82 THE POPULAR SCIENCE MONTHLY. 



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 cor- 

 rect if it is a case of importance, such as a responsive jangle pro- 

 duced by a musical note or accusing wrongly some innocent per- 

 son, as in the case of the lady and the whistling door check. 

 Should your piano be afilicted 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 con- 

 sidered. 



The 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 atfected 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. 



