IOON OF SATURN 177 







c-al..l a w. .rl.l ,-f W..M.I.TS fn.iu \ i \\ 



*xm as his great mirror wan finished, he turned 



Saturn, an tinit nv saw the 



i^ust 28 lie was presented with a 



-a!. llitM, "in such a m and MO 



it ait rendered it impossible take tin 



to see them." Five of these satellites had been 



in a century a sixth was thus 



i C.-nstanlly miitiiniin^ his \\at-h ..n t !.. planet, 



he was rewarded, three weeks aft. r. with -h .-.,-. 

 a seventh so close to the planet he telescopes, 



i use, had failed to tin-l it. 1 K\-n in his 

 great mirror " it appeared no bigger than a very small 



aii'l it li.-s so nrar the planet and it- 



that tine w a cannot easily be 



seen well enough to take its place with accuracy." 



'ie learned from experience, and tail- s the 



lesson, that it is easier to find a small body which has 



been once seen, and whose place has been marked, 



than to detect it for time amid a crowd of 



heavenly bodies. 1 The heavens teach wisdom 



M th. l lings, but the lessons they teach 



an- >Mim-tini-s tW^nUm as s..m a^ l.-arn.-.l. II.- l'..un-i 

 also that th.- tiiaeof a sidereal revolution roun<l th.- 

 hours, 37 minutes, 22 seconds. Both it 

 and the other moon he discovered revolve so near and 

 so parallel to the ring, that he had " repeatedly seen 



1 One dbcormd by Hoyghens in 1655, and four by Caauni in 1671 

 ndonwarda. 



1 Compare the ease with which oheenren detected the tmall companion 

 of Strina, and the " rrape " ring of Saturn after they were 

 (Ball, Story o/Oul/<at*H* t p. 887). 

 12 



