ASTRONOMICAL HISTORY. 183 



that the earth, but various other globes, solid and opaque, 

 were dispersed through the expanse of heaven among the 

 luminous globes. And his opinion did not stop here, but 

 he thought that the latter, namely, the sun, and the most 

 resplendent and brightest stars were composed of a certain 

 solid and, though more shining, equilibrate matter; con 

 founding primitive light with the matter of light, which is 

 supposed to be its image, (for he thought our sea too 

 darted forth light to a certain measureable distance) ; but 

 Gilbertus admitted the existence of no conglobation, except 

 of crass matter, of which the finer and thinner substances, 

 its envelope, are only effluvia, and lost parts, and to 

 them succeeds a vacuum. Yet the idea respecting the 

 moon, that it is of solid matter, might strike the most 

 accurate and sober-minded inquirer into nature. For it is 

 a refractor, not a vehicle of lignt, and is, so to speak, devoid 

 of light of its own, and full of vicissitude, all which are 

 properties of solid bodies. For we see the ether itself, and 

 the atmosphere, which are thin bodies, receive, but by no 

 means reverberate the light of the sun, which the moon does. 

 For such is the force of the sun s rays as to traverse and 

 pierce through clouds of the greatest density, which are of 

 aqueous matter, but through the moon never. But in 

 certain eclipses of the moon there is still visible a light, 

 though an obscure one, in the new and full moon, none, 

 except of the part illuminated by the sun. Moreover foul 

 and feculent flames, of which kind of substance Empe- 

 docles supposed the moon to consist, are no doubt subject 

 to change, but thin inequalities are not fixed in a part, but 

 generally moving. Whereas the spots in the moon are 

 thought to be stationary. To this we add that those spots 

 are discovered by the telescope to have their partial minute 

 inequalities, so that we now find a variety of figures in the 

 moon ; and that Selenography, a map of the moon pro 

 jected by Gilbertus, we have lived to see executed by the 

 labours of Galileo and others. And if we can suppose the 

 moon composed of some solid substance analogous to earth, 

 or a sort of sediment of heaven, (for some such notions 

 have been mooted), we must consider again, whether it be 

 in this respect solitary. For, in the conjunction of Mercury 

 with the sun, there is sometimes visible a spot or partial 

 eclipse. But those dusky spots which are discovered in the 

 Antarctic hemisphere, and are fixed in position, the same as 

 the galaxy, inspire still greater doubts as to opaque orbs, 

 even in the higher regions of the heavens. For in respect 



