Admiralty Office, 21ƒt September, 1812
Sir,

      CAPTAIN Matthew Flinders, of the Royal Navy, having
lately brought under the confideration of my Lords Commiffioners
of the Admiralty a feries of remarks made by himfelf with regard
to the variation of the Magnetic Needle, under certain circumftances
of fituation in a Ship; a courfe of experiments was inftituted, with
the view of afcertaining the particular caufes of error to which he had
adverted, or of obtaining fome general refults from an enquiry fo
intimately connected as this appeared to be with the improvement
of navigation.

I tranfmit to you herewith a printed copy of a ftatement which has
been prepared by Captain Flinders upon this fubject, and I am com-
manded by their Lordships to call your particular attention thereto,
and to fignify their defire that, as opportunities fhall offer, experi-
ments may be made on board the Ship you command: you noting
the refults thereof in a table of columns in the manner which he
has pointed out, and adding fuch remarks as may be fuggefted to
yourfelf, by the particular circumftances under which the experi-
ments fhall be made, and tranfmitting the fame to me, for their
Lordfhips' information.

      I am,
              Sir,
                    Your very humble Servant,
                              JOHN BARROW
To The refpective Captains, Com- manders, and Commanding Officers of His Majefty's Ships and Veffels.