THE PLANET JUPITER.

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which might at first sight seem to contain a reasonable,although somewhat facetiously expressed, suggestion, thatso large a planet ought to have inhabitants correspondinglytall. We there read that Wolfius maintained, that theinhabitants of Jupiter must he 14 feet in height, or rather13,™ feet; and that he proved it by the following argu-ment. “ Wherefore, since in Jupiter the Sun ’s meridianlight is much weaker than on the Earth , the pupil (of theeye) will need to he much more dilateable in the Joviancreature than in the terrestrial one. But the pupil is observedto have a constant proportion to the ball of the eye, and theball of the eye to the rest of the body : so that, in animals, thelarger the pupil the larger the eye, and, consequently, thelarger the body. Assuming that these conditions are un-questionable, he show's that Jupiter’s distance from the Sun ,compared with the Earth ’s, is as 26 to 5 ; the intensity of theSun’s light in Jupiter is, to its intensity on the Earth , in theduplicate ratio of 5 to 26 ; and that it therefore follows, thateven Goliath himself would have cut but a sorry figure amongthe natives of Jupiter. That is, supposing the Philistine ’s alti-tude to be somewhere between 8 and 11 feet.” * Wolfius finallyconcluded the height of the inhabitants of Jupiter to be just^ths of a foot shorter than that of Og the king of Baslian,according to the measure of his bedstead given in the Book ofDeuteronomy .

The considerations which we have put forward would, on thecontrary, lead to the conclusion, that about 28 inches wouldbe a suitable height for an inhabitant of so huge a planet.

It may be remembered that we showed in Lecture IX., p. 205,that a weight of 193 lbs., at the equator of the Earth , wouldweigh 194 at either of its poles, owing partly to the centrifugaleffect of the Earth ’s rotation, and partly to the fact that the sur-face of the Earth at the equator is farther from its centre, andtherefore the attraction of gravity less, than at the poles. OnJupiter both of these effects would be intensified, owing to its

* See Smyth’s “ Celestial Cycle,” vol. i., p. 173, in quoting from whichwe have altered the adjective Jovial to Jovian, which is the form nowgenerally used.