Page:Popular Science Monthly Volume 25.djvu/703

Rh, which he carried out by a modification of the plan that he had matured for the protection of the vessels of the Royal Navy. Two-inch tubes of copper, connected by solid screw plugs and coupling pieces, were affixed to all the more elevated portions of the building. The sum of £2,314 provided for the execution of this work was memorable as being the first grant made by the English Parliament for the protection of a public building against lightning.

About ten years after the erection of the lightning-conductors upon the Houses of Parliament at Westminster, it was found to be desirable to provide a similar protection for the magnificent old Hôtel de Ville at Brussels, in consequence of some damage having occurred to the principal tower of the building during a thunder storm. The communal administration of the city had recourse to the Académie Royale des Sciences for advice in the emergency, and a commission, consisting of M. Duprez, M. Liagre, and Professor Melsens, was appointed to give a careful consideration to the matter. Professor Melsens visited Plymouth and London, to consult with Sir W. Snow Harris, and to examine the plan of defense which had been adopted for the Houses of Parliament. Shortly afterward the commission at Brussels submitted to the communal administration the famous plan of lightning-defense which has since been carried out at the Hôtel de Ville, and which has been described in the minutest detail in an illustrated work entitled "Description détaillée des Paratonnerers établis sur l'Hôtel de Ville de Bruxelles," and printed in 1865, in explanation of his views, by Professor Melsens himself.

Professor Melsens's method of defense differs in one important particular from the measures which had been recommended in the Paris instructions, and which have been most generally adopted in England. He had for some time been inclined to advocate the use of numerous rods of small size, rather than one dominant rod of more ample dimensions, whenever large buildings with numerous projecting pinnacles and gables were concerned. His view virtually is that the aim in such cases should be to throw a sort of metallic net broadcast over the building, with salient points carried up into the air at all projecting parts of the structure, and with numerous rootlets plunging down into the conducting mass of the earth beneath; and he contrived an experiment which he was in the habit of exhibiting to his visitors at the laboratory in l'École de Médecine Vétérinaire de l'État, which certainly went very far to justify the position he had taken up. He prepared a spherical case or cage of stout iron wire, and, having inclosed a small bird in this cage, he passed electric shocks through it from a battery of fifteen very large Leyden-jars, without causing either injury or inconvenience to the bird. A couple of little feathered pensioners were maintained at the laboratory for the performance of this experiment, and were subjected to the ordeal a considerable number of times, and there is no doubt could be subjected to it for any number of times,