The 4-inch Stokes Mortars were originally for use with gas and some were filled with Mustard Gas during the war. This may be of use:
Twenty-seven four-inch Stokes mortars were available for creating smoke screens. The 4-inch
Stokes mortar was rushed into service for the Battle of Loos after a demonstration on 22 August that year. Twenty had been ordered for gas projection on 14 July 1915 so they were readily available. A smoke shell was extemporised out of paper-mach, tin, gun metal and iron and 10 000 rounds were assembled at the First Army workshops at St. Venant from parts and material, including 15 tons of red phosphorous, sent from Britain[1]. The rate of fire was of the 4-inch Stokes mortar was 20 rounds-per-minute but it could be quicker for two minutes. The 11.3kg white phosphorous bomb had a range of 760m. Edmonds, J.E. History of the Great War, Military Operations France and Belgium, 1915. Battles of Aubers Ridge, Festubert, and Loos, Macmillan, London, 1928, pp. 160 & 161; Edmonds, J.E. History of the Great War, Military Operations France and Belgium, 1915. Winter 1914-15: Battle of Neuve Chapelle: Battles of Ypres, Macmillan, London, 1927, pp. 8 & 9.
Twenty-seven four-inch Stokes mortars were available for creating smoke screens. The 4-inch
Stokes mortar was rushed into service for the Battle of Loos after a demonstration on 22 August that year. Twenty had been ordered for gas projection on 14 July 1915 so they were readily available. A smoke shell was extemporised out of paper-mach, tin, gun metal and iron and 10 000 rounds were assembled at the First Army workshops at St. Venant from parts and material, including 15 tons of red phosphorous, sent from Britain[1]. The rate of fire was of the 4-inch Stokes mortar was 20 rounds-per-minute but it could be quicker for two minutes. The 11.3kg white phosphorous bomb had a range of 760m. Edmonds, J.E. History of the Great War, Military Operations France and Belgium, 1915. Battles of Aubers Ridge, Festubert, and Loos, Macmillan, London, 1928, pp. 160 & 161; Edmonds, J.E. History of the Great War, Military Operations France and Belgium, 1915. Winter 1914-15: Battle of Neuve Chapelle: Battles of Ypres, Macmillan, London, 1927, pp. 8 & 9.