the moon every object would be deprived of five-sixths of its weight, because the moon is a comparatively small globe. Were we, however, to be transferred to Jupiter, the weight of every object would receive an extraordinary augmentation. Our muscles would be found utterly inadequate to their work. Walking, or even standing, would involve the most fearful exertion, while rising from bed in the morning would be a difficult, indeed, probably, an impossible process. I see no likelihood that Jupiter can be the home of any life whatever.
We may dismiss from our present consideration such bodies as the comets. A comet moves during the greater part of its course through the depths of space at inconceivable distances from the sun. Out there, the comet traverses regions where the cold would be absolutely incompatible with life of any type conceivable by us. Then for a brief period, to be measured in months, weeks, days, or even hours, the comet is wheeling around the sun, where it is often exposed to a frightful temperature sufficient to fuse and even vapourise bars of wrought iron. A comet, indeed, is not a likely abode for life, though I ought to mention that comets often contain the element carbon. This is a very singular fact when it is remembered that carbon is one of the substances essentially associated with life in the forms in which we know it.
There is, however, one body in our system whose times and whose seasons accord so closely with our own that it is impossible not to believe that life of some kind may there be found. The length of the day and night together on Mars is 24 hours 37 minutes; that is practically only about half an hour greater than the corresponding period for our own globe. The year of Mars is, no doubt
