ERUPTION OF THE VOLCANO OF COLIMA IN JUNE, 1869. 



Communicated by Dr>. Charles Sartokius. 



To the northwest of the town of Colima rise, above lower mountains, 

 two lofty volcanic peaks, the more easterly, capped with snow, being 

 3,790 metres (12,434 feet) in height, the more westerly, with a conspicu- 

 ous crater, 3,580 metres, (11,745 feet.) The latter had an eruption in the 

 year 1818, but had since remained in repose, though thin clouds of 

 smoke often ascended from its summit. 



On the 12th June, 1809, a dense smoke issued from the crater and at 

 night a bright light was visible at its mouth ; detonations like the dis- 

 charge of distant artillery were heard, but no concussion of the earth 

 took place. On the 13th there was observed from the hacienda (farm) of 

 San Marcos, four leagues distant from the volcano, on its northeast si<le, 

 at the foot of the steep cone, a glowing heaving {Anscliwellung) of the 

 surface, which continued to increase, and displayed intensely luminous 

 clefts, from which were ejected smoke and red-hot stones, extending in 

 the direction of the snowy peak above mentioned. 



The civil engineer, Ricardo Orosco, ascended the volcano on the 15th 

 of June, accompanied by two servants and a guide. At G o'clock in the 

 morning he left San Marco's, and reached at 12 o'clock a plain at the 

 foot of the steep cone, where he left the horses. A heavy storm Avas 

 prevailing, the temperature of the air being 10° Reaumur, (55° F.) On 

 a second small plain upon the northeast side of the mountain was the 

 new upheaval, which ascended to the scarp of the cone and stretched 

 in the direction of the snowy peak, the latter being 4,500 metres (2f 

 miles) distant. The upheaval in question seemed to be some 35 metres 

 (114 feet) high and 230 metres (754 feet) broad, forming a flattened arch. 

 The appearance was that of a wild mass of volcanic, red-hot rocks 

 heaped one upon another and constantly in motion, not unlike freshly 

 burnt lime when sjirinkled with water. The rocks which rolled down 

 were, on cooling, of a gray color. A piece broken oft' rang like glass 

 and Avas vitreous and porous. In the middle of the upheaved mass the 

 movement was strongest; there large clefts and intense light were dis- 

 played, while engulfed stones, which were swallowed up in great masses, 

 were followed b^' a noise as of violent wind and by clouds of smoke, 

 sometimes blue, sometimes yellow. The temperature of the air in the 

 vicinity was 42° R., (120° F.) The stones in the midst of the heaving 

 mass seemed to be softened, though not melted, and no flow of lava 

 took place. Orosco ascended the cone in order to observe the i^henome- 

 non from above. This cone is very steep, and consists of sand and \o\- 

 canic rubble. The temperature on the summit, Avhich was reached at 

 2 o'clock p. m., was found to be 4° li., (41° F.) From hence the whole 

 of the new upheaval could be surveyed. In the middle of it the most 

 vehement movement was in progress, attended by the constant upheav- 

 ing and descent of rocky masses, fire, and blue and yellow columns of 

 smoke. 



Th(i upper (ancient) crater has a diameter of 150 metres, (492 feet,) 



