snipers created a requirement for loopholes both for discharging firearms and for observation. Often a steel plate was used with a "key hole", which had a rotating piece to cover the loophole when not in use. Soon the British army began to train their own snipers in specialized sniper schools. Major Hesketh Hesketh-Prichard was given formal permission to begin sniper training in 1915, and founded the First Army School of Sniping, Observation, and Scouting at Linghem in France in 1916. Starting with a first class of only six, in time he was able to lecture to large numbers of soldiers from different Allied nations, proudly proclaiming in a letter that his school was turning out snipers at three times the rate of any such other school in the world. He also devised a metal-armoured double loophole that would protect the sniper observer from enemy fire. The front loophole was fixed, but the rear was housed in a metal shutter sliding in grooves. Only when the two loopholes were lined up—a one-to-twenty chance—could an enemy shoot between them. Another innovation was the use of a dummy head to find the location of an enemy sniper. The papier-mâché figures were painted to resemble soldiers to draw sniper fire. Some were equipped with rubber surgical tubing so the dummy could "smoke" a cigarette and thus appear realistic. Holes punched in the dummy by enemy sniper bullets then could be used for triangulation purposes to determine the position of the enemy sniper, who could then be attacked with artillery fire. He developed many of the modern techniques in sniping, including the use of spotting scopes and working in pairs, and using Kim's Game to train observational skills. In 1920, he wrote his account of his war time activities in his book Sniping in France, to which reference is still made by modern authors regarding the subject. The main sniper rifles used during the First World War were the German Mauser Gewehr 98; the British Pattern 1914 Enfield and Lee–Enfield SMLE Mk III, the Canadian Ross rifle, the American M1903 Springfield, the Italian M1891 Carcano, and the Russian M1891 Mosin–Nagant World War II During the interbellum, most nations dropped their specialized sniper units, notably the Germans. Effectiveness and dangers of snipers once again came to the fore during the Spanish Civil War. The only nation that had specially trained sniper units during the 1930s was