Logo: a Positivist train

Question SA-15. Here is the text reference (p. 146/last & 147/1):

The miner's mother was a tall, thin woman, with white hair. Her pale face had a resigned and sweet expression which softened the brightness of her eyes, where tears seemed always ready to spring out. Her name was María de los Angeles. Daughter and mother of miners, she had aged prematurely under the strain of terrible disasters. Her husband and two sons had been killed one after the other by mine collapses and gas explosions. These were the tributes that her loved ones had paid to the insatiable voracity of the mine. All she had left was that young man for whom her heart always ached. Always fearful of an accident, her imagination never for an instant left the misty coal seam that was possessing the only thing she had left, the only thing she lived for....