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

APPENDIX. 331 dian of the centre of Government House. By the pubHshed survey of Plymouth and Devonport,* the Government- House at Devonport is 0° 1' 48" west of Plymouth old church, the longitude of which is given by Captain King in the preceding copy of his report. This longitude, however, differs slightly from that obtained by the Beagle's chronometers carried from Devonport to Greenwich ; and as the longitude of Falmouth, by her chronometers, agrees with that determined by Dr. Tiarks, I have used in the construction of the table of positions (pp. 65-85) the result obtained directly by these chronometers, because so confirmed. Principal Results of the Beagle's chronometrical measurements between 1831 and 1836; forming a connected chain of meridian distances around the globe, the first that has ever been completed, or even attempted, by means of chronometers alone. Devonport to Port Praya. Twenty Chronometers. Twenty-three Days. A B C D E F G H K L S. H. M. S. 21,68 21, 8o 20,69 20,69 17,03 20,33 20,33 23.03 21,43 21,43 17,16 23,90 21,12 21,12 H. M. S. H. M. S. M 1 17 20,47 20,47 N 24,42 p 17,73 R 19,90 19.90 S 20,52 20,52 V 22,23 W 20,93 20,93 X 21,08 Y 20,58 20,58 Z 21,43 21,43 Preferred. Mean ... 20.87 Ih. 17 m. 20,7s. 20,74 Places of observation The Baths, in the meridian of Government-house, at Devonport. The landing-place at the west side of Quail Island, Port Praya, in the Cape Verde Islands. • In the above-mentioned plan, published by the Admiralty, on a scale of 5,03 inches to a mile, the departure between Devonport Baths and Plymouth Old Church is .5,8 inches ; which in latitude 50° 22' represents 0° 1' 48"1 of longitude. e e 2