Part 25 (1/2)
What is a Microscope?
An optical instrument, by ly large, and viewed very distinctly according to the laws of refraction or reflection Nothing certain is known respecting the inventor of microscopes, or the exact time of their invention, but that they were first used in Germany, about 1621
_Minute_, se in the direction of a ray of light, when it passes through transparent substances of different densities
_Reflection_, a turning back of a ray of light after striking upon any surface
What is the Stea power fro water, which is very great, especially when, as in the steaine, it is confined within a limited compass: this useful machine is one of the most valuable presents that the arts of life have received froreatest i cities ater; in working ation By the aid of steareater swiftness than those which are wholly dependent on the winds and tides; and thus trade is facilitated, and we are enabled to communicate with distant lands in a much shorter space of time than was formerly consumed On land, railroads are constructed, on which stea rapidity, so that a journey which by coach and horses formerly required two or more days, may now be perfor to Mechanics
To whom are we indebted for its invention?
Its invention is by lishman, about 1663; but it does not appear that the inventor could ever interest the public in favor of this, or his other discoveries The stealishman, is the first of which any definite description has been preserved It was invented in 1698 Since that period it has been successively improved by various persons, but it is to Mr Watt and Mr Boulton, of England, that it is indebted for much of its present state of perfection
By as the Steaation?
By John Fitch, of Pennsylvania From papers in the historical collections of Pennsylvania, it appears that the first successful experiments were made at Philadelphia, in 1785, three years before the attempts at Falkirk, and on the Clyde, in Scotland The boat made several trips on the Delaware and Schuylkill rivers, but owing to repeated accidents to her machinery, and the want of funds and competent mechanics for the necessary repairs, she was abandoned In 1807, Robert Fulton, also of Pennsylvania, made his first experimental trip on the Hudson River, with coenious Aation by steam to a state of perfection In 1819, the first steamshi+p crossed the Atlantic froular communication by steamshi+p was established between Great Britain and the United States Since that period, ocean navigation by stearess, and, at the present time, numbers of steamers connect our various seaports with those of other nations, and with each other
What is the Electro-Magnetic Telegraph?
An instruence is conveyed to any distance with the velocity of lightning The electric fluid, when an excess has accumulated in one place, always seeks to transfer itself to another, until an equilibrium of its distribution is fully restored Consequently, when two places are connected by ood conductor of electricity, as, for instance, the telegraphic wire; the fluid generated by a galvanic battery, if the communication be rendered complete, instantaneously traverses the whole extent of the wire, and charges, at the distant station, an electro-net; this attracts one end of a lever, and draws it doard, while the other extremity is thrown up, and, by means of a style, marks a slip of paper, which is steadily wound off from a roller by the aid of clock-work If the communication is immediately broken, only one wave of electricity passes over, and a _dot_ is made upon the paper; if kept up, a _line_ is marked These dots and lines are made to represent the letters of the alphabet, so that an operator ee which is transraph was first introduced upon a line between Baltiton, by Professor Morse, in 1844; at the present time, it is in successful operation between nearly all the important cities and towns of the United States and of Europe
An _Electro-Magnet_ is a piece of soft iron, rendered te placed within a coil of wire through which a current of electricity is passing
CHAPTER XIII
SOAP, CANDLES, TALLOW TREE, SPERMACETI, WAX, MAHOGANY, INDIAN RUBBER OR CAOUTCHOUC, SPONGE, CORAL, LIME, CARBON, OXYGEN, NITROGEN, GAS, HYDROGEN, CHALK, AND MARBLE
Of what is Soap composed?
Of soda or potash, and various oily substances; it is so useful for doarded as one of the necessaries of life; immense quantities of it are consuenerally made of a lye of wood-ashes and quicklime, boiled up with tallow or oil; common household soap of soda and tallow, or of potash and tallohen potash is used, a large portion of common salt, which contains soda, is added to harden it The finest white soaps areof soda and quickli ated appearance The ancient Greeks and Hebrews appear to have been acquainted with the art ofsoap, or a composition very similar to it; and also the ancient Gauls and Germans A soap-boiler's shop, with soap in it, was found in the city of Pompeii, in Italy, which was overwhelmed by an eruption of Mount Vesuvius, AD 79
What is Soda?
Soda, or barilla, is obtained from the ashes of reat depository is the ocean, soda being the basis of salt The marine plants from which the soda is obtained, are endoith the property of deco the soda which it contains It is found native in Egypt, and is there called _natron_; a na the Jews and Greeks
_Depository_, store-house, place where anything is lodged