COPY.
Appendix 1.
509
The Tide Tables issued by the Nautical Almanac Office,
were, for a number of years, based on readings of the Royal
Naval Yard tide gauge. The results showed that the zero of the
gauge was 7.60 feet below mean sea level. "Rambler" Zero being
2.33 on the tide gauge was therefore 5.27 below nean sea level.
When I proposed at one time to try the difference of
level between this gauge and the Copper Bolt, Mr. G. J. E. Sayer
(iate of the Engineering Staff of the Admiralty Works) told me
that it (the gauge) got damaged occasionally, and was repaired
in an indifferent way by an ordinary carpenter, and therefore
its level was not constant.
Dr. Doberce tells me that the gauge was carefully main-
-tained and read during the year 1863, when readings were being
taken as a basis for the construction of tide tables; but when
the Tidal Observatory was established at Kowloon in 1887, and it
was proposed to determine the difference of level between points
on the two sides of the harbour, by comparing the readings of
two gauges, it was decided that the Royal Naval Yard gauge was
not sufficiently reliable for the purpose.
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