CH. xxxix. SIR CHARLES LYELL. 407 



what we find in the rocks might all have been produced by 

 such causes as these, without imagining any extraordinary 

 violence of nature. 



While writing this book he went with another celebrated 

 geologist, Murchison, to Italy and Sicily, and there he 

 studied not only the rocks which the volcanoes of Vesuvius 

 and Etna have been building up for ages, but he also saw 

 at Syracuse and other places enormous beds of limestone 

 filled with shells of kinds which may still be found living. 

 The immense thickness of these limestone beds, amounting 

 in some places to 700 and 800 feet, astonished him greatly. 

 He knew they must all have been formed slowly beneath 

 the sea, out of the remains of corals and other animals, 

 whose skeletons or shells are composed of lime, and that 

 they must afterwards have been raised up to the height of 

 3,000 feet above the sea, at which he found them ; and 

 when he thought of the time which this must have taken, 

 and remembered that it had all happened since the other 

 great masses of rocks below, containing extinct shells, had 

 been formed, he felt more than ever convinced that the world 

 must be very old, to have allowed time for all the wonderful 

 changes that have taken place. 



In 1830 his book was published, and though it met with 

 great opposition because men's minds were prejudiced the 

 other way, yet his facts could not be denied. He showed, 

 for example, on the one hand that the river Ganges in India 

 carries down every year, and deposits in the sea, as much 

 mud as would make sixty of the great pyramids of Egypt, 

 and which if it was brought in ships would require 2,000 

 full-sized merchant vessels laden with mud to sail down the 

 Ganges every day. Here, then, was an example of rocks 

 being now laid down in the sea, not by violent floods and 



