I am aware that some of your correspondents may consider my opinions as extravagant and absurd; I am, however, content with plain practical facts, to which the most scientific must sooner or later be willing to accede; and being neither a mathematician nor an engineer, I run no risk of losing my reputation.

The question appears to lie in a very small compass. The resistance of the atmosphere, in a quiescent state, to the motion of a locomotive engine proceeding on a level railway, with a velocity of 100 miles an hour, would be precisely equal in effect to a strong gale of wind proceeding at the same velocity of 100 miles an hour on the same engine-carriage, without steam or other power. We may, I think, conclude that the effect would not be very great of such a wind, from the fact which occurs continually to the observation of every individual-namely, the effect of the atmosphere during a gale of wind, moving at the rate of 100 miles an hour (and, perhaps, much more), in direct opposition to the progress and advance of a stage-coach with four horses, which must oppose a resistance fully equal to that of the atmosphere on an engine-carriage moving with the same velocity, impelled by steam, through a quiescent atmosphere. We do not find that the horses are arrested in their progress by such a wind, or that the coach and passengers are much impeded by an opposing atmosphere moving at such a velocity, though the horses, coach, and passengers, combined, present a much greater surface to its action than 30

square feet. Perhaps an instance was never known of an additional pair of horses being attached to overcome the resistance of such a storm, though it continually occurs, and is found indispensably necessary, from bad roads.

The

usual and utmost effect has been a little delay. If the locomotive engine were passing through the dense medium of water, the specific gravity of which is to air as about 800 to 1, the opposing force of resistance to a velocity of 100 miles an hour would be immense, because the water, from its density, could not fill up the run of the engine-carriage with sufficient velocity, so as by its pressure behind to counterbalance the opposing or resisting pressure in front. But the case is Lotally different with a carriage on a level railway passing through the atmosphere,

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which, in a quiescent state, would oppose resistance only as 1 to 800 compared with water. A carriage moving with that velocity on a railway would scarcely feel such resistance, because the atmosphere, from its extreme rarity, and a pressure of 15 pounds to the inch, is calculated to fill up the partial vacuum made by the passage of the engine, with a velocity far superior to that of 100 miles an hour; consequently, the pressure at the back of the carriage (and all around it) would be always equal to the pressure

in front.

Viewing the railway system as being yet in its infancy, I have no hesitation in giving it as my opinion, however chimerical it may appear to some of your professional readers and correspondents, that a carriage, on a level railway, moved by a moderate gale of 60 miles an hour, acting upon a sail of proper dimensions, and going before the wind, will be found to move with a rapidity equal to threefourths of the velocity of the wind, because upon a railway there is comparatively no friction, and that little more power would be necessary than to overcome the inertia of the carriage. The narrowness of the railway would, however, be, no doubt, a considerable drawback on such a mode of transit. I am, sir,

Your obedient servant,
W. ALDERSEY.

Homerton, near Hackney.

CHAIN CABLES.

Sir,-Since the introduction of chain in lieu of hemp cables for the use of ships, the capsizing of what is termed the windlass pauls has been a subject of general complaint. Having had a practice of thirty years in the marine-smith line, it has occurred to me, that this defect arises from the diameter of the windlass barrel not exceeding that of the body of the windlass including the whelks; the consequence of which is, that when the ship is riding at anchor, the half diameter of the chain-cable is above the bearing points of the pauls, and of course there is little or no strain on the centre gudgeons.

1 propose to increase the diameter of the windlass barrel to about 4 or 5 inches above the surface of the whelks (for ships of about 200 tons). By this means more

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of the strain of the chain-cable would be
transferred to the centre gudgeons, which
would materially relieve that on the
pauls, and prevent many disasters. I
would recommend the common cast-iron
pauls, in preference to what is termed
the jumper, as this last works with too
much weight on the windlass barrel, and
wears its channelled surface in a very
short time. I think it will not be neces-
sary to increase the weight of metal in
the manufacturing of this description of
windlass barrels, as they may be made
much less in depth than those now in
use, or concave at the ends, in the man-
ner of a cast-iron gun-carriage wheel.
I am, sir,

Your very humble servant,
GEORGE ENNIS.

Specification of Patent granted to Mr. Tyson, August 8, 1831.

"To all whom it may concern, be it known, that I, Nathan Tyson, of the city of Baltimore, in the state of Maryland, have invented certain improvements in the kilndryer, patented by Oliver Evans, on the 22nd day of January, 1808, as specified by him among certain inventions of improvements in the process of the art of manufacturing grain into flour or meal, and for other purposes;' by which improvements in the mode of preparing wheat-flour and other kinds of meal for packing, their tendency to sour, or to become otherwise injured by keeping, if not altogether obviated, is much decreased; and that the following is a full and exact description of the same.

It is a well-established fact, that the various species of fermentation which take place in vegetable matter, are not produced by temperature alone, but require the presence of a certain portion of moisture. The advantage derived from the kiln-drying of grain and of meal depends upon this principle; and my improvement consists in a more effectual and beneficial mode of ac

complishing the end proposed, than any of those which have been heretofore adopted.

"I take the flour, or meal, either as it leaves the mill-stones, or after it has been submitted to the process of bolting, and cause it to pass through cylindrical or other suitable tubes, or boxes, to which a revolving or vibratory motion is to be given, and in which the flour, or meal, is subjected to the action of steam or of heated air. The tubes, or boxes, may be constructed either of wood or of metal, according to circumstances, and they may be suspended and moved in the manner of the common bolter. Within the cylinder or other apparatus, containing the flour, or meal, to be dried, I generally place small ledges, which may stand perpendicular to such cylinder or other apparatus, and project to such height from its inner surface, and have such direction, either parallel with or inclined to its ends, as may appear best calculated to detain, conduct, or agitate the flour, or meal, and expose it for the requisite time to the influence of the artificial heat employed.

"When heated air is used as the drying agent, the cylinder or box containing the flour or meal may be made to revolve within a long oven, or kiln, with the ends of said cylinder open to receive and deliver the flour or meal. I sometimes, however, intend to enclose the cylinder entirely within the oven, or kiln; a tube will, in this case pass through the cover to admit the flour, or meal, to be dried, which will then escape through another tube at the opposite end. When so constructed, the heated air will not only surround, but be contained within, the cylinder or box.

"When steam is applied for the purpose of drying the flour or meal, I surround the tube, or box, which in this case must be made of metal, or other good conductor, with an exterior case, or jacket, within which it revolves; a sufficient space being allowed between the two for the passage of the steam or heated air, which is to be admitted from a boiler, or stove, properly constructed, and conveniently situated for that purpose; such connecting tubes, dampers, and valves, being attached to the apparatus as may be required, according to the various modifications of which it is susceptible. The steam may be admitted through a hollow gudgeon, and allowed to escape in the same way, there being tubes to conduct it to and from the space provided for it.

"Instead of the revolving cylinder, or box, I intend sometimes to construct a cylindrical, or other, chamber, with suitable floors or shelves, one above the other, upon the upper one of which the flour, or meal, may be received, whence it may pass to those below it, being stirred and carried by hopper boys, or

other suitable contrivances. Heated air will, in this case, be admitted into the chamber, and have its exit through suitable openings. For steam, the floors or shelves must be made double, and the steam pass through them in ways well known to every mechanist.

"A current of air, sufficient to carry off the moisture, separated from the flour or meal, must in all cases be admitted into the cylinder, or box, in which the flour, or meal, is contained. In most cases, no particular provision need be made for this purpose; and where this may be requisite, the means of doing it are too obvious to require description. The drawings deposited in the patent-office will serve to illustrate the process and apparatus herein described; but I do not intend to confine myself to any particular form, construction, or position of the tube, or box, or of the other parts or modifications of the apparatus. A series of convoluted tubes may be employed, forming a structure like that of the screw of Archimedes; and, indeed, an almost infinite variety of shapes may be given to the apparatus, all operating upon the same principle, and producing the same effect, with equal, or nearly equal, advantage.

"What I claim as new, and for which I ask a patent, is my improvement in the drying of flour, or meal, either bolted or unbolted, by means of the application of steam, or of heated air, in an apparatus constructed in the manner and upon the principle herein before described.

"NATHAN TYSON."

Remarks by Dr. Jones, the Superintendent of the Patent-office, Washington, and Editor of the Franklin Journal.

The

"When the plan was first made known to the editor, he had no hesitation in declaring that it must prove perfectly successful; as, without the presence of moisture, that fermentation which produces souring cannot take place. It is not a little remarkable, that a plan so simple, and so rational, should not have been adopted long since. kiln-drying of grain is a well-known process, and modes of cooling and drying the flour after it has left the stones have been universally employed; and, indeed, every step, excepting this last and most important one, had been previously taken. We published in vol. vii. p. 102, a communication from one conversant with the subject, on the souring of American flour, and more especially of that from the western country. It was there recommended to employ a wind-fan to blow cool, fresh air, among the meal as it issues from the stones, and in other parts of its manufacture, for the purpose of drying it. Now to effect this object fully, it is

139

manifest that instead of cool air, that which is warm and dry is the most proper agent.

"It appears that from eight to twelve pounds of moisture may be expelled from a barrel of flour, when in the state in which it is usually packed. The greater part, if not the whole, of this moisture, might undoubt edly be discharged in carefully kiln-drying the grain, but the consequence of this would be that superfine flour could not be made from it, as nearly the whole of the bran would be chopped up by the stones. It is probable, too, that a much higher degree of heat would be required to separate the moisture from the grain than from the flour.

"It would be difficult to magnify the importance of an improvement in the manufacturing of flour, which effectually prevent its souring; as this is not an effect produced upon a solitary barrel or two, but not unfrequently upon whole cargoes, which become sour even during the time of short voyages to the West Indies, or the southern portion of our continent; and, indeed, large quantities arrive at New Orleans in this state, although shipped on the waters of the Ohio, immediately after it is packed in barrels. A large portion of that put up for sea stores, on all long voyages, is thus lost; and but few persons would credit the account, were we able to state the proportionate quantity of that so shipped on board our vessels of war, which is eventually thrown overboard, as totally spoiled."

Extract of a Letter from Mr. Tyson to Dr. Jones, dated Baltimore, March 1, 1834.

"In accordance with thy request, I now inform thee that my flour-drying apparatus has been in successful operation for upwards of two years, during which time I have prepared many thousand barrels of flour, which has been shipped to every quarter of the globe, and has stood the test of all climates for from six to twelve months, without any deterioration whatever. Advices from Gibraltar and the West Indies inform me, that, after laying eight or ten months, my flour was found to be quite as "perfect as though just from the mill." Within a few days past I have received the amount of the sales of a lot which I shipped in December, 1832, to Liberia, in Africa, with instructions to keep it twelve months, when it was sold, and proved to be perfectly sound.

1

"Amongst the many to whom I have sold largely of the kiln-dried flour, is the very respectable house of William Patterson and Sons, of this city, a copy of whose certificate is annexed. In no instance whatever have I had a complaint of the dried flour not keeping perfectly; in several instances, a few

140

barrels have been brought back from the East Indies and the Pacific Ocean, and always in as perfect a state as when first made.'

CERTIFICATES.

The design of the following paper is to bring together a variety of expe riments which may be considered as illustrative of the phenomena of flame. By applying to them the canon of philosophical research so beautifully described by Newton, we may, perhaps, arrive at conclusions at once instructive and satisfactory. It is very agreeable, and sometimes very convenient, to take shelter beneath the influence of great names. This love of ease, when the investigation of an intricate subject is concerned, tends very often to perpetuate error. When

ever acknowledged difficulties present themselves, they ought to be fairly met, rigidly examined-and, if possible, immediately removed. A course the very opposite to this is frequently pursued by very excellent and very learned men;

As the papers of Sym and Davies on Flame, referred to by Dr. Thompson, in his Treatise on "Heat and Electricity," 8vo. London, 1830, p. 310, are not accessible to me, I have no means of ascertaining whether the following experi ments have, or have not, been already described. If I have been anticipated in the whole of these investigations,* I can see no reason for rejecting, or undervaluing, on that account, the information they supply.

1. If a piece of wire-gauze be brought down gradually upon the flame of a taper, or candle, the section of the flame, when viewed from above through the wiregauze, will appear as a ring of light surrounding the wick, but not in contact with it.

2. A jet of coal-gas will present a similar appearance. The orifice of the jet may be very distinctly seen in the interior of the flame.

3. If the wire-gauze be brought down in the way already mentioned, upon a flame of coal-gas issuing from an Argand burner, the section of the flame will exhibit two distinct rings of light, and the thickness of the burner will determine the distance between the rings.

4. If an Argand lamp, with a wick supplied with oil, be employed, the thickness of the wick will determine the distance between the rings.

5. When air is excluded from the interior of an Argand burner, the flame, whether it be that arising from gas or oil, which was previously cylindrical, assumes a conical form. Let the wire-gauze be brought down upon this flame, and there will be, as in the case of the taper, or the jet, (1, 2,) one ring of light corresponding with the exterior surface of the wick or burner (3, 4).

6. The flames of alcohol and of hydrogen gas, present, in every respect, the same phenomena as those described (1,2,

* I observe that Mr. Watson, Mechanics' Magazine, No. 551, page 362, has anticipated one of my experiments. I am hence induced to hold them all with a loose hand.

4, 5,) excepting, of course, in the quality of the light.

7. Phosphorus, if inflamed in contact with the atmosphere, and the wire-gauze brought down upon it, exhibits a ring of light. The experiment requires a little caution and dexterity. The opacity of the interior of the flame may, however, be very distinctly recognised."

8. If we take about ths of an inch of wax taper, insert it in a piece of glass tube the same length, employing as a foot to the taper so enclosed a disc of cork, sufficiently large to keep it steady; then, in a saucer, or evaporating dish, coil some filaments of lamp cotton, so as to form a ring about two inches in diameter, and ths of an inch in height; saturate the ring of cotton with alcohol, light the taper, place it in the centre of the ring and inflame the alcohol, the taper will be extinguished. The heat in the interior of the flame of alcohol will be sufficiently intense to vaporise the wax, which vapour will be decomposed and inflamed at the summit of the alcoholic flame, imparting to it a characteristic brilliancy; but the wick of the taper will not be inflamed if the process be properly conducted. To ensure success in this experiment, we must guard against any agitation in the surrounding atmosphere, by moving about the room, opening or shutting doors, or breathing too freely in the immediate vicinity of the alcoholic flame. After observing all these precautions, we shall probably find that the flame will be in a continued flutter, occasioned by a current of rarefied air, and the taper will be alternately extinguished and relighted, just in proportion as the unsteadiness of the flame prevails or subsides.

9. Instead of a taper (8), if we place a piece of phosphorus in a small metallic spoon,* inflame it and pass it into the interior of the alcoholic flame, the phosphorus will be extinguished; suddenly withdraw it, it will inflame; pass it again into the interior, and it will again be extinguished.

The phosphorus, as already remarked of the taper, may be vaporised; and the vapour will become luminous as it enters into combination with oxygen at the sum

* A spoon for this purpose may be conveniently formed by flattening one end of a piece of copper wire.

141

mit of the alcoholic flame. Should it happen that the phosphorus has not been properly dried, small particles of it will be thrown out on every side: these will inflame the instant they come in contact with the external atmosphere.

*

10. We may vary this experiment by placing in the interiors of the alcoholic flame (8) a small metallic cup, containing alcohol, ether, or spirit of turpentine. These materials may be vaporised, but they will not inflame in the cup as long as the alcoholic flame preserves its conical form.

11. If phosphorus (9) be placed in the centre of the flame of an argand burner, (3, 4,) to which atmospheric air has access, it will inflame. If the further ingress of air be prevented, the flame will become conical (5), and the phosphorus will be extinguished.

12. The result will be still more instructive, if we repeat the last experiment in an Argand burner supplied with coalgas, the ingress of air to its interior being prevented. Let the phosphorus be ignited and passed into the interior of the gas flame, the phosphorus will be extinguished. Turn off the gas, the phosphorus will be inflamed; turn on the gas, that will be inflamed, whilst the phosphorus will be again extinguished. (10). If we employ alcohol, ether, or spirit of turpentine, in an Argand burner, supplied with oil or coal-gas, the results will be more uniform and satisfactory than with a large flame of alcohol, for the reasons already stated (8).

13. A lighted taper placed in the interior of the flame of an Argand burner, will continue to burn so as air has access to it: exclude the air (5), and the taper will be extinguished. We may vary this experiment by employing a jet of coalgas instead of the taper. The result will be the same in both cases.

14. If a coil of platinum wire be held above the flame of alcohol, the wire will become incandescent. If we pass the wire into the interior of the flame, its incandescence will cease. In this experiment the effect will be more intelligible if we employ a spirit lamp with an Argand wick. The incandescence of the wire may be determined or prevented, by the admission or exclusion of air (11)."

*For cheapness and convenience, say par of a child's thimble.