848. Why is the arrow propelled forward?
Because the elasticity of the bow, acting equally upon its two ends, to which the string is fastened, produce a line of force in a diagonal direction. It thus illustrates the law, that when a body is acted upon by two forces at the same time, whose directions are inclined to each other, it will not follow either of them, but will describe a line between the two.
849. What forces tend to arrest the flight of the arrow?
The friction of the air, and the attraction of gravitation.
"My son, give, I pray thee, glory to the Lord God of Israel, and make confession unto him."—Joshua vii.
850. Why are feathers usually fastened to the ends of arrows?
Because the greater friction of air acting upon them, opposes the progress of that part of the arrow in a greater degree than it does the other portion. The effect is, to keep the point of the arrow forward, and in a straight line with its opposite extremity. If the arrow were shot the reverse way from the bow, it would turn round, in the course of its flight, in consequence of the friction of the air, offering greater resistance to the progress of the feathered end.