314 APPENDIX II 



southern part of the dome. The snow became very deep, and the influence 

 of the sun melting its crust, which concealed the sharp points of the lava, 

 was very unfavourable to my progress. From this place to the North 

 towards the centre of the dome, the hill is more flattened. Rested a 

 short time, and a few moments before noon, halted near the highest black 

 shaggy chimney to observe the sun's passage. In recording the following 

 observations, I particularly note the places, in order that future visitors 

 may be able to verify them. To the S.W. of this chimney, at the distance 

 of one hundred and seventy yards, stands a knoll of lava, about seventy 

 feet above the gradual rise of the place. The altitude was 104 52' 45",. 

 This observation was made under highly favourable circumstances, on 

 a horizon of mercury, without a roof, it being protected from the wind 

 by a small oil-cloth : bar. 18 953' ; therm. 41 ; in the sun's rays 43 5' ; 

 and when buried in the snow, 31 ; the dew-point at 7 ! ! wind S.W. 

 The summit of this extraordinary mountain is so flat, that from this 

 point no part of the island can be seen, not even the high peaks of Mouna 

 Kuah, nor the distant horizon of the sea, though the sky was remarkably 

 clear. It is a horizon of itself, and about seven miles in diameter. I 

 ought, ere now, to have said that the bird-catcher's knowledge of the 

 volcano did not rise above the woody region, and now he and my two 

 other followers were unable to proceed further. Leaving these three 

 behind, and accompanied by only Calipio, I went on about two miles and 

 a half, when the Great Terminal Volcano or Cone of Mouna Roa burst 

 on my view : all my attempts to scale the black ledge here were ineffectual, 

 as the fissures in the lava were so much concealed, though not protected 

 by the snow, that the undertaking was accompanied with great danger. 

 Most reluctantly was I obliged to return, without being able to measure 

 accurately its extraordinary depth. From this point I walked along 

 upon the brink of the high ledge, along the East side, to the hump, so 

 to speak, of the mountain, the point which, as seen from Mouna Kuah, 

 appears the highest. As I stood on the brink of the ledge, the wind 

 whirled up from the cavity with such furious violence that I could hardly 

 keep my footing within twenty paces of it. The circumference of the 

 black ledge of the nearly circular crater, described as nearly as my cir- 

 cumstances would allow me to ascertain, is six miles and a quarter. The 

 ancient crater has an extent of about twenty-four miles. The depth of 

 the ledge, from the highest part (perpendicular station on the East side) 

 by an accurate measurement with a line and plummet, is twelve hundred 

 and seventy feet. It appears to have filled up considerably all round ; 

 that part to the North of the circle seeming to have, at no very remote 

 period, undergone the most violent activity, not by boiling and over- 

 flowing, nor by discharging underground, but by throwing out stones of 

 immense size to the distance of miles around its opening, together with 

 ashes and sand. Terrible chasms exist at the bottom, appearing, in 

 some places, as if the mountain had been rent to its very roots : no termi- 

 nation can be seen to their depth, even when the eye is aided with a good 

 glass, and the sky is clear of smoke, and the sun shining brightly. Fearful 

 indeed must the spectacle have been, when this volcano was in a state of 



