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...

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...

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...

V. GALILEO AND THE NEW PHYSICS After Galileo had felt the strong hand of the Inquisition, in 1632, he was careful to confine his researches, or at least his publications, to topics that seemed free from theological implications. In doing so he reverted to the field of his earliest studies—namely, the field of mechanics; and the Dialoghi delle Nuove Scienze, which he finished in 1636, and which was printed two years later, attained a... more...

CHAPTER I. THE ASTRONOMICAL OBSERVATORY. Early Astronomical Observations—The Observatory of Tycho Brahe—The Pupil of the Eye—Vision of Faint Objects—The Telescope—The Object-Glass—Advantages of Large Telescopes—The Equatorial—The Observatory—The Power of a Telescope—Reflecting Telescopes—Lord Rosse's Great Reflector at Parsonstown—How the mighty Telescope is... more...

CHAPTER I. INTRODUCTORY. The Sun. The sun's position in the great field of energy is daily becoming more exalted in the estimation of philosophic minds. His labors are being revealed to us with a distinctness never before conceived. He it is that stored the coal in the bosom of the earth, and piled up the polar ice. He it is that aids the chemist, drives the engine, ripens the harvest, dispenses life and health. The study of the sun and solar... more...

Some thousands of years ago there was a city in Mesopotamia called Surippak. One night a strange dream came to a dweller therein, whose name, if rightly reported, was Hasisadra. The dream foretold the speedy coming of a great flood; and it warned Hasisadra to lose no time in building a ship, in which, when notice was given, he, his family and friends, with their domestic animals and a collection of wild creatures and seed of plants of the land,... 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...

Biographical Sketch of Nikola Tesla.   While a large portion of the European family has been surging westward during the last three or four hundred years, settling the vast continents of America, another, but smaller, portion has been doing frontier work in the Old World, protecting the rear by beating back the "unspeakable Turk" and reclaiming gradually the fair lands that endure the curse of Mohammedan rule. For a long time the Slav... more...

INTRODUCTORY NOTES The author in this work endeavours to solve the greatest scientific problem that has puzzled scientists for the past two hundred years. The question has arisen over and over again, since the discovery of universal gravitation by Sir Isaac Newton, as to what is the physical cause of the attraction of gravitation. “Action at a distance” has long ceased to be recognized as a possible phenomenon, although up to the... more...