music-room which adjoined the library. From what little knowledge I have of electricity I should have said it was, in part at least, a galvanometer, one of those instruments which register the intensity of minute electric currents. As nearly as I could make out, in this case the galvanometer was so arranged that its action swung to one side or the other a little concave mirror hung from a framework which rested on the table. Directly in front of it was an electric light, and the reflection of the light was caught in the mirror and focused by its concavity upon a point to one side of the light. Back of it was a long strip of ground glass and an arrow point, attached to which was a pen which touched a roll of paper.
On the large table in the library itself Kennedy had placed in the centre a transverse board partition, high enough so that two people seated could see each other's faces and converse over it, but could not see each other's hands. On one side of the partition were two metal domes which were fixed to a board set on the table. On the other side, in addition to space on which he could write, Kennedy had arranged what looked like one of these new miniature moving-picture apparatuses operated by electricity. Indeed, I felt that it must be that, for directly in front of it, hanging on the wall, in plain view of any one seated on the side of the table containing the metal domes, was a large white sheet.
The time for the experiment, whatever its nature might be, had at last arrived, and Dr. Guthrie introduced Mr. and Mrs. Willoughby to us as specialists whom he had persuaded with great difficulty to come
