round it, and the midland counties south and east of Derbyshire. The third or western coalfield includes South Wales, Gloucestershire, and Somersetshire. The coalfield of South Wales alone is 100 miles long, and 18 or 20 broad. The Workington and Whitehaven coal-mines extend a mile under the sea; several shafts in the latter are 100 fathoms deep; and it is one of the finest in England for extent and thickness of strata, some of the seams being nine feet thick.

The Scotch coalfield occupies the great central low land of Scotland, lying between the southern high lands and the Highland mountains; the whole of that wide tract is occupied by it, besides which there are others of less extent. Coal has been found in seventeen counties in Ireland, but the island contains only four principal coal districts-Leinster, Munster, Connaught, and Ulster. Thus there is coal enough in the British islands to last some thousands of years; and were it exhausted, our friends across the Atlantic have enough to supply the world for ages uncountable. Moreover, if science continues to advance at the rate it has lately done, a substitute for coal will probably be discovered before our own mines are worked out.

THE MINER AT WORK.

Shaft, n. (Sax.) in mining, a pit or long narrow opening into a mine. The direction of the shaft is either vertical or much inclined to the horizon. It is never less than 32 inches in diameter, and sometimes amounts to several yards. Its depth may extend to 1000 feet or more. Lode, n. (Sax.) among miners, any

(From "The Mining Journal.") regular view or course, whether metallic or not, but commonly a metallic vein. The lodes containing metallic ores, are said to be alive; those which contain merely lapideous or stony matters, are called dead lodes. Winze, n. a small shaft sunk from one level to another, for the purpose of ventilation."

We

MINES are not all equally wet; but no one can expect to penetrate very far into a mine and emerge dry from it. have, therefore, to go to the "shifting-room," and attire ourselves in a miner's garb. It consists of a suit of thick flannel, with a stout coat over it, heavy shoes for the feet, and a hat generally made strong enough to "bear a good knock." We must also provide ourselves each with a candle. The candle is stuck into a piece of clay, which again is stuck upon the hat,

which is of the "wide-awake" shape. Thus equipped, we descend the ladders. As we approach the shaft, we perceive a steam rising from it. This, we are informed, is the breath of the men at work below. The very mine itself seems to breathe. There are, at least, six hundred men at work beneath our feet, at various depths, some one hundred, some five hundred, and others sixteen hundred feet. The ladder is very narrow, with iron bars, and is well nigh perpendicular. The bars are moist and greasy, from the men passing up and down, which makes us cling all the more firmly, considering the unknown depth of the shaft, and the almost perpendicular position of our means of descent. We bid adieu to daylight almost by the time we have reached the first level. There is no one at work in it, so we descend to the second. We pass it, and several others, until at length we reach the seventh level. We are then about four hundred feet under ground—a sufficient depth to bury St. Paul's. We take the level to our right, and pursue it until we reach the men at their work. There is a tramroad along the level for "running the stuff" to the shaft, so that it can be raised to the surface. In some of the smaller mines this is done by boys with wheelbarrows, which with the exception of working the ventilating machines, is the only purpose to which boys are put below. We proceed about one hundred feet in a horizontal course, when we come upon the miners. When they take a pitch, they generally work it up, not down-that is to say, the men working from the seventh level work up towards the sixth, not down towards the eighth. Their object is to follow the lode, and extract the ore from it, disturbing as little of the non-metallic ground as possible. When the lode is wide enough, they work nothing but the lode, leaving the matter on either side untouched. A miner will thus work in a lode only eighteen inches wide; but if it is narrower than that, he has to clear away some of the "country"—which is removing a sufficient quantity of the granite, slate, stone, or other substance which may envelop the lode, to enable him to follow it. Those upon whom we have come are engaged at this work. They are preparing to clear away the granite by blasting it. The hole for the powder is made with a "borer," held by one whilst the other strikes it with a large sledge-hammer. The latter is in a state of profuse perspiration, whilst the other is shivering with cold. They are both completely wet-as, indeed, we are ourselves. The man with the hammer has nothing on but his

flannel trousers. The beatings of his heart, which are quick and strong, strike painfully upon the ear. He seems to be galloping through life-and so he is; for the miner is generally but a short liver. We leave this part of the level, and take that on the other side of the shaft, which we follow for a considerable distance, until we come to a hole, through which we have to crawl on all fours. We then find ourselves at the bottom of a winze, which we pass, and pursue the level. The men have worked up for a considerable distance, making stages for themselves as they rise into the lode. The ore is carefully separated from the stuff, and is carried over the tramway to the shaft. Such is the merest outline of the work which the mine exhibits. Space will not permit us to go into details here. We return again to the surface. But to climb a series of perpendicular ladders, reaching as high as St. Paul's, is no joke. We take about half an hour to do it, resting at the different levels as we ascend. We arrive at the top utterly exhausted, and thankful that we have emerged again into daylight.

EXTINCT REPTILES.
(PART I.)

(From the "Leisure Hour.") AMONG the achievements of science, there is no one thing which more deservedly excites our admiration than the restoration of extinct animals. Various writers on geology had shown that the strata of the earth were laid on, one upon another, in a certain and regular succession, and that each class of rock-to use the geological phrase had its own peculiar suit of exuviæ; but this had not supplied us with the true key with which to unlock the cabinet of nature, and call out from her secret treasury those strange creatures which were produced during the earth's childhood. Cuvier, however, has supplied what was wanting in this respect, and, by a rigid application of comparative anatomy, has enabled us to perfect our natural history by introducing scores of animals of whose existence our fathers knew nothing.

The various strata of the earth are, like the leaves of a book, written all over with instructive lessons, and it is the business of the student to observe these signs and give their true significance. In some instances the bones of an animal

P

are found imbedded almost entire; at other times, whole beds of shells are found perfectly preserved; and where this is not the case, it often happens that traces of the former inhabitants are discovered. On a thin bed of fine clay, occurring between beds of sandstone, this evidence is frequently preserved. The ripple-mark, the worm-track, the scratching of a crab on the sand, and even the impression of a rain drop, so distinct as to indicate the direction of the wind at the time of the shower -these, and the foot-prints of the bird and reptile, are all stereotyped, and offer an evidence which no argument can gainsay, no prejudice resist, concerning the natural history of a very ancient period of the earth's life; but the wave that made that ripple-mark has long since ceased to wash those shores. For ages has the surface, then exposed, been concealed under a great thickness of strata; the worm and the crab have left no solid fragment to speak of their form or structure; the bird has left no bone that has yet been discovered; the fragments of the reptile are small, imperfect, and extremely rare; still enough is known to determine the fact, and that fact is all the more interesting and valuable from the very circumstances under which it is presented.

But the reconstruction of an animal, when only a small portion of the skeleton is discovered, is a matter of great difficulty, and requires much scientific knowledge. This, however, may be done; and in some cases a single bone is enough to indicate the size and structure of the animal to which it originally belonged. Suppose, for instance, that the jaw-bone of an unknown species of animal were found, it is surprising how much may be learned from it. The teeth will show whether the animal was carnivorous or herbivorous; then, if the teeth were made for tearing flesh, so the claws must be made to lay hold of it; then again, the paws require strong muscles in the forearm, and a corresponding structure of the shoulder; and in this way the general structure of the creature may be determined. We may also descend to some minutiæ; for the digestive organs must have a similar relation to the parts before mentioned, and may therefore be inferred from the jaw-bone.

In the older strata, however, of the earth, there are no bones. The rocks are divided into two classes the Igneous or Plutonic, and the Aqueous or Sedimentary. As the igneous rocks owe their origin to fire, it is impossible that they should

contain the traces of animal life; we must, therefore, look to the sedimentary rocks for those precious treasures. These rocks, viz., the Aqueous or Sedimentary, are again divided into what we call the Primary and Secondary series. The Primary are all stratified, that is, laid one upon another in regular order, but are destitute of organic remains; the Secondary series are, however, rich in those treasures which have enabled men of science to recall the past world to their imagination, and people it with the plants and animals which it once contained.

There are, as may naturally be expected, certain localities. in which the remains of animals and vegetables are found in great abundance. Our coalfields are rich in vegetables; nor is there a piece of coal that is consumed in our grate, or that sets the steam-engine in motion, which was not once a vegetable. The remains of an old forest were left, perhaps, like the wreck of a stranded bark, upon the banks of some old lake or river; in process of time it was covered over by a layer of mud; that mud hardened into rock, and was covered by other deposits; and now, when the wood is dug up again, it has been converted into coal, and has become an important element in our civilisation. So great is the care which our heavenly Father exercises over all his children, that not an atom is lost which can add either to their instruction or comfort.

EXTINCT REPTILES.
(PART II.)

TO ILLUSTRATE what we have been saying, it is only necessary that we select some one geological period-say the oolite. Professor Ansted has enabled us to recall this period with great precision; for England was then a fine country, although there were no men in it. Let us suppose ourselves, then, upon the south coast, not far from the Isle of Wight, and we shall find ourselves upon a promontory stretching into the sea. Behind us there is a country covered with brushwood, and the distant hills are clothed with lofty pines. The interior of the country is decked with a forest of magnificent trees, and the most beautiful flowers bloom on thousands of shrubs. Added to this, the whole place teems with life. Looking out into the sea, we shall perceive a huge monster lift his head out of the water to breathe the air. It is the most fearful and terrible of