The Savannah morning news. (Savannah, Ga.) 1900-current, 1902-06-15
LIGHT WILL TELL THE TIME.
Harvard Observatory Has Adopted N
New System of Time Signals.

Harvard Observatory Has Adopted n
New System of Time Signals.
Cambridge. Mass. June 14.-To-night
the Harvard Observatory put into OPP
GRAFTON system of giving time signals
by electric lights which will serve the
same purpose as the daily noon time
ball. but will be much more efficient in
many ways. There seems every rea-
son to believe. in fact, that it will. for
many purposes, eventually entirely re-
place the time ball. The system was
devised by Mr. Willard P Gerrish.
who has, for a number of years, had
charge of the time reckonings Of the
Observatory and its great clock and
telegraphic time service. He made his
first experiments in 1889. and practical
ly perfected his present method of OPP
Grafton last year. but the signals at
the Harvard Observatory tonight are
the first that have ever been officially
and regularly brought into use.
Mr.. Gerrish says that the advantages
over the time-ball in employing the
electric flash to indicate an exact
moment of time are several. An ordi-
nary three-foot time-bal is visible to
haps two miles: large bank of in
candescent electric lights can be seen
at least ten miles away and so is Wis
ible to fully twenty-five times as many
people. The operation of the time ball,
moreover involves such expense that
it is impracticable to use it more than
once A day for an attendant has to
hoist it by machinery to the top of
its pole so that it may be ready to
t. 49, I..v ~
MIR. Gerrish's plan is to employ lights
which are already in use, such as
the illuminations on some conspicuous
public building, like the circles of lamps
outlining the dome of the Massachusetts,
State House-or the big electric equip
ment employed on large office build
ings. The mechanism that makes the
flash is very simple, is automatic, and
can be connected easily and without
interference with the regular lighting
system. One other point is that the
human eye is so slow to notice motion
at distance that the ball may fall
half the length of its staff before the
observer sees that it has started: and
as the time is indicated at the instant
on which the ball is released, there is
likely to arise an appreciabe error, of
some consequence in the regulation Of
instruments that require great accu-
racy. The effect of light is of course
practically instantaneous.
Three kinds of night time signals
are proposed. The first and simplest
is a single signal at a preconcerted
hour, say o'clock Fifteen seconds
before that time the lights would be
shut off and exactly on the hour the
automatic mechanism would be re-
leased by telegraph from an astronom-
ical observatory and the lights flash on
again. Ire relighting would mark the
exact moment of time. This would re-
cuire an attendant, of course, lust as
the time ball does, and it would be
necessary for the observer to be
watching for the signal at the prear-
ranged hour. An extension of the idea
includes auxiliary clock work located
at the building on which the lights are
displayed. The mechanism is made to
run exactly four minutes and As sec
onds, and then to shut off the lights
and connect the telegraph apparatus
with them so that when the signal
from the observatory comes they will
be turned on again automatically ex-
actly on the fifth minute. The same
signal Which releases the lights will
give the clockwork another start
which will in turn insure the lights
being turned off again in four minutes
and As seconds ready for the next
signal. In this way signals will be
given every five minutes as long as
che lights burn and any ordinary error
~ timepiece can be corrected by
them accurately
The third plan is much more COM
plete, In fact, n reproducea, by means
OF telegranhic relay or repeating in
strument, al Of the signals OF a great
observatory clock Al the Harvard OBJ
fffvatory the relay connected direct
" with the clock beats every two sec
ends, emitting one beat before each
minute mark is reached. 30 that the
exact minute may be easily noted, ana