An unidentified soldier hoses down the gas trial chamber to help control the temperature. The ...

An unidentified soldier hoses down the gas trial chamber to help control the temperature. The demountable gas trial chamber MKII has plywood cladding and is covered with scaffolding and a tarpaulin. The chamber was used by the Australian Chemical Warfare Research and Experimental Section, later to be known as the 1st Field Trials Company, Royal Australian Engineers (RAE), and was designed by Dr A H (Hugh) Ennor, Jack Legge and the refrigeration engineer Walter Bassett, in Melbourne, Vic. It was a 100 cubic metre, stainless steel chamber, and was air conditioned to control effects of the northern heat and humidity for more accurate testing of chemical warfare gasses on human volunteers. Despite the sophisticated refrigeration design, the chamber was directly influenced by the heat of the sun. The trial chamber was equipped with air locked doors and an ante room containing pressure gauges and meter monitored by laboratory assistants. During testing the volunteers exercised vigorously (moving sacks) usually for up to an hour, wearing respirators and sometimes with protective ointment and impregnated clothing. Without sophisticated instruments to control the release of the gas, Major F S (Freddie) Gorrill (Commanding Officer) used a makeshift method to generate a concentration of gas. Concentrations were achieved by volatising an amount of pure dichloro diethyl sulphide (mustard gas). The chemical was spread on blotting paper, placed on an electric hotplate, and distributed with the aid of an electric fan half a metre away. The walls were saturated with vapour until the concentration stabilised and to maintain as constant a temperature as possible. On the outside, a tarpaulin provided shade for the roof and walls. However, when the volunteers left the chamber the uncontrolled heat and humidity outside multiplied the effect of the chemicals on their clothes and skin. Note the four Porton bubblers in the left foreground. On the right next to the tarpaulin are injector boxes with one of their accompanying gas cylinder visible to the left of the soldier. The handles of more bubblers are visible behind the injector boxes.