FEW persons care to study logic, because everybody conceives himself to be proficient enough in the art of reasoning already. But I observe that this satisfaction is limited to one’s own ratiocination, and does not extend to that of other men.
¹This sketch is condensed from lectures originally written for delivery to an audience of engineers and mechanics, at the Stevens Institute of Technology, in the winter of 1871—’72, and from lectures since prepared for classes in the Department of Mechanical Engineering, and revised to date.
WHEN the details of knowledge had in modern times accumulated to so great an extent as to demand some organization of them into principles, thoughtful men cast about for some law which might serve to relate and connect together, in part at least, the multitude of facts and theories which were in an isolated and incoherent state.
THE Troglodytes or Cave-dwellers of ancient Nubia belonged to a tribe which seems to have formed an intermediate link between the Semitic and Ethiopian races, but which has become entirely extinct before the second century of the Christian era.
EACH of the stars which glitter in the depths of space is a voluminous and massive sun like that which gives light to our earth. Distance alone reduces them to the appearance of fixed points. If we could approach any one of them we should experience the same impression as in passing from Neptune to the sun; the star would increase in size as we should approach it ; it would soon exhibit a circular disk and continue to increase its proportions until they would be as large as the sun ; finally, this luminous disk, continuing to increase in consequence of our approach, would expand and present itself as a fiery furnace filling the entire heavens—a colossal blaze, under which we would be reduced to nothing, melted like wax, vapor ized like a drop of water dropped on red-hot iron ! Such is every star in the heavens.
COULD a man do himself up into a mathematical point and throw himself into the middle of infinite empty space, wherever that is, he would be surprised at the flatness of life under such circumstances. Infinite empty space is absolute sameness.
CONCERNING the Glacial period, geologists hold the most varied opinions, both with regard to its origin and to the mode of action of the ice. Thus at the very threshold of the geological record we tread on uncertain ground, and every guide points to a different path.
A POPULAR error has long existed as to the real character of short-sightedness ; and even medical men have to some extent participated in it. It is not an indication of strength of vision. It is a disease, always inconvenient, and sometimes dangerous.
THE extinction of many animals that are known to have formerly existed on the earth is a subject which cannot very easily be explained, while the number of them is greater than at first sight would be supposed. Various species no doubt undergo gradual extinction by changes which deprive them of their accustomed food ; but others seem to die out from unknown causes.
OPALLID spectre of the midnight skies! Whose phantom features in the dome of Night Elude the keenest gaze of wistful eyes Till amplest lenses aid the failing sight, On heaven’s blue sea the farthest isle of fire, From thee, whose glories it would fain admire, Must vision, baffled, in despair retire!
THE publication of an elaborate life of Servetus in English at the present time will be welcome to many readers, who at present know little more of the man than that he was burned at the stake at Geneva, at the instigation of John Calvin, three hundred and twentyfive years ago.
SIR : Returning a day or two ago to Columbus at the end of our vacation, I last night took up the September number of THE POPULAR SCIENCE MONTHLY. Therein is a letter from Evanston, Illinois, in which some of Prof. Schneider’s mistakes, in his article on “ The Tides,” are pointed out.
IT is a great mistake to suppose that all the influences exerted on the mind by scientific study are necessarily of a widening or liberalizing character. There is an immense amount of legitimate scientific work that does not tend to produce any such effect, but, on the contrary, has a narrowing and cramping influence upon the intellect.
THE Holy Roman Empire dates from the year 800 A. D, when a king of the Franks was crowned Emperor of the Romans by Leo III. ; and it is on the inner nature of this empire, as the most signal instance of the fusion of Roman and Teutonic elements in modern civilization, that the author dwells, treating of the influence which it exercised over the minds of men, and the causes that gave it power ; speaking less of events than of principles, and describing the empire, not as a state, but as an institution created by and embodying a wonderful system of ideas.
“ A New Type of Steam-Engine.”—Prof. R. H. Thurston read a paper at the Nashville meeting of the American Association on “ A New Type of Steam-Engine,” a report of which we find in the American Manufacturer. The author first gave a history of the steam-engine from Hero’s time ; then he discussed the modern type of steam-engine, pointing out its shortcomings ; finally he proposed a new type, designed to prevent loss of heat-energy.
IT has been found by Lechartier and Bellamy that zinc is constantly present in appreciable quantities in the liver of the human subject and of many lower animals. It also occurs in hen’s-eggs, in wheat, barley, and other grains. These facts are of interest for forensic medicine.