New-York tribune., 1906-07-11
THE GREENW1CH oBsERYATORY.

Much uneasiness has been excited in the
breasts of those who understand the nature Of
the work carried on at the Greenwich Observa-
tory because of the threat of serious interfer-
ence with it by a great power house which is
now being constructed in the vicinity of the in
stitution for the London County Council. 1t is
proposed to equip the station with eight huge
reciprocating steam engines, capable Of develop
ing $1,000 horsepower collectively. When these
are In full operation 1t is possible that tremOrs
from the machinery, transmitted through the
SOIL will impair the efficiency Of certain delicate
apparatus in the observatory.
The most important service performed ut
Greenwich is the regulation Of the clock which
gives the British Empire its time standard. To
check the accuracy Of that instrument and make
corrections when necessary it is customary to
note with precision the instant when each of
number OF carefully selected stars passes the
meridian. The time Of such 'transits' having
been computed in advance, the average of
series Of observations on a single night should
indicate 10 fraction Of second whether the
clock is fast or slow and how much. Now, for
reasons which need not here be discussed it is
the practice of astronomers who are engaged
in transit work TO watch the reflection Of a star
in a shallow pool of mercury, instead Of looking
directly at the sky. Obviously, anything which
disturbed the surface of the mirror would
lessen the value Of an observation. IT, indeed. it
did not preclude making one at all.
Much attention is also given at Greenwich to
the movements Of the moon on which the tides
are largely dependent Near though that body
is to the earth there are eccentrcites in its
behavior which not yet fully understood.
careful watch Of them must be kept for the
benefit Of the makers OF nautical almanacs. BY
common consent, responsibility for the prepara-
ton Of lunar tables has been left by the other
observatories TO this One doubtless because of
the familiarity with the subject possessed by
the astronomical staff there. However there is
a chance that either smoke from the chimneys
OF the power house or the tremulOus motion i'm
parted 10 the atmosphere by columns of heated
air from the same source may embarrass tele-
scOpic work, and make necessary either an
abandonment Of the observations for which
Greenwich is famous or else sacrifice
of the Observatory's present reputation for ac-
curacy.
A third class of Investigations for which
Greenwich has been celebrated and whose value
is now imperiled relate to certain phases of
terrestrial magnetism. The daily swing Of three
kinds OF magnets and any disturbance due to
solar influences are registered automatically
The data thus obtained are utilized In freshly
calculating the variation of the mariners and
surveyors cOmpasses from true north the
computation being necessary from the fact that
the degree OF variation is always undergoing
change Al Kew, England, and I'm Washing
ton it was observed years ago that stray trolley
currents would make so much mischief with
observatory magnets that it was hard to tell
what significance to attach TO the records left
by the apparatus. 1t is feared that when the
electric tramways which the London County
Council intends TO provide for Greenwich are
once in operation similar trouble Will be ex-
Derfenced at the observatory there.
These possibilities have been pretty well ven
hlated both IN Parliament and the newspapers
during the last few months. and several RENE
dies AaYe been proposed one Is removal Of