ting rid of very large quantities of very troublesome material, but a source of considerable profit.

NEW MODE OF MANEUVERING A VESSEL.-Floating batteries are being constructed for the protection of the coasts of Sweden. They are provided with a turret: and as the turret does not revolve, in order to secure the power of aiming the gun it contains in all directions, it is necessary that the vessel itself should rapidly turn round. This is effected with ease and certainty, by means of a paddle wheel fixed at the bow, and turning on an axis which is parallel to the length of the vessel. This wheel is entirely immersed and therefore if constructed in the ordinary way with fixed floats, it would produce no motion, the floats on opposite sides neutralzing each other. It is therefore so arranged that the floats, when in a higher position feather, and move through the water horizontally so as to have no effect in producing motion. The floats which are at the time in a lower position produce a maximum effect. This paddle wheel offered little resistance to the progressive motion of the floating battery as the floats are made of thin sheet iron: and they present their edges to the direction in which the vessel is moved. Such an arrangement would however not be suitable with other than vessels intended to remain constantly at or very near the same place.

PRODUCTION OF DETONATING POWDER, WITH THE MATERIALS OF ORDINARY GUNPOWDER.-It has been found that the rapidity of combustion of gunpowder depends greatly on the nature of the charcoal employed; the development of this fact has been carried so far, by a suitable selection of the charcoal, that the combustion becomes so rapid as to be an explosion of the unconfined powder. This is effected by the use of carbon obtained from rice starch, the albumen of blood, or leather. With nitrate of potash such carbon forms not ordinary gunpowder but a detonating material.

LITERARY NOTICES.

SUN VIEWS OF THE EARTH; OR, THE SEASONS ILLUSTRATED. Comprising Forty-eight Views of the Earth as supposed to be seen from the Sun at different Hours and Seasons. With five enlarged Sun Views of England, and a Diagram representing the Earth's daily motion in her orbit. By Richard A. Proctor, B.A., F.R.A.S., late Scholar of St. John's College, Cambridge; and of King's College, London. Author of "Saturn and its System,' "The Constellation-Seasons," etc. (Longmans.) The changes from spring to summer, autumn, and winter, depending on the positions taken up in succession by the earth in its journey round the sun, may be represented by a series of views of the earth as it might be seen from the sun at any point of the journey. The places which the sun looks straight at will receive a full share of light and heat, those which he looks at more slantingly will receive less, and those out of his reach none at all. Mr. Proctor has devised a highly instructive and pleasing set of pictures illustrating these facts, and giving a far better notion of the cause of the seasons than any diagram we have seen. Plate I. gives four coloured views of the earth at the winter solstice (Dec. 21), at 6 a.m., 6 p.m., noon, and midnight; and at a glance it is seen how the northern regions are foreshortened and the polar portions out of the sun's sight. Plate II. has similar views representing the state of things one month later, and so on in succession through spring and summer to a month before the winter solstice, represented in Plate XII. The XIIIth Plate shows on a larger scale the way in which Great Britain, France, Holland, Denmark, etc., are presented to the sun at various periods of the year. We are glad these drawings are published at a very moderate price, because they will, with the help of the explanatory letter-press, be of great use to schools and families, and to teachers who wish to know how these matters may be made most intelligible to their pupils.

We have also received from Messrs. Longman four charts drawn by Mr. Proctor: one of the Zodiac, on which, with the help of an almanack, the paths of the moon and planets may be easily traced; another of Mars representing that planet as seen from the earth at various points of his rotation. Two other charts represent the orbits of Mars, the Earth, Venus, and Mercury; and of Neptune, Uranus, Saturn, and Jupiter. A great deal of astronomical information is compressed in these diagrams, which are well worth attentive study.

HOW TO USE THE BAROMETER, 1868. By the Rev. R. Tyas, M.A. Cantab., F.M.S., Member of the Scottish Meteorological Society. Author of " Favorite Wild Flowers," etc. (Bemrose and Sons.) The author also calls this little book "A Companion to the Weather-glass." It contains useful information about instruments, and a series of tabular forms to facilitate the registration of meteorological changes. These are very handy, though on a somewhat small scale. The author likewise does a little weather prophecying,

founded upon principles which he does not explain, but which, he asserts, have usually led to correct anticipations. He says, "Although we are unable to say positively that there will be rain in any period-say of seven or eight days-yet the probability approximates so nearly to a certainty, that we may reasonably expect rain or fair weather about the times herein stated, and this expectation leads us to watch more carefully the signs of change." Those who buy this little book may amuse themselves by testing the value of these prophecies.

PHOTOGRAPHS OF EMINENT MEDICAL MEN OF ALL COUNTRIES. With brief Analytical Notices of their Works. Edited by Wm. Tindal Robertson, M.D., M.C.P. The Photographic Portraits from Life, by Ernest Edwards, B.A. Cantab. No. 7, Vol. II. (Churchill and Sons.)-The portraits now given of this interesting series are those of Erasmus Wilson, F.R.S., Sir James Bardsley, and Dr. Thomas Hawkes Tanner. They are all good.

CLIMBING THE HILL. A Story for the Household, by the author of "A Trap to Catch a Sunbeam." (Groombridge and Sons.)— A tale by the author of so exquisite a story as "A Trap to Catch a Sunbeam," cannot fail to be welcome. The present story relates to a young couple "climbing the hill." It is gracefully told, and being published in a very handsome form, will make an appropriate new year's gift.

RAIN: HOW, WHEN, WHERE, AND WHY IT IS MEASURED. Being a Popular Account of Rainfall Investigations. With Numerous Illustrations. By G. J. Symons, F.M.S. Editor of "British Rainfall," and "Symons' Monthly Meteorological Magazine." (Stanford: Simpkin.)-This is the best book on the subject to assist in spreading a knowledge of various matters pertaining to rainfall, the methods of measuring it, and the utility of the process. Some of the tabular matter is especially interesting, such as the "Fluctuations in the Fall of Rain from 1726 to 1865," and the " Approximate mean Annual Depth of Rain at 165 Stations," in which we observe Lincoln, Southwell, and Stamford stand lowest at 20 inches, while the Stye, near Southwaite, in Cumberland, is at the head of the wet places, and shows an average of 165 inches. London stands at 24 inches, being the same as Norwich and Edinburgh. In addition to this information, we want to know the average moisture in the air, as places may have a good deal of rain distributed in heavy showers, and yet be on the average much drier than other spots where the rainfall is less, and the quantity of vapour greater. Mr. Symons points out the necessity of using the hygrometer as well as the rain-guage, and we hope that, in a few years, accurate information on the English climatology will be obtained. We agree with Mr. Symons' suggestion that local authorities should undertake the slight expense required for daily observation and records. Wind should be registered as well as rain and moisture, and so should temperature and atmospheric pressure. Magnetic and electric observations need not be so general, but should be established upon a system at public cost.

THE BOY'S OWN BOOK. A Complete Encyclopædia of Sports,

and Pastimes, Athletic, Scientific, and Recreative. A New Edition, thoroughly Revised and considerably Enlarged. (Lockwood & Co.) -We are glad to see a new edition of this book; certainly one of the best ever written for boys, and having the advantage of containing matter for boys of all ages. The new edition is a very handsome volume of nearly 700 pages, richly illustrated. It relates to all kinds of sports and pastimes, indoor and out, and mingles with cricket, archery, gymnastics, etc., directions for keeping birds, rabbits, and other domestic pets, and enough scientific recreations of various sorts to stimulate to graver studies in their proper place. It is a book we cordially recommend as a new year's gift.

ON THE MIDDLE AND UPPER LIAS OF THE SOUTH-WEST OF ENGLAND. By Charles Moore, F.G.S. Reprinted from the Proceedings of the Somersetshire Archæological and Natural History Society, Vol. XIII. 1865-6. (Taunton: F. May.)-A very useful monogram on the subject of which it treats, illustrated with seven nicely executed plates, containing numerous figures.

PROCEEDINGS OF LEARNED SOCIETIES.
GEOLOGICAL SOCIETY. - Dec. 4.

Robert Etheridge, Esq., in the chair.

Henry Alleyne Nicholson, Esq., read a paper on the Graptolites of the Skiddaw series, premising that the slates of that series corresponded with the Quebec group of Canada. He described twenty-four species.

P. Martin Duncan, Esq., M.D., described in a concluding paper the Fossil Corals of the West Indies. Dr. Duncan mentioned several curious facts in the distribution of West Indian corals, both fossil and recent, and especially the circumstance that, whilst Jamaica, San Domingo, and Guadaloupe present solitary species, mixed with those inhabiting shallow water or a reef, Antigua and Trinidad offer for consideration only reef species. In conclusion, the author drew attention to the confirmation by subsequent discoveries of his theory of an Atlantic Archipelago, which he had put forward in his earlier papers.

ROYAL MICROSCOPICAL SOCIETY.-Dec. 12.

James Glaisher, Esq., F.R.S., in the chair.

C. Stewart, Esq., read a paper describing the pedicellariæ of the Cidarida. In the discussion which ensued, Mr. Jabez Hogg stated that he had seen pedicellaria in certain star-fish pass fragments of food from one to another towards the mouth. A Fellow remarked that Agassiz had noticed their removal of fæcal matter from the neighbourhood of the anus. Mr. Stewart said that although such

actions might have been observed in certain species, many pedicellariæ were so situated as not to be capable of performing these functions, and that their real purpose was still undecided.

H. J. Slack, Esq., Sec. R.M.S., read a paper on a microscopic ferment found in red French wine, and probably being the same as M. Pasteur's mycoderma vini, though larger than that gentleman's measurements as given in "Comptes Rendus." The mycaderm he examined consisted of minute cells, which, when the wine was poured out, rose to the surface like a fine powder. It had not turned the wine sour. He succeeded in growing the penicillium glaucum from it in abundance, by simply exposing the wine to the air in a tumbler. Some of the cells placed in moist sugar and water occasioned a butyric fermentation, which seemed to be caused by their decay. After a few weeks the butyric acid and other compounds of nauseous odour disappeared, and the remaining cells then increased in number, and excited a vinegar fermentation. A mixture of the wine containing the cells with treacle and water, kept in a warm place, produced penicillium glaucum, and the fluid became only slightly acid,

NOTES AND MEMORANDA.

COMET III., 1867.-M. Hoek, of Utrecht, writes to the "Astronomische Nachrichten" as follows:-"In my researches on cometary systems, I instanced Comets III. and V., of 1859, as probably belonging to the same system. I did not hesitate to attribute to them this character, on account of the extreme resemblance of their elements, and the short interval between their appearances. Now, all of a sudden comes a new comet to supply un unexpected confirmation of these views; for the circles which represent the planes of these three orbits cross each other at the same point in the heavens. The three planes cut each other in the same line of intersection. Thus this line is necessarily parallel to the direction of the initial movement common to the three bodies at the moment they entered into the sun's sphere of attraction." M. Hoek then gives the elements of their orbits, and states his belief that they had one common origin. Their aphelion points are situated at a considerable distance from the common point of intersection, or rather from the radiating point of their orbits. Their aphelion points are all on the same side of the line of radiation. Captain Jupman, who observed this comet at Portsmouth, in October, found it equal to a star of 8.0 or 8.1 mag., with faint coma and no tail.

NEW PLANET 95).-This body was discovered by Dr. Luther, at BilkDusseldorf, on the 23rd Nov., 1867. It appears of 10 to 11 mag.

NEW STARS NEAR a LYRA.-Mr. Buckingham reports the discovery of three very minute stars near Vega. One, c, is in a line between the well-known B and the great star; e is in the same direction, on the other side of it; d is like c, near Vega, but to the left of B on the meridian. The observations were made with the large object-glasses made by Mr. Wray, one of which (new) is 21 inches in diameter, and, according to Mr. Buckingham's report, works well with powers up to 1800. c and d, in the large object-glass, are little brighter than the companion of Polaris, seen with an aperture of 1.7 inch. (See "Monthly Notices" for November.)

CONFLAGRATION COLOURS AND MOONLIGHT.-On the night of the 6th of December, the burning of Her Majesty's Theatre in the Haymarket occasioned