The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1899-03-22
White Lights as Signal COlOrs
Are to Be Dropped.
Yellow Seems to Be the Best
Tried Substitute.
FOR GREATER SAFETY.
Red and Green Will Be COntin.
ued In Use.
Eastern Roads Beginning to
Make the Change.

Chicago, March 22.-White as a rail-
road signal color is likely to be aban-
doned. The Massachusetts, railroad
commissioners have formally recon-
mended its discontinuance, and the New
York New Haven & Hartford road has
already adopted red, green and yellow
as signal colors instead of red, green
and white. The Lake Street Elevated
road, too, was recently equipped with
red and green signal lights instead of
red and white. Railway managers all
over the country are taking up the ques-
ton, and the white light appears to De
doomed
White was chosen as the signal for
safety as far back as 1S41, at a congress
of railway men held at Birmingham
England. Results of experiments SUP
mitted to that gathering showed that
the visibility of a red light was but one
third that of a white light of the same
intensity, that of a green light one-fifth
and that of a blue light one-seVenth-
White was chosen as the signal 1oT
safety as being the usual light as Wen
as the most easily visible, while req as
the most easily visible of the colored
signals was chosen for the most import
ant signal, that of danger. 1t would
have been desirable for the danger sig
nal to be of the color most easily seen;
but for practical purposes it was deemed
inadVisable to use white for Such d
purpose.
SERIOUS ODJecLlO0S TO the use VI w AAAhS
as safety signal soon became evident,
and the English railways substituted
green signals. The two main objections
to the use of white as signal color are
that if the red lens which forms the
danger signal be broken the light VIII
show safety instead of danger and that
in the event of the danger signal being
eXtinguished the engineer is likely TO
mistake some other white light for the
safety signal.
Heretofore the American railways
have been slow to follow the lead set
by the English companies in abandoning
white safety signals. Among the chief
arguments against making the change
the officials here urge that the engineers
being accustomed to the use or the Whlte
signal any change would be dangerous,
since a white light not on the railway
might be taken as safety signal from
force of ha bit, and also that on account
of the extensive use OF the permlsslVe
block system on American roads 1t IS
necessary to have a signal for caution,
and it appears difficult to find suitable
color for this purpose. Amber or orange
has been suggested but is Objectionable
as being so easily confused with red II
the tint is dark or with white if the tint
is light. Blue is not suitable on account
of its slight visibility, particularly since
the light from the usual lamp flame
contains few blue or violet rays.
Yellow would seem to offer the best
substitute. 1t is so much deeper in
shade than the ordinary white light as
to be instantly distinguished from any
number of white lights that may be in
line, while it is not dark enough to sug-
gest confusion with red. During the
short time that yellow has been used
ford road the general manager reports
that the change has been in every way
satisfactory. The engineers feel relieved
by increased facility of recognizing sig
no danger, of substituting an ordinary
| white light for a broken danger signal.