The infantry battalions of the Great War had two types of machine guns. In 1914, the Patricia’s had only two Vickers .303 machine guns. This belt-fed, water-cooled gun was highly effective, but at 80 lbs was difficult to move over rugged terrain. It required a crew of three and a further two to carry ammunition. This picture shows the crew in gas hoods that were not issued until after the German gas attack at 2nd Battle of Ypres in 1915. It soon became apparent that more firepower was required and by late 1915 Canadian battalions began to be equipped with the lighter air-cooled magazine-fed Lewis gun. Ultimately the each platoon had two Lewis guns with the heavier Vickers being brigaded in machine gun units. The main advantage of the Lewis gun was its mobility. At 26.5 lbs it could be carried by one man to accompany troops in the attack. It was also used in the anti-aircraft role as shown in this picture. It did not, however, have the sustained fire capacity of the Vickers.