Browse the documents Browse the documents Search
Advanced search
The Flinders papersletters and documents about the explorer Matthew Flinders (1774-1814)
You are here: Flinders > Browse the Documents > Documents > Documents
All pages | 1 | Back to Index

Letter from the Admiralty re magnetic variations (7 of 7). With Captain Adam's observations and explanatory notes. (FLI07) Page 1

          Admiralty Office 9th Apl 1814


            I am commanded by my Lords
Commiƒsioners of the Admiralty
to send to you herewith the results
of observations made on board
His Majesty's Ship Invincible
upon the variation of the
Compaƒs, transmitted by Captain
Charles Adam

        I am
                Your very humble servt
                Jn Barrow

Captain M Flinders

[Captain Adam's written explanation of his bearings and mathematical observations]

    When the Ships Head was to the Westward the Compaƒs at the Binnacle is 4° to the Southd of the one placed near the middle of the Quarter deck, but when the Hd is to the Eastd the diff is the same to the Northd consequently the attraction lies abaft the foremost one, or before the other, & from the observations tho' very irregular (from what cause I have not been able to find out except the Cards being in the Ship since first commiƒsioned & their magnetism not very sensible) the attraction appears abaft also. —— It is evident the stantions [sic] under the half deck effect more than any thing on deck, for the compaƒses placed one over the other over the middle of the deck exactly agree, but one placed on the deck only 12 inches on either side the diff. is more or leƒs than a point according to the distance from the stantion [sic] nearest it. ——— The Marines Arms Cutlaƒses Boarding pikes &c kept under the Poop being taken away made very little difference. — From the constant {shaking} motion of a Ship in Commiƒsion it is impoƒsible to find the neutral points exactly, —— but by the experiments made it appears to be in this Ship between the Main & Mizen Masts nearly in the middle of the Quarter Deck so that as many stantions are before as abaft the Compaƒs. The other points I have not been able to find out.
        The foregoing observations and researches were made by Mr Jas Bennett acting 2d Master of the Invincible generally under my immediate inspection.
                        Chas Adam Captain
20 January 1814

All pages | 1 | Back to Index
View Print Friendly Version

Related people
Adam, Sir Charles
Barrow, John


Words and phrases

Related Documents
Other documents written by Barrow, John

Other documents received by Flinders, Matthew

Other documents written in 1814