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The same will hold as to the parts of achain-bridge as to the parts of an animal.The motion in a chain-bridge is more rapid,as the angle with a horizontal line dimi-nishes, or as the part is more distant fromthe point of suspension ; so the motion ofanimals is quickest in the extremities, whei’ethe parts are the smallest, and most distantfrom the point of the suspension of the limb.Neither can two similar chain-bridges, com-posed of chains similar, but unequal as toarea in section, resist any violence alike, or inthe same proportion; for their flexibility orpower of adjustment by their motion will bediminished; and the thicker will be morehurt than the thinner. For example, a chainbridge, one foot wide, containing fourchains, inch square, will be stronger than asimilar bridge containing one chain, twoinches square.

Since it is desirable in a bridge by sus-

same is true of animals; for large animals, by falling,break their bones, whilst lesser ones, falling lower, re-ceive no damage. Thus a cat may fall two or threeyards high and be no worse, and an ant from the top ofa tower.”