12 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
MicHareLt WILson, WILLARD ADAMS SHUMWAY, and JEFFERSON 
FRANKLIN Moser. - 
Mr. A. B. Jonnson then completed his communication on 
THE DIFFICULTY IN DETERMINING THE DIRECTION OF SOUND, 
illustrating his remarks by a model of the topophone. The follow- 
ing is an abstract of the entire paper. 
Mr. Jounson said the hunter could not locate his game by the 
sound it made, unless the sound was frequently repeated; that the 
plainsmen could not locate each others’ site by shouts, until they 
were frequently repeated; that a child calling its mother in a house 
could not tell which room she was in, or even the floor she was on, 
until her voice was heard several times; that it was hard to tell, 
from its noise alone, whether a street-car was going to the right or 
left, in approaching it at right angles; in fact that it was not easy 
to fix by the ear alone, the location of the source of any sound. 
A dog aroused from sleep by the call of his unseen master fre- 
quently dashes in different directions before hitting the right one. 
Game startled by hearing a hunter’s tread will as readily run into, 
as out of danger. Blind people, despite the highly developed con- 
dition of their remaining senses, do not appear to be more able to 
determine the source of sound, other things being equal, than seeing 
people. It seems to be a question whether people generally do not 
use sight, touch or smell, involuntarily in locating sound. Hence, 
when they are so placed that they must depend on hearing alone, 
and err unusually in doing so, they consider such instances as ab- 
normal. 
After referring to subjective errors in audition, which frequently 
arise, Mr. Jounson spoke of the peculiar class of errors in audition 
into which mariners are apt to fall, often resulting in disaster. The 
collision between the ocean steamers Edam and Lepanto, was. 
referred to, in which the former was sunk, as the latter had erred 
an eighth of the compass circle in fixing her position by the sound of 
her fog signal, and thus ran into her. A lawsuit ensued, in which 
Judge Addison Brown, of the U. S. District Court of New York, 
decided against the plaintiff, holding “that an error of five points, 
in locating a vessel by the sound of her whistle in a fog, is not nec- 
essarily a fault, under the proved aberrations in the course of 
sound.” 
