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mixture of glutine and vegetable fibrine, with a liquid composed chiefly of glutine in solution; from this the glutine is precipitated, and then well washed with water or other suitable liquid.

Instead of obtaining first a precipitate of impure glutine, and next a precipitate of pure glutine, the precipitates can be made at one operation; or, instead of precipitating twice, the operation may be extended to three or more precipitations; care being taken to separate each precipitate. When flour or gluten is operated on, bran is held in suspension in the solution, from which it may be separated by sifting, by allowing the solution to rest, or otherwise. The starch and vegetable fibres are separated in the manner described, with reference to the treatment of wheat. Starch waters containing glutine in solution are treated as a solution of glutine.

The solutions may be made, first, of acid waters resulting from the washing of starch; second, of most organic acids; third, of most mineral acids; fourth, of most of the soluble oxides; fifth, of most kinds of salts. The solution is made by submitting to the action of one of the above agents the substances which contain glutine. The precipitation of the glutine is effected by the neutralization of the solution, if it is alkaline or neuter, by the addition of certain acids; and, even if the liquor is acid, by the addition of a number of salts, alkaline, neutral, or acid; or by the introduction of substances capable of forming insoluble combinations with glutine, such as tannin.

Glutine, made in the manner described, is employed for fixing colors on fabrics, paper, textile substances, and others; for painting and varnishing boats, metal, and the like; for giving a finish to, and for preparing, threads, tissues, leather, and paper; and as the gluten can be rendered insoluble, the substances thus treated will be made incombustible, and at the same time they will not be injured by washing; for binding together all sorts of substances, such as wood, stone, glass, metals, stuffs, skins, and the like; for so preparing threads as to give them the strength and appearance of horsehair; for making artificial horn, bone, shells, pearls, coral, and articles manufactured from such like materials; for coating and rendering medicines tasteless; for clarifying all sorts of substances; for the manufacture of beer; for rendering alimentary substances very nutritive; for the manufacture of soap in combination with alkaline solutions; for making imitations in glass, porcelain, pottery; and for many other useful purposes.

The patentee claims, "the method of extracting substances from cereal grains and some of their products, and the application of the substances extracted, in the manner and for the purposes described."

To WILLIAM SMITH and PRINCE SMITH, both of Keighley, Yorkshire, for an improved process of hardening cast-iron caps used in machinery for spinning and doubling wool, cotton, silk, flax, mohair, and other fibrous substances.-[Dated 18th January, 1860.]

THIS invention applies to a certain part of the apparatus used in spinning and doubling machinery, known as the "spindle cap," which consists of a cylinder or cone of cast iron, polished externally, and placed on the spindle. These caps, in consequence of their being made of cast iron, have hitherto been extremely liable to be bruised or damaged by a blow

VOL. XII.

Y

or fall. To remedy this defect, the patentees harden the cast-iron spindle caps by heating them to a red heat, and then putting them into cold water mixed with common salt (chloride of sodium).

The patentees claim, "the method or process of hardening cast-iron spindle caps, by heating them to a red heat, and then plunging the same into cold water, either with or without the addition of chloride of sodium or other suitable chemical salt."

Scientific Notices.

INSTITUTION OF MECHANICAL ENGINEERS.
Continued from page 47.

The paper next read was, "On Giffard's injector for feeding steamboilers," by Mr. JOHN ROBINSON, of Manchester.

THE object of the water injector forming the subject of the present paper, called the "automatic injector," is to feed steam-boilers by a selfacting apparatus, employing the direct application of the steam from the boiler, without the intervention of machinery.

The steam from the boiler to which the apparatus is applied, is admitted through a pipe, governed by a cock, and passes into a perforated cylinder or tube, which is adjustable vertically in the pipe which supports it. This tube is made conical at the bottom, the area of the aperture being regulated by a conical rod, adjusted by a screw and handle with which the rod is fitted. The jet of steam issuing from the conical orifice of the tube encounters the feed-water in a chamber connected with the feed-water pipe; the supply of feed-water is regulated by raising or lowering the tube, by means of a screw of quick pitch, having a loose bearing in a flange of the tube, and working in a tapped shoulder on the pipe which carries this tube. The stream of feed-water propelled by the steam-jet issues from the orifice of a conical tubular prolongation of the feed-water chamber, and passes into the mouth of a pipe set in a line therewith and leading into the boiler; the intervening space between the two pipes being open to the atmosphere, so that the stream of water can be seen through the sight holes in the outer and enclosing pipe, at this part of its passage, while the injector is at work. A check-valve is provided to prevent the return of the water from the boiler when the injector is not working. Any overflow occasioned in starting the injector is carried off by an overflow pipe, and the sight holes are covered by a circular slide.

In starting the injector, the adjustable tube is first brought to the position suited to the pressure of steam in the boiler; this permits the access of water to the instrument and regulates its admission. The steam-cock is then opened, and the screwed rod slightly elevated, which admits a small quantity of steam to the conical tube leading from the feed-water chamber. A partial vacuum is thus produced in the chamber by the rush of steam downwards, and the water flows into it. As soon as this happens, which can be observed at the overflow-pipe, the screwed rod is gradually raised

1st

until the overflow ceases, thus giving full liberty to the steam to act upon the water and drive it into the boiler past the check-valve.

The injector has now been in use upwards of nine months in France, a large number having been put to work there, of which a considerable proportion has been applied to locomotive engines; and these have been found so thoroughly satisfactory, that their application to locomotives, as well as to marine, stationary, and agricultural boilers, is being widely extended: they are especially advantageous for boilers in motion, and when the engines work at high velocities, on account of the certainty of their action, together with their great simplicity of construction and freedom from risk of derangement. Injectors have been working for six months in England, the first having been procured from France by the writer's partner, Mr. Stewart, and tried upon a stationary boiler at their works. It was subsequently put to work upon a ballast engine upon the St. Helen's Railway, where, in the course of a few days, the driver was able to dispense with the use of the engine pumps, and to maintain the level of the water in the boiler by the injector alone. A larger injector was then tried upon a goods engine on the same railway, which proved entirely successful and the writer, with the kind co-operation of Mr. Cross, the engineer of the railway, made experiments with this and another injector of the same size, manufactured at Manchester, to ascertain what effect the temperature of the feed-water, and the vibrations and concussions caused by the action of the break, passing over crossing points or shunting waggons, &c., would have upon the regularity of the water passing through the instrument. The general result ascertained by these experiments was, that the injector would work at all steam pressures up to the maximum working pressure of the boiler, 110 lbs. per square inch; and would draw water from the tender of any temperature up to 110° Fahr.; and that neither the sudden application of the break, nor any shock produced in passing bad points or in shunting, interfered in any way with its efficient working. The only difficulty which arose was when the water in the tender had become hot, and at the same time very low in level, under which circumstances conjoined, the degree of vacuum capable of being produced in the water-chamber of the injector was not sufficient to lift the water to the height at which it was placed, 29 inches above the footplate; this inconvenience was, however, readily obviated by lowering the injector, so as to bring the water entrance within a few inches of the level of the bottom of the tender. In using the injector, no difficulty was experienced in so regulating the openings for steam and water as to produce a constant and regular supply of any required quantity of water to the boiler, without waste, from the overflow pipe. The result of the continued working of these injectors on the St. Helen's Railway was so satisfactory, that ten of them have been ordered for the engines on this railway: and it has been decided to replace all the pumps of the locomotives on a foreign railway by injectors, after careful trial of one of them.

It may be desirable here to mention some collateral advantages arising from the use of the injector on locomotive engines. The space hitherto occupied by the pumps is saved, and becomes available for other purposes: the power of the engine required to work the pumps is economised, and the wear and tear of the parts through which this power is transmitted is entirely avoided: and the water level can be maintained at any desired height, whether the engine be moving or not; also the steam, often blown

off when standing, can be used for the purpose of forcing water into the boiler.

The

For the purpose of ascertaining the limits of the circumstances under which the injector can be worked, a series of experiments was made by the writer with instruments of different sizes, fixed to stationary boilers working at 60 lbs. pressure, one of which being connected with an adjoining boiler, in which the pressure could be reduced to any desired amount, gave great facility for measuring the power of the injector when feeding by lower into higher pressures; the relative pressures being accurately observed by Schaeffer's and mercurial steam gauges. temperature of the feed-water, also, could be varied at pleasure, by introducing into it either hot or cold water, as required. The general results obtained from these experiments were, that water could be forced into a boiler by the injector when the steam pressure was not below 5 lbs. per square inch; that the temperature of the feed-water might be raised up to 148° Fahr., requiring to be varied in the inverse proportion to the pressure of steam; and that surplus power was developed by the instrument, available for forcing water into a boiler at a higher pressure than the one from which the steam was obtained; the injector having been effective with steam of 24 lbs. pressure above the atmosphere in forcing water into a boiler at 48 lbs. pressure. In all cases, the surface of the water in the supply-tank was at least 2 feet below the level of the water chamber of the injector; the vacuum in that chamber being from 1 lb. to 1 lbs. below the atmosphere during the operation.

Mr. C. W. Siemens enquired what increase of temperature took place in the feed-water in passing through the injector, as this would be a measure of the quantity of steam condensed in the jet, and it was important to ascertain the actual expenditure of power in working the instrument. The theory of its action could then be investigated by ascertaining whether the quantity of steam condensed in the jet was sufficient to impart to the jet of water the velocity required for enabling it to overcome the resistance opposed to its entrance into the boiler; for the velocity imparted would be inversely proportionate to the weights in motion, and 1 lb. of steam would impart to 10 lbs. of water 1-10th of its velocity, if no force were lost from friction and eddies in the jet.

Mr. Robinson replied, that there was found to be a rise of temperature of about 60° in the water in passing the injector; the feed-water at 100° being raised to 160°. He showed a specimen of the injector,-taking it to pieces to explain its construction.

Mr. E. A. Cowper asked whether this rise of temperature was measured from the waste water overflowing from the instrument, or from the water in the feed-pipe going into the boiler; the latter, he considered, would be requisite for obtaining the correct result. The instrument was certainly highly ingenious, and an interesting subject for investigation as to the principle of its action.

Mr. Robinson said, the rise of temperature that he had mentioned had been measured only at the overflow, as there was no means of measuring it otherwise at present. The overflow, he further said, was entirely stopped by adjusting the steam and water in due proportion, which took place in a few seconds after starting to work, and the injector then continued working regularly for any length of time without the least over

flow with a pressure continuing uniform; but the overflow could be caused directly by increasing the water supply or diminishing the steam. too much.

Mr. W. B. Johnson had seen the injector at work, and was much struck with its perfect action and extreme simplicity; it was started instantaneously to work without any difficulty, and continued working regularly without the slightest overflow of water; the sight holes could be kept permanently open after it was started in full work, and all that was seen was an apparently solid column of water rushing from one tube into the mouth of the other. He saw an experiment tried whilst the injector was in full work, by insérting a plate between the two orifices to stop the action of the jet; but the stream was instantly established again on removing the interrupting plate.

April 25th, 1860.

The first paper read was, "On some regenerative hot-blast stoves working at a temperature of 1500° Fahr.," by Mr. EDWARD A. COWPER, of London.

THE practical utility of hot-blast has been so thoroughly appreciated since its first introduction by Mr. Neilson, in 1829, that it now needs no advocate to recommend it to experienced ironmasters. Many plans of hotblast stoves have been suggested and tried, and various opinions have been expressed on their merits, owing to the same constant care and watchfulness not having been exercised at different works when using stoves of a similar description. It has been found by many careful observers that the results from the blast furnace are so greatly improved by raising the temperature of the blast, that ironmasters have often tried how far they could go in obtaining a higher temperature, and have, of course, soon arrived at a limit, from the destruction which ensued of the cast-iron pipes; and it is obvious that there must always be a wide difference between the temperature of the air heated inside a cast-iron pipe and the fire outside the pipe heating it, as there will be the difference in temperature between the fire and the pipe, together with the difference in temperature between the pipe and the air passing through it. These differences must be considerable, in order to ensure a tolerable rapid conduction of the heat; so that in no case can the hot-blast approach at all near to the temperature of the fire, nor indeed would the cast-iron stand if anything of the sort were attempted. The temperature at which the products of combustion pass away from ordinary stoves is from 1250° to 1500°, whilst the blast is heated only to about 700°. The economy of fuel for real work done must therefore be very low, as the products of combustion must pass away much hotter than the temperature obtained in the blast-say about double the temperature; and when it is attempted to obtain economy in the blast-furnace by increasing the temperature of the blast, economy is further sacrificed in the stoves, by the greatly increased amount of heat which must necessarily pass away: hence the hotter the blast, the greater is the waste of fuel in heating it in the ordinary stoves.

In the plan of hot-blast stoves to which it is now wished to call the attention of the members, the principle of Mr. Siemens's regenerative furnace is adapted for the special purpose of heating blast, and the stove is en

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