366 COSMOS. 



know how much should here be attributed to imperfec- 

 tion of measurement and barometrical formula. Investiga- 

 tions of this kind might be multiplied on a larger scale 

 and with greater certainty if, instead of often repeated com- 

 plete trigonometrical operations or, in the case of acces- 

 sible summits, the more practicable, though less satisfactory 

 barometrical measurements, operators would confine them- 

 selves to determining, even to fractions of seconds, at com- 

 parative periods of twenty-five or fifty years, the simple 

 angle of altitude of the margin of the summit, from the 

 same point of observation, and one which could with cer- 

 tainty be found again. On account of the influence of 

 terrestrial refraction, I would recommend that, in each of 

 the normal epochs, the mean result of three days' observa- 

 tions at different hours should be taken. In order to obtain, 

 not only the general result of the increase or diminution of 

 the angle, but also the absolute amount of the change in 

 feet, the distance would require to be determined previously 

 only once for all. What a rich source of knowledge relative 

 to the twenty volcanic Colossi of the Cordilleras of Quito, 

 would not the angles of altitude, determined for more than a 

 century by the labours of Bouguer and La Condamine have 

 provided, had those travellers accurately designated as fixed 

 and permanent points the stations whence they measured 

 the angles of altitude of the summits. According to 

 C. von Dittmar the Kliutschewsk was entirely quiescent 

 since the eruption of 1841 until the lava burst forth again 

 in 1853. The falling in, however, of the summit of the 

 Schiwelutsch interrupted the new action {Bulletin de la 

 Clause Physico-Mathem. de V Acad. des Sc. de St. Petersbourg, 

 t. xiv, 1856, p. 246). 



Pour more volcanoes, mentioned in part by Admiral 

 Liitke, and in part by Postels, namely the Apalsk, still 

 smoking, to the south-east of the village of Bolscheretski, 

 the Schischapinskaja Sopka (lat. 55 11'), the cone of fvres- 

 towsk (lat. 56 4'), near the Kliutschewsk group, and the 

 Uschkowsk, I have not cited in the foregoing series from 

 want of more exact specification. The central mountain- 

 range of Kamtschatka, especially in the plain of Baidaren, 

 lat. 57 20', eastward of Sedanka, presents (as if it bad been 

 "the field of an ancient crater of about four wersts, that is 



