Logo: a Positivist train

Question SA-5. Here is the text reference (p. 145/1):

Social protest was the main theme of the best of the Naturalist writers, the Chilean Baldomero Lillo. Lillo's father had gone to California to participate in the Gold Rush, but he returned with no fortune. He did learn much about mining, and he moved to northern Chile to work the nitrate mines. Baldomero Lillo grew up in these mining communities and worked the mines himself. He was exposed to the writings of the French author Emile Zola, who used the philosophy of Positivism and the literary current of Naturalism to try to change the terrible conditions of French coal miners. Lillo was able to observe similar conditions in the Chilean mines and set out to improve the conditions of the workers by dramatizing their plight. Lillo wrote many short stories (collected in two major books, Sub Sole and Sub Terra) which sparked the interest of social activists who were appalled by the conditions in the mines. The story that follows is typical of his efforts.