This paper deals with the research carried out by Eng. Luis Matamoros Sandoval, who in 1902 published in Costa Rica his investigations on seismology in an article entitled "El interior de la corteza terrestre: una nueva teoría sobre el origen de los temblores" (The interior of the Earth's crust: a new theory about the origin of earthquakes). In his work, Matamoros followed the Aristotelic current and mixed it with the hypothesis developed by the Spanish friar Benito Feijoo, who proposed electricity as the physical cause of intense earthquakes perceived over large regions. Matamoros justifies his results by the use of mathematics combined with fundamental physical principles, some which he had great difficulty to explain due in part to the use of criteria and basic concepts that were not supported by the traditional physical knowledge. Despite his conceptual errors, the value of his work resides in the fact that it was the first local formal scientific attempt to explain the origin of earthquakes, a process that even in the great scientific centers of the period was the source of continuous speculation. [ABSTRACT FROM AUTHOR]