laws of health are now attracting to an unusual extent the attention both of the public and of the British Government. The classified records of deaths and their causes, which have of late years been kept by the Registrar-General, led to the discovery that the rate of mortality varied greatly in different localities, so much so that the deaths in some places exceeded by ten, twenty, thirty, and even forty per cent. the number in others, and it was found, on investigation, that the causes of such excess were easily removable by the application of obvious and natural means. A sanitary commission was therefore appointed to consider the application of these means, which consist of draining, ventilation, warmth, habits of cleanliness, and temperance, and so forth; and year after year the reports of this commission repeated that the application of such means was obstructed and all efforts rendered nugatory by the prevalent ignorance among all classes of the natural conditions of health, -an ignorance which prevented the advantages of sanitary measures from being either understood or appreciated. The Government was, therefore, advised to introduce physiology into the common schools of the country, and a remarkable paper was drawn up and signed by sixty-five of the leading physicians and surgeons of London, including the principal teachers of anatomy and physiology, in which are the following words: 'We are therefore of opinion that it would greatly tend to prevent sickness, and to promote soundness of body and mind, were the elements of physiology in its application to the preservation of health made a part of general education.' And here I may refer to the example of America. In no State has the educational system been more carefully or successfully matured than in Massachusetts, and among the general laws of public instruction passed by the Legislature of that State is an 'Act requiring physiology to be taught in the public schools.' The Committee of Council on Education in Great Britian have coöperated with the Board of Trade in the endeavor to introduce physiology into our schools, and a system of instruction has been devised, which has been described by high authority as 'sound and scientific in its basis and character, although limited in extent and popular in expression.' Now if a better knowledge of the laws of health is desirable for all classes, surely it is most desirable for those who are engaged in manufactures and occupations which are too likely to affect health injuriously. If health is essential to the happiness and enjoyment of all men, how much is the importance of that blessing increased in the case of the man who is dependent, not only for enjoyment and happiness, but for the main

tenance and lodging and clothing of himself and his family, upon the active and constant exercise of his bodily powers."

Among the grants of money made at the last meeting of the British Association was one of $500 to Mr. Robert Mallet, in aid of what may be called volcanic experiments. Mr. Mallet has recently made public, in two portly illustrated octavos, a report on the last great earthquake in the Neapolitan territory, and on seismology in general; and, by way of supplementing those researches, he proposes to descend into the crater of Vesuvius, and ascertain by instrumental means the temperature of the active vents, and the quantity of aqueous vapor thrown out. From the quantity of vapor it will be possible to infer the quantity of water which has infiltrated down to the focus of the volcanic action, and from this and other data conclusions may be drawn of great importance to physical science.

The great work which has been progressing for four years past, under the direction and at the expense of the Royal Society (G. B.), namely, the cataloguing of the titles of all the papers and reports published in "The Transactions and Proceedings of Scientific Societies," and in scientific periodicals from all parts of the civilized world, from 1800 to 1860, inclusive, is so nearly complete that it will probably be finished during the year 1863. The work is at present in manuscript, and sixty-two volumes are already accessible for reference in the Society's library. The titles are copied in quadruplicate. When complete, the enterprise will be as meritorious to the Royal Society as it will be useful to all engaged in scientific pursuits. Many a student wastes time and labor through ignorance of what has been already achieved in the several departments of science; and none but those who have endeavored to explore the accumulated mass of scientific periodicals can judge of the weariness and hopelessness of the search. For the sake of all concerned we hope that the Royal Society will not remit their efforts until their great catalogue shall be printed and published at a reasonable price.

An important addition to astronomical literature has been made during the past year, in the publication of a very full and detailed "Account of the Great Comet of 1858," by Prof. G. P. Bond; the whole forming Vol. iv. of the Annals of the Observatory of Harvard College. The work- a large quarto contains fifty-one engravings, many of large size, in which the comet is represented under every aspect during the whole period of its visibility, two hundred and seventy-five days. In twenty-two of these the comet is shown as it appeared to the naked eye, and in twenty others as observed by

the telescope, the effect being assisted by the tinted paper on which the engravings are printed. Mr. Bond has, moreover, taken into his narrative the results obtained by other observers in all parts of the world, and has thus produced the most complete history of Donati's Comet that has yet been written, and, we may say, the most attractive.

The publication of a splendid work, in large folio, entitled "The Satellite," has been commenced in London, by Dr. A. D'Orsan; the chief feature of which is the photographic delineation of the moon. The whole is to be finished in twelve parts. The following are extracts from the preface: "Detail being my principal object, large photographs of various separate spots are given, in addition to those which, taken at different periods of lunation, contain at once many spots and regions, and represent them under different aspects. From the guidance and instruction these afford, together with the fact of their presenting one and the same spot under various degrees of illumination, and consequently diverse appearances, elaborate drawings, founded on many years' observations, will be given, exhibiting approximately the real outline of each respective spot. . . Those photographs of the various lunar parts that have been taken at one and the same period of lunation are also joined together, and thus correct maps are given of the several phases. . . The photographs are all on a scale never before executed, — probably never before attempted."

School maps, as commonly printed, have either so many black lines as to be scarcely legible, or so few as to afford but scanty information to the student. Nor need one wonder at this defect. The text which a map should yield is so various, first, as to the visible nature, the shape of country, the hills and valleys, the lakes and rivers, the woods and plains; next, as to the visible work of man,— the cities and towns, the castles and fortresses, the ports and harbors, the roads and railways and canals, the mines and quarries and sea-works; then the political facts, such as the division into states, counties, and towns,—that it is found impossible to indicate all these facts, without crowding, on a single sheet. To obviate these difficulties, Messrs. Longman & Co., the well-known London publishers, have recently brought out maps on England and Wales on a new plan; i. e., that of treating each group of facts on a separate sheet. It is claimed that in this way, and in this only, the great end of clearness is attained.

The most important event in the scientific and industrial history of the past year was undoubtedly the Great International Exhibition of

the Industry of all Nations, which continued open in London from May to November inclusive, and of the leading characteristics of which very full notices have been given elsewhere in the present volume. M. Michel Chevalier, the distinguished French political economist, in a preface to the "French Jurors' Report," considers that this and other similar international exhibitions exercise their greatest influence for good by the opportunity they afford to nations of taking reckonings of their industrial progress; and, from a comparison of the results shown in the Exhibition of 1862 with those of the French International Exhibition of 1855, and the London one of 1851, he concludes the producing powers of mankind, or, in other words, the amount of work that one man can perform in a given time, is continually on the increase. This result he attributes to improvements in and to the more extended use of machinery, driven by water and steam power; and he gives some interesting illustrations confirmatory of his conclusion. Thus, in the manufacture of iron, M. Chevalier finds that the productive power of man has increased in six centuries to so great an extent that a man can now produce six hundred tons of iron in the same time as was required to produce one ton six hundred years ago. Again, in the production of cotton yarn, dating from 1769, when Arkwright took out his first patent, one man can now spin 400 times more yarn than the best spinner of that period. In grinding grain and making flour one man can do 150 times more work than he could perform one century ago; and in the manufacture of lace one woman can produce as much work in a day as one hundred women could execute a hundred years ago. In the refining of sugar, the whole of the operations last only as many days as it required months about thirty years since. The manufacture of looking-glasses with an amalgam of mercury and tin once occupied six weeks in fixing the amalgam on a large glass; the present process occupies only forty minutes. The engines of a first-class ironclad frigate perform as much work in twenty-four hours as 42,000 horses.

The recent progress made in the working of iron and steel, as shown in the recent International Exhibitions, is so wonderful as also to deserve notice. In the London Exhibition of 1851, the largest mass of rolled iron exhibited was a round bar or roll, weighing a ton and a half; and this was regarded as something extraordinary and deserving of special mention. At the Exhibition of 1862, rolled-iron armor-plates were shown, exceeding thirteen tons in weight. In the Exhibition of 1851, M. Krupp, the celebrated steel manufacturer of

Germany, exhibited a small steel cannon as the most notable achievement hitherto effected in this branch of metallurgy. Four years subsequently, in 1855, M. Krupp sent to the Paris Exhibition a steel ingot that weighed five and one-half tons; while to the one held last year in London he sent a crank axle that weighed no less than twenty tons.

Some extracts gleaned from a recent report by Mr. Fairbairn, the eminent English engineer, on the steam " Machinery of the London Exhibition of 1862," will also be found interesting in this connection. Mr. Fairbairn states "that in 1859 the steam engines employed in the various factories, steamships, and locomotives of Great Britain amounted to 10,950,000 horse power, but that at the present time this sum has increased to 12,000,000 horse power, and this may be taken as the steam motive force in the British Islands."

Mr. Fairbairn further goes on to say, "that nearly all engines at the present time work the steam expansively; that is to say, they are so arranged in the construction of the valve motions as to cut off the communication with the boiler at one-third, one-half, or two-thirds of the stroke, as the case may be, in regard to pressure, or the power to overcome the resistance of the load. Some engineers go so far as to cut off the steam at one-sixth and one-eighth, and expand the remaining five-sixths or seven-eighths of the stroke. Formerly the principle of expansive working was very imperfectly developed; but that system is now thoroughly understood, and is in almost every case resorted to. The result of its introduction has been an immense economy; for the quantity of work now done with the same quantity of fuel is more than double what was formerly accomplished on the old non-expansive principle. It must, however, be borne in mind that this cannot be effected without an increase of the pressure of steam, and hence follows the necessity of having the boilers of increased strength and improved construction. The neglect of these precautions has resulted in serious and fatal accidents, attended with a considerable loss of life and property. Irrespective of increased pressure, and working the steam expansively, the speed of the engine has been increased about one-third since the days of Watt. In his time the piston of the stationary engine travelled at the rate of two hundred and forty feet per minute; now it averages from 300 to 320 feet; and this, combined with high-pressure steam worked expansively, increases the power of the engine, in some cases, upwards of two-fold, and, as already stated, doubles the quantity of work done with the same quantity of fuel. Thus an important saving is effected to this