VOL. XXI. 3 I'HILOSOPHICAL TRANSACTIONS. 42Q 



2. The Celestial World discovered, or Conjectures concerning the Inhabitants, 

 Plants, and Productions of the IVorlds in the Planets. Written in Latin by 

 Christianus Huygens, 8vo. N° 256, p. 337. 



The author having spent much time in making celestial observations and dis- 

 coveries, by telescopes of the largest sizes, and other instruments ; having ac- 

 quainted himself with the latest and best observations and discoveries made by 

 other modern astronomers ; and having well weighed and considered the import 

 and significancy of them, acquaints his brother Constantine Huygens, to whom 

 his book is inscribed, what is his opinion and belief concerning the form, 

 stricture, and fabric of the universe, or the whole visible world. Nor can such 

 inquiry he thinks be detrimental to religion, but will rather be a means to make 

 men have a greater veneration and adoration of that wonderful wisdom and 

 providence which is universally displayed through the whole fabric of the 

 tiniverse. 



As to the form and disposition of the whole, and of the parts of this universe, 

 he agrees with the system of Copernicus ; for the better explication of which 

 he has added two figures, the first showing their order and positions, and the 

 second their comparative magnitudes. And since it hereby appears that the 

 earth is moved about the sun, as well as the other planets, and that those 

 planets are enlightened by the sun in the same manner as the earth is, and some 

 of them, as Saturn and Jupiter, have their own moons, or secondary planets, 

 moving about them, sometimes eclipsing them, and eclipsed by them, as the 

 earth also is by its moon, and that some of them are much larger as well as 

 some others smaller than the earth ; and so that the magnitudes are not pro- 

 portioned, either according to their order or their distance ; since also they are 

 observed to have the same kinds of motion, both annual and diurnal, therefore 

 he thinks it very probable that they resemble the earth also in other qualifica- 

 tions. He therefore thinks we may safely conclude that the other planets have 

 solid bodies, and gravity towards their centres, as the earth has, since we find 

 them to have the same figure, and the same motions, and the same concomi- 

 tants, and that they have atmospheres and air and water, &c. And since it 

 would be too great a depreciating of them, in comparison with the earth, to 

 suppose them not to be likewise adorned with the more admirable productions 

 and fabrics of plants and animals, which more evidently manifest the wisdom 

 and design of the divine architect, which we find the earth to be enriched and 

 beautified with ; but to suppose them only lifeless lumps of matter ; as earth, 

 water, &c. he therefore conceives them to have animals as well as the earth ; 



