CHAPTER XXXIX. SCIENCE OF THE NINETEENTH CENTURY (CONTINUED). Prejudices which retarded the Study of Geology-Sir Charles Lyell traces out the Changes now going on-Mud carried down by the Ganges-Eating away of Sea-coasts-Eruption of Skaptar Jokul— Earthquake of Calabria-Rise and fall of Land-'Principles of Geology' published in 1830-Louis Agassiz: his Early Life — De Saussure's Study of Glaciers-Agassiz on Europe and North America being once covered with Ice-Boucher de Perthes on ancient Flint Implements-MacEnery on Flint Implements in Kent's Cavern, with Bones of Extinct Animals-Swiss Lake-dwellingsAntiquity of Man.' IN 1811, when Cuvier published his work on 'Fossil Remains,' William Smith, who, as you remember (p. 233), first studied the rocks of England, had nearly completed his geological map, and scientific men were beginning, both in England and Germany, to understand something of the dif ferent ages of the formations which have been laid down from time to time on the surface of the globe; yet still they were prevented from reading the past history of the world rightly, by several false notions which continued to prevail. People had so long held the belief that our earth had only existed a few thousand years, that when geologists began to find great numbers of strange plants and animals buried in the earth's crust, immense thicknesses of rock laid down by water, and whole mountain-masses which must CH. XXXIX. SIR CHARLES LYELL. 405 have been poured out by volcanoes, they could not believe that this had been done gradually and only in parts of the world at a time, as the Nile and the Ganges are now carrying down earth to the sea, and Vesuvius, Etna, and Hecla are pouring out lava a few feet thick every year. They still imagined that in past ages there must have been mighty convulsions from time to time, vast floods swallowing up plants and animals several times since the world was made, violent earthquakes and outbursts from volcanoes shaking the whole of Europe, forcing up mountains, and breaking open valleys. It seemed to them that in those times when the face of the earth was carved out into mountains and valleys, table lands and deserts, and when the rocks were broken, tilted up, and bent, things must have been very different from what they are now. And so they made imaginary pictures of how Nature had worked, instead of reasoning from what they could see happening around them. Sir Charles Lyell teaches that the Rocks of our Earth have been formed by Natural Causes, such as are still going on, 1830.-The man who first broke through these prejudices was our great geologist, Sir Charles Lyell, who has only just now passed away from among us. Charles Lyell was born in Forfarshire, in 1797, the same year that Hutton died. From his earliest childhood he had a great love of Natural History and Science, but as his father wished him to become a barrister, he went to Oxford to follow the usual course. Here he attended the lectures of Dr. Buckland, the great geologist of that day, and this decided him to devote his life to the study of geology. He began first by examining the formations round about his own home in Forfarshire, and he soon became convinced, as Hutton had been before him (see p. 219), that we can only learn the past history of the earth by observing the causes now at work. What Hutton had suggested Lyell worked out. He collected with great care all that is known of changes going on now all over the world, and the causes which produce them. Among these were Istly. The fall of rain, and how it wears away the earth and carries it off in little rills to the river. 2ndly. The amount of mud carried by mighty streams, such as the Ganges, the Nile, and the Mississippi, and laid down in the sea at their mouths. 3rdly. The amount of lime, iron, and other minerals brought up by springs from the inside of the earth, and thrown down on the surface. 4thly. The tides and currents of the sea, and how they wash up fresh land on some coasts and eat away the land on others. 5thly. The growth of corals in the sea, and how remains of their skeletons become cemented into limestone. 6thly. The volcanoes which are throwing out lava, and how much they have thrown out in historical times. 7thly. The different earthquakes which man has witnessed, how they have broken and dislocated the land, raising it in some places, as in New Zealand, and causing it to sink in others, as at New Madrid, in America. 8thly. The way in which plants and animals are buried in the mud of lakes, or at the mouths of rivers, or in peat and sand. All these, and many other changes which are taking place all over the world in the present day, Lyell studied with great accuracy, and then began a book to show that 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 sudden catastrophes, but so quietly that no one even notices that nature is at work. Then, on the other hand, he pointed out how in our own little island, on the coasts of Yorkshire and Norfolk, the sea eats away the cliffs, so that towns such as Auburn, Hartburn, and Hyde in Yorkshire, which are marked upon old maps, have been entirely washed away, and the ground on which they stood has been spread out on the bottom of the ocean; and yet this is done so gradually, year by year, that new towns of the same name are built up farther inland, and no one disturbs themselves about the loss. Then to account for the huge masses of basalt and lava which are found in the earth's crust, he reminded his readers of the great eruption of the volcano called Skaptar Jokul in Iceland, which took place in 1783. In this eruption the torrent of lava was ninety miles in length, from seven to fifteen miles in breadth, and in some places 600 feet deep, and the whole mass poured out would have made a mountain as big as Mont Blanc. He then went on to give accounts of the remarkable earthquakes which have taken place in times of history: the earthquakes in India, in Java, and especially in Calabria, in 1783, when new lakes were formed by the sinking in of the ground, and the rivers were made to run in new channels. He showed also how the height of land is sometimes changed in volcanic countries; as on the coast of Italy, near Naples, where the ground on which the famous Temple of Serapis stands can be proved to have been raised and depressed twice even in historical times. And besides all these obvious changes which men cannot help noticing, he proved that other quiet and unnoticed risings and fallings of land are taking place; as, for example, in Norway and Sweden, where the land is rising out of the sea in |