430 PHILOSOPHICAL TRANSACTIONS. [aNNO \66q. 



and consequently plants for their nourishment. And these possibly not very 

 different from those we have ; but that whatever be the difference, it probably 

 arises from the different distances of those globes from the sun. 



And pursuing this train of thought, he thinks them to have rational animals 

 also, and that they have all those senses, and other necessary organs for rea- 

 soning that men have here. 



He endeavours in his second book to give us his judgment concerning the 

 phaenomena of the heavens; what they might appear to one of us supposed to 

 be there in one of them, which he founds on the knowledge we now have of 

 them, as to magnitude, distance, &c. And here, after he has censured Father 

 Kircher's Iter Extaticum, a book published on the like subject, he begins to 

 tell what must be the phaenomena of the sun and planets, seen in Mercury, 

 and next what the same must be seen in Venus, which since with a 6o foot 

 telescope, and all his diligence, he could never discover to have spots, or dif- 

 ferently illuminated parts, as are visible in Mars, Jupiter, and Saturn. He con- 

 jectures that the reflection of light from it is made by the atmosphere about it, 

 and not by the body itself. Thirdly, What they are in Mars, which he makes 

 much less than Venus, or the earth, though without a moon, and further dis- 

 tant from the sun. And fourthly. What in Jupiter and Saturn, which so vastly 

 exceed all the other three, both for their magnitude, and for their concomitants, 

 Jupiter having four and Saturn five, together with a ring, whereas the earth has 

 but one, and the other three none at all. On explaining the phaenomena of 

 these, he more largely insists, and has therein summed up all the latest and 

 best phaenomena that have been observed concerning them, as to the five moons 

 about Saturn, though he confesses that he had not seen the two innermost of 

 them, yet he confides in the observations of Monsieur Cassini, and suspects 

 also that there may be more yet discovered,* when glasses of 170 and 210 feet 

 shall come to be used for that purpose. Then he proceeds to consider the sun 

 and the fixed stars, premising the magnificence of the solar system ; this he 

 does by words, because schemes he could not render large enough to repre- 

 sent the proportionate magnitudes of the orbits to the minuteness of the 

 plenary bodies ; for that Saturn would require an area of 36o feet in diameter, 

 and that of the earth, one of 30 feet, to draw them proportionate to the globes, 

 for the orbit of the earth is 12000 times the diameter of the earth's ball. And 

 consequently the distance of the earth from the sun will be above 1700O, or 

 17000000 of German miles. To make the vastness of these distances the more 

 conceivable, he computes them by the times that a cannon-bullet, supposed to 



* Which conjecture has lately been realized by the observations of Dr. Herschel. 



