This water cart has two points of interest on the back. On the left is an information panel and on the right is an opening that lets you look inside.
The panel says:
This water cart was used at the Tasmania Mine to spray the mine year to rest the dust. The driver could operate the release valves with a foot lever.
The draught horse pulling the cart must have been a powerful animal as the tank held amost a tonne (1000kg) of water!
Portable respirator for people with polio. Developed in Australia in 1937 during a polio epidemic. This plywood "iron lung" was lighter and cheaper to produce than the metal American version from which the common name comes. This particular model was used at the Queanbeyan District Hospital (and is now on display in the local museum)
I would like to find out more about these, but I haven't been able to other than the shelves rotate, and they seem to date from the 1930/40s period.