Part 14

The only mode in which it appears possible for him to have transmitted intelligence, seems to be this: a single divergence of the pith balls, succeeded by an interval of two or three seconds, may have represented A. Two divergencies in quick succession, with an interval following, may have represented B; three divergencies, in like manner, indicated the letter C; and so on for the remainder of the alphabet. Instead of these movements of the pith balls representing letters, they may have indicated the numerals 1, 2, 3, &c. so that with a vocabulary of words, numbered, conducted his correspondence. This appears to be the first electrical telegraph of which we have any account; but does not appear to have been used upon extended lines.

_Reizen’s Electric Spark Telegraph._

In 1794, according to Voigt’s Magazine, vol. 9, p. 1, Reizen made use of the electric spark for telegraphic purposes. His plan was based upon the phenomenon which is observed when the electric fluid of a common machine is interrupted in its circuit by breaks in the wire, exhibiting at the interrupted portions of the circuit a _bright spark_. The spark thus rendered visible in its passage he appears to have employed in this manner.

Figure 34 is a representation of the table upon which were arranged the letters of the alphabet, twenty-six in number. Each letter is represented by strips of tin foil, passing from left to right, and right to left, alternately, over a space of an inch square upon a glass table. Such parts of the tin foil are cut out, as will represent a particular letter. Thus, it will be seen that the letter A is represented by those portions of the tin foil which have been taken out, and the remaining portions answer as the conductor. P and N represent the positive and negative ends of the strips, as they pass through the table and reappear, one on each side of the small dot at A. Those two lines which have a dot between, are the ends of the negative and positive wire belonging to one of the letters. Now if a spark from a charged receiver is sent through the wires belonging to letter A, that letter will present a bright and luminous appearance of the form of the letter A. “As the passage of the electric fluid through a perfect conductor is unattended with light, and as the light or spark appears only where imperfect conductors are thrown in its way, hence the appearance of the light at those interrupted points of the tin foil; the glass upon which the conductors are pasted, being an imperfect conductor. The instant the discharge is made through the wire, the spark is seen simultaneously at each of the interruptions, or breaks, of the tin foil, constituting the letter, and the whole letter is rendered visible at once.” This table is placed at one station, and the electrical machine at the other, with 72 wires inclosed in a glass tube connecting the two stations. He could have operated with equal efficiency by using 37 wires having one wire for a common communicating wire, or with 36 wires by substituting the ground for his common wire. It does not appear that it was ever tested to any extent.

_Dr. Salva’s Electric Spark Telegraph._

In 1798, Dr. Salva, in Madrid, constructed a similar telegraph, as that suggested by Reizen, (see Voigt’s Magazine, vol. 11, p. 4.) The Prince of Peace witnessed his experiments with much satisfaction, and the Infant Don Antonio engaged with Dr. Salva in improving his instruments. It is stated that his experiments were conducted through many miles. No description of his plans appear to have been given to the public.

_Origin of Galvanism._

Galvanism takes its name from Galvani, Professor of Anatomy at Bologna, who discovered it in the year 1790. As the account of the circumstances attending the discovery of this useful and wonderful agent, may not be uninteresting to the reader, we insert it here as related in the “_Library of Useful Knowledge_.”

“It happened in the year 1790, that his wife, being consumptive, was advised to take, as a nutritive article of diet, some soup made of the flesh of frogs. Several of these animals, recently skinned for that purpose, were lying on a table in the laboratory, close to an electrical machine, with which a pupil of the Professor was amusing himself in trying experiments. While the machine was in action, he chanced to touch the bare nerve of the leg of one of the frogs with the blade of the knife that he held in his hand; when suddenly the whole limb was thrown into violent convulsions. Galvani was not present when this occurred, but received the account from his lady who had witnessed, and had been struck with the singularity of the appearance. He lost no time in repeating the experiment: in examining minutely all the circumstances connected with it, and in determining those on which its success depended. He ascertained that the convulsions took place only at the moment when the spark was drawn from the prime conductor, and the knife was at the same time in contact with the nerve of the frog. He next found that other metallic bodies might be substituted for the knife, and very justly inferred that they owed this property of exciting muscular contractions to their being good conductors of electricity. Far from being satisfied with having arrived at this conclusion, it only served to stimulate him to the farther investigation of this curious subject; and his perseverance was at length rewarded by the discovery, that similar convulsions might be produced in a frog, independently of the electrical machine, by forming a chain of conducting substances between the outside of the muscles of the leg, and the crural nerve. Galvani had previously entertained the idea, that the contractions of the muscles of animals were in some way dependent on electricity; and as these new experiments appeared strongly to favour this hypothesis, he with great ingenuity applied it to explain them. He compared the muscles of a living animal to a Leyden phial, charged by the accumulation of electricity on its surface, while he conceived that the nerve belonging to it, performed the function of the wire communicating with the interior of the phial, which would, of course, be charged negatively. In this state, whenever a communication was made by means of a substance of high conducting power between the surface of the muscle and the nerve, the equilibrium would be instantly restored, and a sudden contraction of the fibres would be the consequence.

“Galvani was thus the first to discover the reason of that peculiar convulsive effect which we now obtain from the Galvanic battery, and he attributed it to a modification of electricity. It was left to another to construct an instrument which would give a constant and increased effect, and develop this extraordinary fluid. Whatever share accident may have had in the original discovery of Galvani, it is certain that the invention of the Pile, an instrument which has most materially contributed to the extension of our knowledge in this branch of physical science, was purely the result of reasoning.

“Professor Volta, of Pavia, in 1800, was led to the discovery of its properties by deep meditation on the developements of electricity at the surface of contact of different metals. We may justly regard this discovery as forming an epoch in the history of galvanism; and since that period, the terms Voltaism, or Voltaic electricity, have been often, in honour of this illustrious philosopher, used to designate that particular form of electrical agency.

“He had been led by theory to conceive that the effect of a single pair of metallic plates might be increased, indefinitely, by multiplying their number, and disposing them in pairs, with a less perfect conducting substance between each pair. For this purpose he provided an equal number of silver coins, and of pieces of zinc, of the same form and dimensions, and also circular discs of card, soaked in salt water, and of somewhat less diameter than the metallic plates. Of these he formed a pile or column as shown in figure 35, in which three substances, silver, zinc, and wet card, denoted by the letters S, Z, I, were made to succeed one another in the same regular order throughout the series. The efficacy of this combination realized the most sanguine anticipations of the discoverer. If the uppermost disc of metal in the column be touched with the finger of one hand, previously wetted, while a finger of the other hand is applied to the lowermost disc, a distinct shock is felt in the arms, similar to that from a Leyden phial, or still more nearly resembling that from an electrical battery, weakly charged. These discs are supported by two large discs, _a_ and _i_, of wood, one at the bottom and the other at the top of the pile, with three glass rods, A, B, C, at equal distances around the pile, but not touching it, and are cemented into the wooden base and cover. P represents the wire connecting the silver disc, and N that connecting the zinc.”

_The Decomposition of Water._

“The chemical agency of galvanism, exerted on _fluid_ conductors, placed in the circuit between the poles of the battery, is very remarkable. Among the simplest of its effects is the resolution of water into its two gaseous elements, oxygen and hydrogen. The discovery of this fact is due to the united researches of Mr. Nicholson and Mr. Carlisle, and was one of the immediate consequences of the invention of the pile by Volta. The most convenient mode of exhibiting the decomposition of water by the Voltaic battery, is to fill, with water, a glass tube; to each end of which, a cork has been fitted so as to confine the water, and to introduce into the tube two metallic wires, by passing one, at each end, through the cork which closes it, allowing the extremities of the wires, that are in the water, to come so near each other as to be separated by an interval of only a quarter of an inch. The wires being then respectively made to communicate with each of the two poles of a Voltaic battery, the following phenomena will ensue. If the wire connected with the positive pole of the battery consists of an oxidable metal, it is rapidly oxidated by the water surrounding it; while, at the same time, a stream of minute bubbles of hydrogen gas arises from the surface of the other wire, which is in connection with the negative pole. But if we employ wires made of a metal which is not susceptible of oxidation by water, such as gold or platina, gas will be extricated from both the wires, and, by means of a proper apparatus may be collected separately.”

We shall now see that these two discoveries, viz. the Voltaic pile, and the decomposition of water by the agency of the former are the bases of a plan _for telegraphic_ purposes.

_Samuel Thomas Soemmering’s Description of his Voltaic Electric Telegraph, invented in 1809._

“The fact that the decomposition of water may be produced with certainty and instantaneously, not only at short, but at great distances from the Voltaic pile, and that the decomposition may be sustained for a considerable time, suggested to me the idea, that it might be made subservient for the purposes of transmitting intelligence in a manner superior to the plan in common use, and would supersede them. My engagements were such that I have only been able to test the practicability of my plan upon a small scale, and herewith submit, for the Academy’s publication, an account of the experiment.

“My telegraph was constructed and used in the following manner: In the bottom of a glass reservoir, figure 36, of which A A is a sectional view, are 35 golden points, or pins, passing up through the bottom of the glass reservoir, marked A, B, C, &c. 25 of which are marked with the 25 letters of the German alphabet and the ten numerals. The 35 points are each connected with an extended copper wire, soldered to them, and extending through the tube, E, to the distant station; are there soldered to the 35 brass plates, upon the wooden bar, K K. Through the front end of each of the plates, there is a small hole, I, for the reception of two brass pins, B and C; one of which is on the end of the wire connecting the positive pole, and the other the negative pole of the Voltaic column, O. Each of the 35 plates are arranged upon a support of wood, K K, to correspond with the arrangement of the 35 points at the reservoir, and are lettered accordingly. When thus arranged, the two pins from the column are held, one in each hand, and the two plates being selected, the pins are then put into their holes and the communication is established. Gas is evolved at the two distant corresponding points in an instant. For example, K and T. The peg on the hydrogen pole, evolves hydrogen gas, and that on the oxygen pole, oxygen gas.

“In this way every letter and numeral may be indicated at the pleasure of the operator. Should the following rules be observed, it will enable the operator to communicate as much if not more, than can be done by the _common telegraph_.

“_First Rule._ As the hydrogen gas evolved is greater in quantity than the oxygen, therefore, those letters which the former gas represents, are more easily distinguished than those of the latter, and must be so noted. For example, in the words _ak_, _ad_, _em_, _ie_, we indicate the letters _A_, _a_, _e_, _i_, by the hydrogen; _k_, _d_, _m_, _e_, on the other hand, by the oxygen poles.

“_Second Rule._ To telegraph two letters of the same name, we must use a unit, unless they are separated by the syllable. For example, the name _anna_, may be telegraphed without the unit, as the syllable _an_, is first indicated and then _na_. The name _nanni_, on the contrary, cannot be telegraphed without the use of the unit, because _na_ is first telegraphed, and then comes _nn_, which cannot be indicated in the same vessel. It would, however, be possible to telegraph even three or more letters at the same time by increasing the number of wires from 25 to 50, which would very much augment the cost of construction and the care of attendance.

“_Third Rule._ To indicate the conclusion of a word, the unit 1 must be used. Therefore, it is used with the last single letter of a word, being made to follow the ending letter. It must also be prefixed to the letter commencing a word, when that letter follows a word of _two letters_ only. For example: _Sie lebt_ must be represented _Si_, _e1_, _le_, _bt_, that is the unit 1 must be placed after the first _e_. _Er lebt_, on the contrary, must be represented. _Er_, _1l_, _eb_, _t1_; that is, the unit 1 is placed before the _l_. Instead of using the unit, another signal may be introduced, the cross † to indicate the separation of syllables.

“Suppose now the decomposing table is situated in one city, and the pin arrangement in another, connected with each other by 35 continuous wires, extended from city to city. Then the operator, with his Voltaic column and pin arrangement at one station, may communicate intelligence to the observer of the gas at the decomposing table of the other station.

“The metallic plates with which the extended wires are connected have conical shaped holes in their ends; and the pins attached to the two wires of the Voltaic column are likewise of a conical shape, so that when they are put in the holes, there may be a close fit, prevent oxidation and produce a certain connection. It is well known that slight oxidation of the parts in contact will interrupt the communication. The pin arrangement might be so contrived as to use permanent keys, which for the 35 plates or rods would require 70 pins. The first key might be for hydrogen A; the third key for hydrogen B; the fourth key for oxygen B, and so on.

“The preparation and management of the Voltaic column is so well known, that little need be said except that it should be of that durability as to last more than a month. It should not be of very broad surfaces, as I have proved, that six of my usual plates (each one consisting of a Brabant dollar, felt, and a disc of zinc, weighing 52 grains) would evolve more gas, than five plates of the great battery of our Academy.[19] As to the cost of construction, this model which I have had the honour to exhibit to the Royal Academy, cost 30 florins. One line consisting of 35 wires, laid in glass or earthen pipes, each wire insulated with silk, making each wire 22,827 Parisian feet, or a German mile, or a single wire of 788,885 feet in length, might be made for less than 2000 florins, as appears from the cost of my short one.”

[19] Academy of Sciences at Munich.

_Extract from the Journal of the Franklin Institute, vol. 20, page 325._

“To the foregoing notice, we append an article published in Thompson’s Annals of Philosophy, vol. 7, page 162, 1st series, February, 1816. This article is from the pen of Dr. John Redman Coxe, of Philadelphia, and it is believed that the idea of the employment of galvanism, for a telegraph which it suggests, was then original. Those who are acquainted with the history of the progress of electricity, as evolved by the ordinary machine, are aware that experiments had been made with a view to its employment for a similar purpose; but from the inherent difficulties of the subject, the project had been abandoned.

“It is not pretended, that the state of our knowledge on the subject of galvanism, was such at the time the foregoing suggestion was made, as would have enabled any person to apply it practically; this, if done, will be due to the recent discoveries on the subject of electro magnetism; a subject which has been very successfully pursued by the philosophers of our own country, and particularly by Professor Henry, of Princeton. As some of the philosophers of Europe are disputing upon the question of the authorship of _proposition_ for the employment of Galvanic electricity, telegraphically, we have thought that it would not be altogether inopportune, or uninteresting, to publish the article above referred to.

“_Use of Galvanism as a Telegraph: in an extract of a Letter from Dr. J. Redman Coxe, Professor of Chemistry, Philadelphia._

“I observe in one of the volumes of your Annals of Philosophy, a proposition to employ galvanism, as a solvent, for the urinary calculus, but which has been very properly, I think, opposed by Mr. Armiger. I merely notice this, as it gives me the opportunity of saying, that a similar idea was maintained in a thesis, _three years_ ago, by a graduate of the University of Pennsylvania. I have, however, contemplated this important agent, as a probable means of establishing telegraphic communications, with as much rapidity, and perhaps less expense, than any hitherto employed. I do not know how far experiment has determined galvanic action, to be communicated by means of wires; but there is no reason to suppose it confined, as to limits, certainly not as to time. Now, by means of apparatus, fixed at certain distances, as telegraphic stations, by tubes, for the _decomposition_ of _water_, and of metallic salts, &c. regularly ranged, such a key might be adopted as would be requisite to communicate words, sentences, or figures, from one station to another, and so on to the end of the line, I will take another opportunity to enlarge upon this, as I think it might serve many useful purposes; but like all others, it requires time to mature. As it takes up little room, and may be fixed in private, it might, in many cases, of besieged towns, &c. convey useful intelligence, with scarcely a chance of detection by the enemy. However fanciful in speculation, I have no doubt that sooner or later, it will be rendered useful in practice.”

“I have thus, my dear sir, ventured to encroach upon your time, with some crude ideas, that may serve to elicit some useful experiments in the hands of others. When we consider what wonderful results have arisen from the first trifling experiments of the junction of a small piece of silver and zinc in so short a period, what may not be expected from the further extension of galvanic electricity: I have no doubt of its being the chiefest agent, in the hands of nature, of the mighty changes that occur around us. If the metals are compound bodies, which I doubt not, will not this active principle combine those constituent in numerous places, so as to explain their metallic formation? and if such constituents are in themselves aeriform, may not galvanism reasonably tend to explain the existence of metals in situations to which their specific gravities certainly do not entitle us to look for them?”

_Ronald’s Electric Telegraph, invented in 1816. From the Encyclopedia Britannica, 7th edition, page 662._

“M. Cavællo suggested the idea of conveying intelligence by passing a given number of sparks through an insulated wire in given spaces of time; and some German and American authors have proposed to construct galvanic telegraphs by the decomposition of water. Mr. Ronalds, who has devoted much time to the consideration of this form of the telegraph, proposes to employ common electricity to convey intelligence along insulated and buried wires, and he proved the practicability of such a scheme, by insulating eight miles of wire on his lawn at Hammersmith. In this case the wire was insulated in the air by silk strings. But he also made the trial with 525 feet of buried wire; with this view he dug a trench four feet deep, in which he laid a trough of wood two inches square, well lined within and without with pitch; and within this trough were placed thick glass tubes, through which the wire ran. The junction of the glass tubes was surrounded with shorter and wider tubes of glass, the ends of which were sealed up with soft wax.

“Mr. Ronalds now fixed a circular brass plate, figure 37, upon the second arbour of a clock which beat dead seconds. This plate was divided into twenty equal parts, each division being worked by a figure, a letter, and a preparatory sign. The figures were divided into two series of the units, and the letters were arranged alphabetically, omitting J, Q, U, W, X and Z. In front of this was fixed another brass plate as shown in figure 38, which could be occasionally turned round by the hand, and which had an aperture like that shown in the figure at V, which would just exhibit one of the figures, letters and preparatory signs, for example, 9, _v_, and ready. In front of this plate was suspended a pith ball electrometer, B, C, figure 38, from a wire D, which was insulated, and which communicated on one side with a glass cylinder machine, and on the other side with the buried wire. At the further end of the buried wire, was an apparatus exactly the same as the one now described, and the clocks were adjusted to as perfect synchronism as possible.

“Hence it is manifest, that when the wire was _charged_ by the machine at either end, the electrometers at both ends _diverged_, and when it was discharged, they collapsed, at the same instant. Consequently, if it was discharged at the moment when a given letter, figure, and sign on the lower plate, figure 37, appeared through the aperture, figure 38, the same figure, letter and sign would appear also at the other clock; so that by means of such discharges at one station, and by marking down the letters, figures and signs, seen at the other, any required words could be spelt.

“An electrical pistol was connected with the apparatus, by which a spark might pass through it when the sign _prepare_ was made, in order that the explosion might excite the attention of the superintendent, and obviate the necessity of close watching.

_“Preparatory signs._ A, prepare; V, ready; S, repeat sentence; P, repeat word; N, finish; L, annul sentence; I, annul word; G, note figures; E, note letters; C, dictionary.”

_Electro Magnetism._