On the Construction of Buildings, etc. 21 
Arr. IIIl.—A Consideration of some of the Phenomena and 
Laws of Sound, and their application in the Construction 
of Buildings desioned ee for Musical Effect ; by J. B. 
Urnam, M.D., Bos 
(Concluded from p. 363.) 
We have already pointed out how the resonance eh a room, 
and the quality of the transmitted tone, are affected by the 
which circumscribe the limits of any apartment, the indications 
were plain; for, as we have seen, the same conditions that are 
necessary for a proper amount of resonance are those, also, re- 
quired to maintain the strictest purity of intonation, so far as re- 
lates to the passage of sound from a denser to a rarer medium, 
and vice versa. 
But every sound shut in by the walls of a building, is nae 
to the disturbing influences of reflection and reverberation. 
are consequences which it is of the utmost importance to sonteal 
or subdue, and, these also, are materially modified by the nature 
and conformation of the circumscribing limits. Unfortunately, 
the conditions of structure that would favorably affect the first 
mentioned desirable results, might unfavorably modify the latter. 
0 explain :—so far a s resonance and the perfection of the trans- 
mitted tone are aera, the unity of structure required in the 
main body of the wall should not be disturbed at its surface ; in 
other words, the internal face of such wall should be the solid 
surface of the substance used in its construction.* Now a wall 
of masonry, presenting a smooth and solid surface to the sound, 
will occasion an excess of the residuary portions which constitute 
direct reflection and reverberation ; so that, however satisfactory 
be the effect of an isolated musical tone, the distinct utterance of 
a mg mt of sounds in moderate rapidity i is rendered impossi- 
poe is abundantly confirmed by observation and experi- 
se a metallic chamber at Montrose, which had been con- 
pce for the- preparation of sulphuric acid, Dr. Reid observed 
that any sound produced in it continued in general for seven or 
eight seconds after the impulse which had given rise to it had 
ceased. In the interior of one of Barclay and Perkins’ boilers, 
f-4 
P 
1s sheathed with a lining of metal, loses in great degree its pure and mellow tone, 
though it acquires thereby, in its upper register, a certain ness (brilliancy 
Perhaps,) w. ‘shach hich gives it rap eater prrevinenes in the orchestra, a _compensates, in 
the ears sg many, for its losses in other respects. 
