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We will commence with the series of Magnets, which are prepared for the daily illustration of some of the appearances and effects of electromagnetical and magneto-electrical phenomena. The Electro-Magnet, possessing neither Electricity nor Magnetism, until excited by a very small voltaic battery; it then instantly acquires an enormous power of suspension: on destroying its connexion with the battery, it becomes again unable to support a grain. Another of the same kind, and called the Ferro-Electric Sphere, arranged to show the true cause of the Earth's Magnetism. A third, is a Self-acting Electro-magnetic Machine ; in this also Electricity excites Magnetism, producing motion in a spindle, and by an ingenious contrivance, which effects an alternation in the poles, continues this motion, and gives out an uninterrupted succession of sparks and shocks for an indefinite period. The Magneto-Electric Machine, in this combination Magnetism produces Electricity. This instrument was made in consequence of Professor Faraday's important discovery, that electricity could be obtained by means of magnetism ; and was the actual one from which the first spark was first produced and seen in England. It now exhibits the spark most brilliantly and incessantly,–gives an intolerable shock,-decomposes water,-ignites and fuses platinumwire, &c.
There is also an instrument which belongs to a department yet scarcely explored by scientific research, and one which we fear is too often passed unheeded; we allude to an apparatus for showing the Compressibility of Fluids by means of hydrostatic pressure which can be produced in this machine to the unprecedented amount of 30,000 lbs. to the square
inch. The celebrated Steam-Gun is too well known,--and the unceasing interest it excites, far too generally admitted to require any particular notice. We shall, therefore, merely observe, en passant, that a new barrel has lately been added, which increases the power and the precision of the instrument.
The unique engine for showing the Combustion of Steel, is also well worthy the attention both of the curious or the general observer; although the almost inconceivable velocity with which the wheel rotates, may, naturally, at the first moment excite some alarm.
Amongst the philosophical apparatus possessed by the Society, may be mentioned a Lens or Burning-Glass of nearly four feet diameter. A Cal-oxi-hydrogen Microscope of great power and unrivalled splendour, constructed by Cary, with various consecutive improvements made under the superintendence of the Society; and a Laboratory-intended to facilitate the advance of science and practical knowledge.
The Society receive for exhibition-Models of Inventions-Works of Art and Specimens of Novel Manufacture, subject to immediate delivery in the event of sale, or return on demand; free from any charge whatever to their depositors. It also affords every facility for the practical demonstration of discoveries in Natural Philosophy, or of any new application of known principles to Mechanical Contrivances; reserving only to the Council, the right of determining whether the productions offered are suitable to the Institution.
We shall, in future Numbers, refer to a class of apparatus, for illustrating one of the most attractive branches of Natural Philosophy, namely, Optics; but we have already exceeded our limits, and must not now dwell on them : still less can we advert to the numerous Minerals, Fossils, Paintings, and other objects of Arts, or to the extensive variety of Nautical, Mechanical, Architectural, and other Models. Indeed, it would be foreign to our purpose to enter into any detailed account of the objects in this interesting Collection: this comes more especially within the scope of the Catalogue, in which the Principles of Science, connected with the various models referred to, are familiarly and concisely defined. Our only endeavour has been to throw a cursory glance over its origin, general features, and peculiar character, to bring under the notice of our readers its objects and its tendency, and to show that it is what it professes to be, a GALLERY FOR THE ILLUSTRATION AND ENCOURAGEMENT OF PRACTICAL SCIENCE.
The Society, anxious to extend the utility of the Establishment to the utmost possible degree, directed by an Order of Council, in September, 1835, that a Circular be addressed to all “the scientific and learned Institutions in the empire, proposing to furnish them with the descriptive catalogues of the Establishment, free of expense; inviting the communication of interesting objects for public exhibition; and requesting any suggestions that the local knowledge of the Members of such Societies might enable them to make for the advancement of the Institution, and the instruction and gratification of the Public.”
Number of persons who visited the Gallery in 1835, exclusive of annual subscribers, proprietors, proprietors’ admissions, and free admissions to artists, depositors, and men of science,-80,375.
ON THE NATURE, EVIDENCE, AND ADVANTAGES OF THE
The Inductive Philosophy stands forth as the distinguishing boast of modern intellectual advancement, and the most prolific source of innumerable advantages,-mental, moral, and physical. It has opened the path now universally recognised as alone leading to the correct interpretation of Nature; of that stupendous order of varied existence, and incessant activity of causation, with which we are surrounded and filled. It is justly characterized as a method framed in conformity to experience; and stands essentially opposed to those artificial systems of former ages, which were but the vain chimeras of minds bewildered in the obscurities of verbal mysticism, or deluded by the conceits of gratuitous hypothesis, systems which cramped all energy of thought and invention, and fettered all freedom of opinion and discussion. By a combination of vague and unmeaning abstractions, involved in a pedantic jargon of empty terms, the scholastic disputants thought to settle the order of natural causes, and determine what must be the character of physical laws.
From a few abstract, and those hardly intelligible, arbitrary positions, they affected to advance, by the mere subtilty of their reasoning powers, to a comprehension of the entire system of the material universe.
But the appeal to experiment and observation, and the high and pure physical philosophy inculcated by Bacon, and practically followed up by Galileo, Newton, and their successors, soon established the dominion of principles, at once more correct and rational, and better suited to the limited range of the human faculties. By the humble unpretending path of the inductive method, all the great triumphs of physical discovery have been achieved; by a steady adherence to its principles, can we alone expect the further extension of natural knowledge ; and so long as they are adhered to, we can assign no limit to the progressive advance which may be made. And minds duly impressed with the sublimity of those inquiries which the contemplation of nature suggests, will easily be led to recognise the truth and value of the inductive method. They perceive, in reference to observation and experience, an appeal to the sole testimony of nature: they would interrogate her in her own language, and in the replies to those interrogatories, afforded by experimental results, acknowledge the only real and legitimate authority by which the comprehensive truths and laws of the material world can be successfully elicited and established ; and by which simplicity and order are educed out of the vast mass, and (as might appear) inextricable complexity of accumulated phenomena.
It is not, however,our intention to go on with a mere string of encomiums on the Inductive Philosophy. Its claims are now generally allowed, and its praises held forth; still, not unfrequently, its advocates and encomiasts entertain very indistinct notions of the real nature of the system they support. At all events, in the study of Natural Science, it must be allowed to be a branch of no small interest and importance to examine carefully the nature of the reasoning, and the general grounds of the
evidence, by which experimental laws, and physical truths, are substantiated; and this, in fact, is what is meant by the expressions so commonly used by writers and teachers, “ the inductive method,” “ the inductive logic," "experimental evidence," and the like. Such phrases, perhaps, pass current by the influence of custom ; but it will be both an interesting and profitable topic of investigation, if we analyze their meaning a little more closely, and endeavour to exemplify and elucidate the nature of our convictions and inferences, in these branches of knowledge, the degree of certainty of which they are susceptible; and the sources of failure and error to which we are most exposed in the prosecution of physical inquiry, without some well-grounded principles of this kind as our guide.
We propose, therefore, to devote, in several successive Numbers, a small space to the continued portions of an Essay on the nature, use, and advantages of Inductive Science; and in following out this design, without restricting ourselves to too formal and technical a method, our first object will be to examine briefly the real nature of the inductive process : to illustrate, by familiar examples, wherein the most essential and characteristic features of inductive evidence consist, as distinguished on the one hand from the mere evidence of our senses, and on the other from demonstration.
We will merely observe for the present, that although this is a part of the subject properly belonging to the province of our Journal, yet we are aware it may be imagined likely to prove abstruse and dry; we therefore beg to assure our readers that we have no intention to lose ourselves and disgust them in logical subtilties and metaphysical abstractions: such we trust will be far from the case. We shall merely entreat the patience of the student while we lay down a very few elementary distinctions, which we deem essential to a right understanding of the subject, and shall then proceed to those more general deductions, which will receive abundant exemplification by references to the actual progress which Science has made, or has failed to make, precisely as these great rules of inductive evidence, (which we may, without much impropriety of language, term the logic of nature,) have been observed or disregarded.
ON THE TIDES;
AND THE RECENT PROGRESS OF OUR KNOWLEDGE RESPECTING THEM.
AMONG those grand subjects of contemplation and inquiry which the natural world presents to us, there are perhaps few at once more calculated to excite our curiosity and admiration, and of more practical interest, than the phenomena of the TIDES. To witness, from day to day, at a certain regular succession of hours, an enormous body of water advancing by slow degrees, defying all barriers which may be opposed, until it reaches a certain elevation, and then as regularly falling and retreating ; its very apparent irregularities being soon found to conform themselves to regular periods; and all this without any apparent cause acting to produce it;
and going on with unceasing regularity not merely in one place, but all over the world. These, truly, ought to be among the phenomena most powerfully claiming our attention, and prompting inquiry into their causes and laws. But further, when we look at the great practical importance of the subject,--at the immense utility of these vast fluctuations in the economy of nature, as well as in reference to the
of human arts, their importance to the navigator, and their influence on commerce, it becomes, beyond question, manifest how large a share of interest the subject ought to call forth, and with what care it would be reasonable to expect it should be investigated. Yet we shall find that, until of very late years, it has been singularly ill attended to. The ancients had of course noticed the phenomena, and some philosophers had thrown out vague surmises that the cause of it was due to the action of the sun and moon: but there their speculations terminated. On the revival of learning and science, we find several philosophers hinting at the nature of the cause of the Tides, though no one gave anything like a satisfactory explanation till Newton. He perceived at once that the phenomenon was, at least in its more general features, a simple consequence of his principle of universal gravitation acting between the sun, the moon, the solid earth, and the waters of the ocean.
The great characteristic of gravitation is an attraction, or drawing, of every particle of matter in the universe towards every other particle ; aggregated masses, drawing of course in proportion to their masses; and the intensity, or degree in which they draw each other, increasing exactly in proportion as the squares of the numbers measuring their distances, lecrease. The sun, being a large mass, but at a great distance, attracts the moon, earth, and water; the earth attracts the moon, which is revolving at a certain distance about it, and the water, which is retained in a certain degree of adherence to it, though in a certain degree free to
The moon attracts the earth, as the larger mass, more than it does the water, which is less. If the globe were entirely surrounded by water, the portion of water next the moon would be attracted by the moon, as being nearest; the body of the earth next, as being the largest; and the mass of water on the other side least, as being smaller and also more distant. Thus there would be a rise or swelling out of water on the side towards the moon, and another rise or swelling out on the side away from the moon: the first mass of water being drawn away from the earth; the earth being drawn away from the second. The sun, being at an immensely greater distance, has a less powerful action, but of the same kind. As the earth revolves in twenty-four hours on its axis, any one point on its surface is brought once under the moon, and once into the position opposite ; and at each position, experiences the rise or protuberance of the waters just spoken of; in other words, two daily tides, or high water twice in every twenty-four hours. Such is the elementary conception of the matter which was developed in a general way by Newton. But though these general principles are sufficiently simple, and require nothing further for their comprehension than a clear notion of the nature of the law of universal gravitation, yet, for the complete mathematical analysis of the problem, when pursued into all its