<P> Spotter aircraft would monitor the fall of shells during registration of the artillery . Reconnaissance aircraft would map trench lines, first with hand - drawn diagrams, later with photography, monitor enemy troop movements, and locate enemy artillery batteries so that they could be destroyed with counter-battery fire . </P> <P> In 1917 and 1918, new types of weapons were fielded . They changed the face of warfare tactics and were later employed during World War II . </P> <P> The French introduced the CSRG 1915 Chauchat during Spring 1916 around the concept of "walking fire", employed in 1918 when 250,000 weapons were fielded . More than 80,000 of the best shooters received the semi-automatic RSC 1917 rifle, allowing them to rapid fire at waves of attacking soldiers . Firing ports were installed in the newly arrived Renault FT tanks . </P> <P> The French Army fielded a ground version of the Hotchkiss Canon de 37 mm used by the French Navy . It was primarily used to destroy German machine gun nests and concrete reinforced pillboxes with high explosive rounds, but an armour - piercing round was designed to defeat the German tanks, making it the first anti tank gun . </P>

How does this view of the map show the effects of trench warfare during world war i