1. Detroit River Tunnel No. 5 Section No. 1 - Showing section considerably lower in the water and men leaving valve platforms 2. Detroit River Tunnel No. 7 Section No. 1 - Closer view of section after plunge, showing valves and flexible hose connections on top of buoyancy cylingers. These valves connect with different compartments of cylinders for admission of water or compressed air. Photographer for both items: C.M. Hayes and Co. Detroit [both items previously located at RH PH P824(f)]