or cocks, and the only part requiring adjustment is a stuffing-box for the measuring pole.

A premium which was offered last year by J. Buller, Esq., for the best essay on the natural history of the pilchard, has produced an exceedingly interesting paper on the subject by Mr. Jonathan Couch, from which, however, we can only afford room for one brief extract:

"The quantity of pilchards caught on the coast of Cornwall, can scarcely be made the subject of calculation, since no account is taken of what is reserved for home consumption; we therefore can only here remark on what has been recorded to have been exported. The largest schuls are found late in the season, and commonly in sheltered situations, at a time when the weather is troubled. A few years since, à capture was made in Hemmick Bay, to the amount of two thousand two hundred hogsheads; and Borlase reports the taking of three thousand hogsheads at one shooting of the sean: but even this is not the greatest on record; for, in November, 1834, it is said that three thousand five hundred hogsheads were landed from one sean at St. Ives; and on another occasion, ten thousand hogsheads were enclosed in that port in one day, though not in one sean; thus producing the enormous multitude of thirty millions of living creatures drawn at once from the ocean, for human sustenance.

"The greatest number I was ever witness to, as taken in a drift-boat, was 40,000, but I have been informed, on credible testimony, of 80,000 taken at once, in a single capture; and it was supposed that this alleged number fell short of the whole. About the middle of the eighteenth century, it was not uncommon for the drift-boats to get so much fish entangled in their nets, that they were obliged to sacrifice a portion, by giving some, of their nets and all their contents, to those who would take care of them, on condition that the nets were returned to them again within a few days: the condition was, assistance in securing the remainder."

Besides the articles we have thus particularly noticed, there is an Essay "on the various Diseases incidental to Miners, their Causes, &c.," by C. Carlyon, M.D., which as a first but able contribution to an important brauch of medical statistics too much neglected, deserves, and we hope will attract, the attention of the author's professional brethren; a description of some improvements made since last year by Mr. R. W. Fox on his dipping needle deflector, (see Mechanics' Magazîne, vol. xxiii, p. 97,) and a chart and table showing "the dip and intensity of

the terrestrial magnetism in different parts of England, Ireland, and Wales," as ascertained by this deflector; and no tices of several inventions favourably thought of by the Society, though not comprehended within the scope of its premiums, such as Hoskin's Portable Punching Press (the engraving and deseription of which we gave in our last number), Wilton's Miners' Theodolite, Loam's Wheel Wrench, &c.

We are pleased to find it reported that the funds of the Society are, as they deserve to be," in a flourishing condition." "Their means have exceeded their disbursements." Happy would it be for nations, as well as individuals, were they to keep always within the same prudent limits. Of the evil consequences of exceeding them, a memorable illustration is furnished by an item in this annual budget of our Cornish friends, which still remains to be noticed. item to which we allude is a "Chronological Map of the Wars of the British Em pire from the revolution in 1688-9 to 1835," showing how, from small begin.. nings from a mathematical line without depth or breadth our national debt increased (though the wars aforesaid, and all the destruction of life and property of which wars are the invariable cause) to a seam of 860 millions thick!!!

The

LONDON GRAND JUNCTION RAILWAY. (From Report of the House of Commons Committee, on the Bill for this Railway.)

By an Act passed in the third year of his present Majesty's reign, a Company was empowered to make a railway from Birmingham to London, terminating on the north side of the Regent's Canal, Camden Town. In the last session, an Act was passed for making a branch from that point to Euston-grove, in the parish of St. Pancras, for the conveyance of passengers and light parcels only, but not of merchandise and goods. There are at present, therefore, no means for the conveyance of the present number of passengers proceeding from Camden Town to the City, or for those who will be brought by the Birmingham Railway, except the ordinary vehicles plying in the streets. The only present means for the conveyance of goods from Camden Town is the canal, but as that is at no point nearer the City than the

8

New-road, it could not be available for that purpose. Evidence was adduced to show that it would be a great advantage to trade and commerce to have a railway communication for goods and passengers extended to the City.

The amount of income expected to arise from the conveyance of passengers and goods is 113,5597., of which 90,8187. is expected from the conveyance of passengers, and 22,7417. from the conveyance of goods which are the manufactured articles of Birmingham, Manchester, and other manufacturing towns, and live and dead cattle to Smithfield, Newgate, and Farringdon markets.

The proposed railway is the extension and completion of the Birmingham Railway, and is an integral line between its respective termini.

The only line which can be considered as a competing one is an inclined plane, now in progress, from the Birmingham Railway at Camden Town to Eustongrove, a distance of nearly a mile; but that is only enabled to convey passengers and light parcels. The proposed railway has the advantage of conveying passengers to the centre of the metropolis, about three times that distance, yet at one-fourth less charge. It is also to be adapted for the conveyance of goods, which would otherwise have to be carted from Camden Town.

The whole line will be worked by locomotive engines, without any assistant or stationary power.

There seems to be no peculiar engineering difficulties in the proposed line.

There are no tunnels.

The steepest gradient is 1 in 273, or 19 feet in a mile. The smallest radius of a curve is half a mile.

The length of the line of railroad is two miles and fifty chains. There are no brauches.

The plan seems, in an engineering point of view, well fitted for the objects intended.

No turnpike road will be crossed by the proposed railway on a level.

The estimated cost of the whole work, including the cost of property, is 600,000l. This estimate was proved by George Rennie, Esq., and supported by the evidence of Colonel Landmann, the engineer of the Greenwich Railway, as respects the engineering department; and by George Smith, Esq., and Wil

liam Barnes, Esq., surveyors, in the city of London, as to the valuation of the property to be purchased. Your Committee, therefore, see no reason to apprehend it will be insufficient.......

The estimated annual charge for the railroad, when completed, including all incidental expenses, is 40,000, which was founded on the charges of similar works now completed.

The evidence fully satisfied your Committee that the return would be sufficient to support all the annual charges and maintenance of the railroad, and leave an adequate profit for the shareholders.

Your Committee think it desirable the House should be informed that, as this railroad follows the course of the River Fleet, a considerable portion of the ground is not built upon; so that, in fact, the arches under the railway will form as many dwellings as the railway will displace.

A great part of the houses that will be taken down in and about Hattongarden and Saffron-hill are in a dilapidated and dangerous condition. Several parochial officers gave evidence as to the state of the neighbourhood, and the advantage it would be to have an opening made through that confined and unhealthy part of London.

THE PNEUMATIC RAILWAY.

to

Sir, The peculiar formation of the air tubes which, in one way or other, are intended to form the carriage way of the projected pneumatic railway, appears be that to which the attention of the public has been especially directed in the various articles which have appeared in the Mechanics' Magazine on this subject; but I am not aware that any thing bearing expressly on the mode of procuring the. current of air in the tubes has been published. It seems intended that steam, applied through the instrumentality of stationary engines, should be the generator of power, and that this power should be employed to extract the air of the tubes through the agency of air-pumps. Have not some objections been made to this agency, raised upon the reciprocating action of the pumps, and the elastic nature of the element to be operated upon? If these objections have been thought formidable, might they not both be overcome by the simple application of fans instead of pumps, which are now

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

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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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 an 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 in blocks 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 aliuing of

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 theni, 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

mass, as was anticipated. Calculating from the rods, and from the diminished draught of the ship, Mr. Dixwell estimated 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.

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 spread 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.