Annotation:

      No 33
Nov. 27.1812 Admiralty
Relative to capt. Hayes'
request to be furnished with
more information on the mag-
netism of ships

Admiralty Office 26^th Nov. 1812

Sir,


        I am commanded by my
Lords Commiƒsioners of the
Admiralty to transmit to
you herewith, a copy of a
letter, of the 6^th instant, from
Captain Hayes of His Majesty's
Ship the "Magnificent", requesting
to be furnished with further
information than that which
is contained in the statement
lately prepared for circulation,
from your inquiries, and
from the experiments some
time since distributed to
ascertain the causes of
variation in the magnetic
needle, under particular
circumstances of situation
in a Ship. I also, send to
    you

To Captain Matthew Flinders
N^o 7 Mary Street
        Brook Street, New Road

you a copy of a minute, dated
the 21^st instant, from Captain
Hurd, the Hydrographer for
this department, wherein he
has quoted certain parts of
your general statement from
which he conceives that an
abstract might, with advan-
-tage, be made for the infor-
-mation of those Officers who,
like Captain Hayes, shall be
desirous to regulate the
experiments and remarks
which they are instructed to
make, by a further knowledge
of the subject than is at
present brought under
their views; and I have to
signify their Lordships'
direction to you to report
to me what additional particulars,
of the deductions already obtained,
you would propose to be circula-

-ted for the purpose of
promoting a more intimate
acquaintance with this matter.

I am,
        Sir,
            Your very humble serv^t ,
        Jn Barrow

[Captain Hayes' letter]

His Majesty's Ship Magnificent
Barque Roads Nov. 6, 1812

Sir
        I have had the honor to receive
from the Lords Commiƒsioners
of the Admiralty a printed copy
of a Statement prepared by Cap^t
Flinders of the Royal Navy
upon the Subject of the variation
of the Magnetic Needle under
certain circumstances of situation
in a Ship, with their Lord=
=Ships command to pay
particular attention thereto, and
as opportunities shall offer to
make Experiments on board His
Majesty's Ship under my

command noting the results
thereof in a Table of Columns
in the Manner pointed out by
Cap^t Flinders; and likewise to
add such remarks as may be
suggested to me by the particular
circumstances under which the
Experiments may be made
transmitting the same to the
Admiralty for their Lordships
Information; and being extremely
desirous to aid and aƒsist in
ascertaining the true cause of
such variation, I beg to submit
for their Lordships consideration
the propriety of furnishing the
opinion and explanation Cap^t
Flinders has himself given on
the subject in order to afford

some clue for unravelling the
Mystery in which it, at present
appears to be involved; his
arguments on the Subject in
question although perhaps not
quite correct may tend very
much to the Elucidation of it.
        I have therefore to request
that their Lordships will have
the goodneƒs to order me to be
furnished with the remarks
made by Captain Flinders, or
at least with his opinion relative
to the great difference of the
exceƒs of variation in the
Helder Frigate, and Raisonable
64 armed en flute the former
giving 13° 3' and the latter only
0° 42' while both were at the

same Anchorage. I should
wish also to know whether both
these Ships holds were stowed
with water & Provisions
at the time the Experiments
were made, and if the Iron
ballast in both Ships was
covered with Shingle in the
usual way. ———
                    I have &c,
                    Jm^s Hayes

[Captain Hurd's letter]

Copy
          Hydrographer's Office 21^st Nov, 1812

    It does not appear that Cap^t Flinders
gives any decided opinion on the
Subject of Magnetism in Ships,
but only offers reasons, and
States what he calls well ascertained
facts, for the purpose of being
printed & thereby made public,
in hopes of obtaining some
information on which a substantial
opinion may be grounded, and the
great error in compaƒses either
rectified or allowed for. —
    If in addition to the printed
Extracts already distributed by their
Lordships orders from Cap^t Flinders
account of Experiments, a further

one was to be made from his
general deductions between the
Pages 28 & 32 it might meet
Cap^t Hayes expectations as
well as that of others, and help
to facilitate their conclusions.

[ends here - rest cut away]