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sets are published in the Anlhroj5ometric Insi. Journal 1884 [81], and afford good material for future use in many ways.

Among other instruments that I contrived then or subsequently, were small whistles with a screw plug, for determining the highest audible note, the limit of which varies much in different persons and at different ages. A parcel of schoolboys might interchange very shrill and loud whistles quite inaudibly to an elderly master. I found them to produce marked effects on cats, and made many experiments at a house where I often stayed, in which my bedroom window overlooked a garden much frequented by them. My plan was to watch near the open window, and when a cat appeared and had become quite unsuspicious and absorbed, to sound one of these notes inaudible to most elderly persons. The cat was round in a minute. I noticed the quickness and precision with which these animals direct their eyes to the source of sound. It is not so with dogs.

I contrived a hollow cane made like a walking stick, having a removable whistle at its lower end, with an exposed indiarubber tube under its curved handle. Whenever I squeezed the tube against the handle, air was pushed through the whistle. I tried it at nearly all the cages in the Zoological Gardens, but with little result of interest, except that i,t certainly annoyed some of the lions. I have often met with persons who perceived no purely audible sound when very high notes were sounded, but who experienced a peculiar feeling of discomfort which I have occasionally felt myself. This, I think, was the case with some of the lions, who turned away and angrily rubbed