On 25 July 1916 at Ovillers-la-Boisselle during the Battle of the Somme, Z Company used 80 projectors when the Australians were due to attack Pozières. The early versions had a short range and it was necessary to place the projectors 200 yards out in no-man's-land. The resulting barrage was highly successful in neutralising the German machine-gun posts.[15]
Z Company rapidly developed the Livens Projector, increasing its range to 350 yards and eventually an electrically triggered version with a range of 1,300 yards. This version was successfully used at Messines Ridge in June 1917.[15]
The Livens Projector was then modified to fire canisters of poison gas rather than oil. This system was tested in secret, at Thiepval in September 1916 and Beaumont-Hamel in November.[15] The Livens Projector was able to deliver a high concentration of gas a considerable distance. Each canister delivered as much gas as several chemical warfare artillery shells. Without the need to reload a barrage could be launched quickly, catching the enemy by surprise. Although each projector could be fired just once during an attack, the weapon was sufficiently inexpensive to be deployed in hundreds or even thousands.
The Livens Projector was also used to fire other substances. At one time or another the drums contained high explosive, oil and cotton-waste pellets, thermite, white phosphorus and "stinks". Used as giant stink bombs to trick the enemy, "stinks" were malodorous but harmless substances such as bone oil and amyl acetate used to simulate a poison gas attack, thereby compelling the enemy to put on their cumbersome masks (which reduced the efficiency of German troops) on occasions when gas could not be safely employed.[17] Alternatively, "stinks" could be used to artificially prolong the scale, discomfort and duration of genuine gas-attacks i.e. alternating projectiles containing "stinks" with phosgene, adamsite or chloropicrin. There was even a design for ammunition containing a dozen Mills bombs in the manner of a cluster bomb.[18]
SOURCE: https://en.wikipedia.org/wiki/Livens_Projector
