and therefore we advise the observance of caution, and holding fast to the Grove series until another is invented of unquestionable superiority.

MR. TAL. P. SHAFFNER:

PROVIDENCE, March 30th, 1854.

Dear Sir:-Your letter of the 25th inst., in answer to mine, I have received ;-please receive my thanks for the kindred spirit which you manifest in relation to my invention. I should be very much pleased to have a visit from you.

I think it would be of great advantage to you to become better acquainted with my invention, in relation to its application to telegraphing. You may be sure that telegraphing is to be carried on through the agency of magneto-electricity, instead of galvanic; and if a cable is ever laid across the bed of the Atlantic, it will require the magneto-electric battery to furnish the electric current for telegraph communication, on account of the greater intensity of current (which can be developed from magnets, than can possibly be developed from any arrangement of zinc and acid whatever), which you know it would require to work a long line without intermediate batteries.

In my last letter, wherein I hinted at the mode which telegraphing could be carried on, by the magnetic batteries of my invention, to a better advantage than with the galvanic battery, I would like to call the attention of thoroughgoing practical telegraphers in relation to facts which must be necessarily known, to fairly consider the adoption of my new battery for telegraphing purposes.

1st. It would be necessary to know how many miles of telegraph line there are in operation in the United States in each of the modes of telegraphing-viz., Morse's and House's; for this would determine how much battery power would be required for working all of the lines, so far as relates to the line circuits. The number of Grove's battery cells used would also afford a comparison by which to determine how large to build the several magnetic batteries that would be required to take their place. This latter method would probably afford a more correct data in connection with the former, than could be obtained any other way, because the House lines of the same length require more battery power than the Morse lines; therefore it would be necessary to know the given number of cells used per certain number of miles for each system, to know how to adapt the magnetic batteries to each system.

2d. It would be necessary to know how many independent circuits of telegraph lines there are in the United States under both systems, and what principal cities the greatest number of the whole of those lines emanate from; for this would deter

mine how many batteries would be required, and what places to locate them in-whether it be New-York, Washington, NewOrleans, St. Louis, or any other central city in the United States. Then the length of those independent circuits emanating from each central city or locality, and the number of battery cells employed for each circuit, would determine the size and power of each magnetic battery for each of those central localities.

With this information, I could at once calculate the cost of furnishing such a system of batteries for telegraphing throughout the United States, so as to lay before those pecuniarily interested in telegraphing the merits of it in point of economy.

I could also determine the aggregate amount of power required to operate those batteries to develop the electric current, and make a very exact estimate of the whole expense required to put such a system into practical operation. There are a great many advantages in the use of my magnetic batteries, for telegraphing, that cannot be had on any conditions in the use of the zinc and acid battery. The point developed is more steady, constant, and uniform in its power than the current of the zinc battery; as the uniform power of the current depends upon the uniform speed with which the battery is rotated; which speed can be regulated with as much precision as a clock, if required, while with the zinc battery the current becomes weaker and weaker as the acid loses its strength, and the uniform strength of the current can only be maintained by renewing the acid; which never can be regulated so practically exact as the current developed from my battery. This point is of great practical importance in telegraphing, to always have a uniform reliable current to depend upon, which is always ready (without nursing with acid) to use when the lines are in a working condition. Then the construction of my batteries is so simple, that the only care required to keep them in an operating condition is simply to keep the journals of the shaft which rotates oiled, as this is the only point of friction and wear to the battery. Consequently, a battery well constructed would last any number of years, with no other repairs than to renew the boxes once in ten or twenty years. This little expense, together with the power necessary to rotate them, is all that is required, over and above the first cost, to keep them in operation for hundreds of years, to furnish electricity for telegraphing; and, in comparison, they would shed their streams of electricity to convey human intelligence to all parts of the earth for the purposes of man, as the sun in the heavens sheds its streams of light and heat to promote the growth of vegetation, and inspire life and animation to the tenement of flesh and blood which human intelligence inhabits. The magnetic battery is well calculated every way to take the

place of the galvanic battery to furnish electricity for telegraph purposes; and it is bound to be the instrument chosen, both in point of utility and economy, as well as for reliability.

After obtaining all the facts and information necessary to put this system of magnetic batteries into operation which I have cited, so that I shall be enabled to make a just and proper estimate of the expense required to construct and put into practical operation such a system, and for which information I beg leave to ask for your co-operation in rendering me such part as you may have, I have in contemplation a plan for putting into execution the project, and which I think, with proper and judicious management, will be the best method to adopt. The posi tion which you occupy would enable you to become one of the most prominent co-workers in accomplishing this great project.

I think, Mr. Shaffner, you will consider this plan politic, and the most judicious to be adopted. It will be opening a door for increasing the profits of telegraphing, and cheapening to an enormous extent the expenditure. For, in my system of magnetic batteries, there would be but one first cost for at least two hundred years; while with the zinc battery, saying nothing about the first cost of the platinum used, and other essentials, there is a first cost for zinc three or four times a year, and in some cases oftener, which would in a few years overgo many times the first cost of the magnetic batteries. Therefore, it is obvious that the magnetic batteries, as a substitute for the zinc battery, would in a few years be hundreds of thousands of dollars in the pockets of Telegraph Companies; and it becomes a question of momentous importance whether the magnetic battery shall be adopted or not. To say it shall be adopted, is speaking for the best interests of all who are engaged in telegraphing. The zinc battery has had its day, now let it be cast aside and abandoned in toto for telegraph purposes. Let the magnetic battery take its place; it is adequate to the task in every instance. Not only on line circuits, but local circuits used in the Morse system, can be beautifully worked with a small magnetic battery attached directly to the register, and run by the same weight which operates the register.

There is no longer any need of the zinc battery for telegraphing, after a full supply of magnetic batteries to take its place.

I feel that it is possible to lay a cable across the bed of the Atlantic, which will permit the transmission of electricity through the bowels of the mighty deep, for telegraph purposes. If the condition of the bed of the ocean between Newfoundland and Ireland is, as Lieut. Maury represents, a plateau from fifteen hundred to two thousand fathoms in depth, and at the bottom as calm as a mill-pond, there is no reason why it could not be accomplished; and there is no reason, if such a line of

communication be established, that it may not be filled with the lightning from a magnetic battery located one at each end of the line, sufficient to operate the beautiful and sensitive instrument of Professor Morse's invention, and thereby bring Europe and America within speaking distance of each other; so that the thoughts of two great divisions of human beings, thousands of miles apart, shall be interchanged with each other as though space did not intervene.

I will write to you again at another time, when I will give you some description of my new battery, and the ends which I claim to accomplish when I shall have completed my invention. Very truly, yours,

CALVIN CARPENTER, JR.

Art. V.-AN ELECTRIC TELEGRAPH AROUND THE WORLD.*

A CABLE ACROSS THE ATLANTIC OCEAN-THE CABLES IN EUROPE-A LINE ACROSS BEHRING'S STRAITS THE GIRDLE AROUND

THE GLOBE CONSIDERED.

"THE project of establishing a telegraphic communication all round the globe is one upon which public attention on both sides of the Atlantic is fixed with growing interest, and which will cease to be considered impracticable as soon as no other difficulty remains than such as may be overcome by the union of science, industry, and capital. The remarkable progress of the present age, which has been brought about by the harmonious combination of these three mighty agencies, leaves little room for doubt as to the ultimate accomplishment of the project. It is only a question of time. Sooner or later, we may rest assured, the world will be girt round with an electric wire, by means of which all the principal cities and courts, as well as all the chief seats of commerce and homes of science, will be indissolubly united. What has been effected within the recollection of many, renders this glorious consummation quite within the bounds of possibility. Public opinion, enlightened and encouraged by the past achievements of human industry and skill, will ere long believe in the feasibility of the grand project, and call for its execution, though the conviction is not yet so widely spread and so firmly established as could be desired. The project is, however, already looked upon by many as an inevitable result of the numerous lines of steamboat communication which span the world, and the innumerable railways with which every country is now interlaced. Both in America and Europe the prevalent idea appears to be, that the next step towards the re

*From the Illustrated Magazine of Art.

alization of the mighty scheme must be a submarine telegraph across the Atlantic. And the history of past efforts shows that there is reason in this. The first short line of communication across the English Channel has, after some little interruption arising from accident, been made to work well; a second attempt, on a larger scale, to connect England and Ireland, has proved equally successful, in spite of similar obstacles at first; and the third line, which was laid down last summer between Doverand Ostend, is also in full operation. These successes have convinced many that a submarine telegraph may be laid down across the Atlantic, connecting Halifax with the most westerly promontory of Ireland.

Another circumstance also requires to be taken into account in connection with this subject. A wire laid down across the Atlantic could only serve for the conveyance of communications to and from two points at a distance of 2,000 miles apart. At no intermediate point could messages be received or dispatched. Along the whole line no accessory advantages could be reaped. It would be like an extra line of railway from NewYork to Boston, without any intermediate station.

There is, however, a course round the globe by which both the danger of interruption from one cause or another, and the useless expense attendant upon a submarine telegraph across the Atlantic, might be avoided. The government or people of the United States will soon extend the main line of their telegraph, via California, to Oregon. On the other hand, the telegraphic lines of Europe stretch towards the East nearly as far as the Uralian mountains. The necessity of a speedy communication with her Asiatic provinces will soon induce Russia to extend the line of telegraph in this direction. Certainly she will, for her own ends, carry it quite up to the Uralian mountains. The whole of the territory between this point and California is in possession of the United States, Great Britain, and Russia. It would not be necessary to ask a right of way for the telegraphic wire from any other government between these two distant extremities. Why, then, should not a combination be entered into for the establishment of a line across Behring's Straits? What physical or pecuniary difficulty could there be in such an undertaking which these three powers might not easily overcome, if united? Is the mere distance to be considered an insuperable difficulty? Telegraphic wires have already been established along a greater distance among ourselves, and that too by a private company, through a country with few large cities to encourage such a project. Ought there to be any difficulty about stretching a line across Behring's Straits? They are reckoned to be not more than thirty or forty English miles in breadth, with two or three islands between, which might serve as