Susquehanna bridge, at Havre de Grace, U.S., is now nearly completed. It is being constructed to unite the hitherto severed portions of the Philadelphia, Wilmington, and Baltimore Railroad. The superstructure, which is for a single line, is of wood, built on the Howe plan, with arches, and consists of twelve spans of 250 ft. 9 in., and a draw span of 174 ft. 9 in. The whole distance between the abutments is 3,273 ft. 9 in. Arrangements are in progress for building a second suspension bridge across the Niagara. This new bridge will be much larger than its neighbour below, the clear span of which is 822 feet.

The East India Irrigation and Canal Company has at last been entrusted with the carrying out of a system of irrigation from the Soane River, in the lower Provinces of Bengal. Had this work been undertaken when it was first designed by Colonel Dickens, much of the past and present calamities of famine in those districts might have been averted.

A prospectus has been issued of the Valparaiso Waterworks Company, to supply that city with water through a canal to be cut from the Aconcagua river, flowing from the Andes. This canal, a portion of which has already been completed, is at the same time calculated to yield a revenue by furnishing water for irrigation to the lands throughout its course.

Three companies have recently been started for establishing a through line of telegraph between England and India. The lines of one company are proposed to pass through France, Italy, Sicily, Malta, Alexandria, and Suez, to Bombay; whilst another would pass through Prussia, Russia, Persia, and along the Persian Gulf to Kurrachee. The third company-which we believe has amalgamated with the first-proposed to carry independent lines from Falmouth to Gibraltar, Malta, &c.

A contract has been concluded for the manufacture of a new cable, to be laid by the Submarine Telegraph Company, between England and Belgium.

Both the shore ends of the Florida and Cuba cable were successfully laid early in August last, but just as the splice was about to be made, the cable suddenly parted about half-a-mile east of the buoy, and the ends sank into the sea.

The foundation stone of the Holborn Valley Viaduct was laid on Monday, June 3rd. Within the past century a total sum of 6,742,8537. has been expended by the Corporation of London on public works, buildings, and street improvements.

The American life-raft, which recently crossed the Atlantic in forty-three days, is formed of three cylinders, charged with air and connected by canvas, stiffened by planking. She is 24 feet long, 12 feet broad, and carries two masts.

A company has been formed to remedy the obstacles which

the bar of the Mississippi offers to navigation. The system which this company proposes to apply to the relief of ships consists of an apparatus of caoutchouc, forming a kind of floating dock, which will be manoeuvred with the aid of two tugs. The company hopes by this means to raise to the extent of 8 feet ships drawing 20 feet of water, and to enable them to go over the bar in less than three hours.

The drainage works of Eastbourne have recently been completed and opened.

On the subject of docks, &c., we have to report the admission of water into the Millwall Docks, on the Thames, on 29th August last. On the 1st idem, the first stone of the new graving dock at Malta was laid; this dock, when completed, will be the largest ever constructed, its dimensions being-length, 468 feet; width, 104 feet, and depth, 39 feet. A new slip dock has recently been opened on the Clyde, capable of taking in ships of 2,000 tons; it is 850 feet long, aud 57 feet broad. A new floating railway pier at Burntisland, which has been under construction for the past two years, has just been completed. The pier commences about 330 yards east of the Burntisland passenger station, and extends for 1,000 feet in a south-westerly direction, thus forming a harbour which is accessible at all states of the tide.

A process is now being carried out by Messrs. Whitworth, of Manchester, of subjecting steel to a high pressure during the process of casting; the object being to obtain sounder castings, and to do away with the necessity for great "heads" of metal. Mr. Whitworth is also endeavouring by hydrostatic pressure to effect the rolling, or otherwise shaping, under pressure, of cast-steel in the liquid state. Mr. A. L. Holley, of Harrisburg, U.S., has recently patented a plan for casting Bessemer steel ingots from the bottom instead of from the top as is usual; and it is found that ingots thus cast are square and sound at the top as well as at the bottom, and they are more free from cracks and external honeycombs, and much smoother than ingots cast from the top.

A new form of tyre-lathe has recently been introduced by Messrs Greenwood, of Leeds, which has been designed to facilitate the boring of railway tyres, by enabling the whole operation to be completed without shifting the work in the machine, the arrangement being such that cutting tools can be simultaneously brought into action on the opposite faces of the tyre, and also on its inner surface.

VOL. IV.

2 N

7. GEOLOGY AND PALEONTOLOGY.

(Including the Proceedings of the Geological Society.)

THE energy of the Secretary of the Palæontographical Society (the Rev. T. Wiltshire) has borne fruit in the appearance this quarter of another volume of the Society's Monographs,-that for 1866,— after an interval of only six months from the date of publication of the one we last noticed.

This volume opens with a second instalment of Dr. Duncan's Monograph of the British Fossil Corals, in which are described the Zoantharia from the Liassic zones of Ammonites planorbis and A. angulatus. These zones have recently been the subject of much discussion, especially as regards their more or less close relationships with those above and below. We have recently given a summary of Dr. Duncan's interpretation of the coral evidence, in recording the publication of his paper "On the Madreporaria of the Infra-Lias of South Wales," so on this occasion we shall confine our attention to some of the author's considerations on the philosophy of zone classifications generally. The Liassic and Oolitic formations have been subdivided into a number of "zones," each of which is characterized by, and named from, the occurrence of a certain species of Ammonite. The more enthusiastic advocates of this classification seem to believe that the range of other organisms is more or less co-extensive with that of the Ammonites, and that the latter, being abundant in these deposits, and tolerably easy of determination, afford the easiest means of identifying the zones; it has also been stated that they are the best test of horizons, because their range is less uncertain than that of other organisms. Dr. Duncan's researches into the distribution of the Liassic Corals have not enabled him to strengthen the arguments in favour of zone classifications; on the contrary, he has been led to the conviction that "the endeavour to give definite horizons to, and to correlate, Saurian, Insect, Ostrea, Ammonite, and Lima beds has resulted in the production of confusion instead of the reverse;" also " that no stratigraphical Paleontology can be perfect in a classificatory sense, and that zones of species may have little to do with the notion of time."

Holding this opinion the author's practice may appear inconsistent with his preaching; but in reality he accepts the principle of a zone-classification in a modified sense. "The groups of Madreporaria have a general relation to certain zones of life and to certain strata; and if they are associated for the sake of a necessary classification with certain Ammonite-zones, it must be understood that it is only an approximative classification, and that both the

Ammonites and the Madreporaria may range out of their supposed restricted zone, or not even be represented in certain portions of its area." In point of fact, Dr. Duncan is one of the few paleontologists who can view the birth and death of the life of a period as symbolized by a line that is elastic, and not rigid.

Mr. Salter's contribution to this volume, being Part IV. of his Monograph of British Trilobites, consists almost entirely of descriptions of the species of the genus Illanus and of its subgenera; Mr. Davidson continues his description of the Silurian Spiriferida and commences that of the Rhynchonellida; and Professor Phillips makes considerable progress in the description of the Liassic Belemnites.

The volume is illustrated by forty well-executed plates, which are mostly beautiful specimens of scientific lithography, some being English and some French.

The most recent publication of the Geological Survey of India, another contribution to Indian Paleontology, is a work of more than Indian importance. It contains the first portion of Dr. Stoliczka's description of the Gasteropoda of the Cretaceous rocks of Southern India, including the Pulmonata and the siphonostomatous Prosobranchia; but its general interest will be due to its containing an elaborate essay on the classification of the Gasteropoda-the illustrative examples being necessarily chosen from the Cretaceous fossils of Southern India. It will be sufficient for us to mention here that Dr. Stoliczka's plan is to subdivide the old generic groups, such as Fusus, Murex, &c., into a number of smaller groups which he considers to be still of generic value. Although, in this course, Dr. Stoliczka has to some extent followed many able conchologists, the plan has not yet found much favour with British paleontologists.

The Journal of the Royal Geological Society of Ireland contains several meritorious papers on drift deposits and theories of denudation. Our space will not admit of our giving analyses of these memoirs; but we may especially draw the attention of our readers to Mr. G. H. Kinahan's "Notes on some of the Drift in Ireland; and to a very elaborate essay by the Rev. Maxwell H. Close, "On the General Glaciation of Ireland."

In a communication to the Royal Institute of Lombardy,† Sign. Lombardini describes some traces of the Glacial period which he had observed in the great depression of Central Africa. He therefore infers that confirmatory evidence will be found in the mountainous districts of Abyssinia, and in the more southern and tropical regions of Kenia and Kilimandjaro. Collating his results with those of M. Reclus in the Sierra Nevada, and of M. Agassiz in Brazil, he comes

*Paleontologia Indica, vol. v., fasc. 1-4.

† Rendiconti del Reale Istituto Lombardo di Scienze e Lettere. Classe di Scienze Matematiche e Naturali, vol. iii., fasc. 3, p. 85.

to the conclusion that the phenomena of the Glacial period were spread over the whole surface of the globe.

These investigations have a direct bearing on the speculations of Mr. Croll and others, the basis of whose hypotheses is the assumption that the glacial phenomena were limited to extra-tropical regions. Mr. Croll, indeed, has recently published a modification of his original hypothesis to account for changes of climate, namely, alterations in the obliquity of the ecliptic; and has thus got into another controversy with his old opponent, Mr. J. Carrick Moore. The several papers which have been published on this subject will be found in the numbers of the Philosophical Magazine' issued during the past quarter.

The geological survey of the Grand Duchy of Hesse has recently made considerable progress; and several sheets of the map with descriptive memoirs have come under our notice. Amongst them we wish especially to draw attention to the map and description of the Section Alzey by M. Ludwig; and to those of the Section Mainz by Herr Grooss. These maps and memoirs furnish us with the most accurate descriptions yet published of two of the most classical of all the German Tertiary localities, and therefore deserve more than a local circulation.

The Geological Magazine' for the quarter has contained a large number of original articles, but we have space to notice only two or three of the most important.

In the first place we must draw attention to a paper by Professor King in the June number and an answer to it by Mr. Davidson in the July number, with a notice in the latter of a paper by Mr. Meek -all on the subject of the perforation or non-perforation of certain Paleozoic Brachiopoda. Dr. Carpenter has also taken part in the discussion, and has published papers on the subject in the January and July numbers of the Annals and Magazine of Natural History.' The chief cause of the discussion appears to be the rather remarkable fact that two forms of Spirifer (S. cuspidatus), though otherwise undistinguishable, are respectively characterized by the perforation of the shell in the one case, and its non-perforation in the other.

The August number of the Magazine is chiefly remarkable for containing a verbatim report of Dr. T. Sterry Hunt's lecture on the chemistry of the Primeval Earth, which was delivered at the Royal Institution on May 31st.

PROCEEDINGS OF THE GEOLOGICAL SOCIETY.

An important paper by Mr. Tate "On some Secondary Fossils from South Africa," forms the commencement of the last number of the Society's Journal. It contains descriptions of a large