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the deflection, to a certain limit, and be-yond that limit its motion will be so rapidthat it will break to pieces. *

* Mr. Emerson has these scholia. “ It is impossiblethat mechanic engines can be increased to any big-ness. For when they arrive at a particular size, theirseveral parts will break, and fall asunder by their weight.

“ It is also impossible for Nature to produce animalsabove a particular size at pleasure, except some sort ofmatter could be found to make the bones of, which is somuch harder and stronger than any hitherto known; orelse that the proportion of the parts be so much altered,and the bones and muscles made thicker in proportion,which will make the animal distorted, and of a monstrousfigure, and not capable of performing any proper ac-tions. And being made similar, and of common matter,they will not be able to stand or move, but, being bur-dened by their own weight, must fall down.

“ On the contrary, when the size of animals is di-minished, their strength is not diminished in the sameproportion as their weight, and therefore a small animalwill carry far more than its own weight, whilst a greatone cannot carry so much as its own weight. Andhence it is that small animals are more active, will runfaster, jump farther, or perform any motion quicker fortheir weight, than larger animals; for the lesser the ani-mal, the greater the proportion of the strength to thestress. And Nature seems to have no bounds as to thesmallness of animals, at least, in regard to their weight.

“ Neither can any two unequal and similar machinesresist any violence alike, or in the same proportion, butthe greater will be more hurt than the lesser. And the

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