Various

“ And the boilermaker, if he be dishonest, is doubly tempted if the broad width of a continent intervenes between him and the farmer for whom his work is intended, and if in the place where the boiler is to be used there are no inspection laws in force. The farmer who lives many miles from a city, and who has no means of testing any boiler he may purchase, is wholly at the mercy of the boilermaker, and must run it until it explodes or time proves it to have been honestly made. ”

“ On a clear, cloudless night, when nothing seems to interfere with the brightness of the stars, we cannot, by looking upward, perceive any moisture present in the atmosphere; but if we cast our eyes to the horizon, whereby we see through the mass of atmosphere endwise, as it were, and note the appearance of the stars there, or the rising or setting moon, we will see that the atmosphere there gives a redness to the rising body, which it does not have when it has ascended to mid-heaven. ”

“ In order to understand the color of our sky, we must understand the subject which is so immediately connected with it and its creation.
The earth is a sphere in space; generally speaking, it is composed of land and water. These are two factors; the heat that it derives from the sun forms a third factor; the three--land, water, and heat--are essential to life, at least the higher conditions of life which culminate in man. ”

“ The whole ridge is well supplied with clean, soft running water, even in the driest of the season. There are no marshes, swamps, or bogs, no still water--not even a "puddle" for long--for the soil is of such a character, that surface water quickly filters away into the sands and mingles with the streams in the gulfs. Springs of mineral water are abundant everywhere. Probably there is not a square mile of Walden's Ridge which does not furnish chalybeate water abundantly. ”

“ If the delicate redness of the sky is not caused by dust, what is it caused by?
But for the weather map, I think we should still be in the dark in regard to it.
In the first place, this redness is nothing new, only the conditions are more favorable sometimes than at others. It has always existed and always will exist, independent of earthquakes, volcanoes, etc. Nature is ever changing; the movements of the atmosphere more resemble the kaleidoscope than any thing else. ”

“ When we see a comet approaching the sun with its tail following in the orbit of the nucleus, we have no great difficulty in believing the common theory that a comet consists of nucleus attracted toward the sun, while the tail is repelled ”

“ When the extent of the gold and silver mining industries is considered, and when it is borne in mind that a considerable percentage of the precious metal present in the ore is, in the ordinary process of extraction, lost through defective amalgamation--due to insufficient contact with the mercury or to a total absence of contact, as in the case of float gold--it is obvious that the introduction of any system obviating such loss is a matter of very great importance to those who are interested in the above mentioned industries. ”

“ The mercury is connected with the negative pole of the voltaic battery or other electro-motor, and the lead made with the positive pole of the same source. When the current passes there is formed according to the nature of the electrolyte, a hydrogen amalgam, or an amalgam of hydrogen with a metal electro-positive to hydrogen. The electrolyte, which, it will be understood, is distinct and apart from the body of water passing over the table, will last almost indefinitely, there being no consumption of any of its constituents, excepting hydrogen and oxygen from the water of solution. ”

“ As is seen above, the course of instruction in mechanical engineering includes some trade education. The engineer is dependent upon the machinist, the founder, the patternmaker, and other workers at the trades, for the proper construction of the machinery and structures designed by him. He is himself, in so far as he is an engineer, a designer of constructions, not a constructor. ”

“ Climate, we know, is a fixture; it has a government; it has rules; the weather may change, but climate does not; it is a permanent out-door affair, and what is true of to-day was true centuries ago, and will be true forever, in the measure of any practical scope, at least. ”

“ In a system of arc lighting, however, we have to deal with entirely different conditions; for, while in the incandescent system the adding of a lamp, which diminishes the resistance, requires no increase of electromotive force, the contrary is the case in the arc light system. Here every additional lamp added to the circuit means an increase in resistance, and consequent increase in electromotive force or potential. Taking for example a well known system of arc lighting, we find that the lamps require individually an electromotive force of 40 volts with a current of 10 amperes. ”

“ In States and cities where inspection laws are in force that give the methods and rules by which the safe working pressure of a boiler is calculated, there is no alternative except to follow the rules; and if certain requirements regarding construction are a part of the law, there is no authority or right to depart from it, and yet there are boilermakers who try to force their boilers into such localities when their work is not up to the requirements of the law. ”

“ But we can go a step further than this; we can overbalance the exciting coils by setting the deflecting coil at a greater angle than necessary for the mere elimination of the former, and thus attain that an increase of current results in a slight weakening of the field in which the needle swings, thus allowing the increment of the angle of deflection to be comparatively large even for large currents. In this way it is possible to obtain a more evenly divided scale than in the case when the deflection follows the law of tangents, as in an ordinary tangent galvanometer. ”

“ The rays of the sun in passing through or near the nucleus are so modified as to become visible in their further progress through the cometic atmosphere, while all the rest remain invisible. What we call the tail is merely a radius of the cometic atmosphere made visible, and as the comet moves through space, only different portions of the atmosphere come in sight, in obedience to the ordinary laws of light. There is no difficulty in accounting for the rise and fall of the tail at perihelion, nor for the tail preceding the nucleus afterward. ”

“ During the ten years that I have practiced medicine in the neighborhood of the Cumberland Tablelands, I have often heard it said that the people on the mountains never had consumption. Occasionally a traveling newspaper correspondent from the North found his way down through the Cumberlands, and wrote back filled with admiration for their grandeur, their climate, their healthfulness, and almost invariably stated that consumption was never known upon these mountains, excepting brought there by some person foreign to the soil, who, if he came soon enough, usually recovered. ”

“ The top of the ridge is one level stretch of plain, broken only by the "gulfs" before mentioned and an occasional prominent sandstone wall or bowlder. The width on top is, I should judge, 6 or 7 miles. The soil is of uniform character, light, sandy, and less productive for the ordinary crops of the Tennessee farmer than the soil of the lowlands. The grape, apple, and potato grow to perfection, better than in the valleys, and are all never failing crops; so with rye and buckwheat. Corn grows well, very well in selected spots, and where the land is made rich by cultivation. ”

“ In a cell is an element which has a determined lower capacity than those in the rest of the battery. Over this element is placed a gas-tight chamber in which is a diaphgram, this diaphragm being of very flexible material placed in the cover of the box of cells. When charging has proceeded as long as is desirable, or proceeds too fast, hydrogen is evolved, and this collecting in the chamber referred to acts upon the diaphragm, and by means of a rod connected thereto, switches the current, which is supplied to an electro-magnet and by which circuit is made through the medium of mercury contacts. ”

“ If Mueller's formula were correct for all currents, absolute saturation could only be reached with an infinite current. Whether this be the case or not, it is certain that the greater the exciting current the less will a variation in it affect the magnetic moment of the core. To imitate as nearly as possible permanent steel magnets, it is therefore necessary to use electro magnets, the cores of which are easily saturated. The core should be thin and long and of the horseshoe type; the amount of wire wound round it should be large in comparison with the size of the core. ”

“ The latter teaches, simply, the practical methods of either of the trades subsidiary to the several branches of engineering, with only so much of science as is essential to the intelligent use of the tools and the successful application of the methods of work of the trade taught. The distinction between the two departments of education, both of which are of comparatively modern date, is not always appreciated in the United States, although always observed in those countries of Europe in which technical and trade education have been longest pursued as essential branches of popular instruction. ”

“ Stevens may be supplemented by gifts from other equally philanthropic and intelligent friends of technical education, among the alumni of the school and others, this germ of a trade school maybe developed into a complete institution for instruction in the arts and trades of engineering, and may thus be rendered vastly more useful by meeting the great want, in this locality, of a real trade school, as well as fill the requirements of the establishment of which it forms a part, by giving such trade education as the engineer needs and can get time to acquire. ”

“ The course, finally, should conclude with exercises in the construction and erection of complete structures and in the making of peculiar details, such as are regarded by the average workman as remarkable "tours de force." The trade school usually gives instruction in the common school branches of education, and especially in drawing, free-hand and mechanical, carrying them as far as the successful prosecution of the trade requires. The higher mathematics, and advanced courses in physics and chemistry, always taught in schools of engineering, are not taught in the trade school, as a rule ”

“ The quantity of acid or saline material contained in the electrolyte is so very small that there can be no difficulty in finding a supply in any district. The question of the supply of electricity is one which in many mining districts involves considerations of practical importance, since a large supply would necessitate water or steam power. It has been found that two cells having an electromotive force of about two volts each will in this process suffice; if preferred, however, a very small dynamo machine can be used. ”

“ A true, upright, honest man, an earnest, devoted and zealous physician, universally esteemed and beloved by all who knew him; himself the subject of tuberculosis, dying in the prime of a brilliant manhood. ”

“ In order to determine the current which proves fatal we need only to apply the formula which expresses Ohm's law, viz., C=E/R, or the current (ampere) equals the electromotive force (volt) divided by the resistance (ohm) .
According to the committee of Parliament investigation, the electromotive force dangerous to life is about 300 volts; this then is the quantity, E, in the formula. There remains now only to determine the resistance in ohms which the body offers to the passage of the current. ”

“ This becomes clear by considering the current to leak from another spot of different potential, to pass through the ground and into the body; thus, on touching the wire the body virtually makes a connection between the two points of the circuit. In clear dry weather such leaks are insignificant; but in damp and rainy weather, and with poor insulation, they may rise to such a point at which it would be dangerous to touch the circuit even with one hand, the leaks being sometimes so great as to cause the lamps to burn in a fitful, desultory manner, and to go out entirely. ”

“ The measurement will be exact if the thing against which we weigh or counterbalance the current itself retains its original standard value. Where permanent magnets or springs are used as a balancing force, this condition of constancy in our weights and measures is not always fully maintained, and to make matters worse, there is no visible sign by which a change, should it have occurred, can be readily detected. A spring may have been overstrained or a steel magnet may have become weakened without showing the least alteration in outward appearance. ”

“ The nights on the table are cooler than in the lower lands by several more degrees than the days; how much I have thus far not been able to state. The late fall months, the winter, and early spring are not so much colder than the valleys as the summer months, the difference between the average temperature of the mountains and valleys being at that time four or five degrees less than in the summer. There is no record of so hot a day ever having occurred on the Cumberladd Mountains as to cause mercury to run so high as 95° F., or so cold a day as to cause it to run so low as 10° below zero. ”

“ The spawning oyster does not allow its ripe eggs to fall into the water, as do many other mollusks, but retains them in the so-called beard, the mantle, and gill-plates until they become little swimming animals. The eggs are white, and cover the mantle and gill-plates as a semi-fluid, cream-like mass. As soon as they leave the generative organs the development of the germ begins. The entire yolk-mass of the egg divides into cells, and these cells form a hollow, sphere-like body, in which an intestinal canal arises by the invagination of one side. ”

“ For the extremity of the tail farthest from the sun will be required to pass with lateral motion from its perpendicular 100,000,000 miles, so that it may be in advance of the nucleus and again rest on its orbit. This orbit is an impassable line, and therefore instantly arrests the prodigious lateral velocity of the tail. That impassable orbital line is to it as solid and inflexible as a wall of adamant. The motion so instantly arrested would be disastrous to any tail, whether composed of gas, meteorites, or electricity, whatever that may be. ”

“ The electro magnet and deflecting coils are wound with from 50 to 100 ohms of fine insulated copper wire, and an additional resistance coil of from 450 to 900 ohms of German silver is added, which can, however, be short circuited by depressing a key when the instrument has to be used for reading low electromotive forces. In this case the indication of the pointer must be divided by ten. If a current be sent through the instrument the wrong way, the needle turns through an angle of 180°, and thus brings the pointer to the side of the dial opposite to where the scale is. ”