The phenomena of clairvoyance, as thus defined, have been observed with great care in the case of an American lady, Mrs. Piper. Mrs. Piper had been known for some years in the United States as a clairvoyante and spirit medium, and her trance utterances had been carefully studied by Professor James and Dr. Hodgson. In the winter of 1888-89 she spent two months and a half in this country, at the invitation of certain members of the S.P.R. She came to England as a complete stranger, and was met on her landing at Liverpool by Professor Lodge, and during the whole period she stayed either in the houses of Professor Sidgwick or Mr. Myers at Cambridge, in Professor Lodge's house at Liverpool, or in rooms in London selected by Dr. Leaf. Neither at Cambridge nor Liverpool were there any opportunities of her acquiring knowledge of the histories and circumstances of the persons who visited her for experiments, other than those afforded during the actual progress of the experiment, or by inquiries of servants and children, the examination of books and photograph albums, or from the newspapers and private correspondence. Practically she was under close and almost continuous surveillance during the whole period, and, independently of the special precautions taken to guard against the acquisition of knowledge by any of the means above indicated (_Proc. S.P.R._, vol. vi. pp. 438-440, 446-447, etc.), it is important to note that the sitters were in almost every instance introduced to Mrs. Piper under an assumed name; that some of them, and those not the least successful, were persons in no way connected with the S.P.R., whose admission was due to circumstances more or less accidental; and that on several occasions she stated facts which were not within the conscious knowledge of any person present, and which could not conceivably have been discovered by any process of private inquiry.[134]