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Showing: 1-10 results of 127

PREFACE. This work was originally written to be delivered as a lecture; but as its pages continued to multiply, it was suggested to the author by numerous friends that it ought to be published in book-form; this, at last, the author concluded to do. This work, therefore, does not claim to be an exhaustive discussion of the various departments of which it treats; but rather it has been the aim of the author to present the more interesting... more...

THE SCIENTIFIC EVIDENCES OF ORGANIC EVOLUTION. Although it is generally recognised that the Origin of Species has produced an effect both on the science and the philosophy of our age which is without a parallel in the history of thought, admirers of Mr. Darwin's genius are frequently surprised at the ignorance of his work which is displayed by many persons who can scarcely be said to belong to the uncultured classes. The reason of this ignorance... more...

It is very easy to gain a knowledge of the stars, if the learner sets to work in the proper manner. But he commonly meets with a difficulty at the outset of his task. He provides himself with a set of the ordinary star-maps, and then finds himself at a loss how to make use of them. Such maps tell him nothing of the position of the constellations on the sky. If he happen to recognize a constellation, then indeed his maps, if properly constructed,... more...

CHAPTER I ON RAYS PROPAGATED IN STRAIGHT LINES   s happens in all the sciences in which Geometry is applied to matter, the demonstrations concerning Optics are founded on truths drawn from experience. Such are that the rays of light are propagated in straight lines; that the angles of reflexion and of incidence are equal; and that in refraction the ray is bent according to the law of sines, now so well known, and which is no less certain... more...

PART I THE SPECIAL THEORY OF RELATIVITY PHYSICAL MEANING OF GEOMETRICAL PROPOSITIONS In your schooldays most of you who read this book made acquaintance with the noble building of Euclid's geometry, and you remember — perhaps with more respect than love — the magnificent structure, on the lofty staircase of which you were chased about for uncounted hours by conscientious teachers. By reason of our past experience, you would... more...


The very high character of Mr Lavoisier as a chemical philosopher, and the great revolution which, in the opinion of many excellent chemists, he has effected in the theory of chemistry, has long made it much desired to have a connected account of his discoveries, and of the new theory he has founded upon the modern experiments written by himself. This is now accomplished by the publication of his Elements of Chemistry; therefore no excuse can be... more...

CHAPTER I. THE DISCOVERY OF THE UNIVERSE The beginning of the victorious career of modern science was very largely due to the making of two stimulating discoveries at the close of the Middle Ages. One was the discovery of the earth: the other the discovery of the universe. Men were confined, like molluscs in their shells, by a belief that they occupied the centre of a comparatively small disk—some ventured to say a globe—which was... more...

THE PRESENT CONDITION OF ORGANIC NATURE. When it was my duty to consider what subject I would select for the six lectures [*To Working Men, at the Museum of Practical Geology, 1863.] which I shall now have the pleasure of delivering to you, it occurred to me that I could not do better than endeavour to put before you in a true light, or in what I might perhaps with more modesty call, that which I conceive myself to be the true light, the... more...

THE EVOLUTION OF PHYSICS The now numerous public which tries with some success to keep abreast of the movement in science, from seeing its mental habits every day upset, and from occasionally witnessing unexpected discoveries that produce a more lively sensation from their reaction on social life, is led to suppose that we live in a really exceptional epoch, scored by profound crises and illustrated by extraordinary discoveries, whose... more...

THE FUTURE OF ASTRONOMY BY PROFESSOR EDWARD C. PICKERING HARVARD COLLEGE OBSERVATORY It is claimed by astronomers that their science is not only the oldest, but that it is the most highly developed of the sciences. Indeed it should be so, since no other science has ever received such support from royalty, from the state and from the private individual. However this may be, there is no doubt that in recent years astronomers have had granted to... more...