|Description||Study of Benjamin Robins' machine for determining the velocity of bullets. Headed: 'Experiments relating to The Force of Gunpowder, the Velocity of Musket & Cannon shot, & the resistance of the Air'. Below 'Fig. 1st.' With some rough calculations verso.|
Projectiles were aimed from various distances at the square plate which was intended to pivot on an axis - the arc length described by the pendulum allowed Robins to calculate the speed of the bullet.