Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1917-01-13
BY ARTHUR EDWIN KRows

BY ARTHUR EDWIN KNOWS
Passage of sound from the stage to the
seat is beset with many difficulties. IL 10
such tricky subject. In fact that most
theatre architects let it severely alone and
build their houses on seemingly tried and
proved plans, without inqulrIng into scien-
tihc why's and wherefores.
We have in America one OF the greatest
constructive authorities on theatre acoustics
In the wurld-Dean wallace G. Sabine, OF
Harvard. He has made HIS findings public
on many occasions for the good of the the
atre in general.
He takes his views from vitruvius the
ancient architect. who said that for a ths-
atre, place must he taken where the voos
falls softly and not so reflected as to pro-
duco confused effect the ear
Acoustics of theatre are now deter
mined IN advance from the plans, almost
as readily as lines OF sight alNl the method
of doing so is intensely interesting.
'rhe process in favor Is that known as
the Toeppler- Boys-Foley method. devised
by three authorities on the subject First,
II scale model OF tho projected theatre IL
constructed. Sides of this are removed
and q sound is produced at that point cor
responding to the acting zone Of the stage.
As the sound Is passing through the model
is Illuminated from one side by a fine and
somewhat distant electric spark. After
passing through the model the light falls
distance on the other side This light Is re-
fraCted by the sound waves, which act az
their own lens In producing photograph.
The resultant picture shows a silhouette
frame from shadows cast by the model,
and all within this frame constitutes an
actual photograph of the sound waves and
their echoes. BY taking n series of pic
lures at different times after the sound haa
been started, a complete record OF tmN \
waves their interferenCes and echoes, is oh
tanned,
Through such analysis the new Scolal
Theatre in Boston was prevented from
heiug acoustically faulty by change In
plan before any building operations werS
commenced Minor adjustments are mads
in the actual theatre after construction, for
the scale model does not take account or
seats draperies and so forth. These minor
changes are commonly accomplished py
placing rejecting walls and panels OF
ac0u,tic invented by Sabine himself
in various parts Of tile auditorium, re-
moving heavy valances. rehanEing chande-
lers and adjusting other details. There are
architectural firms that make specially
Of acoustical correction.
= Of the corrected New Theatre, which.
with its echoes. has been target for much
rjdicuie by pesons who did not understand
its problems. Sabine says. 1T is safe to
say there are few--possihly no modern the
aires or opera hOusea--sO free from this
particular disturbance as the New Theatre
vt the present time
Dean Sabine was called upon by VIM
throp Ames to correct the echoes and inter-
fcrenCes Of the QuOUdam New Theatre, He
succeeded so splenddly that when Mr.. Ames
prepared to build his own Little Theatre
his plans were submitted to the Dean foY
criticism from the aCoust.Cal standpoint
And the Little Theatre is. therefore one o.
the most acoustlcally correct theatres in
America.
Sabine found the plans of the Little The
atre, New York. we'll defined and presenting
all points necessary for his profound con-
slderation. It was designed. he was told
for production Of plays which could be ad-
cquately rendered only by the most delicate
shades of expression; 1t was 10 seat just
less than 300 and all seats We're TO be as
nearly as possible OF equal excellence The
important assurance was given that every
seat should he occupied at every perform
aucr (Which indicates. parenthetcaly,
another danger of empty theatre seatsD
The Dean himself explains what hap,
ueued. The first sketch showed a slight
reverberaton SO the floor was lowered
at the front, the ceiling was lowered, and
the walls near the stage were brought in
aud reduced in curvature. with corresponds
ing changes In architectural treatment. The
rear wall was made straight the side walls.
near the stage, We're curved. In order to
still further reduce TeyerberatiOn and to
break acoustiCally, the curvature OF the side
and rear walls, acoustic felt was applied
in nanels-three panels on the side walls
and seven panels on the rear wall" These
panels. may add are hidden beneath
pa uted tapestries
When / issued a story from the press
department OF the Little Theatre in 1915,
declaring that in that playhouse the stage
whisper had been perfected | meant it,
and actually hear a genuine whisper on
the stage