The Fargo forum and daily republican. [volume] (Fargo, N.D.) 1894-1957, 1913-06-25
AUDITORIUM

Continued From Page One.
small factor the item of expense, I
shall endeavor to- rate the relative i'm
portance OF my several suggestions In
order that YOU may select among
them.
Approves Balcony Scheme.
Il desire to approve your piercing
the screen that constitutes the balcony
front; if you can increase the amount
of these openings, SO much the better.
On the other hand, the supporting
concrete beam is Immediately below
the lower tread of the balcony and
thereby not merely raises the balcony
front but presents a large re1ect1ng
surface. This surface is the more seri-
ous in creating an echo in that it is
set back. 1t would be an improvement
and [ should think not impossible.
s~tructurally, TO make this beam use
the full depth of the hrst riser.
THE vertical scale of your auditori-
UNI as a whole is certainly not exces-
siva architecturally, but aeoustically
it is. 1t is unfortunately true that
large auditorlums. long n broad, es-
tpeclally when the floor is level, require
a lower rather than a higher ceiling.
THE pitch in the balcony is excellent
1 Clld - u 4LsFA
Considers Material.
above ALL" still further cautions
Professor Sabine, The material to be
used IN the construction must be tax
en- into consideration. There is no
harder material used today for intert-
Ior finish than reinforced concrete. 1t
is an almost perfect reflector of sound.
This, of course intenSities every echo,
reverberation and cavity resonance.
Its use calls for the introduction OF
some compromising absorbing mate
rial.
Your simplest method of correcting
both Nos. 8 and 4. is to arrange panels
of felt, covered with a porous fabric,
on the sloping surfaces of the ceiling,
This is the method being employed in
the great auditorium to seat 10000
people for the sPanama-Pacific expost-
ton, where for several reasons it is
undesirable to change either the scale
or the material, and whereas in your
Auditorium, the ceiling is to be of con-
crete.
Either of two kinds Of felt can be
used for this purpose-either that
known on the market as saddler's felt
or a special felt known as acoustical
felt devised under my general direc-
ton by Mr.. Swan, formerly an in
structor in the Massachusetts Institute
of Technology and later a student with
me in this subject. This felt is both
cheaper and better than Saddler's but
I mention both as I should be sorry to
have you feel you are tied up to any
one material.
II have Indicated on the ceiling plan
the felt arranged in panels. Thus ar
ranged 1t serves to break the regu-
larity of the ceiling echo as well as to
diminish the general reverberation
throughout the auditorium. 1t is a
matter Of absolutely no moment
whether these panels r arranged
lengthWise Or crossWise of the room.
II have arranged these considera-
tionS in the ascending order Of their
importance. The use of the felt in
proportion to its cost will accomplish
much more than any hung ceiling or
simple structure change which you
could introduce, maintaining the
a~daptability of the hall to the varied
uses for which / have assumed it to
be planned. If. however, these restric-
tions do not apply and you can vary
lgreatly the whole arrangement, main
tanning seating capacity only and con
slider nothing but acoustics, please let
me know, for in that case my recon-
mendations would take an entirely diff
ferent form.
Upholstered Seats.
"Inasmuch as your floor, as well as
all the treads and risers in the balcony
are concrete, / would strongly recon-
mend that you use upholstered seats
In order that the acoustics may be as
nearly as possible the same with 8
whole and with a partial audience
concludes Professor Sabine in his sug-
gestioris to Mr.. Crabbe.
The nature of the seats will, OF
course, make no difference when the
auditorium is fully occupied. but as
this condition is neither always nor
generally fulfilled, and as an auditori-
UNI Is often Judged by its partial use.
this recomm andation should at least
receive your consideration