Various

“ While its development has not been so brilliant or so startling as that which we can note in the employment of electricity, it holds, among the applications of heat, the most important place of any invention made within that period. Even amid the contrivances by which, in recent times, the other forces of nature have been subdued to the uses of man, there are only a few which rival the gas-engine in practical importance. With regard to the steam-engine itself, it is remarkable how little that is new has really been invented since the time of Watt and Woulfe. ”

“ I have all along spoken of efficiency as a percentage of the total quantity of heat evolved by the fuel; and this is, in the eyes of a manufacturer, the essential question. Other things being equal, that engine is the most economical which requires the smallest quantity of coal or of gas. But men of science often employ the term efficiency in another sense, which I will explain. If I wind a clock, I have spent a certain amount of energy lifting the weight. ”

“ When the eggs are near the hatching point they darken in color, and a magnifying glass reveals through the delicate transparent shell a sight which fills the observer with amazement; the embryo caterpillar is seen in gradual course of formation, and if patience and warmth have permitted it, the observer will witness slight movements within the life-case, and presently the shell will break and a black head with moving jaws will be thrust out; the little caterpillar unfolds and slowly crawls away from the egg-shell, and inserts its jaws into the green leaf. ”

“ Flying insects of every kind are equally drawn to the plant; and directly they taste the fluid, they act very curiously. After feeding upon the secretions for two or three minutes they become quite stupid, unsteady on their feet, and while trying to pass their legs over their wings to clear them, they fall down.
It is of no use to liberate any of the smaller insects; every fly, removed from the leaf upon which it had been feeding, returned immediately it was at liberty to do so, and walked down the fatal cup as though drawn to it by a species of irresistible fascination. ”

“ In the same way if I heat air or water, I communicate to it energy of heat, which remains potential as long as the temperature does not fall, but which can be spent again by a decrease of temperature. In every heat-engine, therefore, there must be a fall from a higher to a lower temperature; otherwise no work would be done. If the water in the condenser of a steam-engine were as hot as that in the boiler, there would be equal pressure on both sides of the piston, and consequently the engine would remain at rest. Now, the greater the fall, the greater the power developed ”

“ In his closing argument before the Congressional Committee on Mines and Mining in 1872, Adolph Sutro of the Sutro tunnel said: "The deepest hole dug by man since the world has existed is only 2,700 feet deep, and it remains for the youngest nation on earth to contribute more to science and geology by giving opportunities of studying the formation of mineral veins at a greater depth than has ever been accomplished by any other nation in the world." ”

“ Before the invention of the steam-engine, the only powers employed in mechanics were those of wind and water mills, and animal power. In the first two, no conversion of one force into another took place; they were mere kinematic devices for employing the mechanical force already existing in the gale of wind and the head of water. With regard to the power developed by man and other animals, we had in them examples of most efficient heat-engines, converting into power a large percentage of the fuel burnt in the lungs. ”

“ A pound of bread or beef, or oats or beans, costs a great deal more than a pound of coal; while it does not, by its combustion, generate nearly so much heat. The steam-engine, therefore, took the place of animal power, and for a long time stood alone; and nearly all the motive power derived from heat is still produced by the mechanism which Watt brought to such great efficiency in so short a time.
Now the practical question for all designers and employers of heat-engines is to determine how the greatest quantity of motive force can be developed from the heat evolved from a given kind of fuel ”

“ The electrical energy is more evenly distributed, and the current can not so readily form a path of highest temperature, and consequently of least resistance through the mass along which the entire current or the bulk of the current can pass. The operation must necessarily be conducted within an air-tight chamber or in a non-oxidizing atmosphere, as otherwise the carbon will be consumed and act as fuel. The carbon acts as a deoxidizing agent for the ore or metalliferous material treated, and to this extent it is consumed, but otherwise than from this cause, it remains unimpaired. ”

“ In course of time the worm is changed into the beautiful winged butterfly, which breaks its case and emerges soft and wet; but it quickly dries and spreads its wings to commence its life in the air and sunshine. ”

“ We may define a eutectic substance as a body composed of two or more constituents, which constituents are in such proportion to one another as to give to the resultant compound body a minimum temperature of liquefaction—that is, a lower temperature of liquefaction than that given by any other proportion.2 It will be seen at once by this definition that the temperature of liquefaction of a eutectic substance is lower than the temperature of liquefaction of either or any of the constituents of the mixture. ”

“ The metal employed is silver or copper of very great conductivity, seeing that the increase of temperature in a conductor, due to a sudden increase of the current, is inversely proportional to the product of the electric resistance by the specific heat of the conductor; that these metals are best adapted for giving constant and definite results; and that the contacts are better than with lead or the other metals of low melting point which are frequently employed in circuit cutters. ”

“ Crossley's works you will have an opportunity of seeing a large engineering factory employing several hundred mechanics, and without a chimney, in which every shaft and tool is driven by gas-engines supplied by Dowson's gas, and in which the consumption of coal is only 1.2 lb. per indicated horse power. The greatest economy ever claimed for the steam-engine was a consumption of 1.6 lb.; and this with steam of very high pressure, expanded in three cylinders successively. Thus in a quarter of a century the gas-engine has beaten in the race the steam-engine ”

“ The heat evolved reduces the ore and distills the zinc, and the zinc fumes are condensed in the condensing chamber, precisely as in the present method of zinc making, with this important exception that, aside from the reaction produced by heating carbon in the presence of zinc oxide, the electric current, in passing through the zinc oxide, has a decomposing and disintegrating action upon it, not unlike the effect produced by an electric current in a solution. This action accelerates the reduction, and promotes economy in the process. ”

“ Several hundred people during five months in every year depend entirely on that source for all the water they use. With their frail pitchers and flaring torches they wend their way, gasping for breath, through the intricate passages, and reaching the water, are so profusely perspiring that they must wait before quenching their thirst. The way back is even harder, and they are tired and loaded ”

“ Another well known insect is illustrated in the figure in the upper portion—the peacock butterfly (Vanessa Io) . The curious spiked and spotted caterpillar feeds upon the common nettle. This beautiful butterfly—common in most districts—is brilliantly colored and figured on the upper side of the wings, but only of a mottled brown on the under surface, somewhat resembling a dried and brown leaf, so that it is no easy matter to detect the conspicuous, brightly-decked insect when it alights from flight upon foliage, and brings its wings together over its back after the manner of butterflies. ”

“ Why does not the gas-engine everywhere supersede the steam-engine? My answer is a simple one: The gas we manufacture is a dear fuel compared with coal. Ordinary coal gas measures 30 cubic feet to the pound; and 1,000 cubic feet, therefore, weigh 33 lb. Taking the price at 2s. 9d. per 1,000 cubic feet, it costs 1d. per lb. The 30 cubic feet at 630θ give 19,000θ all available heat. Although good coal may yield 14,000 units by its combustion, only about 11,000 of these reach the boiler; so that the ratio of the useful heat is 11/19. ”

“ The ore or light material to be reduced—as, for example, the hydrated oxide of aluminum, alum, chloride of sodium, oxide of calcium, or sulphate of strontium—is usually mixed with the body of granular resistance material, and is thus brought directly in contact with the heat at the points of generation, at the same time the heat is distributed through the mass of granular material, being generated by the resistance of all the granules, and is not localized at one point or along a single line. ”

“ The camellia is so hardy that it will live in the open air in many parts of Great Britain, and herein lies a danger to many cultivators. Because it is quite or almost hardy, they keep it almost cool. This is all very well if the cool treatment be not carried to extremes, and persisted in all the year round. Camellias in a dormant state will live and thrive in any temperature above the freezing point, and will take little or no hurt if subjected to from 3°-4° below it, or a temperature of 27° Fahr. ”

“ The energy consumed by the reduction of the ore is almost entirely electrical, only enough carbon being used to unite with the oxygen of the ore to carry it out of the furnace in the form of the carbon monoxide, the aluminum remaining behind. Consequently, the plant necessary to produce aluminum on a large scale involves a large number of the most powerful dynamos. These are to be driven by water-power or natural gas and marine engines of great capacity. ”

“ The pitcher plant undoubtedly derives its principal nourishment from the insects it eats. It, too—unlike most other carnivorous plants, which, when the quantity of food with which they have to deal is in excess of their powers of digestion, succumb to the effort and die—appears to find it easy to devour any number of insects, small or large, the operation being with it simply a question of time. ”

“ Experiments already made so that aluminum, silicon, boron, manganese, magnesium, sodium and potassium can be reduced from their oxides with ease. In fact, there is no oxide that can withstand temperatures attainable in this electrical furnace. Charcoal is changed to graphite. Does this indicate fusion or solution of carbon? As to what can be accomplished by converting enormous electrical energy into heat within a limited space, it can only be said that it opens the way into an extensive field for both pure and applied chemistry. ”

“ During the breaking of the tender leaves and the growth of the young shoots in their first stages, the plant should be shaded from direct sunshine, unless, indeed, they are a long way from the glass, when the diffusion and dispersion of the rays of light tone down or break their scorching force; few young leaves and shoots are more tender and easily burned than camellia, and scorching not only disfigures the plants, but also hinders the formation of fine growths and the development of flower-buds. ”

“ As regards the steam-engine, it is the opinion of competent authorities that the limits of temperature between which it works are so restricted, and so much of the heat is expended in producing a change of state from liquid to vapor, that little further improvement can be made. With respect to gas-engines, the limits of temperature are much further apart. A change of state is not required, and so very great improvement may still be looked for. ”