Part 26

Shortly after Mr. Crosse’s return to Fyne Court, while pursuing his experiments for forming crystals from a highly caustic solution out of contact with atmospheric air, he was greatly surprised by the appearance of an insect. Black flint, burnt to redness and reduced to powder, was mixed with carbonate of potash, and exposed to a strong heat for fifteen minutes; and the mixture was poured into a black-lead crucible in an air furnace. It was reduced to powder while warm, mixed with boiling water, kept boiling for some minutes, and then hydrochloric acid was added to supersaturation. After being exposed to voltaic action for twenty-six days, a perfect insect of the Acari tribe made its appearance, and in the course of a few weeks about a hundred more. The experiment was repeated in other chemical fluids with the like results; and Mr. Weeks of Sandwich afterwards produced the Acari inferrocyanerret of potassium. The Acarus of Mr. Crosse was found to contribute a new species of that genus, nearly approaching the Acari found in cheese and flour, or more nearly, Hermann’s _Acarus dimidiatus_.

This discovery occasioned great excitement. The possibility was denied, though Mr. Faraday is said to have stated in the same year that he had seen similar appearances in his own electrical experiments. Mr. Crosse was now accused of impiety and aiming at creation, to which attacks he thus replied:

As to the appearance of the acari under long-continued electrical action, I have never in thought, word, or deed given any one a right to suppose that I considered them as a creation, or even as a formation, from inorganic matter. To create is to form a something out of a nothing. To annihilate is to reduce that something to a nothing. Both of these, of course, can only be the attributes of the Almighty. In fact, I can assure you most sacredly that I have never dreamed of any theory sufficient to account for their appearance. I confess that I was not a little surprised, and am so still, and quite as much as I was when the acari made their first appearance. Again, I have never claimed any merit as attached to these experiments. It was a matter of chance; I was looking for silicious formations, and animal matter appeared instead.

These Acari, if removed from their birthplace, lived and propagated; but uniformly died on the first recurrence of frost, and were entirely destroyed if they fell back into the fluid whence they arose.

One of Mr. Crosse’s visitors thus describes the vast electrical room at Fyne Court:

Here was an immense number of jars and gallipots, containing fluids on which electricity was operating for the production of crystals. But you are startled in the midst of your observations by the smart crackling sound that attends the passage of the electrical spark; you hear also the rumbling of distant thunder. The rain is already plashing in great drops against the glass, and the sound of the passing sparks continues to startle your ear; you see at the window a huge brass conductor, with a discharging rod near it passing into the floor, and from the one knob to the other sparks are leaping with increasing rapidity and noise, every one of which would kill twenty men at one blow, if they were linked together hand in hand and the spark sent through the circle. From this conductor wires pass off without the window, and the electric fluid is conducted harmlessly away. Mr. Crosse approached the instrument as boldly as if the flowing stream of fire were a harmless spark. Armed with his insulated rod, he sent it into his batteries: having charged them, he showed how wire was melted, dissipated in a moment, by its passage; how metals--silver, gold, and tin--were inflamed and burnt like paper, only with most brilliant hues. He showed you a mimic aurora and a falling-star, and so proved to you the cause of those beautiful phenomena.

Mr. Crosse appears to have produced in all “about 200 varieties of minerals, exactly resembling in all respects similar ones found in nature.” He tried also a new plan of extracting gold from its ores by an electrical process, which succeeded, but was too expensive for common use. He was in the habit of saying that he could, like Archimedes, move the world “if he were able to construct a battery at once cheap, powerful, and durable.” His process of extracting metals from their ores has been patented. Among his other useful applications of electricity are the purifying by its means of brackish or sea-water, and the improving bad wine and brandy. He agreed with Mr. Quekett in thinking that it is by electrical action that silica and other mineral substances are carried into and assimilated by plants. Negative electricity Mr. Crosse found favourable to no plants except fungi; and positive electricity he ascertained to be injurious to fungi, but favourable to every thing else.

Mr. Crosse died in 1855. His widow has published a very interesting volume of _Memorials_ of the ingenious experimenter, from which we select the following:

On one occasion Mr. Crosse kept a pair of soles under the electric action for three months; and at the end of that time they were sent to a friend, whose domestics knew nothing of the experiment. Before the cook dressed them, her master asked her whether she thought they were fresh, as he had some doubts. She replied that she was sure they were fresh; indeed, she said she could swear that they were alive yesterday! When served at table they appeared like ordinary fish; but when the family attempted to eat them, they were found to be perfectly tasteless--the electric action had taken away all the essential oil, leaving the fish unfit for food. However, the process is exceedingly useful for keeping fish, meat, &c. fresh and _good_ for ten days or a fortnight. I have never heard a satisfactory explanation of the cause of the antiseptic power communicated to water by the passage of the electric current. Whether ozone has not something to do with it, may be a question. The same effect is produced whichever two dissimilar metals are used.

The Electric Telegraph.

ANTICIPATIONS OF THE ELECTRIC TELEGRAPH.

The great secret of ubiquity, or at least of instantaneous transmission, has ever exercised the ingenuity of mankind in various romantic myths; and the discovery of certain properties of the loadstone gave a new direction to these fancies.

The earliest anticipation of the Electric Telegraph of this purely fabulous character forms the subject of one of the _Prolusiones Academicæ_ of the learned Italian Jesuit Strada, first published at Rome in the year 1617. Of this poem a free translation appeared in 1750. Strada’s fancy was this: “There is,” he supposes, “a species of loadstone which possesses such virtue, that if two needles be touched with it, and then balanced on separate pivots, and the one be turned in a particular direction, the other will sympathetically move parallel to it. He then directs each of these needles to be poised and mounted parallel on a dial having the letters of the alphabet arranged round it. Accordingly, if one person has one of the dials, and another the other, by a little pre-arrangement as to details a correspondence can be maintained between them at any distance by simply pointing the needles to the letters of the required words. Strada, in his poetical reverie, dreamt that some such sympathy might one day be found to hold up the Magnesian Stone.”

Strada’s conceit seems to have made a profound impression on the master-minds of the day. His poem is quoted in many works of the seventeenth and eighteenth centuries; and Bishop Wilkins, in his book on Cryptology, is strangely afraid lest his readers should mistake Strada’s fancy for fact. Wilkins writes: “This invention is altogether imaginary, having no foundation in any real experiment. You may see it frequently confuted in those that treat concerning magnetical virtues.”

Again, Addison, in the 241st No. of the _Spectator_, 1712, describes Strada’s “Chimerical correspondence,” and adds that, “if ever this invention should be revived or put in practice,” he “would propose that upon the lover’s dial-plate there should be written not only the four-and-twenty letters, but several entire words which have always a place in passionate epistles, as flames, darts, die, language, absence, Cupid, heart, eyes, being, drown, and the like. This would very much abridge the lover’s pains in this way of writing a letter, as it would enable him to express the most useful and significant words with a single touch of the needle.”

After Strada and his commentators comes Henry Van Etten, who shows how “Claude, being at Paris, and John at Rome, might converse together, if each had a needle touched by a stone of such virtue that as one moved itself at Paris the other should be moved at Rome:” he adds, “it is a fine invention, but I do not think there is a magnet in the world which has such virtue; besides, it is inexpedient, for treasons would be too frequent and too much protected. (_Recréations Mathématiques_: see 5th edition, Paris, 1660, p. 158.) Sir Thomas Browne refers to this “conceit” as “excellent, and, if the effect would follow, somewhat divine;” but he tried the two needles touched with the same loadstone, and placed in two circles of letters, “one friend keeping one and another the other, and agreeing upon an hour when they will communicate,” and found the tradition a failure that, “at what distance of place soever, when one needle shall be removed unto any letter, the other, by a wonderful sympathy, will move unto the same.” (See _Vulgar Errors_, book ii. ch. iii.)

Glanvill’s _Vanity of Dogmatizing_, a work published in 1661, however, contains the most remarkable allusion to the prevailing telegraphic fancy. Glanvill was an enthusiast, and he clearly predicts the discovery and general adoption of the electric telegraph. “To confer,” he says, “at the distance of the Indies by sympathetic conveyance may be as usual to future times as to us in a literary correspondence.” By the word “sympathetic” he evidently intended to convey magnetic agency; for he subsequently treats of “conference at a distance by impregnated needles,” and describes the device substantially as it is given by Sir Thomas Browne, adding, that though it did not then answer, “by some other such way of magnetic efficiency it may hereafter with success be attempted, when magical history shall be enlarged by riper inspection; and ’tis not unlikely but that present discoveries might be improved to the performance.” This may be said to close the most speculative or mythical period in reference to the subject of electro-telegraphy.

Electricians now began to be sedulous in their experiments upon the new force by friction, then the only known method of generating electricity. In 1729, Stephen Gray, a pensioner of the Charter-house, contrived a method of making electrical signals through a wire 765 feet long; yet this most important experiment did not excite much attention. Next Dr. Watson, of the Royal Society, experimented on the possibility of transmitting electricity through a large circuit from the simple fact of Le Monnier’s account of his feeling the stroke of the electrified fires through two of the basins of the Tuileries (which occupy nearly an acre), by means of an iron chain lying upon the ground and stretched round half their circumference. In 1745, Dr. Watson, assisted by several members of the Royal Society, made a series of experiments to ascertain how far electricity could be conveyed by means of conductors. “They caused the shock to pass across the Thames at Westminster Bridge, the circuit being completed by making use of the river for one part of the chain of communication. One end of the wire communicated with the coating of a charged phial, the other being held by the observer, who in his other hand held an iron rod which he dipped into the river. On the opposite side of the river stood a gentleman, who likewise dipped an iron rod in the river with one hand, and in the other held a wire the extremity of which might be brought into contact with the wire of the phial. Upon making the discharge, the shock was felt simultaneously by both the observers.” (_Priestley’s History of Electricity._) Subsequently the same parties made experiments near Shooter’s Hill, when the wires formed a circuit of four miles, and conveyed the shock with equal facility,--“a distance which without trial,” they observed, “was too great to be credited.”[52] These experiments in 1747 established two great principles: 1, that the electric current is transmissible along nearly two miles and a half of iron wire; 2, that the electric current may be completed by burying the poles in the earth at the above distance.

In the following year, 1748, Benjamin Franklin performed his celebrated experiments on the banks of the Schuylkill, near Philadelphia; which being interrupted by the hot weather, they were concluded by a picnic, when spirits were fired by an electric spark sent through a wire in the river, and a turkey was killed by the electric shock, and roasted by the electric jack before a fire kindled by the electrified bottle.

In the year 1753, there appeared in the _Scots’ Magazine_, vol. xv., definite proposals for the construction of an electric telegraph, requiring as many conducting wires as there are letters in the alphabet; it was also proposed to converse by chimes, by substituting bells for the balls. A similar system of telegraphing was next invented by Joseph Bozolus, a Jesuit, at Rome; and next by the great Italian electrician Tiberius Cavallo, in his treatise on Electricity.

In 1787, Arthur Young, when travelling in France, saw a model working telegraph by M. Lomond: “You write two or three words on a paper,” says Young; “he takes it with him into a room, and turns a machine enclosed in a cylindrical case, at the top of which is an electrometer--a small fine pith-ball; a wire connects with a similar cylinder and electrometer in a distant apartment; and his wife, by remarking the corresponding motions of the ball, writes down the words they indicate: from which it appears that he has formed an alphabet of motions. As the length of the wire makes no difference in the effect, a correspondence might be carried on at any distance. Whatever the use may be, the invention is beautiful.”

We now reach a new epoch in the scientific period--the discovery of the Voltaic Pile. In 1794, according to _Voigt’s Magazine_, Reizen made use of the electric spark for the telegraph; and in 1798 Dr. Salva of Madrid constructed a similar telegraph, which the Prince of Peace subsequently exhibited to the King of Spain with great success.

In 1809, Soemmering exhibited a telegraphic apparatus worked by galvanism before the Academy of Sciences at Munich, in which the mode of signalling consisted in the development of gas-bubbles from the decomposition of water placed in a series of glass tubes, each of which denoted a letter of the alphabet. In 1813, Mr. Sharpe, of Doe Hill near Alfreton, devised a _voltaic_-electric telegraph, which he exhibited to the Lords of the Admiralty, who spoke approvingly of it, but declined to carry it into effect. In the following year, Soemmering exhibited a _voltaic_-electric telegraph of his own construction, which, however, was open to the objection of there being as many wires as signs or letters of the alphabet.

The next invention is of much greater importance. Upon the suggestion of Cavallo, already referred to, Francis Ronalds constructed a perfect electric telegraph, employing frictional electricity notwithstanding Volta’s discoveries had been known in England for sixteen years. This telegraph was exhibited at Hammersmith in 1816:[53] it consisted of a single insulated wire, the indication being by pith-balls in front of a dial. When the wire was charged, the balls were divergent, but collapsed when the wire was discharged; at the same time were employed two clocks, with lettered discs for the signals. “If, as Paley asserts (and Coleridge denies), ‘he alone discovers who proves,’ Ronalds is entitled to the appellation of the first discoverer of an efficient electric telegraph.” (_Saturday Review_, No. 147[54]) Nevertheless the Government of the day refused to avail itself of this admirable contrivance.

In 1819, Oersted made his great discovery of the deflection, by a current of electricity, of a magnetic needle at right angles to such current. Dr. Hamel of St. Petersburg states that Baron Schilling was the first to apply Oersted’s discovery to telegraphy; Ampère had previously suggested it, but his plan was very complicated, and Dr. Hamel maintains that Schilling first realised the idea by actually producing an electro-magnetic telegraph simpler in construction than that which Ampère had _imagined_. In 1836, Professor Muncke of Heidelberg, who had inspected Schilling’s telegraphic apparatus, explained the same to William Fothergill Cooke, who in the following year returned to England, and subsequently, with Professor Wheatstone, laboured simultaneously for the introduction of the electro-magnetic telegraph upon the English railways; the first patent for which was taken out in the joint names of these two gentlemen.

In 1844, Professor Wheatstone, with one of his telegraphs, formed a communication between King’s College and the lofty shot-tower on the opposite bank of the Thames: the wire was laid along the parapets of the terrace of Somerset House and Waterloo Bridge, and thence to the top of the tower, about 150 feet high, where a telegraph was placed; the wire then descended, and a plate of zinc attached to its extremity was plunged into the mud of the river, whilst a similar plate attached to the extremity at the north side was immersed in the water. The circuit was thus completed by the entire breadth of the Thames, and the telegraph acted as well as if the circuit were entirely metallic.

Shortly after this experiment, Professor Wheatstone and Mr. Cooke laid down the first working electric telegraph on the Great Western Railway, from Paddington to Slough.

ELECTRIC GIRDLE FOR THE EARTH.

One of our most profound electricians is reported to have exclaimed: “Give me but an unlimited length of wire, with a small battery, and I will girdle the universe with a sentence in forty minutes.” Yet this is no vain boast; for so rapid is the transition of the electric current along the line of the telegraph wire, that, supposing it were possible to carry the wires eight times round the earth, the transit would occupy but _one second of time_!

CONSUMPTION OF THE ELECTRIC TELEGRAPH.

It is singular to see how this telegraphic agency is measured by the chemical consumption of zinc and acid. Mr. Jones (who has written a work upon the Electric Telegraphs of America) estimates that to work 12,000 miles of telegraph about 3000 zinc cups are used to hold the acid: these weigh about 9000 lbs., and they undergo decomposition by the galvanic action in about six months, so that 18,000 lbs. of zinc are consumed in a year. There are also about 3600 porcelain cups to contain nitric acid; it requires 450 lbs. of acid to charge them once, and the charge is renewed every fortnight, making about 12,000 lbs. of nitric acid in a year.

TIME LOST IN ELECTRIC MESSAGES.

Although it may require an hour, or two or three hours, to transmit a telegraphic message to a distant city, yet it is the mechanical adjustment by the sender and receiver which really absorbs this time; the actual transit is practically instantaneous, and so it would be from here to the antipodes, so far as the current itself is concerned.

THE ELECTRIC TELEGRAPH IN ASTRONOMY AND THE DETERMINATION OF LONGITUDE.

The Electric Telegraph has become an instrument in the hands of the astronomer for determining the difference of longitude between two observatories. Thus in 1854 the difference of longitude between London and Paris was determined within a limit of error which amounted barely to a quarter of a second. The sudden disturbances of the magnetic needle, when freely suspended, which seem to take place simultaneously over whole continents, if not over the whole globe, from some unexplained cause, are pointed out as means by which the differences of longitude between the magnetic observatories may possibly be determined with greater precision than by any yet known method.

So long ago as 1839 Professor Morse suggested some experiments for the determination of Longitudes; and in June 1844 the difference of longitude between Washington and Baltimore was determined by electric means under his direction. Two persons were stationed at these two towns, with clocks carefully adjusted to the respective spots; and a telegraphic signal gave the means of comparing the two clocks at a given instant. In 1847 the relative longitudes of New York, Philadelphia, and Washington were determined by means of the electric telegraph by Messrs. Keith, Walker, and Loomis.

NON-INTERFERENCE OF GALVANIC WAVES ON THE SAME WIRE.

One of the most remarkable facts in the economy of the telegraph is, that the line, when connected with a battery in action, propagates the hydro-galvanic waves in either direction without interference. As several successive syllables of sound may set out in succession from the same place, and be on their way at the same time, to a listener at a distance, so also, where the telegraph-line is long enough, several waves may be on their way from the signal station before the first one reaches the receiving station; two persons at a distance may pronounce several syllables at the same time, and each hear those emitted by the other. So, on a telegraph-line of two or three thousand miles in length in the air, and the same in the ground, two operators may at the same instant commence a series of several dots and lines, and each receive the other’s writings, though the waves have crossed each other on the way.

EFFECT OF LIGHTNING UPON THE ELECTRIC TELEGRAPH.

In the storm of Sunday April 2, 1848, the lightning had a very considerable effect on the wires of the electric telegraph, particularly on the line of railway eastward from Manchester to Normanton. Not only were the needles greatly deflected, and their power of answering to the handles considerably weakened, but those at the Normanton station were found to have had their poles reversed by some action of the electric fluid in the atmosphere. The damage, however, was soon repaired, and the needles again put in good working order.

ELECTRO-TELEGRAPHIC MESSAGE TO THE STARS.

The electric fluid travels at the mean rate of 20,000 miles in a second under ordinary circumstances; therefore, if it were possible to establish a telegraphic communication with the star 61 Cygni, it would require ninety years to send a message there.

Professor Henderson and Mr. Maclear have fully confirmed the annual parallax of α Centauri to amount to a second of arc, which gives about twenty billions of miles as its distance from our system; a ray of light would arrive from α Centauri to us in little more than three years, and a telegraphic despatch would arrive there in thirty years.

THE ATLANTIC TELEGRAPH.

The telegraphic communication between England and the United States is so grand a conception, that it would be impossible to detail its scientific and mechanical relations within the limits of the present work. All that we shall attempt, therefore, will be to glance at a few of the leading operations.