superior to what has previously been introduced, as to warrant some prominence being given to the subject. Some years ago a steamengine used in an industrial establishment at Muhlhouse in France, was converted into an aero-steam engine by the simple addition of a pump to force air into the boiler; a considerable increase of power was stated to have been thereby secured, but its success does not seem to have continued long, and the experiment did not then secure much general favour. Recently, however, the subject has been revived, and two inventors claim the support of the public on behalf of their respective inventions. The first of these is Parker's steam and air engine, and the second Warsop's aero-steam engine; the general principles involved in each are the same up to a certain point, but the methods of applying them differ considerably. In Parker's engine the air is drawn directly into the steam-pipe, leading from the boiler to the engine, by means of the force of the steam passing through it; this steam-pipe is sometimes passed through a small coke fire, in order to raise the temperature of the united steam and air, but this is not considered in any way essential to the utility of the apparatus. Experiments made with it are reported to have resulted in considerable economy of fuel combined with increased efficiency of engine power.

Warsop's aero-steam engine consists in the use of an air-pump, worked either by the steam-engine itself, or by a donkey-engine; this pump takes in cold air which, after being compressed, is forced on through an air-pipe passing through the smoke-box, or some other part of the boiler where heat can be taken up from contact with the waste gases. The highly-heated air passes a self-acting clack-valve into the bottom of the boiling water, and is so distributed by simple mechanical means, that it rises constantly through the water. On rising above, the air is saturated by the steam, and the two together pass on to their duty in the cylinder. From a series of experiments carried out with this engine at Nottingham, it appears that in the amount of useful work done for fuel expended, the advantage rested with the combined steam and air system, as compared with when steam only was employed.

Thames Embankment.-Upwards of eight years have now elapsed since the reclamation of the foreshore of the Thames between Westminster and Blackfriars Bridges was undertaken by the Metropolitan Board of Works. This magnificent boulevard was opened on 13th of July last. It consists of a roadway 100 feet in width throughout, having on the river-side a foot pavement 20 feet wide, and on the opposite side one of 16 feet; the former is edged by a row of trees, planted at intervals of 20 feet. The total amount of land reclaimed is 374 acres, of which the carriage-road and footways occupy 19; 8 acres will be converted into ornamental gardens for the public use, and the remaining 10 acres pass over to the original

proprietors of the foreshore. From the official description of the Victoria Embankment, it appears that the works and material employed comprise 144,000 cubic yards of excavation, 1,000,000 cubic yards of earth filling, 140,000 cubic yards of concrete, 80,000 cubic yards of brickwork, and 650,000 cubic feet of granite. The total cost of the works has been 1,260,0007., and the amount paid for compensation 450,0007. Beneath the roadway lies hidden a portion of the London main sewage system, above which is a subway, behind the embankment wall; on the opposite side, the works of the Metropolitan District Railway have been carried on contemporaneously with the Embankment, and there are four stations, namely, at Westminster, Charing Cross, the Temple, and Blackfriars, accessible direct from the roadway. Communications will no doubt shortly be completed between the Embankment and the several roads leading southwards from the Strand, as without such connections this handsome new boulevard would be deprived of half its value as a means of communication; according to an existing Act of Parliament, however, the right to make such connections is prohibited.

Chatham Dockyard Extension.-For some time past extensive works have been in progress for the extension of Chatham Dockyard. They are being executed upon 380 acres of land, and comprise, amongst other works, the reclamation of a marshy tongue of land known as St. Mary's Island, which was formerly submerged at high water; in addition to which the scheme includes the construction of a series of three extensive docks along the line formerly occupied by St. Mary's Creek, and the erection of workshops. The reclamation of St. Mary's Island has necessitated the erection of a considerable portion of embankment and river-wall, the latter consisting of a brickwork face with concrete backing; the island was then raised, by means of spoil tipped upon it, to a level well above high-water mark. The first basin, next Chatham Reach, has an area of 22 acres; it will be used for repairs, and is furnished on its south side with four large graving docks, the first stone of which was laid on 21st April, 1868. The middle, or factory basin, 20 acres in extent, will be provided with factory buildings on the southern side, including fitting and erecting shops, boiler shops, smithy, foundry, stores, &c.; whilst on the northern side will be the camber for a floating dock, a docking platform, and ten slips for laying up frigates, with the necessary worksheds. The third, or fitting-out basin, into which vessels entering for repairs will pass to be dismantled prior to going into the other basin, or, if leaving, they will be rigged and receive their supplies and stores, is 33 acres in area. The repairing basin, with its graving docks, and the communication with the factory basin, are expected to be opened in April next. The factory basin will probably be opened by the end of 1871, and the works of the other basin are also in a forward state.

MEETINGS OF SOCIETIES.

Institution of Mechanical Engineers. The meeting of this Society was held at Nottingham on the 3rd August last. Amongst the papers read were the following:-"On Self-acting Machinery for Knitting Hosiery by Power," by Mr. Arthur Paget, of Longborough; "On the mode of working Coal in the Midland Counties," by Mr. George Fowler, Manager of the Hucknall Colliery; "Conclusions derived from the Experience of Recent Boiler Explosions," by Mr. E. B. Marten, Chief Engineer of the Midland Boiler Assurance Company; and "On a Self-acting Safety and Fire-extinguishing Valve for Steam-Boilers," by Mr. G. D. Hughes. Space will not admit of our giving a reasonable abstract of all the above papers; we shall therefore confine ourselves to a few remarks on the first and last two mentioned subjects. Mr. Fowler's lectures are reviewed elsewhere.

Self-acting Machinery for Knitting Hosiery by Power.-The date at which appliances for knitting have been brought within the limits of machinery is very recent. It is one of the greatest peculiarities of the hosiery manufacture that it shapes wearing apparel without the intervention of the tailor or of the milliner; thus there exists a necessity that the machines employed should be easily adapted to make articles of very great variety of shape, thickness, and degrees of elasticity. Mr. Paget gave a description of a selfacting power-frame of his own invention, which, on account of its necessarily great complication of parts, it would be impossible to describe without illustrations. A skilful framework knitter with his hand-frame would, it was stated, knit about 5400 stitches per minute; whereas a girl could, on the same work, attend to three of Mr. Paget's self-acting machines, making in the aggregate 40,500 stitches per minute.

Boiler Explosions.--Mr. Marten remarked that from the result of the experience of the last four years, he was enabled to confirm the opinion he previously held, that all boilers, however good in original construction, are liable, in the course of time, to get into bad order and explode. The causes of explosions appear to be three, viz.-1. Faults in construction or repair; 2. Faults in working, which creep on insidiously and unnoticed; and 3. Faults which might be seen and guarded against by careful attendants. Nearly all the faults would be detected by periodical examination, which is indeed the only true safeguard against explosions. Each cubic foot of water has the explosive effect of one pound of gunpowder, and the explosion of a boiler assimilates more nearly to that of gunpowder than of any other explosive agent. Mr. Marten enters into some detail regarding the various explosions that have come under

his notice, and sums up with some very excellent rules for the avoidance of such disasters.

Safety-Valve for Steam-Boilers.-This apparatus is intended to serve the double functions of fusible plugs and low-water alarums. An internally loaded valve of spherical form is placed in a steamchamber, and a pair of steam-pipes connect this chamber with the furnace crown of the boiler. The safety-valve is dead weighted, and should the pressure of steam lift it up, it escapes into the chamber and down the pipes into the furnace. Any over-pressure is thus dealt with, and the motion of a float is made to act in a similar way on the same safety-valve. Another independent safety-valve is adjusted to blow off at a pressure somewhat lower than that at which the dead weight is adjusted.

Liverpool Polytechnic Society.-A very interesting paper was recently read before this Society by Mr. T. B. Thorburn, C.E., Surveyor to the Birkenhead Commissioners, "On the method adopted in Birkenhead for Ventilating Sewers, and carrying away the Gaseous Emanations generated therein." This paper, which it would be impossible to follow in detail, contains an account of the extent of the Birkenhead sewers, and not only states the different ventilators employed, but gives also the cost of constructing them according to the several arrangements adopted.

7. GEOLOGY AND PALEONTOLOGY.

(Including the Proceedings of the Geological Society and Notices of Recent Geological Works.)

*

Professor John Phillips, M.A., D.C.L., LL.D., F.R.S. &c.-Few men have by their own labours contributed a larger share to the advancement of scientific knowledge than Professor Phillips, and we are glad to obtain a sketch of his career, which is probably as full of noble achievements as that of any scientific man we have ever known. Brought very young (by the death of his father) under the care of his uncle, William Smith, originally known as "Strata Smith," and afterwards called "the father of English Geology," he was early led to take delight in the identification of strata by their fossil contents, and accompanied his uncle through the greater part of England during his geological investigations, which resulted in the first geological map of England and Wales. Few men of science have had a more distinguished career. Appointed Keeper of the Yorkshire Philosophical Society's Museum in 1825, that Society grew and flourished under his care, and led in

* 'Geol. Mag.,' vol. vii., 1870, p. 301.

1831 to the establishment of the British Association, of which he became the Assistant General Secretary in 1832, and continued to act in that capacity until 1863. In 1834 he became Professor of King's College and a Fellow of the Royal Society. In 1840 he resigned York Museum, and entered upon the duties of the Geological Survey of England and Wales, to which he contributed Memoirs on the Paleozoic Fossils of Cornwall, Devon, and Somerset, and afterwards on the Malvern Hills, &c. In 1844 he became Professor of Geology in the University of Dublin. In 1849 he was appointed one of Her Majesty's Commissioners to inquire into and report upon the system of ventilation employed in mines. In 1853 he commenced the duties of the Chair of Geology at Oxford, which he has continued to hold ever since the death of Dr. Buckland. In 1859 he was elected President of the Geological Society of London; in 1865, President of the British Association. His various geological works are above seventy in number, and his astronomical and other papers are also very numerous. Besides the York Museum which enjoyed the advantages of Professor Phillips's attention, the present Oxford Museum may be said to have been created by him, and is a model for any city in the world to copy.

Lecture on Volcanoes.-Mr. David Forbes, F.R.S., recently* delivered an interesting lecture at St. George's Hall on Volcanoes. Speaking of the relative energy displayed by volcanic forces in the older geological periods, Mr. Forbes said, "We must bear in mind that we still have volcanoes whose craters, several miles in diameter, send forth at times streams of molten stone forty miles and more in length, or showers of ashes which bury the surface of the ground to a depth of 400 feet below them, and, furthermore, see volcanic mountains and islands literally rising up before our eyes to an elevation of even thousands of feet, in what, geologically speaking, is but a second of time, it does not to me seem at all necessary to assume that such internal or cataclysmic forces were so much more energetic in any other period than at present."

The author believes that sufficient importance has not been given to the effects produced by the cataclysmic action of volcanoes. He points out that all the chief features of the earth's surface are due to the elevatory forces within, and that volcanoes not only form the most lofty mountains in the world, but that the backbone of most of the others is composed of eruptive rocks. It must therefore be admitted that the changes effected in the physical geography of the world have resulted from a combination of two great but most opposite agencies, the internal and external, igneous and aqueous, cataclysmic and uniformitarian; and that all the phenomena of nature result from a combination of one or more forces, the same phenomena, at times, being the result of totally different agencies.

*June 19, 1870.