Mechanics Magazine,


No. 94.]

SATURDAY, JUNE 11, 1925.

[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 affairs : 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 why wh shit 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 from 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


147 purposes for which they were in- being then all that would be required for tended. To particularise the expe-structions, in language it were impossi

purposes of inflation. Printed inriment recently tried, of tlırowing ble to misunderstand, would, of course, an anchor on shore by means of a accompany the case containing the magun, might appear invidious, were chine, pointing out the exact proportions it not selected (as it really is) on ac- to be used in mising the ingredients for count of its excellence, within any producing the gas, together with the distance its capabilities command, method of doing so; which, in fact, which, however, from its nature, are

amounts to nothing more thanimmersing

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 müto 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 same as then, is a principle on which it were

the common bunghole of a cask, the hopeless to attempt succeeding ; and balloon will, of course, be inflated.' The

jugredients 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, by too uncertain a means to need or de- screwing the brazen neck or pipe into serve a moinent's consideration. All, of a lever, for doing which, with faci

the bung-hole-a key, ou the principle then, that remains, is to proceed at lity, will accoinpany the machine. It is once to a description of a machine,

to be observed, that a little white lead which, depending for success on a ought to be laid round the screw, prenatural cause (the lightness of hy- vious to inserting it into the bung-bole, drogen gas, as compared to atmo- in order to prevent any of the gas froin spheric air), can scarcely, it is estic escaping through the instertices existing

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 froin the land, constitute I am, Sir,

the remaining portion of this invention.

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

for exploding a sheil, will, however, be

left sutiiciently long, when originally Machine,

supplied, to answer any distancı', but

may be cut shorter, should the danger This inreution 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 suficient 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 balloou being completed, which not ingated, may be compressed within will of course be known bvihe expansion a very smail 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 bunga scription 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 hydrogen gas, for inflating the secured to a belaying-pin by a strong above-mentioned balloon, may at any rope, to prevent its rising, until the retime be produced by an union of zinc, mainder of the apparatus is afiixed. The water, and sulplruric 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 miglit 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,

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ELECTRIC TELEGRAPHS. This liaving been done, and a small grap- smoke 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 ways drive it towards the land, the dis- Addison ór Steele. We are to learn, tance from which will, of course, regu- therefore, not too hastily to reject late the size of the rope that should be applied to the grapnel, being smaller in

even those hints which are not improportion to the length it has to go. It mediately clear to us. is scarcely necessary to observe, that if sufficient rope is supplied, the balloon I venture to propose to you, that a

Under protection of this remark, cannot fail in conveying the grapnel over the land, or that, when the fire of the telegraphic communication may be fuse reaches the powder, it will explode, held, at whatever distance, without and thereby detach the grapnel and rope

a 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, tric shock. the light, whilst in the air, together with 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 fourpounds 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

ble, without exposure to the public box is screwed on.

eye, as in the usual telegraphi, 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 gunship.

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- been made for the expected event,

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

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

he reigns, and receive the congratu-
Sir,—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





149 INFLUENCE OF COPPER, ETC. ON valuable miscellany, a short Table,

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

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, 450 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

chased under a discount, and resold at In the ring of copper, 33 oscillations, 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.

d. 24

2 11 32 5

5 5 34


11 2 22 SIR, -Agreeing with the motto of a


14 5 94 15

17 15 Tate Number of your publication, that


21 4 3 " Trade is the Golden Girdle of the


25 0 0 Globe," I beg to offer “something to


078 the general use," upon a subject that


33 6 8 deeply concerns every one connected with trade.


37 18 74 30

42 17 6 As “ M. W.," in his own defence,


48 2 111 has ably exposed the “gross blunders”


53 16 11 of your Birmingham Correspondent,


60 0 0 I need not address a word to him or


66 13 4 the “very large manufacturing dis


73 18 3; trict” that (as he says) adopts the


81 16 41 the same false principles for their

90 9 54 constant practice;" but I would beg


100 00 to submit, through the medium of your





75 10




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