Читать книгу A Study of Recent Earthquakes - Charles Davison - Страница 13

As regards destruction to life and property, however, the Neapolitan earthquake owns but few European rivals. Less favourable conditions for withstanding a great shock are seldom, indeed, to be found than those possessed by the mediæval towns and villages of the meizoseismal area. In buildings of every class, the walls are very thick and consist as a rule of a coarse, short-bedded, ill-laid rubble masonry, without thorough bonding and connected by mortar of slender cohesion. The floors are made of planks coated with a layer of concrete from six to eight inches thick, the whole weighing from sixty to a hundred pounds per square foot. Only a little less heavy are the roofs, which are covered with thick tiles secured, except at the ridges, by their own weight alone. Thus, for the most part, the walls, floors, and roofs are extremely massive, while the connections of all to themselves and to each other are loose and imperfect.

Again, the towns, for greater security from attacks in early times, are generally perched upon the summits and steep flanks of hills, especially of the lower spurs that skirt the great mountain ranges; and the rocking of the hill-sites, in Mallet's opinion, greatly aggravated the natural effects of the shock. The streets, moreover, are steep and narrow, sometimes only five feet, and not often more than fifteen feet, in width; and the houses, when shaken down, fell against one another and upon those beneath them. As Dolomieu said of the great earthquake in 1783, "the ground was shaken down like ashes or sand laid upon a table."

Of the total amount of damage, not even the roughest estimate can be made. The official returns are clearly, and no doubt purposely, deficient, and obstacles were placed in Mallet's way when he endeavoured to ascertain the numbers of persons killed and wounded. Taking only the towns into account, he calculated that, out of a total population of 207,000, the number of persons killed was 9,589, and of wounded 1,343.[8] A few towns were marked by an excessively high death-rate. Thus, at Montemurro, 5000 out of 7002 persons were killed and 500 wounded; at Saponara, 2000 out of 4010 were killed; and, at Polla, more than 2000 out of a population of less than 7000.