An ancient military engine, used for destroying the walls of fortified places, but which, since the invention of gunpowder,;s no longer used for that purpose, as, by means of cannon, the attack can be made from a much greater distance; but machines of this description are still sometimes employed in taking down old and massive walls. The battering rams of the ancients were of two kinds: the first consisted merely of a heavy beam, with a head of iron, which the soldiers bore in their arms, and assailed the walls by main strength. The second sort was much more powerful and effective. In these the beam was suspended by chains from a frame; the centre of gravity of the mass of the beam being pulled out of the perpendicular by ropes, they were suddenly let go, causing the head of the ram to strike the wall with a force proportional to the weight of the mass, and the space through which it moved. Some of these instruments were of enormous dimensions, and of immense power. That of Vespasian is said to have been 120 feet long, and to have weighed 100,000 lbs.

The effect of some of these instruments, was much superior to any we can produce by our breaching cannon; for if the weight of a battering ram, moving with a velocity of 10 feet in a second, were no more than 170 times that of a cannon ball, moving at the rate of 1700 feet in a second, the momenta of both forces would be equal; but as the weight of these ancient machines was much greater than 170 times that of our heaviest cannon balls, their momentum, or impetus, to overturn walls, and demolish buildings, was much superior to that exerted by our modern artillery.

Battering Ram 137