NOTES. XC1 



be reached almost entirely on horseback. The cone of cinders and rapilli, about 

 1000 feet high, rises out of an encircling ridge (a crater of elevation). On the 

 flatter north-eastern portion of the summit lies the proper crater, between 7000 

 and 8000 feet in circumference, and which never sent forth streams of lava. Its 

 eruptions of scoriae have often been accompanied, in 1723, 1726, 1821, and 

 1847, by earthquakes which have destroyed towns, and have extended from 

 Nicaragua or Rivas to Panama. (Oersted.) Dr. Carl Hoffmann, in a recent 

 ascent of Irasu, in May 1855, examined the summit crater and the orifices of 

 eruption more closely. The height of the volcano is, according to a trigono- 

 metric measurement by Galindo, 12,000 Spanish (11,000 English) feet. (Bon- 

 ulandia, 1856, No. 3.) 



El Reventado (9486 feet), with a deep crater, whose southern margin has 

 fallen in, and which was formerly filled with water. 



Barba (about 8500 feet), north of San Jose', the capital of Costa Rica, with a 

 crater which encloses several little lakes. 



Between the volcanoes of Barba and Orosi there is a line of volcanoes, which, 

 running east and west, crosses the principal chain, of which the direction in Ni- 

 caragua and Costa Rica is S.E. N.W. On this cross-fissure rise, beginning 

 from the east, Miravalles and Tenorio (each about 4700 feet high) ; in the mid- 

 dle, south-east of Orosi, Rincon, also called Rincon de la Vieja* (Squier, vol. ii. p. 

 102), which every spring, at the beginning of the rainy season, has small erup- 

 tions of ashes ; and most to the west, near the little town of Alajuela, the vol- 

 cano of Votos *, rich in sulphur (7513 feet). Dr. Oersted compares this phaeuo- 

 menon of the direction of volcanic activity over a cross-fissure, with the east and 

 west direction, which I found in the Mexican line of volcanoes from sea to sea. 



Orosi*, still active, in the most southern part of the State of Nicaragua (5220 

 feet) ; probably the Volcan del Papagayo on the chart in the Deposito Hidro- 

 grafico. 



The two volcanoes of Mandeira and Ometepec* (4160 and 5220 feet), on a 

 small island in the Laguna of Nicaragua, called by the Aztec inhabitants of the 

 district, " ome teptl" or "two mountains." (Compare Buschmann, Aztekische 

 Ortsnamen, S. 178 and 171.) The island-volcano Ometepec, wrongly called by 

 Ignarros, Ometep (Hist, de Guatem. t. 1, p. 51), is still active. It is drawn in 

 Squier, vol. ii. p. 235. 



The extinct crater of the island Zapatera, but little raised above the level of 

 of the sea. The period of its former eruptions is wholly unknown. 



The volcano of Momobacho, on the western shore of the Laguna de Nicaragua, 

 a little to the south of the town of Granada. As this town (which is also called 

 Mombacho, Oviedo. Nicaragua, ed. Ternaux, p. 245) is situated between this vol- 



