The advent of the reflecting circle is
generally attributed to the English, who
by the mid 1700's saw makers like
Ramsden, Gregory, Adams, Borda and Mayer
innovating and producing such
instruments. Initially these instruments
were used at sea to find the longitude
by the lunar distance method.
Oddly,
perhaps because of the adverse reaction
given to Mayer's reflecting circle by
Captain John Campbell in 1758, the
reflecting circle never really gained
popularity on the English side of the
Channel.
By the end of the 18th century,
with the widespread acceptance of the
marine chronometer as a more reliable
tool with which to find the longitude,
reflecting circles were relegated to use
in hydrographic surveying and chart
making. It was left to the French and
Germans to refine these complex
instruments during the 19th century.
The
ability to measure large angles and the
accuracy of averaging several
observations were features which found
favor on the Continent, despite the
circle's inherent size and awkwardness
in taking sights.
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