railway through submerged tubes laid at the bottom of the sea; and 3. For the improvement of the passage-boats, or, in other terms, the construction of a huge Steam Ferry between the two countries. A fourth class of projects may be enumerated, namely, those having for their object the construction of a high-level bridge across the Channel, but such hardly come within the category of practical schemes. That which can be constructed at least cost and with most expedition is the Channel Ferry project, and this we are inclined to think will, for the present at least, be found the most practical solution of the difficulty. New York Society of Practical Engineering.-At a meeting of this Society, on 13th October last, a most useful and practical paper was read by Mr. C. Williams, C.E, on " Railway Accidents and the Means of Prevention." In the absence of wooden tie sleepers, the author advocated the laying of rails upon sleepers bedded upon sand confined in trenches formed either transversely or longitudinally with the track. The importance of securely attaching the rails to the substructure was dwelt upon; and, lastly, improved fish-joints and methods for avoiding the breaking of railway carriage axles were discussed, and the methods for effecting such means of security were dwelt upon at some length. LITERATURE. The Theory of Strains in Girders and similar Structures,'* by Bindon B. Stoney, B.A.-The first volume of this work appeared three years ago. The present volume treats of the subject of girders under compression and in tension, as well as elasticity, temperature, and the practical designing and estimating of girder-work; and in the former part of the volume numerous references are made to the experiments carried out by Mr. Kirkaldy and Mr. Hodgkinson. As a text-book for practical engineers this will be found a useful work, but it would be impossible to enter fully into its merits within the space to which we are limited. 'A Practical Treatise on Concrete, and How to make it; with Observations on the Uses of Cements, Limes, and Mortars,' by Henry Reid, C.E.-At the present day when the use of concrete and cements is being so largely introduced into almost all engineering works, a more perfect knowledge of their properties is a subject much to be desired, and every fresh information coming from a reliable source is much required. During the earlier period of the introduction of concrete, which, in this country, is attributed by General Pasley to Sir Robert Smirke, it was regarded as being only fitted for foundations, or hidden work of a similar kind; but of late years that material has acquired a higher standard, and is now * Longmans, Green, & Co., London. † E. and F. N. Spon, London. VOL. VII. The being extensively employed in the construction of buildings of various kinds with most satisfactory and economical results. preparation of concrete is treated very fully by Mr. Reid, who devotes distinct chapters to lime concretes, concretes with compound matrices, Roman cement concretes, and concretes made with Portland cement. He also gives descriptions of machinery for mixing concretes and mortars, as well as remarks on building by frames. In conclusion, some general observations of considerable value are given on the advantages possessed by Portland cement as a building material, in the course of which he mentions the success which has resulted from the use of such concrete as a material for pavements. Altogether this is a very useful work, which may beneficially be consulted by all classes interested in the use of concrete. 7. GEOLOGY AND PALEONTOLOGY. (Including the Proceedings of the Geological Society, and Notices of Recent Geological Works.) Memoirs of the Geological Survey.-Two of these Memoirs, forming an important contribution to British Geology, have reached us during the past quarter. One is a very elaborate Essay on the Triassic and Permian Rocks of the Midland Counties of England,' by Edward Hull, M.A., F.R.S., &c. (now Director of the Geological Survey of Ireland). No less than twenty sheets of the Geological Survey' (one-inch) maps are referred to in this Memoir, which include parts of the counties of Gloucester, Hereford, Worcester, Warwick, Leicester, Stafford, Salop, Denbigh, Flint, Cheshire, Derby, Notts, York, and Lancaster. The rocks are treated in ascending order, under the following headings, or general classification: A 1. Rhætic, or Penarth Beds. A 2. New Red Marl (Keuper). A 3. Lower Keuper Sandstone (Letten Kohle ?). TRIASSIC SERIES (B. C 1. PERMIAN SERIES C 3. Lower Mottled Sandstone (Bunter Sandstein). 1. Upper Permian (Zechstein). The Lower Permian series may be arranged under two distinct types of strata, called respectively the "Salopian" and the "Lancashire," which differ lithologically, and were deposited in separate hydrographical basins, the disconnecting barrier having been produced by the upheaval of the Lower Carboniferous rocks along a tract of country crossing from east to west below the central plain of Cheshire. Our readers will remember Mr. Hull's paper, recently read before the Geological Society, in which he entered fully upon this question. The unconformity is noticed between the Triassic and Permian series, which was pointed out by Professor Sedgwick more than forty years ago; the newer beds rest indiscriminately on any of the older formations, whether Silurian, Devonian, Carboniferous, or Permian. The lithological peculiarities of the beds exhibited in different localities and their organic remains are noticed. Though it is as well to mention that the subdivision of the Bunter Sandstone, or Lower Trias, into three members, which was propounded by Mr. Hull in the course of his detailed examination of the rocks over a large area, was altogether dependent on inorganic evidence. Some little space is of course devoted to the beds of Rock-salt interstratified with the Red Marls and clays of the Keuper. The Rhætic, or Penarth Beds, are also briefly noticed; but these beds have not yet been traced farther northward than the outlier of Copt Heath, near Birmingham, and at Abbots Bromley, in Staffordshire. Mr. Hull is inclined to regard these beds as referable to the Triassic formation, although it seems to us better to regard them as passage-beds between the Lias and Trias-the lower beds passing into the latter, the upper being more closely related, and sometimes appearing to graduate into the Lower Lias above. The Physical Geology of the Permian and Triassic periods are treated of; also the distribution of the Coal Measures beneath them. The Bunter Sandstone is considered as a source of water-supply, and is regarded, with the exception perhaps of the Chalk and Lower Greensand, as by far the most important water-bearing formation in England. In an appendix is given a list of the Fossils in the Warwick Museum, from the Keuper and Permian Sandstones, by the Rev. P. B. Brodie, revised by Mr. Etheridge, Palæontologist to the Survey. The second Memoir is on the 'Geology of the Carboniferous Limestone, Yoredale Rocks, and Millstone Grit of North Derbyshire, and the adjoining parts of Yorkshire,' by A. H. Green, M.A., F.G.S., Dr. C. Le Neve Foster, B.A., F.G.S., and J. R. Dakyns, M.A. They give a detailed description of the geological structure of the district, together with observations on the physical features and drainage, followed by an appendix, giving a list of the Carboniferous Limestone fossils of Derbyshire, furnished by Mr. Etheridge. The formations described in this Memoir are as follow: Both these Memoirs are well illustrated with sections and diagrams. The authors give due credit to other observers who have previously described these districts. They will be found of the greatest service to all who may need to consult them, either for professional purposes or as amateur geologists. In November, 1867, the Rev. Thomas Wiltshire, M.A., F.G.S., read a highly interesting paper before the Geologists' Association, "On the Chief Groups of the Cephalopoda." This has just been published, and will be found very useful by the student. The author touches upon the structure and habits of these animals, and gives schedules of the recent and fossil Cephalopods, wherein are analyses of the families and genera; he also gives an appendix on the range of the genera in geological time. Mr. E. D. Cope has published the first part of an elaborate 'Synopsis of the extinct Batrachia and Reptilia of North America.' He has thought it best to describe only those species and types which are new, and those portions of imperfectly known forms which will throw additional light on their relations and affinities. In the course of his investigations, prosecuted during the past six years, with reference to the structure and relations of the extinct Reptilia, the following general conclusions have been arrived at, besides many of lesser significance:-- 1. That the Dinosauria present a graduated series of approximations to the birds, and possess some peculiarities in common with that class, standing between it and the Crocodilia. 2. That serpents exist in the Eocene formations of this country. 3. That the Chelydra type was greatly developed during the American Cretaceous period; and that all the supposed marineturtles described from it are really of the first-named group. 4. That the Reptilia of the American Triassic period are of the Belodon type. 5. The discovery of the characters of the order Pythonomorpha. 6. The discovery of the characters of the order Streptosauria. 7. The development of the characters of numerous members of the Batrachian sub-order Microsauria in the United States. The Memoir is illustrated with eleven plates and numerous woodcuts. Mr. Cope's work is peculiarly interesting, as bearing upon the researches of Professor Huxley on the affinities of the Dinosauria with the class Aves independently carried on in this country. The Geology and Mineral Veins of the Country around Shelve, Shropshire, with a Notice of the Breidden Hills,' by G. H. Morton, F.G.S., F.R.G.S.I., President of the Liverpool Geological Society (extracted from the Proceedings of the Society), Liverpool, 8vo, Pp 41. This work treats of both the Geology and the Archæology of Shelve, which is situated in western Shropshire. The lead mines were worked in the Roman period, as shown by their coins, pottery, and mining implements; pigs of lead bearing on their stamp the name of Hadrian have been found there. The remains of Roman encampments exist in the neighbourhood, as well as several Druidical circles; the largest of which, the Circle, or "Hoar stones," has still thirty-two stones standing, and seems originally to have contained thirty-six. Very red copper ore, "Redruthite," has been found in the neighbourhood, but workings have only lately been commenced. The average direction of the greatest number of the veins is W.N.W. by E.S.E.; most of them are simply fissures in the rock (Lower Silurian), which is prominently developed in this district, filled with Barytes Calcite and irregular strings and nests of Galena and Blende, interspersed with fragments of the slate-rock. The author observes, "It is remarkable that in the Upper Llandeilo rocks the veins principally contain Barytes; the Lower Llandeilo rocks, lead; and the Cambrian rocks, copper.' There are several interesting sections given, showing the disturbances caused in the Lingula flags, Llandeilo and Cambrian beds, &c., by the eruptive intrusion of greenstone and other trap-rocks. Lists of the fossils found in these formations and maps of the mineral veins are also appended. The Breidden Hills, about ten miles N.W. of Shelve, range to the height of 1200 feet above the sea-level, are surrounded by the Llandeilo strata, and are interesting from the many varieties of porphyritic and amygdaloidal greenstone, trap-breecia, and ash, of which they are composed. The Geological Magazine' for October, November, and December contains an abundant supply of interesting papers, only a few of which we have space to notice. 1. A novel theory of the formation of the Chesil Bank is propounded by Messrs. H. W. Bristow and W. Whitaker. The question they deal with is simply the cause of the position of the beach, separated as it is from the mainland throughout its greater length by a strip of water called "the Fleet." The authors are of opinion that this channel was formed subsequently to the heaping up of the shingle, which they think was originally formed against the land. East of Abbotsbury the ground is comparatively low, and numerous streams run into the Fleet; while for some distance west of this village there are no streams, the ground is much higher, with cliffs, and the beach is not separated from the land. The conclusion arrived at is that after the beach was formed against the land, these streams in flowing down towards the sea would turn eastwards for some distance before filtering through the shingle (as is the case with streams west of Burton |