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HORSE-WORKED FIRE-ENGINE.

so generally employed for forming currents of air in many, nay in most of the cotton and other large manufactories throughout the kingdom? The injurious effect of the reciprocating action is by this simple apparatus completely done away with, and a constant and uniform action obtained in its place. The air in the tubes thus acted upon will be like a wire spring, continually on the stretch, and the evil effects which the elasticity of it produces when acted upon by an unsteady force would no longer exist.

It may be noticed that a fan thus em

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HORSE-WORKED FIRE ENGINE.

Sir, It has always appeared inconsistent to me that horses when they can be employed should stand spectators, whilst men are perspiring and almost ready to sink with the fatigue of working. An illustration of this I witnessed lately at the lamentable fire in the Burlington Arcade, where horses were standing in groups idle, whilst the men were pumping the engines. Even this, however, would not be so bad were the power of the men advantageously employed; but the reverse is the case in the present method of working the fire-engine. There is nothing, perhaps, which seems capable of greater improvement; the present vertical method is almost the worst that could be adopted, as there is one point in the stroke at which there is scarcely any power available, I mean when the levers are horizontal, and consequently when the arms of all the persons working them are also in that posi

tion, in which they are least capable of exertion. It is not as if the persons on one side were at the dead point while the others were in full play, but both sides lose their power at the same time, and the only way they are enabled to go on is by the persons on the one side elevating themselves so as to have a downward thrust, and those on the opposite side stooping down so that they can push upwards. The levers always stop when they arrive at the horizontal position until the men on one side raise themselves, and the others stoop when they again go on; and on coming up again they stop at the same point. Sometimes, indeed, the men when fresh will work down and up without stopping at the centre, but this rarely continues for any length of time.

A plan has occurred to me for using the horses that drag the engines for working the pumps; a sketch of which I now send you.

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THE ICE TRADE BETWEEN AMERICA AND INDIA.

AA are two wooden levers, which are put into the head of the spindle b in the manner of capstan bars; on this spindle is placed the bevel-wheel, cc, which works into the two smaller ones, dd; and on the shafts of these two smaller wheels are the cranks, which work the pumps by means of the connecting-rods, e e,

This is merely a first sketch, and is no doubt capable of many different arrange.

ments.

Should it be objected to on account of occupying too much room, I am prepared to show in another paper the different measurements requisite, and also the length of levers necessary for producing the quantity of power which is at present requisite for working the fire-engine, also the sizes of the different wheels, &c., when I am quite sure this objection will be removed.

In the event of the horses being very much fatigued after coming a long distance, and others not being at hand, this plan is equally applicable to, and certainly much more advantageous for, applying the force of men. When the

engine is not in use, the levers may be taken out and placed by the side of it. I am, Sir, Yours respectfully,

Westminster.

T. P.

THE ICE TRADE BETWEEN AMERICA AND INDIA.

(From the Asiatic Journal.) The arrival of the Tuscany with a cargo of ice from America forms au epoch in the history of Calcutta worthy of commemoration, as a facetious friend remarked, in a medal of frosted silver. In the month of May last we received a present of some ice from Dr. Wise at Hugli, (whose efforts have been so long directed to the extension of its manufacture by the native process,) as a proof that the precious luxury might be preserved by careful husbandry until the season when its coolness was the most grateful, little did we then contemplate being able to return the compliment, with a solid lump of the clearest crystal ice at the conclusion of the rains! nor that we should be finally indebted to American enterprise for the realization

of a pleasure for which we have so long envied our more fortunate countrymen in the upper provinces; nay, even the beggars of Bokhara, who in a climate at times more sultry than ours, according to Lieutenant Burnes, "purchase ice for their water, even while entreating the bounty of the passenger." Profes sor Leslie with his thousand glass exhausters, and his beautiful steam-air pumps, tantalized us with the hopes of a costly treat, and ruined poor Taylor, the bold adopter of his theory; but Science must in this new instance, as on many former occasions, confess herself vanquished or forestalled by the simple practical discovery, that a body of ice may be easily conveyed from one side of the globe to the other, crossing the line twice, with a very moderate loss from liquefaction.

We are indebted to Mr. J. J. Dixwell, the agent of the proprietors, for the following interesting particulars relative to the Tuscany's novel cargo, and the mode of shipping ice from America for foreign consumption.

The supplying of ice to the West Indies and to the southern states of the Union, New Orleans, &c,, has become within these few years an entensive branch of trade under the successful exertions of its originator, Frederick Gudar, Esq., of Boston, with whom S. Austen, Esq., and Mr. W. C. Rogers, are associated in the present speculation.

The ponds from which the Boston ice is cut, are situated within ten miles of the city; it is also procured from the Kennebec and Penobscot rivers, in the state of Maine where it is deposited in ice-houses on the banks and shipped from thence to the capital. A peculiar machine is used to cut it from the ponds injblocks of two feet square, and from one foot to eighteen inches thick, varying according to the intensity of the season. If the winter does not prove severe enough to freeze the water to a convenient thickness, the square slabs are laid again over the sheet ice, until consolidated and so recut. The ice is stored in warehouses constructed for the purpose at Boston.

The shipping it to the West Indies, a voyage of ten or fifteen days, little precaution is used. The whole hold of the vessel is filled with it, having alining of

THE ICE TRADE BETWEEN AMERICA AND INDIA.

tan, about four inches thick, upon the bottom and sides of the hold; and the top lifts covered with a layer of hay. The hatches are then closed, and are not allowed to be opened till the ice is ready to be discharged. It is usually measured for shipping, and each cord reckoned at three tons: a cubic foot weighs 58 lbs.

For the voyage to India, a much longer one than had been hitherto attempted, some additional precautions were deemed necessary for the preservation of the ice. The ice hold was an insulated house, extending from the after part of the forward hatch to the forward part of the after hatch, about fifty feet in length. It was constructed as follows:-a floor of oneinch deal planks was first laid down upon the dunnage at the bottom of the vessel; over this was strewed a layer, one foot thick of tan; that is, the refuse bark from the tanners' pits, thoroughly dried, which is found to be a very good and cheap nonconductor: over this was laid another deal planking, and the four sides of the ice hold were built up in exactly the same manner, insulated from the sides of the vessel. The pump, well, and mainmast, were boxed round in the same

manner.

The cubes of the ice were then packed or built together so close as to leave no space between them, and to make the whole one solid mass: about 180 tons were thus stowed. On the top was pressed down closely a foot of hay, and the whole was shut up from access of air, with a deal planking one inch thick nailed upon the lower surface of the lower deck timbers; the space between the planks and deck being stuffed with tan.

On the surface of the ice, at two places, was introduced a kind of float, having a gauge rod passing through a stuffing-box in the cover; the object of which was to denote the gradual decrease of the ice, as it melted and subsided bodily.

The ice was shipped on the 6th and 7th of May, 1833, and discharged in Calcutta on the 13th, 14th, 15th, and 16th of September, making the voyage in four months and seven days. The amount of wastage could not be exactly ascertained from the sinking of the icegauge; because, on opening the chamber, it was found that the ice had melted between each block, and not from the exterior only, in the manner of one solid

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mass, as was anticipated. Calculating from the rods, and from the diminished draught of the ship, Mr. Dixwell esti mated the loss on arrival at Diamond Harbour, to be fifty-five tons, six or eight tons more being lost during the passage up the river; and probably about twenty in landing. About one hundred tons, say three thousand maunds, were finally deposited in the ice-house on shore; a lower room in a house at Brightman's Ghaut; rapidly floored, and lined with planks for the occasion.

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The sale has not, we believe, been so rapid as might have been expected, amounting to no more than ten maunds per diem, although Mr. Rogers has fixed the price at the low rate of four annas per seer, one half of the price estimated for the Hugli ice, which was calculated to be somewhat cheaper in proportion than saltpetre. The public requires to be habituated to it, and to be satisfied of the economy of its substitution for the long-established process of cooling. There may also be some doubts of the best mode of preserving so fleeting a commodity; but on this head we cannot but advise an imitation of the methods pursued on a large scale on board of the Tuscany. For the applica, tion of the ice to the purposes of cooling, ample directions have been given in the "Gleanings of Science," vol. iii. p. 120. A box or basket, or tin case, with several folds of blankets, or having a double case lined with paddy chaff, or any non-conducting substance, will preserve the ice until wanted; and for cooling water or wine, the most effectual method of all is to put a lump of the clear crystal into the liquid. The next best is to spreal fragments upon the bottles laid horizontally, and have them wrapped in flannel for a couple of hours,

So effectual was the non-conducting power of the ice-house on board, that a thermometer placed on it did not differ perceptibly from one in the cabin. From the temperature of the water pumped out, and that of the air in the rim of the vessel, Mr. Dixwell ascertained that the temperature of the hold was not sensibly affected by the ice. Upon leaving the tropic, and running rapidly into higher latitudes, it retained its heat for some time; but after being several weeks in high latitudes, and becoming cooled

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to the temperature of the external air and sea, it took more than ten days in the tropics before the hold was heated again to the tropical standard.

VENTILATION OF MINES.

Sir, I have read the numerous important and interesting extracts in your valuable Magazine, from the evidence taken before the Parliamentary Committee, on accidents in mines, with some degree of attention; and perceive that the grand desideratum in the opinion of all parties examined, and others who have observed on the subject, is a better ventilation than has been hitherto effected.

I notice, too, that the air-pump has been tried, though in what manner has not been stated in the details I have seen, but evidently without any important result.

My present object is, therefore, now to suggest an application of the air-pump, in a manner which I think would be found to effect the object desired; viz. a complete ventilation of the most extensive mine.

The simplicity of my plan is such, that any person conversant with these matters will be immediately able to form a judgment of its practicability; and, although I have no practical knowledge of mining, I feel theoretically some degree of confidence that it will produce the desired effect.

My plan is this: on the top or the mouth of the shaft, over the most remote part of the mine, let a double-barrelled air-pump be erected, with a pipe of leather to descend to the bottom, and thence to that part which may be found contaminated with bad air. The end of the pipe, which may be eight or ten inches wide, should be left open, and kept distended throughout its whole length by small hoops at convenient distances. All apertures at the top of the shaft through which the pipe descends, should be closely stopped and made air-tight; and all others, wherever they may be found, except the principal shaft. By this means, when the pump is put in motion, the air in the immediate neighbourhood of the mouth of the pipe would necessarily be taken away through the pipe, and its place supplied by that surrounding it; and finally, the whole atmosphere

of the mine would be put in motion, and supplied with pure air from the mouth of the great shaft of the pit.

A double-barrelled pump might be proportioned to the extent of the mine; say each cylinder to contain 30 gallons, which would take out one hogshead at every stroke of the engine; and supposing it made 40 strokes in one minute, it would remove 2,400 hogsheads of air in one hour. This would be sufficient to keep the atmosphere of the pit perfectly salubrious. I think the working of the pump a few hours a day would be sufficient for the purpose.

This contrivance is so simple, that it requires no further explanation; and if you will oblige me by giving it a place in your widely circulated Magazine, its merits, if it possess any, will soon be appreciated by those whom it may more immediately concern.

I am, Sir, respectfully,
Your obedient servant,

Birmingham, March 28, 1836.

P. HALLIDAY.

CIRCULATING DECIMALS.

Sir, It appears to me a matter of surprise that none of your mathematical readers ever took notice (at least none have been published) of a question you inserted from me, in the 18th volume, respecting circulating decimals. I am the more persuaded that the subject is altogether new and original, from the fact that, in most cases, some one of your readers is ever ready, sometimes too ready, to correct the unfortunate wight who, in full anticipation of the honours due to an inventor, has communicated to your pages a new discovery of something which the aforesaid readers can prove, or at least attempt to prove, is as old as the hills.

The question is as follows: "Given 3488372+ a part of a decimal circulating series, required the whole of the series and its equivalent vulgar fraction."

The solution of this question depends upon, as I have before observed, one among several newly-discovered, or rather observed, properties of circulating decimals: some of these I noticed prior to, and others just after, the appearance of a communication on the

CIRCULATING DECIMALS.

subject in your 9th volume from Mr. Utting, which was followed by some others, the most interesting of which was a notice of the late H. Goodwin, Esq.

The property to which I allude is, that every deciinal circulate is formed by a continuity of combined geometrical progressions, of every ratio from two upwards to one less than the denominator of the portion from which the series is produced. A knowledge of one of these ratios, which I have named the circular multiplier, or ratio, enables us to form the series in the shortest possible space of time, and by what may appear singu lar, beginning at the end: thus to find the decinal circulate of put down unity on the right hand, and multiply it by 3 (the circular multiplier for this series); place the product unit figure on the left of the 1, then multiply it by 3; and again place the unit's figure of the product to the left of the former figure: continue to repeat this operation until the figures recur, and the result will be the decimal circulate 0344827586 206890551724137931. To solve the given question, multiply the part given by 2, 3, 4, 5, &c., until among the pro ducts some of the given figures are found to be repeated: these will generally be combined with some of the unknown part of the serie, which may therefore be united to the given part: this additional part being multiplied, will furnish more of the unknown figures of the series, and by continuing the operation the recurrence of the same figures will show where the series is completed. If unity be divided by five or six figures of the series, where it is decimally of the least value, the quotient will be the denominator of the fraction: this denominator multiplied by five or six of the given figures will give the numerator. In the present example, it will be found that when 3488372 is multiplied by 4 in the product 3953488, the first four figures are repeated, combined with 395.

The

part known will now be 3953488372: this, or rather the new part, multiplied by 4, adds three more figures to the series; viz. 581. Repeating the works we at last obtain 348837209302325581395. for the whole of the series where 0232 is of the least decimal value: therefore,

1 ⚫0232

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43 gives the denominator of the

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In many examples the work may be facilitated, and considerably abridged, by the assistance of some other properties, particularly that one noticed by Mr. H. Goodwin; viz. that every decimal circulating series has a complementary part.

Although I have no doubt that the ratio of the circumference and diameter cannot be expressed by any finite number to one, yet as the two, considered separately, are of finite-dimensions, they must be capable of being expressed by two finite numbers, which two numbers are the numerator and the denominator of the fraction equivalent in value to the decimal series expressing the ratio; this decimal series is already known as far as 132 places of figures; hence it appears to me probable, that by some of the newly observed properties of deciinal circulating series, the whole of the series may be found, and from it the vulgar fraction equivalent thereto. Since, however, the decimal circulate of a fraction, whose denominator is a prime number, may consist of as many digits as the number expressed by the denominator less 1, the immense number of figures in the series may present an almost insurmountable obstacle towards its attainment, without, however, affecting its possibility, if means can be devised for overcoming that difficulty.

Judging from what I have read upon the subject, it appears to have been very little studied, and if the attention of a few minds were directed to it, I feel assured that some very important results, as to the nature of the combination of numbers when multiplied by other numbers would be obtained, decimal numbers differing only from whole numbers in being decreasing instead of increasing series.

I am, Sir,
Yours respectfully,
ANTHONY PEACOCK.

January 20, 1836.

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