The New Thoughts of Galileo

from this it follows that a horse, or some other large animal, would break its bones if it fell from a height of five or six fathoms approx. 30 to 36 feet, whereas a dog or a cat would not hurt itself: that an ant falling from the top of a tower, or even from the Moon, would not do itself any harm: that a small child does not injure himself as much in falling as a large man; and that an oak two hundred fathoms high would not support its branches as well as a small oak, etc. This is why nature cannot make a horse or a man ten times larger than ordinary ones without a particular miracle, because the bones would break of their own accord, even if they kept the proportion of the large to the small. This is why one cannot raise large columns and needles of marble without great risk of breaking them; because their weight contributes more to their rupture than that of small columns. To this he relates the accident of a column that broke in the middle after an artisan had put a third support under said middle, fearing that it would break at that spot, whereas it had not broken when it only had two supports at its two extremities.