Sight Unseen — Mary Roberts Rinehart

The rather extraordinary story revealed by the experiments of the Neighborhood Club have been until now a matter only of private record. But it seems to me, as an active participant in the investigations, that they should be given to the public; not so much for what they will add to the existing data on psychical research, for from that angle they were not unusual, but as yet another exploration into that still uncharted territory, the human mind.