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(which cannot be varied), otherwise their practice is not worth the name. In another part of his letter (alluding to the practical proof required) the writer seems to say, that if my objections bore any other name than a protest it would be more agreeable, and that I ought to have examined some of the mines, &c. This certainly is going from the question. Suppose I had said, "I do not believe, or I deny such an increase of duty”— this would not have altered the case, and why require me to show, particularly by calculation, how the errors have found their way into the stated amount of duty, when the Cornish engineers, or their calculators, are the most fit to give that information? Again, the writer says, perhaps some one of the large mines (meaning the proprietors, I presume,) might undertake the necessary trouble and expense for the satisfaction of known parties of eminence, but certainly not to satisfy idle curiosity. All this is scarcely worth notice, and Mr. Enys, of Enys, ought not to have said so; but it will be quite time enough to accuse me of idle curiosity when I take a trip to Cornwall for nothing, as he has. hinted; and had he mentioned the degrees of eminence or qualification suitable to their views, I could have answered him in various ways. I certainly cannot go farther back in your columns than September, 1832, No. 473, which will be sufficient for this case, and show that I am not of yesterday, and that certain gentlemen deeply interested in Cornwall did not hesitate to profit, and still do, from the result of my professional exertions. I allude to the copper-smelting affair at Swansea, and other places. I still hope there are some honourable men amongst them, and that 1 shall experience the fruits.

I must now conclude with a few words to Mr. Enys. I would advise him, 1st, to abandon all contention; 2dly, use his influence to get this affair practically settled in the way that I have described; and 3dly, when that is done, that the water is all taken from one level; and "to prove as far as practicable the coincidence (or difference) of theory and Cornish practice," so that the tables may not be turned upon him, and that the Cornish engineers may be freed even from suspicion. If they cannot do so much with a bushel of coal as they have said, I am sure the

public will appreciate their endeavours such as they are, and I shall be one o the first to acknowledge their unparal leled exertions and perseverance in this most useful and scientific pursuit.

I am, Sir, yours respectfully,
JONATHAN DICKSON, Engineer.

9, Charlotte-street, Blackfriars-road,
Nov. 2, 1836.

MR. MACKINTOSH'S CONCLUDING LECTURE ON THE ELECTRICAL THEORY OF THE UNIVERSE.

In this lecture (delivered on the 7th inst.) Mr. Mackintosh remarked, that if the earth be gradually approaching the sun, it was natural to conclude that the length of the year was becoming less in a relative proportion. Accordingly, we find that the Chinese, Indians, Chaldeans, Egyptians, Greeks, and Romans, however they differed on other points, all agreed in giving to the year a value greater than that which was known to be the true value at the present day. Now, the great object of the ancient astronomers being the calculation of eclipses, unless they had a knowledge of the true time, how could they have predicted the recurrence of an eclipse with any certainty? But the Sothiac period of the Egyptians put the matter beyond dispute. The Egyptians had more than one calendar, in one of which the year consisted of 365 days; they had no leap-years, but the supernumerary hours and minutes were allowed to accumulate until they formed a whole year, which was added to the amount, and this they called a Sothiac period, which originally consisted of 1,461 years-at the present day it would require 1,506 years to complete a Sothiac period; the difference being 45 years. And were we to suppose that the Egyptians (the most eminent astronomers that the world ever produced) could not bring their Sothiac period nearer than within 45 years of the true time!-we could not come to this conclusion,-and yet with this very imperfect time these astronomers could calculate and predict eclipses! To suppose so was an absurdity; it was impossible to calculate an eclipse unless the true time were known.

It was also found, that the apparent diameter of the sun was greater at the present day than it was found to be by the ancient Greek astronomers; and this also agreed with the assumption of the earth's approach to the centre. We were too apt to consider that these differences arose from the imperfect modes of observation pursued by the ancients, without considering that it was not only possible, but natural, that there should be an actual difference; seeing there is nothing stationary in nature, and that both the

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ancient and modern observations might be correcte

In conclusion, Mr. M. remarked, whether this theory were founded on truth or otherwise, by inquiring into its merits our knowledge of the physical world would be extended and improved. So long as our inquiries were conducted with a proper spirit, and confined to subjects within the reach of the human understanding, the improvement of that understanding must be the result of those inquiries: there were some things beyond the reach of that understanding, and concerning those things it was neither needful nor proper that we should inquire. That, space was infinite in extent that time was infinite in duration

and that the Divine Mind, being infinite in its attributes, presided over all matter and motion throughout this infinitely extended space and time were propositions in them'selves so plain, that they might be regarded as axioms. But they were, at the same time, propositions upen which we could not reason, because the limited capacity of the human mind could not comprehend infinite quantities. Nor was it proper that we should at tempt to investigate the attributes or essence of the Divine Nature. The modus operandi, or manner of connexion between the external world and the volitions of the Deity, being beyond our comprehension and above our control, such investigation could lead to no useful result. But we might and ought to reason and inquire concerning the physical agents employed by Him in operating the various processes of the material creation which surrounded us, and of which we formed a part. This inquiry had a useful object, because it would lead us to useful and valuable knowledge. All the changes in the modes and qualities, or forms and attributes, of matter, were the results of motion-without motion there could be no change. If, therefore, men did truly and fully know the laws which regulated the motions of matter, it was evident their power over matter could be extended. On these considerations was founded the claim to inquire freely concerning the Jaws of matter and motion.

ACOUSTICS.

Many opinions of the probability of conveying intelligible sounds to great distances have been at different times entertained. Mr. Dick, of Glasgow, in his "Christian Philosopher," thinks it highly probable, that by means of acoustic tunnels, a clergyman sifting in his own room in Edinburgh might address a congregation in Musselburgh, or Dalkeith, or even in Glasgow. And Mr. Curtis, to whom the public are indebted for the invention of many valuable and ingenious-acoustic instruments, while speaking in

his new work on the physiology and

of the ear, of his acoustic chair, of

which is in the Adelaide-street Gallery, states, that intelligence might be conveyed by it from St. James's to the Houses of Lords and Commons, and from London to the Castle at Windsor. On the same principle, a song sung at the Italian Opera House might he heard at all the other theatres in London, In these days of universal improvement, might not these suggestions be turned to good account?

NOTES AND NOTICES.:

Sir,-In page 62 of the 690th Number of your Magazine,Litera" expresses a wish to be put in possession of a small machine by which he may be able to take several copies of a letter on letter, paper. If Litera" will apply by private letter to H. Truman; St. Owen-street, Hereford, he will Jearn of a small machine which will enable him to take off, expeditiously, as many copies as he may want, and without the assistance of either clerks. or printer.-F. P. [Will F. P. favour us with a description of the machine in question? Any person whom he may depute will, en calling at our office, receive the balance of the sum transmitted in F. P.'s letter, after deducting the postage.]

Errata in Mr. Cheverton's article in our last Number:

P. 90, cal. 2 line 7 from bottom, for "that" read than," and dele"

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CAPTAIN SMITH'S FIRE-EXTINGIUISHING APPARATUS AND FIRE-ESCAPE.

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CAPTAIN SMITH'S FIRE-EXTINGUISHING

APPARATUS AND FIRE-ESCAPE.

Sir, The object of the following plan is twofold-to produce a much more powerful effect from fire-engines, and to introduce a fire-escape. These are subjects worthy of the consideration of every man, for it is daily too evident, even with the means at command in the metropolis, that the chances of arresting a fire which bursts out with fury is a forlorn hope. The water, which is generally negligently and scantily supplied, is fritted away by a variety of engines; rarely any one of them throws a volume of water actually on the burning matter, the greater part falls on the outside walls or on the flames, rivalling the wetted rod that feeds a fire at a forge.

To expect to introduce a fire-escape is also a forlorn hope, people in general having come to the conclusion, that before any one could have transported such a thing from a parish-church or engine. house, the unfortunate victims at fires suffered by suffocation, or were burnt to death. The fact is, "what is every body's business is nobody's." It would, therefore, be in vain to recommend for adoption any thing, howsoever simple, that persons had to bring to a fire to act exclusively as a fire-escape. But it is confidently hoped that the annexed diagram, when described, will convince the most seeptical, that such a desideratum may be brought into action with success in aid of suffering humanity.

*

The drawing represents a fire-escape in operation, and the most powerful fireengine with its hose directed on a fire, from the top of a pole about 40 feet long, raised in its centre; the pole can be raised or lowered when required, like the mast of a barge, round it is a sliding iron collar, having three oaken legs, with a stop-joint, the ends pointed with iron; these are opened out and placed on the ground, to steady the pole; a yard, about 40 feet long, the end cased with very sheet-iron, is hoisted up by a chain through an iron pulley; to the upper half of the yard, which is rather the longest, a hose is attached, reaching from the extreme end or yard-arm, then down the pole to the engine; this is always to be

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The pole may be in two pieces, like a mast and topmast; the mast might be always kept upright: if iron; the topmast could slide inside of it.

kept ready fitted to the yard (this hose,
as seen in the drawing, is not used whilst
the yard is employed as a fire-escape).
The yard is balanced so that the lower or
shortest end would move upward, if not
thus
held down by men with ropes;
slung, it forms an universal joint; the
upper end can be pointed perpendicularly
about 60 feet (which is higher than any
ladder), lowered towards the ground, or
moved at pleasure to the right or left,
with great facility. At the end of the
yard is a light iron frame, called a basket,
capable of containing two or three per-
sons, attached to a chain rove through an
iron pulley, and running along to a second
pulley at the slings of the yard, and then
down by the pole to the engine.

Action. On the engine reaching its destination under a clever director, he must take up his position correctly, raise the pole, cross the yard, and while the hoses are preparing to act as if it were an ordinary engine. Should any person be observed to have his retreat cut off, and present himself at a window for escape, the yard-arm, with the basket, is to be directed to him by the men holding the ropes attached to the lower end. When he is safe in, if there are any flames under him, the yard is to be turned round by the ropes, and the basket lowered down. Here the yard has a great advantage over a ladder (and it can perform the office of one at any length), as per sons are frequently cut off in their de scents by flames below. If no one is seen to require assistance, but it should be supposed that there are helpless children or persons in such a state as to prevent them from saving themselves, a parent or fireman may in some cases venture up in the basket and proceed in search of them Now, if the fire-engine could not be brought into play whilst these acts of humanity were performing, the invention would meet with little encouragement from the Fire-office establishments, and justly, as it would not be advisable to leave a powerful engine idle. It is there fore to be observed, that during the operations of the fire-escape the fire-engine can act, if every thing is properly or ganised, as effectually as a first-rate engine on the old plan, with the advantage of playing on a fire from the top of the pole, if circumstances require it. But as soon as every effort has been used to rescue persons requiring assistance, the

hose connected to the yard is to be brought into play (which is the mainstay of the invention), and the water forced where most serviceable in a powerful body, guided by the ropes used to the fireescape; this may be expected to produce an effect seldom witnessed, and prove that the introduction of the pole and yard, without reference to their uses as a fire-escape, would be highly beneficial; indeed, the hose of a second engine may be brought to play from the top of the pole. The highest stories of houses and stores may be reached by their assistance, and the roofs of others effectually wetted, to preserve them from catching fire. Valuable property, as pictures, &c. may be removed safely by this invention.

When the heat of the fire would admit of it (on its breaking out, for instance), a fireman might be placed in the basket and by means of a short flexible mouthpiece screwed to the hose, direct the water more immediately on the place on fire. These are little refinements that may be found practicable, but it is presumed that sufficient has been shown to prove, that human beings may be saved who otherwise would be left to perish; and that a powerful stream of water may be directed on the object on fire, whether it be at the end of a room or a passage, instead of being scattered to the wind, reaching little more than the outside of the building, whilst the destroyer is within.

Finally, walls and floors may be examined after a fire from the yard-arm, at a time that it would be dangerous to place a ladder against them.

The humble inventor who urges the adoption of this plan until something better can be found, takes the liberty to remind reflecting persons, that it is not a single life, this or that house-but familes, streets, and towns, that are often nearly swept away by fire under the present inefficient system; yesterday it was so at New York and in London, to-day at Quebec! It is, therefore, high time to be prepared to face the enemy with improved means of defence, and no longer be content with those which, judging from their effects, may be likened in many cases to

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the well-known plan for raising water adopted by an old woman.

As in cases of fire there are generally too many persons anxious to command, especially amateurs, with more zeal than judgment, it would be beneficial if a director were appointed to act, by consent of the whole of the fire-establishments of a city or town; the director to be the leading man of the first engine that reached the fire, who might be awarded a certain sum; aspeaking-trumpet should be used by him in cases of emergency, by which his voice might at once be known by the tone it would give it, his orders would then be more promptly obeyed. When necessary (and it is so too often), to pull down a building to arrest the progress of a fire, a distinct order should be given by some responsible person. To prevent confusion, any suggestion an influential character or other person at a fire might wish to make should be made through the director. At Constantinople the Sultan is required to attend personally at fires.

Should it be thought preferable to have the engine distinct from the pole and yard, particularly when the engines are small, a platform on trucks, about ten feet long by six or eight wide, would be required to transport them (this might precede the engine and carry the firemen); in this case, also, the short hose which is fitted to the yard and pole must be always kept properly fitted to them; and whenever the fire-escape is not wanted, the hose must be attached to an engine at the fire, a second may be carried up to the top of the pole to make it more effective.

If the above plan be worthy of adop tion, then, in London or in places where soldiers are quartered, it should be their especial province to proceed on this Polar expedition to a fire on the first alarm being given. It may be observed, that since the establishment of the New Police in all the great towns, a space may always be kept clear for operations of this nature, which renders their adoption in the present day more feasible than here. tofore.

In Russia every city is divided into districts (from personal observation, it is so at St. Petersburgh, Moscow, and Smolensko), each district having a watchtower, from which signals are made on the instant a fire is discovered, with balls by day and lanterns by night, to indicate

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