Pagina-afbeeldingen
PDF
ePub

grey-headed émigrés and ancient courtiers returning to the city which had risen in madness to immolate his brother and to destroy the monarchy. We shall not attempt to retrace the incidents of a scene often described before, and forming one of the most impressive spectacles ever witnessed on the great stage of history. The prince was hailed with a general acclaim; and, as was finely said, Paris saw in him a pledge of reviving peace and happiness across a dark waste of ruin and bloodshed. But if the exultation truly expressed the joy of a people freed, as was thought, from revolution and uncontrolled despotism, it revealed the weak points in the national character; its sounds fell on the ears of a victorious enemy; its echoes rose from around the Column and the Arches of Triumph; it was the voice of a race that was crying down its own past, and proud years of glory, because it could not endure defeat and misfortune. quote a few words from M. de Vitrolles' narrative:

We

'We arrived at the gates of Notre-Dame in the midst of this triumph. The prince was received by the clergy; Cardinal Maury was not present. The crowd had forced through all the barriers; the priests who surrounded Monsieur, and the canopy borne over his head, scarcely protected him. As for us, we found it extremely difficult not to be separated from his person. Tossed and driven about here and there, we could scarcely get on. I contrived, however, to reach the chair where Monsieur was seated, and placed myself, standing, behind him. I was pressed by the crowd, and Marshal Ney was jammed against me. The cathedral had never beheld such a concourse. municipality, the high courts of justice, and the other authorities, had places laid out for them; but these had been invaded; the Senate alone was not there in state. It had done this deliberately, but no one noticed its absence. The Te Deum chanted by the clergy was caught up by the audience, and the Domine salvum fac regem was sung by thousands of voices.'

The

The attitude of the Imperial marshals, fresh from the desertion of Fontainebleau, but uncertain as to their future position, was different from that of the shouting crowds; but it was not dignified, and it showed no trace of loyalty or regret for their fallen master.

'Certain marshals and generals of the Empire-Ney, Marmont, Moncey, Serrurier, Kellermann, &c.-still wore the tricolour in their helmets. Cries of "Vive le Roi" rang out louder and louder at their approach, as if to influence them. They stood in astonishment. Some of them moved their lips; you could not tell whether it was to express approbation or a protest. The face of Marshal Ney, however, was easily read; his features were contracted; flashes of anger seemed to break out from his eyes. He seemed scarcely to keep his hand off his

sword-hilt. Nevertheless he uttered, in the name of his companions in arms, some laboured expressions which he had learned by rote.'

At this point we close our review of the first part of this interesting work. The succeeding volumes-the second of these has been published within the last few weeks-will describe the conduct of M. de Vitrolles on the unsettled question of the Constitution and the restored monarchy; the part he played in 1815-16; his position in the councils of Charles X., and his attitude during the Revolution of July. The book is a contribution of real value to the history of France and even of Europe.

ART. II.-1. Des Paratonnerres, à Pointes, à Conducteurs et à Raccordements Terrestres Multiples. Par M. MELsens, Membre de l'Académie Royale des Sciences de Belgique. Bruxelles: 1877.

2. Lightning Conductors, their History, Nature, and Mode of Application. By RICHARD ANDERSON, F.C.S., F.G.S., Member of the Society of Telegraph Engineers. With numerous Illustrations. London: 1879.

3. Information about Lightning Conductors issued by the Academy of Sciences of France. Translated by RICHARD ANDERSON, F.C.S., F.G.S. London: 1881.

4. Report of the Lightning-Rod Conference. Edited by the Secretary, G. J. SYMONS, F.R.S. London and New York:

1882.

5. Electricité Statique: Paratonnerres. Rapport par M. E. ROUSSEAU. Bruxelles: 1882.

6. Notes et Commentaires sur la question des Paratonnerres. Par M. MELSENS. Bruxelles : 1882.

7. The Action of Lightning, and the Means of defending Life and Property from its Effects. By ARTHUR PARNELL, Major, R.E. London: 1882.

THE

HE first lightning conductor was erected by Benjamin Franklin upon his own house in Philadelphia in 1752. The invention is, therefore, now a little more than one hundred and thirty years old. Franklin was led to the investigations which resulted in its construction by the fortuitous circumstance that about six years previously he had been present at a lecture on electricity delivered in Boston by Dr.

Spence. In the same year-that is, in 1746-he received a present from Peter Collinson, a member of the Royal Society in London, who was also the agent of the Library Company in Philadelphia, of one of the London electric tubes, and an account of some experiments that had recently been made by Dr. Watson, Martin Folkes, Lord Charles Cavendish, Dr. Bevis, and others of their contemporaries. The idea had already suggested itself to these investigators that the luminous gleam which was elicited from glass tubes when they were rubbed in dark cellars, in performance of the frequently repeated and fashionable experiment of the day, might possibly be of a kindred nature to the lightning of the thunderstorm. In a book describing some physico-mechanical experiments that he had made, published in London in 1709, Francis Hawksbee remarked that the luminous flash and crackling sounds produced by rubbing amber were similar to lightning and thunder. In 1720 Stephen Gray, the pensioner of the Charterhouse, so celebrated for his electrical investigations, boldly and uncompromisingly affirmed that if great things 'might be compared with small,' the light and sound called forth when glass rods were rubbed were of the same nature as lightning and thunder. Franklin, from the time when the electrical experiments came under his notice, enthusiastically adopted this view. In a letter written to a friend in 1749 he very clearly expressed his reasons for this belief. In this communication he insisted upon the facts that the electric spark gives light like lightning; that the luminous discharge follows a similar crooked track; that this discharge is swift in its motion, is conducted by metals, is accompanied by an explosion when it escapes, rends bodies that it passes through, destroys animal life, melts metals, sets fire to inflammable substances, and causes a smell of sulphur; all of which attributes seemed to him to point to the identity of the phenoHe also observed that the electric discharge was attracted by points, and stated that he was bent upon ascertaining whether lightning had not the same tendency. In the autumn of the following year he wrote to Mr. Collinson to say that he had satisfied himself in this particular, that he was entirely convinced of the identity of the so-called electricity with lightning, that he believed the damage done by lightning descending from the clouds to the earth might be altogether

mena.

It is, perhaps, worthy of remark that in this lecture the experiments were made by the primitive instrumentality of a glass rod and silk pocket-handkerchief.

VOL. CLX. NO. CCCXXVII

D

prevented by placing iron rods with sharp points upon the summits of buildings, that he intended to test experimentally the soundness of his belief in that matter, and that he hoped other persons would assist him in his labours by following his example. This was virtually the definite forecast of the conductor which Franklin attached to his house in 1752.

In the meantime the suggestion that buildings might be protected from lightning by the use of iron rods with sharp points was incidentally communicated by Mr. Collinson to the editor of the Gentleman's Magazine' in London, who, at once perceiving the practical importance of the hint, offered to print an account of Franklin's views in the form of a pamphlet. This offer was accepted, and in the month of May, 1751, a pamphlet was published in London entitled 'New Experiments and Observations on Electricity made at Philadelphia in America by Benjamin Franklin.' The pamphlet was not very warmly received in England, but it was enthusiastically welcomed and appreciated in France. Count de Buffon had it translated into French, and the translation appeared in Paris within four months of the publication of the original pamphlet in England. It was soon afterwards translated into German, Italian, and Latin. The attention of scientific men in Paris was quickly drawn to the method of defence proposed by Franklin, and M. Dalibard, a man of some wealth, undertook to erect the apparatus at his country residence at Marlyla-Ville, some eighteen miles from Paris. The situation of the house was considered to be eminently favourable for the purpose, as the buildings stood some 400 feet above the sea. A lofty wooden scaffold, supporting an iron rod an inch in diameter and eighty feet long, was erected in the garden. The rod was finished at the top by a sharp point of bronzed steel, and it terminated at the bottom, five feet above the ground, in a smaller horizontal rod which ran to a table in a kind of sentrybox, furnished with electrical apparatus. On May 10, when M. Dalibard was himself absent in Paris, the apparatus having been left temporarily in the charge of an old dragoon named Coiffier, a violent storm drifted over the place, and the old dragoon, who was duly instructed for the emergency, went into the sentry-box and presented a metal key, partly covered with silk, to the termination of the rod, and saw a stream of fire burst forth between the rod and the key. The old man sent for the Prior of Marly, who dwelt close by, to witness and confirm his observation, and then started on horseback to Paris, to carry to his master the news of what had occurred. Three days afterwards, that is, on May 13, 1752,

M. Dalibard communicated his own account of the incident to a meeting of the Académie des Sciences, and announced that Franklin's views of the identity of the fire of the storm-cloud with that of the electrical spark had been thus definitely established.

Before the success of M. Dalibard's experiment could be reported in America, however, Franklin had secured his own proof of the identity by the memorable experiment with the kite, so well known to the scientific world. He was anxiously waiting for the erection of the first steeple in Philadelphia for the opportunity which this would afford him for the support of a lofty iron rod, when the happy idea occurred to him to try, in the meantime, upon some suitable occasion, whether he could not contrive to hold up a lightning conductor towards a storm-cloud by means of a kite. On the evening of July 4, that is, fifty-two days after the experiment of M. Dalibard, his kite was raised during a thunderstorm, and, with the help of his son, he drew electric sparks from the rain-saturated string, as the two stood in the shelter of an old cowshed in the outskirts of Philadelphia. He held the kite by a silken cord that was attached to a key at the bottom of the string, and with this arrangement he charged and discharged an ordinary Leyden jar several times in succession. Franklin at first not unnaturally conceived that he had actually drawn the lightning down from the storm-cloud. He was, however, no doubt mistaken in this. The storm-cloud had inductively excited the neighbouring surface of the earth, and what Franklin saw was the electric stream escaping out through the wet string towards the storm-cloud to relieve the tension set up by this induction. It was in the summer of the same year, after the performance of this world-renowned experiment with the kite, that Franklin attached to his house a lightning conductor, which was composed of an iron rod, having a sharp steel point projecting seven or eight feet above the roof, and with its lower end plunged about five feet into the ground.

As a matter of course the new doctrine of Franklin and his allies was not received without considerable opposition. A sharp shock of an earthquake having been experienced in Massachusetts in 1755, this was forthwith attributed to the evil influences of Franklin's lightning-rods. A Boston clergyman preached against them in 1770 as impious contrivances 'to prevent the execution of the wrath of Heaven.' Even as late as 1826 an engineer in the employment of the British Government recommended that all lightning-rods should be removed from public buildings as dangerous expedients, and

« VorigeDoorgaan »