Page:Isaiah Bowman - Desert Trails of Atacama (1924).pdf/163

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Earthquakes at Copiapó
147

not difficult if you can command the right materials and good carpenters, but during three hundred years it has proved to be more than the unskilled artisans of Chile could do, handi- capped, as they have been by poor wood, wretched mortar, and the evil inheritance of adobe buildings. They used to put together structures that were pinned with wooden pins and tied with rawhide, which were both strong and elastic. Some of them have passed through the earthquakes of the past cen- tury without serious damage. The introduction of iron nails, which are so easily driven, appear to hold so well, but in fact pull out with ease, has resulted in much weaker frames, that are quite unequal to the task of upholding the heavy walls and roofs of adobe. Back to the good old joinery should be the cry. Rawhide should be used if convenience and cheapness require, but galvanized fence wire is better when skillfully stretched or tied. And adobe should be used only to fill thin walls, never in heavy masses…

“There is one thing about building to resist earthquakes that people seem to forget: an earthquake can exert no more force to wreck a building than is necessary to overcome the inertia of the structure, or of some part of it. A heavy mud- roof, such as is heaped on Chilian houses, will wrack and ruin the walls, where one of light shingles would sway with them.”[1]

Regarding the earthquake of 1922 Professor Willis in a personal communication to the author says further:

“It was felt from Valparaiso to Iquique, a distance of a thou- sand miles, disturbed the coastal region and also valleys at altitudes of 12,000 to 14,000 feet in the Andes, and shook the volcanic island of San Felix 500 miles west of the coast. It was not a very intense shock, but because of the wretched construc- tion of adobe buildings it killed some 880 people of whom 600 were in the town of Vallenar and 200 in Copiapó. Both of these cities are built on loose ground and the unstable founda- tions had much to do with the destruction.

“This earthquake was accompanied by an earthquake wave which was noticed all along the coast from Valparaiso to Anto-

  1. Earthquake-proof Houses, Science, No. 1499, Vol. 58. 1923, September 21, pp. x-xii; reference on p. xii.