Reports of the United States Commissioners

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Seite 381 - The pressure in the boiler expels it without necessitating the use of a pump. The stop-cock may be set so as to supply very accurately the water in proportion as it is wanted. The vessel X is formed of two concentric cylinders, and between these are two spiral tubes, formed of the tube W continued, and conveying the water drawn from the bottom of the boiler. These spirals are immersed in a liquid filling the annular space between the cylinders, •which is the reconstituted ammoniacal solution on...
Seite 71 - C (100° F) by a pressure of fourteen. If a refrigerator could be created having a constant temperature of 0° C, or lower, liquid ammonia would furnish a motive power of great energy, without the use of any artificial heat. The heat necessary to its evaporation might be supplied by placing the vessel containing it in a water-bath, fed, at least during summer, from any natural stream. Such a condenser could not be economically maintained. A condenser at 21° C, however, and an artificial temperature...
Seite 306 - After tliis the stone is placed, for a longer or shorter time, according to the size of the object, under a shower bath of cold water. This is not, by bathing, to convert it into Bath stone, although were the Bath stone a sand stone instead of an oolitic formation, this name would do as well as any. The salt, or chloride of sodium, deposited throughout the interstices, is sought out and washed away, in brine, by the water, and were it...
Seite 437 - ... the Hoe press being wholly dispensed with. The substitution of an automatic system of feeding for hand-feeding, which is one of the greatest economical advantages of this press, has been effected by introducing the paper into the machine, after it has been subjected to a moistening operation, by passing through a shower of fine spray, in the form of an endless roll. A single roll will contain several thousand sheets, and the printing operation, including the cutting of the paper into proper lengths,...
Seite 304 - The sand, a clean-grained, slightly brownish sort, just such as a dishonest grocer might select for increasing the gravity, specific or otherwise, of his sugar, comes from near Maidstone. There is no end to the quantity of it, and we believe it costs less than three shillings a ton in the Thames. There are flints enough for a hundred years to come brought up from the chalk pits at...
Seite 137 - The tube conveying he air to the perforators was two decimetres (nearly eight inches) in diameter. The air was under a pressure of six atmospheres, and its velocity in the tube was nine decimetres (three feet) per second. The transmission of the power to this distance, and under these conditions, was attended with no sensible loss. The pressure was not perceptibly less at the working extremity of the tube when all the perforators were in operation, than when the machinery was entirely at rest.
Seite 355 - Messrs. Emile and Pierre Martin, of Sireuil, have also commenced steel-inaking in a Siemens furnace. They melt a quantity of pig iron, and introduce wrought-iron scrap, puddled steel, or other malleable iron into the mass while exposed to the oxidizing influence of the flame. They have produced steel of excellent quality by this method, and are now about to introduce their process into several steel works in France. The great advantage obtained by them, and one which has not yet been arrived at by...
Seite 304 - It lias no oxidizable constituent; for silica, or silicic acid, is already oxidized, and thus it is unalterable in air; and as the new stone is almost impermeable, it will suffer little, if any, injury from moisture or frost. "And how marvellous, for its simplicity and beauty, is the process by which this stone is made! Some toiling mason or other, hewing in the quarry or in the builder's yard, must have...
Seite 305 - ... soda manufacture, are bought of the wholesale chemists. The silicate of soda is made from the flints and caustic soda as follows : The flints are heaped upon iron gratings within a series of cylindrical digesters, of the material, size, and form of small steam-boilers. A solution of caustic soda is then added ; the digester is then closed steam-tight, and the contents are boiled by steam of seventy pounds taken from a neighboring boiler and led through the solution in a coil of iron pipes. The...
Seite 306 - It is practically a fictile manufacture, although not indurated by fire, and, unlike fictile goods, having 'no shrinkage or alteration of color in the making. Whatever the required size of the finished stone, it is moulded exactly to that size, with no allowance, as in moulding fire-clay goods or in pattern-making for castings in iron. The heaviest blocks for works of stability, and the most elaborately ornamental capitals, tracery, or copies of statuary may be made with almost equal facility. For...

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