352 On the Construction of Buildings 
thus reflected from a plane surface, only when the angle of inci- 
dence is greater than forty-five degrees, whereas, if the sonorous 
wave is incident on a surface at an angle less than forty-five de- 
grees, it suffers little or no reflection, but is moved along in close 
proximity to the plane against which it is projected, and thus 
gives rise to the phenomena of reverberation. Mr. Russell de- 
rives from these supposed facts some practical suggestions, which 
he deems important in the construction of buildings intended for 
public speaking. Such rooms, he contends, should be so ar- 
‘maxims he lays down in order to avoid (on his theory) the undue 
* 
r. Russell further says that, though, in his own mind, oe 
convinced the action of sound, in these particulars, 18:20, 0000" 
ance with the manner just stated, he can offer no philosophical 
of sound may be considered a force of continuous progres 
while such is not the case with a ray or wave of light, (@ ites 
ence, the existence of which we must deny in toto,) we will no 
delay, in this connection, to follow out and refute his saree 
It is satisfactory to us, that the doctrines we have adopiel 
regard to reflection and reverberation of sound are strong 12 UIE" 
nalogy to the known laws of light, in its similar phenomen?, 
and, while on this ground, we can equally well explain the pei 
important maxims deduced by Mr. Russell, we will nee , 
seek to disturb those harmonious relations of sound wit ight, 
* The walls of the Boston Music Hal thus treated, and the ceiling is deeP'¥ 
pannelled, me. ow Hada 
