) The various proportions and relative qualities as to melting-point and gravity are collected from a multitude of sources, the best attainable.
The authorities, however, differ somewhat widely, and this can only be accounted for from the fact that so few metals can be obtained pure.
The differences in the metals obtained from different localities are often unsuspected, and are fully proven in the variable statements of the cohesion in the tables compiled by Muschenbroek, Tredgold, Barlow, Brown, Rumford, Rennie, Telford, Bramah, and others.
The difficulty that has thus arisen has caused variable statements in the formulas for bell and ordnance casting, and has very considerably affected the exactness of statement in all the alloys, especially the more fusible ones, where the various combinations of lead, tin, and bismuth give such variable results.
It appears to be scarcely possible to give any sufficiently general rules, by which the properties of alloys may be safely infer
are the following ingredients.
The specific combination in each case might be given would space permit.
1. Forms of carbon: —
Starch of flour.Aloes.
Cutch.Fatty matterslery.) A band of a bridle, head-stall, or halter, which passes in front of the horse's forehead, and has loops at its ends, through which pass the cheek-straps.
A process by which the surfaces of articles of iron acquire a shining brown luster; this may be produced by chloride of antimony.
Browning, or Bronzing se kind of wrapping-paper, which is made from unbleached material, such as junk, hemp, refuse flax, etc. It is made of various qualities, from manilla to straw.
A common variety of pottery, named from its color.
（Carpentry.) A beam that goes across a building.
A concave tool use
of the Baltic used ropes of twisted rawhide thongs.
The latter were used in Britain till the third century, and are yet used in Western Scotland for boats and draft.
Chain-cables were used by the Britons. (CAeSAR.) They were common long ago in small sizes, but were only lately made for heavy craft.
They have shackles at every 15 fathoms, sometimes swivels at 7 1/2 fathoms.
Chain-cables were made in England by machinery in 1792, and introduced into the British merchantservice by Captain Brown of the Penelope, West India merchantman, 400 tons burden, 1811.
The cable had twisted links.
Brunton patented the stay in the middle of the link.
The chain-cable was introduced into the British navy in 1812.
In making chain-cables, the bar of 1, 1 1/2, or 2 inch iron is heated, and the scarf is made by a cutting- machine; an oblique cut on the end of the rod, giving a chamfer or lap to the cut surfaces, brings a larger surface of the iron into welding contact.
around a common center.
They are used for various purposes.
Several are shown under the heads equational box; sun and planet motion; parallel motion; epicycloidal wheel, etc.
Their forms are numerous, curious, and ingenious.
(See page 120, Brown's Five hundred and seven mechanical movements. ) Quite a number of applications of the device have been made to harvestingmachines, in transmitting the motion of the drivingwheel axle to the cutter-bar.
a b c d are forms of epicyclic gearing. ank for an escapement in clocks, and received a bounty of £ 65 from the London Society of Arts.
Its advantage was silence.
A number of curious and ingenious escapements may be found in works on horology, in Denison's volume in Weale's series; Brown's Five hundred and seven mechanical movements ; and Piaget's The watch; its history and manufacture.
Es-cape — valve.
（Steam-engine.) a. A loaded valve fitted to the end of the cylinder for the escape of the condensed steam, or of water c
Were it not for the stud m, the lever, with the whole brake apparatus, would move round in a circle with the shaft, so that this stud has to withstand a certain force from the lever pressing against it. Now place gradually upon G such a weight as will counteract the pressure of the lever against m, and bring it back to its horizontal position.
It is evident that this weight, in combination with the lever F, expresses the amount of friction between the blocks and the drum.
A device for connecting two shafts by bringing a piece on one shaft in contact with a piece on another shaft, which revolves with such force that the former partakes of the motion of the latter.
In Fig. 2103, the shipper-handle F carries the shaft, and with it the toggles J J, expanding the segments against the rim of the pulley.
See also clutch.
A form of friction-coupling in which the connecting p
tion or expansion of gas in a closed cylinder.
The first gas-engines were gunpowder-engines, the gas generated by the explosion being the means of expelling the air, the condensation of the gases producing a partial vacuum in the chamber.
See Brown's English patent, vacuum engine, 1824.
D'Hautefeuille, in 1678, seems to have been the first to use this power; Hugyhens applied if in a cylinder so that the atmospheric pressure might force a piston downward when the vacuum was thus formed ain and fusee.
b. A ratchet-wheel with pawl and spring on the shaft of the great wheel, by which the works are kept going while the clock is being wound up. Invented by the celebrated English watchmaker, Harrison.
Harrison's going-barrel (Brown's mechanical movements).
In this, the larger ratchet-wheel, to which the click t is attached, is connected to the great wheel g by a spring s. While the clock is going, the weight acts upon the great wheel g through the spring; but as soon as
quart; alum, a small quantity.
Green ink: a mixture of blue and yellow.
Orange ink: a mixture of red and yellow.
Purple ink: a mixture of red and blue.
Brown ink: a mixture of black and yellow.
Sympathetic ink is an ink which is invisible till the writing is subjected to a subsequent operation, such as warming, exposns, subsequently dried, will be rendered visible by the means cited, developing certain colors.
Acetate of lead.Liver of sulphur.Brown.
Gold in aqua regia.Tin in aqua regia.Purple.
Infusion of galls.Sulphate of iron.Black.
Dilute sulphuric acid.Heat.Black.
Cobalt in dilute aqua regia.Heat.Green.
Precipitated oxide of cobalt in acetic acid and saltHeat.Blue.
Marking-ink is an aqueous solution of lunar caustic thickened with sap green and gum. It is written on a surface prepared by a weak solution of carbonate of soda and gum-arabic.
A marking-ink requiring no preparation of the surface is
tes that the instrument is level.
The level stands on a circular graduated table, from the center of the under side of which is suspended a plumb in the usual manner.
This plumb being adjusted over any point (as the corner of a building-lot) and the first line laid out, stakes can be set in a line drawn at any desired angle to the first line, by simply turning the level upon a central pivot, provided for that purpose, the required number of degrees as indicated on the graduated table.
Brown's level (e) is shaped like a pair of compasses; the cross-bar, which is marked at midlength, shuts up between the legs when closed for transportation, in which condition the instrument resembles a walking-stick.
It has the usual plumb-line.
The level is used to find a line parallel to the horizon.
Practically speaking, two places are on a level which are equally distant from the center of the earth, but as the line of sight is a tangent and does not follow the curvature, in an observati
titute of siliceous sand, its place being occupied by coarse powdered gypsum or native sulphate of lime.
Stone mortar. 8 parts cement, 3 parts lime, and 31 parts of sand.
Brick mortar. 8 parts cement, 3 parts lime, and 27 parts of sand.
Brown mortar. Lime, 1 part; sand, 2 parts; and a small quantity of hair.
Khorassar, or Turkish mortar, used for the construction of buildings requiring great solidity.
1/3 powdered brick and tiles, 2/3 fine sifted lime.
Mix with water to the requifrom its work, and has also a longitudinal movement, to pass along the edge of the cutter.
（Surgical.) A substance burnt on the skin to form an ulcer.
The soft, woolly leaves of the artemisia are used.
Dr. Brown-Sequard repeatedly applied moxas to the back of our late Senator Sumner.
He regarded the treatment as the most severe he had ever applied to any living creature, — not excepting his guinea-pigs, which, in various states of dilapidation and des<
p and chart holder.
Brown paper.Metallic paper.
Cap-paper.Mus paper through a trough of size between two endless felts.
1853. Brown and McIntosh, Aberdeen, Scotland.
Hollow perforated mold, covered ng, varnishing, painting, or what not, according to its purpose.
Brown and Macintosh, English patent 14,131 of 1852, describes a mode of mr envelope.
See also American patent of French and Frost, 1856; Brown and Smith, 1851; Hatfield, 1862.
Fig. 3533 illustrates the prince, is pronounced by Loudon one of the best modes of paving.
Lieutenant Brown (England, 1830) suggested a gravel foundation, dressed blocks ws projecting from the inner ring.
a′ shows a dowel-plate.
b is Brown's, 1869, which has metallic springs, thrusting outwardly the elastiarying the points of attachment to the load or to the support.
See Brown's 507 Mechanical Movements.
In White's pulleys (k)