Various

“ Iron pipes are either laid in trenches filled in with earth or are laid in cement. Iron pipe will of course rust out in time, and if absolute permanence in construction is desired, should be laid in cement, for after the pipe rusts out, the duct of cement is still left. However, if we are going to the expense of laying in cement, it would be much preferable to use cement lined pipe, which is not only cheaper than iron pipe, but makes the most perfect cable conduit, as it affords a perfectly smooth surface to draw the cable over and give a good duct edge. ”

“ The coal tar, be it either crude or distilled, is not a perfect impregnating material, and the roofing paper, saturated with it, possesses several defects. Let us in the following try to ascertain their shortcomings, and then express our idea in what manner the roofing paper may be improved. It was previously mentioned that every tar roofing paper will, after a greater or smaller lapse of time, assume a dry, porous, friable condition, caused by the volatilization of a part of the constituents of the tar. ”

“ It has been usual to compare the weight directly with the indicated horse-power, and to express the comparison in pounds per horse-power. So long as the machinery thus compared is for vessels of the same class and working at about the same speed of revolution, no great fault can be found; but as speed of revolution is a great factor in the development of power, and as it is often dependent on circumstances altogether external to the engine and concerning rather the speed of the ship, the engines fitted to high speed ships will thus generally appear to greater advantage than is their due. ”

“ No gunpowder can be smokeless in which saltpeter or any oxygen-bearing salt having a metallic base is employed, for when the salt gives up its oxygen, the base combines with other elements to produce a sulphate, a carbonate, or other salt, which, being solid, produces smoke. Therefore, to be smokeless, a gunpowder must contain no other elements than oxygen, hydrogen, nitrogen, and carbon, and in such proportions that the products of combustion shall be wholly gaseous. The nitric ethers--gun-cotton and nitro-glycerine--constitute such explosive compounds. ”

“ Many years ago the attention of inventors was directed to the practicability of constructing a railroad up the side of a mountain on grades which, to an ordinary engine, were quite impossible. The improvements in locomotives twenty-five and thirty years ago rendered them capable of climbing grades which, in the early days of railroad engineering, were deemed out of the question. The improvements proved a serious stumbling block in the way of the inventors, who found that an ordinary locomotive was able to climb a much steeper grade than was commonly supposed. ”

“ The engineer is a wizard at whose command space and matter are annihilated. The highest mountain, the deepest valley, has no terrors for him. He can bridge the latter and encircle or tunnel the former. ”

“ Black powder simply requires to be set on fire; while a smokeless powder, on the contrary, not only requires that it be set on fire, but that a certain degree of pressure be set up inside of the cartridge case. For instance, if a primer of a certain size should be found to operate perfectly well, giving prompt ignition in the cartridge case of a rifle of small caliber, it would be found that the same primer would not ignite a charge of the same powder if loaded into a gun of one inch caliber. ”

“ To communicate this very high rotary movement to the bullet in the instant of time during which it is passing through the barrel, the rifling of the gun has to exert an enormous torsion on the bullet. Lead, no matter how hardened, is not sufficiently strong, as it will not only strip and pass straight through the gun without taking any rotary movement whatever, but under such very high pressures it behaves like wax, and is thrown from the gun in a distorted mass. ”

“ Roofing paper can be called good only when it is essentially made from woolen rags, and contains either very few or no earthy additions. It is beyond doubt that the durability of a roofing paper increases with the quality of wool fiber it contains--vegetable fibers and earthy additions cause a direct injury. Reprehensible altogether is any combination with lime, either in form of a carbonate or sulphate, because the lime enters into chemical combination with the decomposition products of the tar. ”

“ The most ordinary and cheapest thickener was the coal pitch. Although the resinous substances are increased thereby, still the light tar oils remain to evaporate, and the paper prepared with such a substance readily becomes hard and brittle. A better addition is the natural asphaltum, because it resists better the destroying influence of the decomposition process, and also, to a certain degree, protects the coal tar in which it is dissolved. The addition of natural asphaltum doubtless caused the name of "asphaltum roofing paper." ”

“ Another cause for the smoke of gunpowder is the formation of small liquid vesicles which condense from some of the products of combustion thrown into the air in a state of vapor, in the same manner as vesicles of aqueous vapor form in the air on the escape of highly heated steam from the whistle of a locomotive.
Broadly speaking, an explosive compound is one which contains, within itself, all the elements necessary for its complete combustion, and whose heated gaseous products occupy vastly more space than the original compound. ”

“ It is certain the process of oxidation favors the destruction of adipose, and that everything which inhibits such destruction tends to fat accumulation.
Since the earliest period of history, there seems to have been an anxiety to secure some regimen of general application that would reduce or combat obesity. Thus Hippocrates says:
Fat people, and all those who would become lean, should perform laborious tasks while fasting, and eat while still breathless from fatigue, without rest, and after having drunk diluted wine not very cold. ”

“ After the saccharification is complete I may partially or wholly neutralize the nitric acid, preferably with potassium or Ammonium carbonate, preferably employing only one-half the amount necessary to neutralize the original quantity of nitric acid used, so that the mass now ready to undergo fermentation has an acid reaction. The purpose in view here is to keep the peptones in solution also, because an acid medium is best adapted to the propagation of the yeast cells. It is not absolutely necessary to even partially neutralize the nitric acid, but it is preferable. ”

“ A mixture of water and liquefied carbon dioxide upon being discharged through pipes at high pressure causes the rapid expansion of the gas and converts the mixture into spray more or less frozen, and portions of the liquid carbon dioxide are frozen, owing to its rapid expansion, and are thus thrown upon the fire in a solid state, where said frozen carbon dioxide in its further expansion not only acts to put out the fire, but cools the surface upon which it falls, and thus tends to prevent reignition. ”

“ As much wool as possible should be employed, because the wool fiber has a greater resistance than vegetable fiber to the effects of the temperature. By wool fiber is understood the horny substance resembling hair, with the difference that the former has no marrowy tissue. The covering pellicle of the wool fiber consists of flat, mostly elongated leaves, with more or less corners, lying over each other like scales, which makes the surface of the fiber rough ”

“ It is not advisable to pull more than one cable into a duct, and never advisable to pull a cable into a duct containing another cable, but if two or more cables have to go into the same duct, they should always be drawn in together. Lead covered cables and those with no lead on the outside should never be pulled into the same duct, for if they bind anywhere the soft cable will suffer where two lead covered cables would get through all right. ”

“ Where practicable it is always a good plan to pull the cable through as many manholes as possible without cutting the cable; for the joint is, especially in telephone or telegraph cables, the weak point. To do this the rope should be pulled through the proper duct in the next section without unfastening it from the cable; the winch should be moved to the next manhole, and pulling through then done as before. There should always be a man in every hole through which the cable is running to see that it does not bind anywhere and to keep protectors around the cable. ”

“ It is founded on the fact that, if the feed water as it is drawn from the hot well be raised in temperature by the heat of a portion of steam introduced into it from one of the steam receivers, the decrease of the coal necessary to generate steam from the water of the higher temperature bears a greater ratio to the coal required without feed heating than the power which would be developed in the cylinder by that portion of steam would bear to the whole power developed when passing all the steam through all the cylinders. ”

“ Notwithstanding the necessity, the proposal to establish a railroad met with general derision, but the scheme was soon shown to be perfectly practicable, and a beginning was made in 1879. The road is what is known as a cable road, there being a single sleeper with three rails, one on the top which really bore the weight, and one on each side near the bottom, which supported the wheels, which coming out from the axle at a sharp angle, prevented the vehicle from being overturned. ”

“ The crude paper is the foundation of the roofing paper. The qualities of a good, unadulterated paper have already been stated. At times, the crude paper contains too many earthy ingredients which impair the cohesion of the felted fibrous substance, and which especially the carbonate of lime is very injurious, as it readily effects the decomposition of the coal tar. The percentage of wool, upon which the durability of the paper depends very largely, is very small in some of the paper found in the market. ”

“ The Austrians use the Mannlicher steel jacketed bullet. The steel casing or jacket is first tinned on the inside and then the lead is cast in, thus melting the tin and adhering firmly to the jacket. This projectile sets up enormous friction in the barrel of the gun when used with smokeless powder; as the smokeless powder leaves the gun barrel perfectly clean and the two steel surfaces being in absolute contact cause tremendous friction; and as the coefficient of friction varies with every shot, the pressure in the gun constantly varies greatly. ”

“ During the stay of the empress, the shepherds, mounted upon their stilts, much amused the ladies of the court, who took delight in making them race, or in throwing money upon the ground and seeing several of them go for it at once, the result being a scramble and a skillful and cunning onset, often accompanied with falls. ”

“ It is perfectly safe to manufacture, handle and transport. There is no more danger of its exploding accidentally than there would be of an explosion of shavings or sawdust; for, unless well confined and set off with a strong primer, it will not explode at all. In the open its combustion is so slow as to in no way resemble or partake of the nature of an explosion.
4th. It is perfectly stable, and will keep any length of time absolutely without undergoing any change whatever, under all conditions of temperature or exposure to which gunpowder would ever be subjected. ”

“ The workmen quickly learn by experience how fast to turn the crank. The hotter the tar, the more rapid the saturation; the high degree of heat expels the air and evaporates the hygroscopic fluid in the pores of the paper. The strong heating of the tar causes another advantage connected with this method. The surface of the paper as it issues from the squeezing rollers is still very hot, and a part of the volatile oils evaporate very quickly at this high temperature. ”

“ But if the going up excites tremor, much more peculiar are the feelings aroused on the down grade. The trip begins with a gentle descent, and all at once the traveler looking ahead sees the road apparently come an end. On a nearer approach he is undeceived and observes before him a long decline which appears too steep even to walk down. ”

“ Gun-cotton alone and in its fibrous state has been found to be too quick, or violent, for propulsive purposes, such as use in firearms; as under such conditions of confinement it is very likely to detonate and burst the gun. However, if gun-cotton be dissolved in a suitable solvent, which is capable of being evaporated out, such as acetone, or acetate of ethyl, which are very volatile, it becomes, when thus dissolved and dried, a very hard, horn-like, amorphous substance, which may be used for a smokeless gunpowder. ”

“ In the laying of light and power cables every joint, as made, should be tested for insulation with a Thomson galvanometer, as the insulation must necessarily be very high, and if one joint or section of cable is any weaker than another it may be very important in the future to know it. All tests must be made after the joint has cooled, for while hot its insulation resistance will be very low.
Tests for copper resistance should also be made to determine if the splices are electrically perfect; an imperfect splice may cause considerable trouble. ”

“ The gun, the cartridge case, primer, and bullet have been as much the subjects of experiments in adapting them to the use of smokeless powder as has the smokeless powder in being adapted to them. To impart a velocity of 2,000 feet per second to a rifle ball, with corresponding long range and accuracy of flight, has been a question as much of improvement in rifles and projectiles as in the powder. To give a velocity of 2,000 feet per second to a bullet, requires a pressure of at least 15 English tons in the chamber of a gun. ”

“ It is not necessary that the coating applied should harden quickly, as it assumes soon after its application a firmness sufficient to prevent it from running off the roof. Coal tar is to be classed among lacquers. If it has been liberated by distillation from the volatile oils, it is made better suited for the purpose than the ordinary kind. The mass contains much more asphaltum, and after drying, which takes place soon, it leaves a far thicker layer upon the roof surface, while the pores, which had formed in the roofing paper consequent on drying, are better filled up. ”