“That point cannot be supported,” answered his father, “unless the ring be so held that the line of direction shall fall within the base of the support, which will be the case whether you poise the ring on the tip of your finger, or suspend it by a string, as represented in the figures which I have copied from the ‘Conversations on Natural Philosophy.’ I need scarcely add, that it will be more stably supported in the latter position, because the centre of gravity is below the point of suspension; whereas in the former the base is extremely narrow, and it will, consequently, require all the address of the balancer to prevent the centre of gravity from falling beyond it. As you are now in possession of all the leading principles upon which the operations of the centre of gravity depend, I shall put a few practical questions to you, in order that I may be satisfied you understand them. Tell me, therefore, why a person who is fearful of falling, as, for instance, when he leans forward, should invariably put forward one of his feet, as you did the other day, when you looked into Overton well?” “To increase his base,” answered Tom; “whenever I lean greatly forward, I should throw the line of direction beyond it, did I not at the same instant put out one of my feet, so as to extend my base, and thus to cause the line to continue within it.” “Rightly answered; and, for the same reason, a porter with a load on his back leans forward, to prevent his burthen from throwing the line of direction out of the base behind. So the horse, in drawing a heavy weight, instinctively leans forward, in order to throw the whole of his weight as a counterbalance; and yet,” observed Mr. Seymour, “we are in the habit of ignorantly restraining him by a bearing rein, in consequence of which he has to call in the aid of his muscles, by which a very unnecessary exhaustion of strength is produced. Thus is it that German and French horses draw heavy weights with apparently greater ease to themselves, because the Germans tie a horse’s nose _downwards_, while the French, more wisely, leave them at perfect liberty. But to proceed. Did you ever observe the manner in which a woman carries a pail of water?” “To be sure,” said Tom; “she always stretches out one of her arms.” “The weight of the pail,” continued Mr. Seymour, “throws the centre of gravity on one side, and the woman, therefore, stretches out the opposite arm, in order to bring it back again into its original situation; did she not do this, she must, like the English draught horses, exert her muscles as a counteracting force, which would greatly increase the fatigue of the operation: but a pail hanging on each arm is carried without difficulty, because they balance each other, and the centre of gravity remains supported by the feet.”