Stonesfield Slate. Fossil Mammalia. Fuller's Earth. Inferior Oolite and Fossils. Northamptonshire Slates. Yorkshire Oolitic Coal-field. Brora Coal. Palaeontological Relations of the several Subdivisions of the Oolitic group.

The coals here are very full of gas, which even percolates to the cellars of houses in the town. A bore hole which was sunk in 1852 to a depth of 150 feet, gave off a stream of gas, which ignited, and burnt for many years with a flame some feet long. The Zwickau coal-field in Saxony is one of the most important in Europe.

As compared with some of the American coal-fields, those of Britain are but small, both in extent and thickness. They can be regarded as falling naturally into three principal areas. The northern coal-field, including those of Fife, Stirling, and Ayr in Scotland; Cumberland, Newcastle, and Durham in England; Tyrone in Ireland.

It takes so much capital for sinking and pumping and crushing, and things of that sort, that companies have to be formed outside, and the miners mostly work just for wages. And when a reefing field gets old it's as bad as a coal-field or a factory town. You're just working for other people, and the bigger the dividends the more anxious they seem to be to knock wages"

The largest is the Candiota coal-field, in Brazil, where sections in the valley of the Candiota River show five good seams with a total of 65 feet of coal. It is, however, worked but little, the principal workings being at San Jeronimo on the Jacahahay River.

The intercalated coal-beds, sixteen in number, are generally from one to five feet thick, one of them, which has two or three layers of clay interposed, attaining nine feet. At other points in the same coal-field the shales predominate over the sandstones.

The thickest of known Russian coals occur at Lithwinsk, where three seams are worked, each measuring 30 feet to 40 feet thick. An extension of the Upper Silesian coal-field appears in Russian Poland. This is of upper Carboniferous age, and contains an aggregate of 60 feet of coal. Of its 370 seams there are no less than 117 workable ones, and these contain 350 feet of coal.

The measures here are so folded in zigzag fashion, that in boring in the neighbourhood of Mons to a depth of 350 yards vertical, a single seam was passed through no less than six times. Germany, on the west side of the Rhine, is exceptionally fortunate in the possession of the famous Pfalz-Saarbrücken coal-field, measuring about 60 miles long by 20 miles wide, and covering about 175 square miles.

There are in all about 57 different seams in the Great Northern coal-field, varying in thickness from 1 inch to 5 feet 5 inches and 6 feet, and these seams comprise an aggregate of nearly 76 feet of coal.

The Yorkshire and Derbyshire coal-fields, together with the Lancashire coal-field, with which they were at one time in geological connection, give us an area of nearly 1000 square miles, and other British coal-fields show at least some hundreds of square miles.