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speed, determines by the connecting rack and segment the position of the valve in the steam-pipe. Silver's momentum-wheel governor has a heavy revolving wheel, whose momentum acts upon the throttle-valve when any change occurs in the rate of motion of the engine. See also marine-governor. The hydraulic governor or cataract is the invention of Smeaton. A quantity of water is pumped at each stroke, and forced by counter weights through an orifice of a certain size. See cataract. Davis's governor (English) consists of a single hollow ball with a zone round it, having an opening through the bottom to admit of an upright spindle, attached to the ball by a joint in its center. One side of the ball and zone is made much heavier than the other, and consequently, when at rest or moving slowly, it hangs down; but when driven fast, the centrifugal force of the heavy side overcomes its gravity, and the zone assumes a nearly horizontal position. When this is the case, a small link
er apparatus for this purpose, the process consists in subjecting the lumber to the action of a gradually increasing temperature, in an air-tight chamber, until all or nearly all the moisture has been extracted from it; in retaining all the heat and watery vapor about the lumber until a temperature of about 170° Fah. has been attained in said air-tight chamber; and, finally, in compelling the heated moistened air to escape slowly from said chamber while the temperature is reduced therein. Davis and Symington's lumber-dryer, English patent, 1843, acts by means of a heated blast upon lumber or wooden articles placed in a chamber through which the blast is driven. By their process, — Mahogany is reduced in weight24.4 per cent. Pine is reduced in weight34.5 per cent. Fir is reduced in weight12.5 per cent. Lum′ber-kiln. A heated chamber for artificially drying lumber. See lumber-dryer. Plank should never be allowed to remain undisturbed until it seasons; but should all
the dropping of water from a clepsydra. There is a reference also to a similar instrument in the third century. A planetarium is described in a letter from Angelo Politiano to his friend Francesco Casa, as seen by the former at Florence in the fifteenth century. The inventor was one Lorenzo of Florence, and the apparatus was constructed to illustrate the Ptolemaic theory of the heavens. The various parts were moved by trains of cog-wheels. Life of A. Politiano, published by Cadell and Davis, London, about 1800. A planetary clock was made by Finee, 1553, and a planetarium by De Rheita in 1650. Or′se-dew. Leaf metal of bronze. Dutch metal. Or′tho-graph. A drawing representing a structure in elevation, external or internal. The internal orthograph is usually termed a vertical section or sciagraph. The ground plan is the ichnograph. The view of the whole building, the scenograph. Or-tho-scop′ic lens. (Optics.) An arrangement of two achromatic compoun
ent also allows longer strings to be employed in proportion to the length of the case, or a shorter case with the same length of string, than in the usual piano-forte actions. Steinway's piano-forte actions. J K are, respectively, the horizontal and upright piano-forte actions of Steinway and Sons. Others might be mentioned would space permit, embracing the peculiar constructions of instruments whose fame is wider than the continent, such as the Chickering, Knabe, Weber, Hallet and Davis, Schomacker, and others. On the stringing and construction of pianos, see Lehrbuch des Pianofortebasses, Weimar, 1872. In Pepys's diary, October, 1664, another form of stringed instrument played by keys is thus described: — To the musique meeting at the post-office, where I was once before. And thither anon come all the Gresham College, and a great deal of noble company; and the new instrument was brought called the Arched Viall, where, being tuned with lute-strings and played on wit
e instrument for ascertaining the latitude. It consists of a little square board, with a string fast to the center, at the other end of which are certain knots. The upper edge of the board is held by one hand, so as to touch the north star, and the lower edge the horizon. Then the string is brought with the other hand to touch the tip of the nose, and the knot which comes in contact with the nose tells the latitude. A quadrant was constructed by Copernicus at Thorn in 1510. In 1590, Davis dispensed with the plumb and adapted the quadrant for use at sea. Previous to this the astrolabe and mariner's cross had been universally employed by seamen for determining the latitude; the longitude was derived from dead reckoning or guess-work. The telescope was adapted to the astronomical telescope by Picard. All these old forms were superseded for nautical purposes by the reflecting quadrant, invented by Sir Isaac Newton, 1670. He communicated the invention to Dr. Halley, who
rses. The Baltimore and Ohio Railway was commenced July 4, 1828, and was the first passenger railway in America, 15 miles being opened in 1830. The cars were drawn by horses till the next year, when a locomotive was put on the track, built by Davis of York, Pa. It had an upright boiler and cylinder. The Mohawk and Hudson, 16 miles, from Albany to Schenectady, was the next line opened, during the same year, and the cars were drawn by horses till the delivery of the locomotive De Witt Clinrating or paying fabric or paper with a water-resisting compound, or preparing metallic plates for roof covering. Roof-guard. Haven, 1857. The sheet is drawn down through a hopper containing tar, and passes out between pressurerollers. Davis, 1858. The canvas is drawn through a vat containing coal-tar. Pomeroy and Allen, 1859. Anderson, 1861. Steam-pipe to heat composition. Robinson, 1865. Coat sheets of felt, etc., with asphalt on one side, the other being supported by a
26, 1872. 137,618O'NeilApr. 8, 1873. 138,996DavisMay 20, 1873. 146,721TaylorJan. 20, 1874. 1. 9, 1869. 89,417McArthurApr. 27, 1869. 93,665DavisJuly 27, 1869. 96,713LyonNov. 9, 1869. 96,886 10, 1859. 26,906JohnsonJan. 24, 1860. 27,620DavisMar. 27, 1860. 27,999McCurdyApr. 24, 1860. 3413, 1867. 69,095HolcombSept. 24, 1867. 76,720DavisApr. 14, 1868. 6. Hemmers. (continued). No.6, 1874. 146,684JohnsonJan. 20, 1874. 151,202DavisMay 26, 1874. 151, 807Terry et al.June 9, 1874 2, 1866. 89,085ScharffeApr. 20, 1869. 93,063DavisJuly 27, 1869. 93,979EverissAug. 24, 1869. 10(Reissue.)3,491WeissenbornJune 8, 1869. 93,064DavisJuly 27, 1869. 93,743PreissAug. 17, 1869. 96,,477.Richardson et al1871 Reissued.45,703.Davis1865116,216.Pratt1871 45,821.Emery1865116,885.ued.52,293Kennedy1866118,417.Wyatt1871 53,777.Davis1866119,019Evans1871 Reissued.59,089.Smitho the lamp, and is used as an extinguisher. Davis's level and inclinometer. Spir′it-lev′el. [8 more...]<
nation of the pole to the plane of the ecliptic, and the constancy of the pole during the entire yearly revolution; the apparent movement through the constellations of the zodiac; the phenomena of eclipses, day and night, sunrise and sunset, and the seasons; the varying declination of the sun; the equation of time; the motions and phases of the moon; and affording a model whereon to illustrate the theory of the tides, lunar disturbances, etc. See No. 66,791, Campbell, July 26, 1867. In Davis's tellurium (Fig. 6282), a ball S′ representing the sun is attached to an upright shaft rotated by a crank through the medium of intermediate gearing, and passing through a sleeve rotated by gearing driven by the same crank, and carrying a toothed disk k engaging a rod passing through a horizontal tubular arm attached to and at right angles to the sleeve. The rod has a series of wheels at its outer end, which impart a rotary motion to the ball representing the earth, placed on an arm inclin
s the solution is withdrawn, steam is readmitted, and the wood similarly treated with muriate of lime; the reactions produce sulphate of lime and muriate of iron, which remain within the substance of the wood, rendering it much heavier and harder, and preventing the attacks of insects. Soaking timber in lime-water has been recommended for preserving it from dry-rot and the effects of the weather; also, superficial carbonization by a gas-flame or the flame of the heavy hydrocarbon oils. Davis and Symington, in England, introduced a desiccating hot-blast to remove moisture. Behr's patent embraces the employment of boiling solution of borax. Szerelmey's patent: 1st, immersing wood in boiling solution of potash and lime, and treating it with cold dilute sulphuric acid; and, 2d, coating it with compounds of petroleum, asphaltum, lime, zopissa, and sulphuric acid. Wood-preserving apparatus. L. S. Robbins's method consists in removing the surfacemoisture from the wood by h
, and the roads leading through north Georgia. I have ordered troops to Atlanta and Newnan, to care for the public property, and effectually watch and guard the country to the north and eastward, connecting with General Judah's troops. I had also requested General Grierson, who arrived at Eufaula the day before yesterday, to move by the way of Union Springs, Tuskegee, Montgomery, and Selma, towards Mississippi. He will send forward to put all the troops in central Alabama on the alert. Mr. Davis cannot possibly get through the country with wagons and a large escort, but it will be quite difficult to apprehend him if he attempt it well mounted with one or two attendants. I have already heard rumors, but which I can trace to no reliable source, that he went through this State between Atlanta and Marietta, five or six days ago. As soon as I hear from General Upton I shall increase the force now on the way to Atlanta, so as to make it sufficient to meet all contingencies. Colonel