214 NOWM OROANUM 



We have an instance of the second kind in the telescope, 

 discovered by the wonderful exertions of Galileo; by the 

 assistance of which a nearer intercourse may be opened (as 

 by boats or vessels) between ourselves and the heavenly 

 objects. For by its aid we are assured that the Milky Way 

 is but a knot or constellation of small stars, clearly defined 

 and separate, which the ancients only conjectured to be the 

 case; whence it appears to be capable of demonstration, that 

 the spaces of the planetary orbits (as they are termed) are 

 not quite destitute of other stars, but that the heaven begins 

 to glitter with stars before we arrive at the starry sphere, 

 although they may be too small to be visible without the 

 telescope. By the telescope, also, we can behold the revolu 

 tions of smaller stars round Jupiter, whence it may be con 

 jectured that there are several centres of motion among the 

 stars. By its assistance, also, the irregularity of light and 

 shade on the moon s surface is more clearly observed and 

 determined, so as to allow of a sort of selenography. 66 By 

 the telescope we see the spots in the sun, and other similar 

 phenomena; all of which are most noble discoveries, as far 

 as credit can be safely given to demonstrations of this 

 nature, which are on this account very suspicious, namely, 

 that experiment stops at these few, and nothing further has 

 yet been discovered by the same method, among objects 

 equally worthy of consideration. 



We have instances of the third kind in measuring-rods, 

 astrolabes, and the like, which do not enlarge, but correct 

 and guide the sight. If there be other instances which assist 



66 Pere Shenier first pointed out the spots on the sun s disk, and by the 

 marks which they afforded him, computed its revolution to be performed in 

 twenty -five days and some hours. Ed. 



