Mechanics' Magazine,


No. 94.]

SATURDAY, JUNE 11, 1825.

[Price 3d,

“ Isthinc est sapere, non quod ante pedes modo est

« Videre, sed etiam illa quæ futura sunt prospicere.” Terence. " True wisdom consists not in seeing that which is before our eyes, but in the foresight of that which is to happen."





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SIR,-Previous to entering into a the shore not wholly impracticable. description of the machine invented This being the case in nineteen cases for the above purpose, it may be out of twenty-in fact, at all times necessary to premise, that shipwrecks when there is no local peculiarity in (except in cases of foundering), are the shore, either from the existence seldom, if ever, attended with loss of of a surf, or the set' of a tide (cirlives, save when such calamity occurs, cumstances it is impossible in every technically speaking, on a lee-shore; instance to guard against or provide or, in other words, when the wind for), it will be undoubtedly admitblows towards the land. This is too ted, that a certain means of opening manifest to need demonstration to a communication from a ship or vesany except such as are utterly un- sel in distress, with a leeward shore, acquainted with nautical atfairs : not is a desideratum whose value would withstanding which, it may be neces- be in proportion to the certainty with sary to point out the reasons wliy which it would at all times act-a resuch is ever the case, not only to sult only to be estimated by putting bring within view the particular pur- it practically to the proof, and fronte poses to which the machine is appli- the principles on which it is concable, but also to prevent the possi- structed. bility of misconception, or the exist. Innumerable as have been the atence of a doubt.

tempts hitherto made to discover a With the wind off the land, a ship means, or invent a machine, for the may at all times keep a proper offing; above purpose, it is a melancholy or, in the event of her accidentally fact, that the whole have either tostriking, or being endangered from tally failed, or are applicable only any other cause, the sinoothness of within a very limited distance. This the water, owing to the direction of may have been owing either to a want the wind, will generally be such as of practical knowledge in the invento enable the crew to reach a land- tors, or from their proceeding on ing-place with safety in their boats, mistaken principles, hastily adopted, or, at least, render assistance from or inadequate in themselves to the MACHINE TO PRESERVE PERSONS FROM SHIPWRECK. 147 purposes for which they were in- being then all that would be required for tended. To particularise the expe

the purposes of inflation. Printed inriment recently tried, of throwing

structions, in language it were impossian anchor on shore by means of a accompany the case containing the ma

ble to misunderstand, would, of course, gun, might appear invidious, were chine, pointing out the exact proportions it not selected (as it really is) on ac- to be used in inising the ingredients for count of its excellence, within any

prodacing the gas, together with the distance its capabilities command,

method of doing so; which, in fact,

amounts to nothing more thanimmersing which, however, from its nature, are

the zinc in the water, and afterwards necessarily very circumscribed. The adding the sulphuric acid. weight of the anchor or grapnel it To prevent either trouble or delay in self would prevent the possibility of

affixing the balloon to the cask of water its flying far, were the resistance

for inflation, a brazen tube, two inches made by the chain or rope attached

deep, having a strong sharp screw cut

on the outside of it, will be, when mato it, and its shape, peculiarly un- nufactured, affixed to the neck of every adapted for dividing the air, left en balloon. Through this pipe or neck, tirely out of the question. This,

which will be in diameter the saine as then, is a principle on which it were

the common bunghole of a cask, the

balloon will, of course, be inflated. The hopeless to attempt succeeding ; and

ingredients for producing the gas having floating any thing towards the shore, been mixed, the balloon is to be athas been proved from experience as tached to the cask containing them, bv too uncertain a means to need or de screwing the brazen neck or pipe into serve a moinent's consideration. All,

the bung-hole-a key, ou the principle then, that remains, is to proceed at

of a lever, for doing which, with faci

lity, will accompany the machine. It is once to a description of a machine, to be observed, that a little white Icad which, depending for success on a ought to be laid round the screw, prenatural cause (the lightness of hy viouz to inserting it into the bung-bole, drogen gas, as compared to atmo

in order to prevent any of the gas froin

escaping through the instertices existing spheric air), can scarcely, it is esti

between the wood and the screw. mated, fail; at the same time esta

A strong wooden box, or magazine, blishing the utility of an art (I allude capable of containing four pounds of to aërostation), which, although ac gunpowder, with a common fuse or portknowledged wonderful, has been ala

fire inserted into it, the length of which ways heretofore described as useless.

(the fuse) will depend on the distance

the vessel is from the land, constitute I am, Sir,

ine remaining portion of this invention.

The fuse inserted into the magazine. Your obedient servant, being on the same principle as that used

for exploding a sheil, will, however, be i F. HIGGINSON,

left sufficiently long, when originally supplied, to answer any distancı', but

may be cut shorter, should the danger .. This intention consists, in the first be inminent, and the land very near : place, of a silk bag, air tight; in fact, a although it would be better at all times common balloon, capable of containing to leave sufficient length to permit the at the most, 2000 feet of hydrogen gas, balloon to get well over the land before and, consequently, of raising a weight of the magazine explodes. The inflation sixty pounds averdupois. This, when of the balloon being completed, whiclı not indated, may be compressed within will of course be known by the espansion a very small compass; but to guard of the bag, a nipper, or piece of cord, is · against any possible flaw or injury exist- to be passed tightly round the neck of ing either in the material, or arising the bag, above the brazen ring or screw, from accident, every ship or vessel ought in order to prevent the gas escaping;. to be supplied with three distinct bags and the machine disengaged from the or balloons. Before I proceed to a de cask, by unscrewing it from the bungscription of the other parts of the ina hole with the key or lever. Previous to chine, it may be uecessary to observe, doing so, the balloon must, of course, be that hydrogeu gas, for inflating the secured to a belaying-pin by a strong above-ruentioned balloon, may at any rope, to prevent its rising, until the retime be produced by an union of zinc, mainder of the apparatus is affixed. The water, and suipiruric acid. The sul magazine or box is then to be fastened phuric acid, together with the zinc, to the balloon, by inserting the screw at might be packed in the case containing the neck, into a socket fitted to receive the machine; a barrel or cask of water it, attached to the upper part of the box,




ELECTRIC TELEGRAPHS. This liaving been done, and a small grap- šmoke into light, and light into nel, with a rope attached, hung to the glory." This early idea of gas-light, bottom of the magazine or box, by an eyebolt fixed there for the purpose, the

to which it seems plainly to refer, fuse is to be set on fire, and the machine was received as an idle dreain, and liberated. The direction of the wind, as is only preserved to us, like straws before observed, on a lee-shore, will al- in amber, by the wit and satire of

IS- Addison or Steele. We are to learn, tance from which will, of course, regulate the size of the rope that should be

therefore, not too hastily to reject applied to the grapnel, being smaller in

even those hints which are not improportion to the length it has to go. It is scarcely necessary to observe, that if Under protection of this remark, sufficient rope is supplied, the balloon I venture to propose to you, that å

telegraphic communication may be the land; or that, when the fire of the fúse reaches the powder, it will explode,

held, at whatever distance, without

held, at w and thereby detach the grapnel and rope å moment's loss of time in transfrom it. This, however, is not the only mission, and equally applicable by purpose the fuse is intended to answer; day or night, by means of the elecas, should the calamity occur at night, the light, whilst in the air, together with

tric shock. the explosion, will direct the inhabitants

An experiment of this kind has on the beach to the place where the grap- been tried on a chain of conductors nel will fall. The advantages of a com of three miles in extent, and the munication thus opened with the land, shock returned without any percepit is needless to dwell upon; personal

tible time spent in its going round; experience having shown me, could such have been effected, a number of valuable and may not the same principle be lives might have been saved. Should, applicable for 100 or 10,000 miles ? however, even one unfortunate be res- Let the conductors be laid down cued in the hour of his distress, the under the centre of the post-roads, knowledge would constitute in itself

imbedded in rosin, or any other, the more than a reward for the anxiety and trouble the perfecting this machine has'

best nonconductor, in pipes of stoneentailed on the inventor,

ware. The electric shock may be so

disposed as to ignite gunpowder; but Description of the Engravings. if this is not sufficient to rouse up a Fig. 1. A, the balloon, capable of con- drowsy officer on the night-watch, taining 2000 feet of hydrogen gas, and let the first shock pass through his raising a weight of sixty pounds, at elbows, then he will be quite awake tached by the neck-screw to the box or to attend to the second; and by a semagazine.

ries of gradations in the strength B, the magazine.containing four pounds and number of shocks, and the inof powder.

terval between each, every variety of C, a keg or lever detached, when the

signal may be made quite intelligi. box is screwed on.

ble, without exposure to the public

eye, as in the usual telegraph, and D, the fuse, or port-fire.

without any obstruction from darkE, neck-screws.

ness, fogs, &c. It was mentioned F, the rope communicating with the before, that electricity will fire gun. ship.

powder—that is known; we may G, a grapnel hung from the eye-bolt.

imagine, therefore, that on any worFig. 2 represents the scene of a ship

thy occasion, preparations having wreck on a lee-shore, and the instru

been made for the expected event,

as the birth of a royal heir, a moment in operation.

narch might at one moment, with his own hand, discharge the guns of

all the batteries of the land in which ELECTRIC TELEGRAPHS.

he reigns, and receive the congratuSir,—There is, I think, in one of lations of a whole people by the like, the numbers of the Spectator, dated return. about a hundred years ago, a passage

I am, Sir, tending to ridicule some projector of Very respectfully yours, that day, who had proposed to“ turn



which I formed some years ago for my

own use, and which, I think, will be M. Arago lately communicated to found to be according to “Cocker,” the Academy of Sciences some in and upon the universally received and teresting experiments relative to the correct principles of our best comoscillations of a magnetic needle, mercial writers-e.g. Evans's Tables surrounded by different substances.

of Profit and Discount, a 4to. volume, He had ascertained that the copper

the seventh edition of which has recently

appeared, price only one guinea. Now, rings, with which dipping needles

as I believe that each item of this exare generally surrounded, exerted

pensive work may, by the aid of the on the needles a very singular action, subjoined method, be as correctly and the effect of which was rapidly to very expeditiously obtained, I need not diminish the ainplitude of the oscil- make any other apology for troubling lations without sensibly altering their you. Should this be deemed worthy duration ; thus, when a horizontal insertion, I shall feel a pleasure in apneedle, suspended in a ring of wood pearing again upon your pages, in by a thread, without tension, was

further elucidation of this and other moved 45° from its natural position,

commercial calculations. aud left to itself, it made 145 oscil

- I am, Sir, lations before the amplitude was

Yours respectfully, reduced to 10°. In a ring of copper

W- Lthe amplitude diminished so rapidly that the same needle moved 45° from

Windsor-street, Islington, its natural position, and only oscil

May 15, 1825. láted 33 times before the arc was reduced to 10°. In another ring of copper, of less weight, the number of oscillations between the arcs of

A TABLE, 45° and 100 were 66. The time of

Exhibiting to immediate view the addithe oscillations appeared to be the

tional rate per cent. required to sustain same in all the rings.

the reaction of a given discount, withIn the ring of wood, 145 oscillations, out affecting the principal; also, show45 deg. to 10 deg.

ing the gain or profit upon goods pur*In the ring of copper, 33 oscillations,

chased under a discount, and resold at 45 deg. to 10 deg.

the gross price. In a lighter ring, 66 oscillations, 45 deg. to 10 deg.

Rate per Cent. Profit or Discount.

£. S. d.

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PROFIT AND DISCOUNT. SIR, --Agreeing with the motto of a Tate Number of your publication, that " Trade is the Golden Girdle of the Globe," I beg to offer “something to the general use," upon a subject that deeply concerns every one connected with trade.

As “ M. W.," in his own defence, has ably exposed the “ gross blunders" of your Birmingham Correspondent, I need not address a word to him or the “very large manufacturing district” that (as he says) adopts the the same false principles for their “constant practice;' but I would beg to submit, through the medium of your

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