (this example has no non-return valve); the copper breast plate with a brass, non-adjustable pepper-pot valve to front, the rim surrounded by brass clamp bars stamped with the makers name and numbered for the correct mounting order, with butterfly locking nuts -- 18½in. (47.5cm.) high old dents and wear; together with a brass butterfly nut tightener, all contained within a Siebe Gorman trunk (later)