Unpublished letter, regarding observations with invariable pendulum from Tho [Thomas] Brisbane to Capt [Henry] Kater Brisbane reports to Kater on observations made by himself and [James] Dunlop using an invariable pendulum lent to them by the Board of Longitude. He writes that he will soon be visiting Port Macquairie and Morton [Moreton] Bay. He adds that Mr [Karl Ludwig Christian] Rumker is in a bad state of health. Subject: Geodesy Written by Brisbane in Government House, [Parramatta?], New South Wales [Australia] an addressed to Kater at Union Place, Marylebone [London]. 6 November 1824