THE RECENT ERUPTIONS OF CO LIMA 755 



At dawn the volcano was wrapped in a cloud of its own erupting. During the 

 rest of the day there was a constant emission of thin vapor, which sallied as 

 if filtered through the west side of the crater. 



Febricary26. — V'W\\\-i p.m., enveloped in cumulus clouds; after that 

 hour, inactive. There must have been an eruption during the night, since at 

 dawn the summit of the Nevada was covered with sand. 



February 2y and 28. — Almost inactive. 

 . March T. — Completely inactive. 



March 2. — At 6 :5o p.m., a maximum eruption, less, however, than those 

 of the 1 8th, 2 1 St, and 24th past ; it was so spread by the southwest winds 

 that at 8 p. M. it reached the opposite horizon. After this eruption, grains of 

 porphyritic stone rained down upon the fields situated at twenty kilometers 

 southeast of the volcano. Of these grains I collected in Piaya and in Pla- 

 tanar some of the size of grains of corn. At places nearer the volcano stones 

 fell. From the ranch of Cauzentla, one of the nearest to the volcano, three 

 were found weighing one hundred and thirty-six, thirty-four, and thirteen 

 grams — the two larger being of the same nature as the grains of Piaya and 

 the sands of other localities. The nature of these pebbles, of the grains, and 

 of the sands gives reason to believe that all are derived from the rocks con- 

 stituting the cone, broken and reduced by heat and the force of projection. 

 The fine dust, commonly called ashes, which exists in great quantity over the 

 flanks of the volcano and which is also distributed by the eruptions, is of 

 pumiceous nature and proceeds from the solid and broken lavas of the inte- 

 rior of the crater. 



March J. — At dawn Mr. Diaz observed with the telescope a new change 



in the form of the crater From this alteration it appeared that the 



crater, which had become almost completely clogged during the period of 

 little activity (Fig. 4), had been thoroughly opened (Fig. 5). Little columns 

 of vapor were seen ascending from the bottom of the crater. During the 

 middle part of the day the volcano was covered with atmospheric clouds. At 

 5:45 p. M. there was a great eruption, almost maximum; as the air was 

 calm, the vertical cloud could be long observed. The cloud was driven by a 

 high current from the southeast, until, at 9 p. m., it touched the northwest side 

 of the horizon of the valley of Zapotlan. 



March 4. — At 6 p.m., a great eruption, driven by the southwest wind, 

 until it promptly disappeared. This eruption produced an overflow of scoriae 

 on the eastern flanks. 



March §. — At 10:45 a.m., a great, almost maximum, eruption, borne 

 toward the east. 



March 6. — Insignificant emissions. 



March y. — At 7 : 10 A. m., a maximum eruption, preceded by an explo- 

 sion (Fig. 6). A great eruption at 8 : 20 and another at 8 : 45 A. m. All of 

 these drifted to the east. During the rest of the day there were moderate 

 eruptions, some of which lasted several minutes. 



