A study in the psychology of harnessing the subconscious. Miguel Alberto Mantilla, a prodigy of mental caluclation. Tested by JH Hyslop from the Society for Psychicial Research. Speculation on origins of M's gift. Others prodigies with similar gifts. Argu
'Lightning Calculators', McClure's
“Lightning Calculators,” Past Periodicals, accessed October 21, 2021, https://unsettlingscientificstories.omeka.net/items/show/19660.