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REPORT OF EXPERIMENTS ON THE EXPLOSIONS OF $TEAM-BOILERS, 187 which furnished the nitrogen gas, before re, interior. As no inflammable gas had as yet ferred to as issuing from the boiler, was not been obtained, and as the gas which issued derived from the water injected. The in- was nitrogen mixed with oxygen, the entrance jection of one fluid ounce and a quarter troy of air into the boiler was obviously the source (2:25 cubic inches) of water, never gave less of the gas collected. than 2:6 cubic inches of gas, and sometimes, A new glass plate was substituted on the potwithstanding the leakage, gave 17.28 cu- third day for the broken one, and a copper bic inches, But water absorbs, according to plate was screwed upon the opposite opening Saussure, from 5 to 54 per cent. of its bulk of the boiler, which was thus rendered as of atmospheric air, giving for 2:25 cubic tight as the nature of the apparatus perinches only •118 of a cubic inch of air, not mitted. The experiments were made at reone-twentieth part of the minimum quantity gular intervals, varying in different parts of of gas derived from the boiler by the injection the series from 60 to 10 seconds, and in such of 2.25 cubic inches of water. On observing a manner that the bottom of the boiler might closely the cracked glass plate, it was seen, be found in nearly the same state, in some of that after a certain period in the production the experiments, with each interval. The of steam by the water thrown into the boiler, interval was counted from the time at which the vapour ceased to issue through the crack, gas ceased to issue in a previous experiment, and, finally, that a bending inwards of the to the instant of injecting water. The unit pieces of glass indicated that the pressure of measure of the gas was 1.8 cubic inches. within the boiler was less than that without, The results were as follows: and that atmospheric air had access to the

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In this series we remark, first, that the mean result for an interval of 60 seconds, is 8.5 measures; for an interval of 30 seconds, 9ol measures; for 20 seconds, 7•5 measures; and for 10 seconds, 6.9 measures.

If atmospberic air leak into the boiler, the air will enter until the pressure within and without become equal. Hence an increase in the interval between two experiments in which the air should be expelled, would, above a certain point, be attended with no increase in the quantity of gas which would be expelled; the only effect being to consume, more completely, the oxygen of the entering air. Up to this point an increase of interval should be attended by an increase of air which would leak in, and consequently by an increase in the amount subsequently ex

pelled. The mean results given above do, in fact, show an increase in the quantity of gas obtained after an interval of 20 seconds over that obtained for 10 seconds; of 30 seconds over 20 seconds. They give a slight decrease from the interval of 30 seconds to 60 seconds, which will find its explanation on a further examination of the results.

Second; we observe from the table, that after a number of short intervals, the succeeding long interval never gave as much gas as when the long interval bad been repeated ; and, vice versa, that after a series of long intervals, the next succeeding short interval gave a higher result than that which followed. The experiments, with an interval of 30 seconds, were not as much interspersed among the short intervals, in the last part of

• The numbers marked (t) signify that an unmeasured portion of the gas escaped.



trogen, and 94 per cent. of oxygen : in each case the results were obtained by exploding a mixture of the gas with hydrogen.

The boiler was now thoroughly cleansed, that the scale of oxide upon the bottom might be removed; in doing this, the hand. hole was necessarily removed, and had to be repacked. Paper was placed between the glass plate at the back end of the boiler and its metallic covering, that the boiler might oe tightened. To ascertain the amount and direction of the current setting into, or out of, the boiler at any time, a copper pipe, terminating in a glass tube, was attached to one of the stop-cocks on the head, at the fire end of the boiler, the glass tube dipping into a vessel containing water,

The injection water was, on resuming the experiments, heated over a sinall furnace, to boiling, in a metallic vessel, from which it was drawn by the pump. When the bottom of the boiler was at a bright red heat, the lowest thermometer had attained a temperature of 5700, and was soon aster removed. The quantity of water thrown in at each stroke of the pump, was now by no means so regular as when the action of the pump was not impeded by the formation of steam within it, from the injection water. The results obtained were:-

the series, as were those of 60 seconds; the mean of the results for this latter interval is, therefore, diminished.

No increase in the amount of gas was ob. tained by increasing the quantity of water injected. The mean of four experiments, when the bottom was at a glowing red heat, and the thermometer 7 inches from the bottom, at from 5530 to 5590 Fah., was 5:75 measures for 1} ounces of water; from 5720 to 580°, by the same thermometer, 10:5 measures for the same quantity of water injected; above the range of the scale of the same thermometer, 12 measures for li ounces, and about the same quantity for 2 ounces. During these experiments, mercury, which was on the top of the boiler, in a clay receptacle, boiled freely. The best evi. dence is thus given that the bottom of the boiler was not wanting in heat; it was, in fact, at a bright red heat during the last part of the experiments.

The peculiar odour, before remarked, as belonging to the gas expelled from the builer, still continued, indicating the presence of sediment within the boiler; this could be seen when the metal was glowing. A scale of oxide also appeared on the bottom, which now and then cracked, presenting irregular luminous lines as the boundaries of the scale,

The experiments just detailed were, on a succeeding day, repeated, to ascertain whether the same results would be reproduced. The bottom of the boiler being at a bright red heat, an interval of 60 seconds gave, as the mean of four experiments, 11:5 mea. sures of gas for one ounce of water injected; an interval of 30 seconds gave, as the mean of five experiments with three-fourths of an ounce of water, 13 measures; an interval of 20 seconds gave, as the mean of four experiments with half an ounce of water, 10.6 measures : and again, in a second series, the same interval gave 10:5 measures for the mean of four experiments with five-eighths of an ounce of water. Towards the close, the numbers for 10 seconds of interval were very variable, the meanos six experiments with .65 ounces of water, injected when the boiler was at a cherry red, was 6.3 measures, of gas ; with a heat which, to all appearance, was the same, the gas collected diminished to 3.5 mea. sures, and averaged 3 measures at a bright red heat. For an interval of 5 seconds, with 18 ounces of water injected, 4 measures of gas were obtained. The conclusions to be drawn from these results agree with those already deduced from the previous experiments, which were thus confirmed. The gas collected was carefully transferred, over water, to the labo. ratories, where it was analysed. One specimen yielded Professor Hare, nitrogen with seven per cent. of oxygen ; another, examined by Professor A. D. Bache, gave ni

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A combustible gas had appeared for the first time. The injection water was changed for cold water, and a gas obtained, which burned as before; Il measures of air and one measure of the gas detonated slightly, also one to 8 measures of air ; neither detonation was sufficiently violent to extinguish the candle held at the mouth of the jar in which the gases were fired.

The gas now came over, not in copious bubbles and during a short time, but slowly and continuously, as if resulting from a constant, but not violent, chemical action. After these results had been obtained, the violent and brief bubbling, when the water was injected, recommenced, and the combustible gas was no more obtained. The


change of hot injecting water for cold, and the collection of the combustible gas after the change, showed that the gas was not derived from any effect produced by the increased temperature of the liquid introduced. The other circumstances which had been different from those of former experiments, were the superior cleanliness of the bottom of the boiler, and the repacking of the hand hole with cloth, oil and putty, and of the glass window with paper. Before proceeding to the detail of tbe experiments, in examination of the source of the combustible gas obtained, it may be well to mention that the glass tube, already spoken of, showed, after the water injected in some of the experiments had evaporated, a current of air, due to a force equivalent to a liead of from to 1} inches of water, from the exterior into the boiler; in one experiment it is noted that the water, in the tube referred to, soon fell, which indicated'a leak in some part of the boiler.

On the day following that upon which the experiments just given were made, nothing conclusive was obtained ; no combustible gas appeared, but the heat was hardly as high as

on the preceding day. Small disks of wood, thrown into the boiler, gave a combustible gas, which came over just as was noticed in relation to the inflammable gas of the preceding day's experiments. That these in. Aammable gases, in mixture with the oxygen, remaining in the atmospheric air within the boiler, produced no explosion, is in accordance with the well-known fact in relation to them ; pure hydrogen, in such a mixture, combines with oxygen under the influence of a body heated to redness.

On the following day of experiment, circumstances proved entirely favourable; the bottom of the boiler was heated as intensely as on the former occasion. After much incombustible gas had been obtained, traces of an inflammable one appeared. A strong smell of oil was noticed about the hand hole, at the back end of the boiler; the packings were now white on the exterior. The fire was urged, and the boiler became strongly heated throughout its whole length. The following results are from the journal of the experiments:

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atmospheric air deprived, by the heated metal, of more or less of its oxygen.

2. That this air was derived, principally, from the current into the boiler when surcharged steam had ceased to be formed, and the boiler was left dry; there will, therefore, be no such quantity in a working boiler, where the air must be supplied from the cold water thrown in.

3. That water in contact with heated iron in a steam boiler, the surface being in its ordinary state, clean, but not bright, is not decomposed by the metal.

(To be continued in our next.)

RECENT AMERICAN PATENTS. (Selected from the Franklin Journal, for May.)

IMPROVED DOUBLE SPEEDER, William Field, Rhode Island. — This improvement si consists in a plan of compressing the roving on the spool so hard, or compact, that the same quantity may be put on a spool of only one-fifth of the common size. A machine with this improvement will occupy only one half of the room, will require much less power, and will run at least one-third faster than common speeders.” The usual plans for drawing, twisting, and winding the roving, are followed; but the spools are run faster than the Ayers, to take up the roving, instead of permitting them to fall back, in the common manner. The flyers are supported wholly above and independent of the spindles, are about one-half the usual length and diameter, and have a hoop at their lower ends to prevent their expanding.

The condensation of the roving is effected by the pressure of a thin circular plate against it, as it is wound on the spool; the plate being about the same diameter as the spool.

The claims are to “ the plan of compress. ing roving on spools by circular plates, hav., ing a rotary motion, acquired by their pressure on the spools, the edges of which act on the roving as it is received from the flyers, and thereby condense it, so that a much greater quantity can be deposited on spools of the same size. The sliding rail in the rear of the spools, on which the circular plates are placed, and the connexion between the increasing size of the spools, and the traverse motion of the belt guide, so that the spools may cause the variation of speed which their cons‘antly increasing size requires. The application of a heart motion for traversing the spools, so formed as to cause them to rise with greater velocity than they fall, so that a less quantity of roving may be deposited on the spools when rising than when falling.”

DISTILLING ALCOHOL FROM APPLES, Anson Walcott, New York.-The pommage is to be put into a steam-tight tub, into which steam is to be admitted through a tube, which descends nearly to the bottom of it; a series of vessels, similarly connected by tubes, and perfectly resembling Woulfe's apparatus, is terminated by a condensing worm. The three last vessels, as represented, are to be hollow globes of metal, placed within open tubs, the water in which is to be sufficiently warm to keep the alcohol in the state of vapour, as, otherwise, it would condense in the hollow globes. The claim is to "s the application of steam in extracting alcohol from apple pommage, without first making it into cider, aud the globular metallic condensers."

SAFETY STEAM-ENGINE BOILER, JohnC.F. Saloman, Reading, Pennsylvania.—The claim under this patent is to “the principle of constructing boilers with inverted arches, so arranged as that their convex surfaces shall resist the pressure of the steam; and the surrounding of the boiler so formed by a cylindrical or polygonal casing, forming a chord to each arch the whole length of the boiler, and thus preventing the spring of the said arches; whilst at the same time the spaces between the cases and the arches thus formed may serve as fire-places and flues for generating and conducting heat."

Not only is the body of the boiler to consist of arched segments, riveted together at their edges, but the heads also are to be concave inwards, so as to be pressed on by the steam in the manner of a dome.

Such a boiler would have a much less capacity in proportion to its weight than one of the cylindrical form, and there would scarcely be a single point within it which, by yielding to the internal force, when not sufficient to rupture it, would not thereby enlarge its capacity.

The arched form, in a malleable, flexible substance, such as iron, will not operate in the same way with the stones in an arch of masonry; every indentation in the metal is a commencing point at which it may give way, and be followed by all the parts which surround it. Besides this, we see not how the places of juncture exposed to the action of the fire, and the metal forming the chord of the arches thus exposed, are to be kept from heating, and burning out. The thing at first view is specious in its appearance, but it will not stand the test of examination, or the still more searching one of fire.

APPLICATION OF HYDRAULIC POWER, Robert Mills and H. B. Fernald, Portland.The rising and falling of the tide is to be employed for the purpose of condensing atmo.


191 spheric air, which condensed air is to be is twice glazed in its passage between the afterwards applied as a motive power, to rollers, thereby preventing the necessity of machinery. The mode of condensing con- performing the operation a second time. In sists in placing a reservoir in the water, which the ordinary calender, it is said that the shall rest on the bottom. This reservoir is boxes in which the gudgeons of the top roller to be open at bottom, to admit the water, run, last generally but sixty days, the weight but closed at top, to retain the air; the top having to be applied on them, whilst by the is to rise to a convenient height above the new arrangement, in which a large roller line of high water; at this line there must

with a slow motion receives the weight, the be a horizontal partition, or diaphragm,

boxes will last for two years. furnished with valves, opening upwards, to MANUFACTURE OF TUBES AND HINGES, admit the air as the water rises, and to retain William Shaw, Buffalo.—The machine init in the air-chamber when it falls. This tended to be described is one for bending chamber is to be “ provided with suitable sheet metal to form the tubular knuckles of screw-valves, to admit of using the condensed hinges; the description is a very imperfect air at pleasure ;" it is to be applied like one, and there is not any claim made; we steam."

“ In the falling of the water, there think, however, so far as the materials before will be a vacuum created, or a tendency to us will justify an opinion, that the machine that effect, in the air-chamber, or room ; is sufficiently original to be claimed as a and the atmosphere being admitted through whole. The sheet metal is to be passed in a valve, opening inward, will rush with a between two blocks of steel, and beld in its force proportionable to the base of the air- place by a tightening screw; when, by turnroom, or chamber, and thus a power will be ing a crank, the end of it is bent round a gained, in the falling of the tide, or water, pin, which pin is to be pushed out by placing which may also be employed to condense the hand upon a lever, thus forcing up a more air, or otherwise, by making the pres- round punch, or wire, for that purpose. sure of this air to work a wheel, or piston, as it enters the air-chamber.”

ARTIFICIAL STONE, &c., Charles Clinton,

New York.-Limestone is to be burnt until We noticed a patent, obtained, about two

about two-fifths of it is converted into lime; months since, by one of the above-named

to four bushels of this, when cool, four gentlemen, for applying the rising and falling of the tide to the propelling of machinery,

pounds of pearl-ash and three pounds of and showed that the plan then proposed was

alum are to be added, and the whole ground

fine; the composition is to be put into open old, referring to a former patent for the same

barrels, and to remain there until the lime thing, and our remarks thereon. Although the mode there proposed is not, we thick,

is perfectly slacked, after which it is to be

mixed with water to a proper consistence, likely to come into extensive use, there are

and used as a hard finish for walls; when situations where the power obtainable might

rubbed down, it is to look like polished marbe usefully applied; but if that now brought

ble. For outside walls, about one-third part forward is interded an improvement

of sand is to be added. The composition thereon, we are very certain that the thing will be « mended worse.” To use the con

may be variegated in its colours by the addensed air to advantage, would be an under

dition of proper materials for that purpose, taking of great practical difficulty, and, in

and a variety of modes are suggested for

varying the ornamental appearance of it. the present case, could not be effected, but by a very considerable loss of power ; the

Blocks, pillars, &c., may be formed of

the cement, and, when sufficiently dry, may patentees, however, have furnished us with no plan for doing this, and we will not attack

be plastered, as before directed, and po

lished." windmills. We do not know even what they mean by“ screw-valves ;' these are

MR. HANCOCK'S STEAM-CARRIAGES. certainly novelties in mechanics. There is 20 point more clearly ruled than that a Statement of One Month's Performances on the patent cannot be sustained for a principle,

Paddington-road, from May 16 to June 15. but only for the carrying of a principle into

42 trips from the City to Paddington. effect by certain means; but, in the case


Islington. before us, no means are given.*

Number of pas-engers carried ..2970. CALENDERING Cloth, Zenas Bliss John

On the occasion of the opening of Moorston, Rhode Island.--The improvement here

gate-street by the Lord Mayor, on Monday patented consists in the addition of a roller last, the “ Enterprise” entered immediately above the three ordinarily used in calenders,

after the train of Aldermen, when one of the by the aid of which additional roller the cloth

City officers mounted the roof, waving a

large flag. The steamer was full of pase * See Mech. Mag., vol. xvi. pp. 375 and 438. sengers, and loudly cheered by the populace.


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