1915] ON THE CHARACTER OF THE " S" SOUND 339 and recoveries, indicating that the distance from the burner was now 5 x this distance'was then measured. The first observations were upon a whistle on Edelmann's pattern of my own construction. The flame and reflector gave X = 1*7 in., about a semi-tone flat on Kohler's optimum. As regards the character of the sound, it seemed to me and others to bear some resemblance to an s, but still to be lacking in something essential. I should say that since my own hearing for s's is now distinctly bad, I have always confirmed my opinion by that of other listeners whose hearing is good. That there should be some resemblance to an s at a pitch which is certainly the predominant pitch of an s is not surprising; and it is difficult to describe exactly in what the deficiency consisted. My own impression was that the sound was too nearly a pure tone, and that if it had been quite a pure tone the resemblance to an s would have been. less. In subsequent observations the pitch was raised through \ = T6 in., but without modifying the above impressions. Wishing to try other sources which I thought more likely to give pure tones, I fell back on bird-calls. A new one, with adjustable distance b'etween the perforated plates, gave on different trials X = 1*8 in., X = l-6 in. In neither case was the' sound judged to be at all a proper s, though perhaps some resemblance remained. The effect was simply that of a high note, like the squeak of a bird or insect. Further trials on another day gave confirmatory results. The next observations were made with the highest pipe from an organ, gradually raised in pitch by cutting away at the open end. There was some difficulty in getting quite high enough, but measures were taken giving A. = 2'2 in., X = 1-9 in., and eventually X = 1*6 in. In no case was there more than the slightest suggestion of an s. As I was not satisfied that at the highest pitch the organ-pipe was speaking properly, I made another from lead tube, which could be blown from an adjustable wind nozzle. Tuned to give X = 1-6 in., it sounded faint to my ear, and conveyed no s. Other observers, who heard it well, said it was no s. In all these experiments the sounds were maintained, the various instruments being blown from a loaded bag, charged beforehand with a foot blower. In this respect they are not fully comparable with those of Prof. Titchener, whose whistle was actuated by squeezing a rubber bulb. However, I have also tried a glass tube, 104 in. long, supported at the middle and rubbed with a resined leather. This should be of the right pitch, but the squeak heard did not suggest an s. I ought perhaps to add that the thing did not work particularly well. It will be seen that my conclusions differ a good deal from those of Prof. Titchener, but since these estimates depend upon individual judgment, perhaps 22—2p. 32$.this quantity, it is not surprising that the influence of linear scale should fail to manifest itself. cm.2 '