F THE CUMBERLAND AT MAURITIUS, AND IMPRISONMENT OF THE
COMMANDER DURING SIX YEARS AND A HALF IN THAT ISLAND.
BY MATTHEW FLINDERS
COMMANDER OF THE INVESTIGATOR.
IN 2 VOLUMES WITH AN ATLAS.
VOLUME 1.
LONDON:
PRINTED BY W. BULMER AND CO. CLEVELAND ROW,
AND PUBLISHED BY G. AND W. NICOL, BOOKSELLERS TO HIS MAJESTY,
PALL-MALL.
1814

[Facsimile Edition, 1966]

TO
The Right Hon. George John, Earl Spencer,
The Right Hon. John, Earl of St Vincent,
The Right Hon. Charles Philip Yorke, and
The Right Hon. Robert Saunders, Viscount Melville,
who, as First Lords Commissioners of the Admiralty,
successively honoured the Investigator's voyage
with their patronage,
This account of it is respectfully dedicated,
by
their Lordships'
most obliged, and
most obedient humble servant,

Matthew Flinders.

London,
20 May 1814.

PREFACE.

The publication in 1814 of a voyage commenced in 1801, and of which all
the essential parts were concluded within three years, requires some
explanation. Shipwreck and a long imprisonment prevented my arrival in
England until the latter end of 1810; much had then been done to forward
the account, and the charts in particular were nearly prepared for the
engraver; but it was desirable that the astronomical observations, upon
which so much depended, should undergo a re-calculation, and the lunar
distances have the advantage of being compared with the observations made
at the same time at Greenwich; and in July 1811, the necessary authority
was obtained from the Board of Longitude. A considerable delay hence
arose, and it was prolonged by the Greenwich observations being found to
differ so much from the calculated places of the sun and moon, given in
the Nautical Almanacks of 1801, 2 and 3, as to make considerable
alterations in the longitudes of places settled during the voyage; and a
reconstruction of all the charts becoming thence indispensable to
accuracy, I wished also to employ in it corrections of another kind,
which before had been adopted only in some particular instances.

A variety of observations with the compass had shown the magnetic needle
to differ from itself sometimes as much as six, and even seven degrees,
in or very near the same place, and the differences appeared to be
subject to regular laws; but it was so extraordinary in the present
advanced state of navigation, that they should not have been before
discovered and a mode of preventing or correcting them ascertained, that