The times. [volume] (Richmond, Va.) 1890-1903, 1900-10-28
,rd-will cause a greater or less varia-

word-wil cause a greater or less Nafia-
ton. But it is now possible to calcu-
late the effect of all these changes. ana
by making still other compromising
changes to retain the special values oil
any auditorium that one may have chosen
to take as :; model for good hearing
Symphony Hall is Il case in point. The
architects. Messrs. McNim, Mead & White
of New York, had at first prepared plans
for - building along classical lin $. ana
Mr. McKim visited EIIropc-for the pur-
pose of consulting with scientific authori-
ties in France and Germany 1t was
decided finally that a Greek theatre as
a music hall would be too dangerous an
experiment in acoustics; and 1T was at
first decided by the committee to follow
the general proportions and arrangement
of a well-known auditorium. the GeWand-
faus. in Leipsic. But the seating capaci-
ty of this hall, only about 500, was too
small. and the plan had to be Abandoned.
The new hall. with its two galleries.
its stage recess, its stoping floor, ana
above ALL its increased seating capacity,
is a copyo of the old hall, only in certain
acoustical results, not in the archftec-
turaI means by which these results were
attained. The Boston hall contains about
10000 cubic Feet more than the one IN
Germany; yet, owing to skillful reckon
ing and careful balancing. the reverb2ra-
ton of the former, as expressed III the
formulas prepared at Harvard, is 2.Si.
against 80 for LeipsiC-
WONDERFUL WORK.
The Investigations at Harvard have
embraced practically every detail OF archi-
tectural acoustics. and have been carried
on with q ninutenesS and q patience that
are fairly stonishing to the layman. Not
only have the more obvious problems been
studied but calculations have been made
10 establish the acoustic differences
between a room containing small audi
ence and the same room when completely
filled: and something has even been done
towards establishing the effect OF pants
when placed in auditorium The
three essentials of a good music hall are,
of course. fairly obvious-the sound from
/ the stage should be sufficiently loud the
| component parts of a complex sound must
| keep the proper balance of intensity. and
| succession of sounds must come out
! distinctly. without confusion among them
| selves or from without. The problems
| arising on all these points have been
F! carefully worked out, although the
! results of this study have not yet, in al
! cases been fully tabulated
| In the important matter OF referbera-
/! ton however. 4 most interesting state
| ,nant has lust been made. with particular
/ reference aside from the purely nlathe-
i natical treatment tof the subject. to The
| Qualities which various objects have OF
! absorbing sound. Sound is one form OF
, energy. and can be changed into any
| other form. Usually it passes into heat.
(, This process of decay" as It is called
is known as absorption; and sound is
absorbed. more or less, by any substance
| with which it comes in contact
! Regeneration is sufficiently Well under
stood An echo is q spzeia' example OF
it. but the more general sort OF rever-
], beration is. q confused mass OF sound as
. II were, which unlike an echo. is incapa-
| bic OF being analysed into its various
! parts Rcvcrberatou has spoiled many
| = nublic halt bat on the other hand A
certain amount of it is not only not
| objectionable but is actually Desirable IN
a good music hall, In the ordinary ttie-
atre where reVerbcration Is reduced 10
tho lowest practicable limit. an orchestra
! like the Boston symphony would sound
} mutt1ed and dead. rs compared with 4
performance in q hall like its present one.
whers the conductor. Mr. Gericke de
manded. in order 70 obtain the best re-
s,lfts. that the architects should not cum
irate the reVerberatlon peioW aelissi's
limit
The use OF various materials as absorb
en.s of rsverberation. therefore. and the
ca1culation of the effect Of each. is onf
| ~ the most interesting problems OF
acoustics The lecture-room in Cam
| bridge. where the present experiment:
we're begun. was so exceedingly slow II
| absorbing sound. that word spoken II
an ordinary tone of voice was audini'
five and a half seconds after it had peer
uttered During this time even very
/ deliberate speaker would have uttered
dozen or more succeeding syilables- i he9'
] successive entinciations were Blended my
I . io.1d noise tt-cJryen as's9 9afve Wiz
! il was necessary to distinguish the OF
derly progression of the speech
! could not be done across the room am
1 even near the platform the effort 10 MS
ten for any length OF time was "eal :
some. BY bringing into this room sum
1910 cushions from the seats o. Sdii'ei ;
Tbe,tra in Memorial Hall. and Arranging
| Them so as to expose the iafsss, po s.
I hya s,rrface the length Of raNssas sa!.
was reduced - 49,, hssn before. The
r,,shions had absorbed the rest oi us'
In calculating ABSORPTION an omen WIN
fov.sIs taken as the rnit-since u '''s
No e7;ffarenct. whether sound essai's7 siit'
q tha onen air or is transformed 10 hea
=, come substance-ard an edual are.
NJ any other material Is camparfs. W.
this INIT as q Standard ne s.o as9 49,
S nf glass. for example, Is mus eA !s'
nv the fraction -0ea: and pihs st'esi neat y.
of1 More curious are the fisures 10
nersons. or for an aud,ence e's ma a.,
sssso- that her dress offers create
SURFACE Fer the same reason psrsu'