It was during the season of 1846 that the extraordinary spectacle was witnessed at Astley’s of an elephant on the tight-rope. It is not more difficult, however, for an elephant, or any other beast, to balance itself upon a stretched rope than for a man to do so; the real difficulty is in inducing the animal to mount the rope. The art of balancing consists in the maintenance of the centre of gravity, which, it may be explained, is that point in any body, animate or inanimate, upon or about which it balances itself, or remains in a state of equilibrium in any position. In any regular-shaped body, whether round or angular, provided its density is uniform through all its parts, the centre of gravity is the centre of the body; but in an irregular-shaped body, or a combination of two or more bodies, the centre of gravity is the point at which they balance each other. If we place any regular-shaped body on a table, it will remain stationary, or in a state of rest, provided an imaginary line drawn from its centre of gravity, and passing downward in a direction perpendicular to the table, falls within its base. But, if the centre of gravity is in a part of the body above any part of the table that is outside the base, the object will topple over, and assume some position in which the centre of gravity will be within the base. Take, for example, a five-sided block of wood, and place it upon the table. If the five sides are each of the same superficies, it will stand upon either of them; but if they are unequal, and it is so placed that the centre of gravity is above a part of the table that is outside the face upon which you attempt to make it stand, it will fall down. There is a little toy which I remember having seen when a child, and which, as it illustrates the natural law upon which the art of balancing depends, I will here describe. It was made of elder pith, fashioned and coloured into a rough resemblance to the human figure, and weighted with a piece of lead, like the half of a small bullet, which was attached to its feet with glue. The centre of gravity was, consequently, so low that, in whatever position the figure might be placed, it immediately assumed the perpendicular, and could be kept in any other only by holding it. Now, if the feet of a human being were as much heavier than the head and trunk, as the lead in this toy was heavier than the pith, we should never be in any danger of losing our balance; and an infant might be allowed to make its first essay in walking as soon as its legs were strong enough to support it, without being in any danger of a fall. But the head is, in proportion to its bulk, much heavier than the trunk; and the breadth of the trunk considerably exceeds that of the feet, which constitute the base. The balance is, therefore, easily lost; because a stumble throws the centre of gravity beyond the base.