Example - for a 3-bedroom, 2,000-sq.ft. home, with an exhaust-only ventilation strategy, and a target ventilation rate of 50 CFM you would need to install a 50 CFM fan with an adjustable-speed DC motor for continuous operation.
Quick Answer. Trenches were built during World War I to protect stalemated troops on both sides from artillery and rifle fire. Although the war began with rapid movement of the German army, when the Allied forces stopped the Germans, both sides dug trenches to help avoid losing territory they had gained.
AUTHOR'S PURPOSE Purpose Lincoln had many purposes for asking to speak at the dedication of the Soldiers Cemetery. He hoped to honor those who had died in the battle of Gettysburg and instill a passion in the hearts of the remaining soldiers. Also, with this speech Lincoln hoped to change the purpose of the Civil War.