Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2- Appendix): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

318 APPENDIX. No. 55. Remarks on the Chronometrical Observations made during the Sur- veying Vo)'ages of H. M. Ships Adventure and Beagle, between the years 1826 and 1836. Before I iiroceed to notice the chronometrical observations made during the Beagle's latter voyages, fi-om 1831 to 1836, it appears to me necessary to give a copy of Captain King's Report of those made under his direction between 1826 and 1830. Copy of a Report of the Chronometrical Observations made during a Voyage for the purpose of surveying the southern extremity of America, in H.M. Ships Adventure and Beagle, between the years 1826 and 1830, under the orders of CaptamP. P. King, by direc- tion of the Right Honourable the Lords Commissioners of the Admiralty. Among the important objects to which my attention was directed by the Lord Commissioners of the Admiralty, upon my appointment to the command of the Expedition for the survey of the southern part of South America, was that of measuring the differences of certain meridians in the north and south Atlantic Oceans by means of chronometers ; and for this purpose I -was supplied from the Royal Obsen'atory at Greenwich with nine chronometers ; eight of which, at the suggestion of the Astronomer Royal, were suspended in gim- bals, and divided into two boxes ; and the ninth, an eight-day box- watch, was fitted in the usual manner. ITae whole were fixed in a chest that was firmly secured to the deck as low down as possible, and as near to the middle part of the ship as could be managed, in order to diminish the eflfect of the ship's motion, and to counteract that of the ship's local attraction, which, whatever it might have been, always remained the same, as the chronometers were never moved from their positions. Tlrese nine chronometers were made by Mr. French. Their description and number were as follows : Eight-day box chronometer, No. 3233 designated Z Two-day 3296 A Two-day 3295 B^ ™ Two-day 3271 c °"^ ^°'^- Two-day 3227 D