Page:Popular Science Monthly Volume 45.djvu/94

82 an idea occurred to the postmaster, who was of a practical turn of mind, and he asked the lady to step out to the door a moment. Opening the door at which she entered, he let it close again, when citt, that insulting sound again. The lady was asked if that was the noise she heard, and she said, "Why, yes, that's it." Then the obliging postmaster explained to her the new door check, pointing up at the top of the door, how it worked, etc., much to the surprise and mortification of the lady, who apologized and soon left, muttering about the "new-fangled things men are always getting up."

The point I wish to make in this illustration is that the lady was completely deceived as to the location or source of this sound, and unfortunately put it in the wrong place, viz., in an innocent man's mouth several feet in front of her, when as a matter of fact it came from directly over her head. Many familiar instances of the inability of locating the source of vocal or other sounds occur every day, but I think sufficient has been said to at least put those on their guard who may read this article, should they meet with any such experiences.

In conclusion, I would suggest that the first impression of the origin or source of a sound should not be taken as absolutely correct if it is a case of importance, such as a responsive jangle produced by a musical note or accusing wrongly some innocent person, as in the case of the lady and the whistling door check. Should your piano be afflicted on one of its notes by an apparent bad sound or jangle, before sending for a tuner investigate a little on your own account while some one sounds the key.

If the trouble is due to a jangle in some part of the room, a tuner, if sent for, no doubt would "fix it," but he would in all probability tune the supposed bad string a little high or a little low, and for the time avoid the jangle in that way, collect his fee and depart, when the trouble would afterward reappear again as bad as ever. I would say further that I am not aware of any existing rules that will direct one in the correct location of sound. We can only use our ears and common sense as occasion requires, and if sometime errors are made they should not be wondered at, when the deceptive nature of the phenomena of sound is considered.

behavior of the luminiferous ether near matter has been investigated by Prof. Oliver Lodge. The question bears upon that of whether the earth in its motion carries the ether of space with it. Prof. Lodge moved a lump of matter and ascertained whether the velocity of light in the space near it is affected by the movement. He found no such effect, and concluded that the ether slips through a solid like wind through a grove of trees; and that the connection between ether and matter is not mechanical.