2

WARPING VESSELS UP RAPIDS.

SIR,-I observe, in a Number of the Mechanics' Magazine for January, a Plan for Warping Vessels up Rapids, and now in operation on the Delaware. The principle is precisely that which occurred to me five years ago, when in Canada, and which, by the united action of machinery and the current, I wished to apply to steam-vessels navigating the St. Lawrence. I accordingly

inserted an advertisement in the

"Canadian Courant," published in Montreal, addressed to the proprietors of those vessels.

Allow me, Sir, to present you with the following detail, under the expectation that you will insert it, and, by placing it on record, do me that justice which I consider is due

to me :

"To the Proprietors of Steam-Boats

navigating the St. Lawrence.

"The Proprietors of Steam-Boats navigating this river, are respectfully informed that the subscriber is possessed of a plan by which the ascent of those vessels up the rapid below this city, may be greatly expedited. The principle is such, that its extension may greatly improve the mechanical navigation of the rivers of America, open new routes for its application, and, by giving it action where it has heretofore been dependent on the operation of towing, render it superior to natural impediments.

"T. H. BELL. "Montreal, June 20, 1820."

I explained the plan to the Editor of the "Canadian Courant," Mr. Driscol, and the following are his remarks, which appeared in the same Paper:

:

“INVENTION.—An ingenious person in this city has lately favoured us with a description of an addition to the present machinery of a steam-boat, by which those vessels may be made to stem currents hitherto impassable. It is well known that, in currents of a certain rapidity, the mechanical power becomes totally ineffective, the descent of the water being quicker than the revolution of the paddles. In order to ascend, recourse must, therefore, be had to cattle or manual labour. To obviate this inconvenience is the intention of the present improvement, it being calculated to

propel a steam vessel twenty-five yards per minute, in any current, the mechanical power increasing as the velocity of the water increases. Though not deeply versed in mechanics, so simple is the principle, we venture to predict that it will be found to answer all that is above attributed to it; an ingenious mechanic, not the inventor, being confidently of the same opinion."

The above advertisement appeared for some weeks, but was unnoticed by those to whom it was addressed, and I never again agitated it until considering it to be the greatest immy return to England, when, still provement that could be made in the mechanical navigation of American rivers, and highly desirable on the St. Lawrence, I sent a drawing and description to the Society of Arts, but without any view to a reward; for, to be able to add a single fact to science, is, I consider, a sufficient remuneration for the trouble of its discovery.

The following is a copy of my letter which accompanied the drawing, and the Secretary's reply

"Alnwick, June 8, 1822.

"SIR,-I beg leave, through you, to submit the enclosed drawing of an im provement in mechanical navigation, to the inspection of the Society for the Encouragement of Arts, &c.

"In my passage from Quebec to Montreal, in November, 1819, I observed that the power of the engine became totally ineffective in a current called Sainte Marie, a little below the city of Montreal. In consequence, recourse was had to cattle and manual labour to tow the vessel against the stream. It occurred to me, at the instant, that the power of the engine might be applied to wind the vessel up, or to render her automatic in any current, by a very simple arrangement of machinery, and an arm, as it were, be added to mechanical navigation. To effect this I would fix the cog-wheel, A, on the axle of the water-wheels, which would drive the wheel, B, and its concentric stream, or drum, C. At the head of the current, or a little above where the engine would be sufficient to impel the vessel, I would sink a kedge, with a buoyant hawser attached, to remain floating in the stream. This hawser being grappled on board, and applied to

*This remark supposes the paddlewheels to perform 25 revolutions per minute, and the diameter of the drum to be only one foot.

the drum, C, one man or more taking it off (in the manner represented in the drawing), the vessel would herself ascend the current with a velocity proportioned

to the revolutions of the water-wheels and the diameter of the drum. I may observe, that the current itself would assist the engine, and thus the very impediment to the navigation be made one of the means of overcoming it.

"T. H. BELL.

"P.S. In situations such as the current Sainte Marie, a kedge would be unnecessary, for the hawser could be fastened on shore, and two, applied alternately, would haul up the vessel. This principle of motion might be otherwise usefully extended. One application, perhaps of some magnitude, would be its adoption on canals, where the action of water-wheels is injurious to the banks. Boats, in canals, which at present are dragged by horses, might be towed, several together, by a single coiling-boat, driven by steam or horse-power. Hawsers might be made any length, and, where the canal was winding, be retained in their proper position by rollers placed along the banks.

"Arthur Aikin, Esq."

"Society of Arts, &c. "Adelphi, London, Dec. 3, 1822. "SIR,-I am directed to inform you, that your Plan for Warping Steam-Boats up Rapids has been considered by a Committee appointed for the purpose, and their opinion confirmed by the Society; the result of which is, that your endeavours, in this instance, are not entitled to their reward, but that they consider themselves obliged to you for your good intention and exertions.

"ARTHUR AIKIN, Sec.

"Mr. T. H. Bell."

I remain, Sir,
Your most obedient servant,
THOMAS H. BELL.

Alnwick, March 4th, 1825. [The principle of Mr. Bell's plan is evidently the very same as that of Colonel Clark (described in our 71st Number), whose success, in reducing it to practice, furnishes the best commentary that can be offered on the soundness of the judgment passed upon it by the Society of Arts.EDIT.]

PURIFYING COAL-MINES.

SIR,-I give "A Staffordshire Farmer and Land-Drainer" (as your Correspondent, at page 317, Num

ber 71, of your Magazine, calls himself) full credit for his humanity, Coal Mines will be of no farther use but I am afraid his plan for airing than to inform his practical readers that he has never been in one.

It is certainly true, that hydrogen gas, in a state of quiescence, floats at the top of atmospheric air, and is found at the roof or upper part of a mine; but when there is a current of fresh air passing through the workings of a mine, as must be the case if they are to be kept pure, it is well known that these gases mix and render a mechanical separation impossible. Had it been otherwise, this gas would have been innoxious, as it is the combination that makes it so explosive.

To a practical reader it would be worse than waste of time to enter into a refutation of your Correspondent's plan; I will content myself with making a remark or two, en passant, on some of his means of carrying it into effect. In the first place, as to "boring upwards." The operation of boring is done by chisels and inflexible iron bars or rods, called boring-rods, about three feet long,

with alternate screws and sockets at the ends; the uppermost one having a cross-head or handle to it, for the convenience of the workman. These rods are of considerable weight, and this weight, when they have bored a few yards down, is the power applied to drive the chisel into the stone below; the workmen's employment being to raise them a little way out of the hole, and, after turning them partially round, to let them descend by their own weight. Now, how

your Correspondent could imagine that a ton or more weight of rods could be held in a vertical position, to bore upwards, I am at a loss to imagine. Boring upwards is certainly done to explore dikes, &c. for a few feet, but beyond that it is found impracticable.

With regard to your Correspondent's strong box, &c. it is so absurd that I only notice it to remark, that the most general cause of explosion in coal-mines is the falling of strata composing the roof of the mine, which stops up the air-courses, and

a

I will now endeavour (as briefly as possible) to account for the phenomenon in question.-Let a (in the above figure) be a vessel, bc a tube fitted to it, and filled with water to the top, ; the upper stratum of particles, from c to d, will be pressed on with the same force as those from e to c; because the column bc, meeting with these particles at c, presses them outwards or sideways, and, as they cannot escape the pressure, on account of the top and sides of the vessel, they must therefore exert the same force downwards as those from c to c; consequently the bottom, e e, will be pressed on with the same force as it would if the vessel were made of the bulk of e e, ƒƒ, and filled with water to the top.

1 will now notice the question on the Weight of the Atmosphere (page 332), as it is, in some measure, connected with the foregoing subject; I will also include the following one, and endeavour to answer them both together.

How is it that the atmosphere is thicker or more dense in warm weather than in cold, when, from what we know of heat, it possesses the property of rarefying air?

To answer these questions I will first give you my opinion of the nature of the heat we receive from the sun. I do not believe that the suu is a body of fire (which is the opinion of many), but that it is an opaque body, like our earth, surrounded by a luminous atmosphere, the rays of light from which, mixing with our atmosphere, produce the heat that we feel; thus, then, the heat we feel, as proceeding from the sun, is not of the

* As I never believe any thing, except I am convinced in my own mind of the reasonableness of my belief, I could adduce many arguments in favour of this

same nature as the heat proceeding from a fiery body.

If we suppose, then, that the rays of the sun, wherever they shine on our earth, possess the property of accumulating the particles of our atmosphere, both questions may be easily answered. In this supposition I must be allowed to differ with C. D. Y., as I think the atmosphere, where the sun shines most, is accumulated, and, consequently, increased both in height and density.

I must yet beg a little more room, just to notice the question on the Syphon (page 286). The reason is, because the depth of the water is greater in the long leg than in the short one; it is, therefore, of greater pressure at the extremity of the leg, consequently the fluid descends, because it overbalances the pressure at the extremity of the other leg. As there cannot be a vacuum between the legs, the weight of the atmosphere pressing on the surface of the fluid in which the shorter leg is immersed, supplies the discharge by forcing it up the short leg.

If I have stated any thing that is incorrect, nothing would give me greater pleasure than in being set right by some of your better-informed Correspondents.

I cannot conclude without bestowing my warmest approbation on your valuable and useful Magazine, for thus encouraging useful and scientific inquiry; for directing the attention of the middling and working classes to subjects which otherwise, perhaps, they would never have thought of; and for affording, to all, a better medium through which to express their wishes, thoughts, and experience, than had existed before its commencement. I remain, Sir, Yours very respectfully,

Bath.

J. E. COOMBS.

SIR, Should the following answers to your Correspondent, + W. X. (p. 285, vol. III.) appear worthy a place in your useful Magazine, I should feel much obliged by their insertion.

First. Why an additional pint of water will have the effect of bursting a hogshead filled with that fluid, if introduced by a small tube of sufficient height?

No part of any confined body of water (excluding the consideration of its own

hypothesis, but will not now take up more of your valuable room than what is necessary to the explanation of the present question; however, should any of your Correspondents deem it requisite, I would gladly resume this subject, and give my reasons and arguments, which would, I think, render the truth of what I have already said beyond a doubt.