I have not seen these photographs of "Katie," but Mr Podmore has, and when comparing them with contemporary portraits of Miss Cook herself he is inclined to consider the likeness between the two sets unmistakable. "The apparently greater breadth of 'spirit' face," he writes, "may well be due to the fact that, whereas Miss Cook wore hanging ringlets, 'Katie's' hair is effectually concealed by the drapery, which in most cases comes down over the forehead, and falls in two thick folds on either side of the head, something like the headgear of a sphinx. Again, as Miss Cook, when photographed, wore her ordinary dress, which concealed her feet, the apparent difference in height on some occasions between herself and the spirit figure cannot be relied upon. One piece of evidence would, indeed, have been conclusive--that the ears of the spirit form should have appeared intact, for Miss Cook's ears were pierced for earrings. But the encircling drapery effectually concealed both the ears and the hair of the spirit 'Katie.'" The evidence for photographs of invisible people which we sometimes hear abduced as adequate is surprisingly feeble. For instance, in a recent anonymous and weak book, said to be written by a member of the Society for Psychical Research, two photographs are reproduced which are said to have been obtained under what are considered crucial conditions; but the narrative itself at once suggests a simple trick on the part of the photographer--viz. the provision of backgrounds for sitters with vague human forms all ready depicted on them in sulphate of quinine. Sir Oliver Lodge is of opinion that it is by no means physically impossible that some of these temporary semi-material accretions might be inadequate to appeal to our eyes, and yet be of a kind able to impress a photographic plate; but here he confesses that the evidence, to his mind, wholly breaks down, and he admits that he has never yet seen a satisfying instance of what is termed a spirit photograph; nor is it easy to imagine the kind of record apart from testimony which in such a case would be convincing, unless such photographs could be produced at will.