Page:Midland naturalist (IA midlandnaturalis01lond).pdf/374
In the work before us there is every evidence that on the part of each author this labour has been a work of love, and the perusal of the book will convince everyone that the work has been thoroughly and well done.
Commencing with a useful list of books written on the Geology of West Yorkshire, we lave an introductory explanation of the chief physical features, main faults, and measures of the district, which is followed by a succession of chapters devoted to the several divisions of rocks—from the Silurian to the Post-tertiary—represented in the locality. The county, as a whole, furnishes a most comprehensive field for geological study, for the anther says, "If the whole of the county be taken: we have all the great divisions well represented, except . . . the Cambrian and Laurentian, thus presenting m small an areca a more glorious epitome of the strata comprising the earth's crust than can be found in any other locality of similar, or even much larger extent in the world."
The Silurian beds are the Coniston limestone, with the superincumbent Flags and Grits and the Bannisdale Slates, which altogether attain a great thickness, and represent the beds above and below the line of division of the Lower and Upper Silurian beds, as laid down by Sedgwick, who devoted a great deal of time and attention to the examination of the Coniston Rocks, The occurrence of a bed of sandstone 20 feet thick, with fossils of the Ludlow type, at so great a depth (1,200 feet) below the Ludlow beds, is an interesting and remarkable circumstance.
The succeeding period of Sedimentary Rocks {the Devonian) is but imperfectly represented in West Yorkshire. At page 41 the author gives an interesting account of what was going on between the deposition of the Silurian beds and that of the Carboniferous Limestone.
The Carboniferous Rocks, consisting of the Mountain Limestone, Yoredale Beds, Millstone Grit, and Coal Measures, seem all to be peculiarly well developed in this district, and they are very particularly described, with the faults, &c. The numerous sections and long lists of fossils show how accurately these beds have been investigated, and, apparently, they offer a very wide field for examination. The purity of some of the coals of the district is of great economical importance, among which we may especially mention the Vetter Bed Coal, of which the author says {p, 113)—"It is extensively worked in the Lowmoor district, for the purpose of smelting the iron ore found in the shale above the Black Bed Coal. Its freedom from sulphur and other impurities renders it peculiarly valuable for smelting purposes; and it is partially to this coal that the excellence of the Lowmoor iron is attributed." We believe it was this head of coal which Professor Huxley described as being entirely composed of lycopod spores, to which, probably, it owes its great purity. We notice our author does not give us any lists of fossil coal plants, the study of which seems unfortunately to have an attraction for only very few of our Botanists. The Permian rocks of the district seem to he more developed than in our own district, but we notice the absence of the several sub-divisions of the Bunter beds Which are found in the Midlands.
There is an interesting chapter devoted to the Glacial and Past-glacial deposits, together with a brief account of the exploration of the Settle and other caves.
The second part of the work commences with an outline of the physical geography of West Yorkshire, and is followed by an examination of the flora of the ten divisions into which the district is sub-divided, according to river drainage. This is accompanied by a good map, from which can be seen at a glance the several districts treated of in the successive chapters. The flora is an extremely rich one, for the author