THE fifteenth meeting of the American Association for the Advancement of Science was appointed to be held at Nashville, Tennessee, April, 1861; but, owing to the breaking out of the civil war, the meeting was necessarily postponed to some future and more auspicious occasion.

The thirty-first annual meeting of the British Association for the Advancement of Science was held at Manchester, September, 1861, Mr. William Fairbairn, the eminent engineer, being in the chair.

This meeting appears to have exceeded all others before held, in the numbers present, in the amount of general and local subscriptions (upon which the efficiency of the Association in promoting investigations mainly depends), in the value and number of the papers read, in the interest of the personal discussion, and in the excellence and variety of the evening discourses. Among the lectures of special interest was one by Professor Airy, the Astronomer Royal, "On the Solar Eclipse of 1860,” and one by Prof. Miller, on the recent remarkable researches of Bunsen and Kirchhoff on 66 Spectrum Analysis;" abstracts of both being given in this volume. The subjects which commanded most general attention, however, among those brought before the Association, were the "Origin and Antiquity of Man" and "Iron-plated Ships." The next meeting was appointed to be held at Cambridge, when the Prince of Wales is expected to take the chair.

From the annual address of the President, which was mainly a review of the recent progress of science, we make the following

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"Were I to enlarge on the relation of the achievements of science to the comforts and enjoyments of man, I should have to refer to the present epoch as one of the most important in the history of the world. At no former period did science contribute so much to the uses of life and the wants of society. And in doing this it has only been fulfilling

that mission which Bacon, the great father of modern science, appointed for it, when he wrote, that 'the legitimate goal of the sciences is the endowment of human life with new inventions and riches,' and when he sought for a natural philosophy which, not spending is energy on barren disquisitions, 'should be operative for the benefit and endowment of mankind.'


Looking, then, to the fact that, whilst in our time all the sciences have yielded this fruit, I shall probably best discharge the duties of the office I have the honor to fill by stating, as briefly as possible, the more recent scientific discoveries which have so influenced the relations of social life.

"The history of man, throughout the gradations and changes which he undergoes in advancing from a primitive barbarism to a state of civilization, shows that he has been chiefly stimulated to the cultivation of science, and the development of his inventive powers, by the urgent necessity of providing for his wants and securing his safety. There is no nation, however barbarous, which does not inherit the germs of civilization, and there is scarcely any which has not done something towards applying the rudiments of science to the purposes of daily life.

"Again, if we compare man as he exists in small communities with his condition where large numbers are congregated together, we find that densely-populated countries are the most prolific in inventions, and advance most rapidly in science. Because the wants of the many are greater than those of the few, there is a more vigorous struggle against the natural limitations of supply, - a more careful husbanding of resources; and there are more minds at work.

"Astronomy. Without tracing the details of the history of astronomical science, we may notice that in more recent times astronomical discoveries have been closely connected with high mechanical skill in the construction of instruments of precision. The telescope has enormously increased the catalogue of the fixed stars, or those landmarks of the universe,' as Sir John Herschel terms them, 'which never deceive the astronomer, navigator, or surveyor.' The number of known planets and asteroids has also been greatly enlarged. The discovery of Uranus resulted immediately from the perfection attained by Sir William Herschel in the construction of his telescope. More recently, the structure of the nebulæ has been unfolded through the application to their study of the colossal telescope of Lord Rosse.

"Our knowledge of the physical constitution of the central body of our system seems likely, at the present time, to be much increased. The spots on the sun's disk were noticed by Galileo and his contem

poraries, and enabled them to ascertain the time of its rotation, and the inclination of its axis. They also correctly inferred, from their appearance, the existence of a luminous envelope, in which funnelshaped depressions revealed a solid and dark nucleus. Just a century ago, Alexander Wilson indicated the presence of a second and less luminous envelope beneath the outer stratum; and his discovery was confirmed by Sir William Herschel, who was led to assume the presence of a double stratum of clouds, the upper intensely luminous, the lower gray, and forming the penumbra of the spots. Observations during eclipses have rendered probable the supposition that a third and outermost stratum of imperfect transparency encloses concentrically the other envelopes. Still more recently, the remarkable discoveries of Kirchhoff and Bunsen require us to believe that a solid or liquid photosphere is seen through an atmosphere containing iron, sodium, lithium, and other metals in a vaporous condition.

"Magnetism. Guided by the same principles which have been so successful in Astronomy, its sister science, Magnetism, emerging from its infancy, has of late advanced rapidly in that stage of development which is marked by assiduous and systematic observation of the phenomena, by careful analysis and presentation of the facts which they disclose, and by the grouping of these in generalizations, which, when the basis on which they rest shall be more extended, will prepare the way for the conception of a general physical theory, in which all the phenomena shall be comprehended, whilst each shall receive its separate and satisfactory explanation.

"To refer to a single instance of the elucidation of magnetic phenomena, we have seen those magnetic disturbances· - so mysterious in their origin, and so extensive in simultaneous prevalence, and which less than twenty years ago were designated by a term specially denoting that their laws were wholly unknown-traced to laws of periodical recurrences; revealing, without a doubt, their origin in the central body of our system, by inequalities which have for their respective periods the solar day, the solar year, and, still more remarkably, an until lately unsuspected solar cycle, of about ten of our terrestrial years, to whose existence they bear testimony, in conjunction with the solar spots, but whose nature and causes are in all other respects still wrapped in entire obscurity. We owe to General Sabine, especially, the recognition and study of these and other solar magnetic influences, and of the magnetic influence of the moon, similarly attested by concurrent determinations in many parts of the globe, which are now held to constitute a distinct branch of this science, not inappropriately named celestial,' as distinguished from purely terrestrial magnetism.

"Chemistry. The most remarkable advance in this science is that made by Bunsen and Kirchhoff, in the application of the colored rays of the prism to analytical research. We may consider their discoveries as the commencement of a new era in analytical chemistry, from the extraordinary facilities they afford in the qualitative detection of the minutest traces of elementary bodies. The value of the method has been proved by the discovery of the new metals, cæsium and rubidium, by M. Bunsen; and it has yielded another remarkable result, in demonstrating the existence of iron, and six other known metals, in the


"I must not, however, pass over in silence the valuable light which chemistry has recently thrown upon the composition of iron and steel. Although Despretz demonstrated many years ago that iron would combine with nitrogen, yet it was not until 1857 that Mr. C. Binks proved that nitrogen is an essential element of steel, and more recently M. Caron and M. Fremy have further elucidated this subject; the former showing that cyanogen, or cyanide of ammonium, is the essential element which converts wrought iron into steel; the latter combining iron with nitrogen through the medium of ammonia, and then converting it into steel by bringing it, at the proper temperature, into contact with common coal-gas. There is little doubt that in a few years these discoveries will enable Sheffield manufacturers to replace their present uncertain, cumbrous, and expensive process by a method at once simple and inexpensive, and so completely under control as to admit of any required degree of conversion being obtained with absolute certainty. Mr. Crace Calvert also has proved that cast-iron contains nitrogen, and has shown that it is a definite compound of carbon and iron, mixed with various proportions of metallic iron, according to its


"Geology. It is little more than half a century since Geology assumed the distinctive character of a science. Taking into consideration the aspects of nature in different epochs of the history of the earth, it has been found that the study of the changes at present going on in the world around us enables us to understand the past revolutions of the globe, and the conditions and circumstances under which strata have been formed, and organic remains imbedded and preserved. The geologist has increasingly tended to believe that the changes which have taken place on the face of the globe, from the earliest times to the present, are the result of agencies still at work. But whilst it is his high office to record the distribution of life in past ages, and the evidence of physical changes in the arrangement of land and water, his results hitherto have indicated no traces of its beginning, nor have they afforded evidence of the time of its future duration.

"Applied Mechanics. During the last century the science of Applied Mechanics has made strides which astonish by their magnitude; but even these, it may reasonably be hoped, are but the promise of future and more wonderful enlargements."

Referring to the progress of steam navigation, Mr. Fairbairn remarked, "that the paddle-wheel system of propulsion has maintained its superiority over every other method yet adopted for the attainment of speed, as by it the best results are obtained, with the least expenditure of power."

"Great changes in the cultivation of the soil are undoubtedly destined to be effected by the steam-engine. It is but a short time since it was thought inapplicable to agricultural purposes, from its great weight and expense. But more recent experience has proved this to be a mistake; and already in most districts we find that it has been pressed into the service of the farm. The small locomotive, mounted on a frame with four wheels, travels from village to village, in Great Britain, with its attendant, the thrashing-machine, performing the operations of thrashing, winnowing, and cleaning, at less than one half the cost by the old and tedious process of hand labor. Its application to ploughing and tillage on a large scale is, in my opinion, still in its infancy; and I doubt not that many members of this Association will live to see the steam-plough in operation over the whole length and breadth of the land. Much has to be done before this important change can be successfully accomplished; but with the aid of the agriculturist in preparing the land so as to meet the requirements of steammachinery, we may reasonably look forward to a new era in the cultivation of the soil.

"Iron Ship-building.—In iron ship-building, an immense field is opening before us. Our wooden walls have, to all appearance, seen their best days; and as one of the early pioneers in iron construction, as applied to ship-building, I am highly gratified to witness a change of opinion that augurs well for the security of the liberties of the country. From the commencement of iron ship-building, in 1830, to the present time, there could be only one opinion amongst those best acquainted with the subject, namely, that iron must eventually supersede timber in every form of naval construction. The large ocean steamers, the Himalaya,' the 'Persia,' and the Great Eastern,' abundantly show what can be done with iron; and we have only to look at the new system of casing ships with armor-plates to be convinced that we can no longer build wooden vessels of war with safety to our naval superiority and the best interests of the country. I give no opinion as to the details of the reconstruction of the navy; but I may state that I

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