SCIENCE 



NEW YORK, MAY 13, 1893. 



MOUNT ORIZABA OR CITLALTEPETL. 



BT J. T. SCOVELL, TEERE HAUTE, IND. 



The central portion of Mexico is a plateau from 3,000 to 8,000 

 feet in elevation. About 19° north of the equator a broad belt of 

 this plateau is composed of volcanic formations, which culminate 

 in the snow-clad peaks of Citlaltepetl, Popocatepetl, and Ixtacci- 

 huatl. 



Citlaltepetl stands on the eastern margin of the plateau, about 

 80 miles from the coast, its eastern slope rising from the Gulf, 

 the others from the plateau. 



Orizaba, the name of a city on the eastern slope, is the name by 

 which the mountain is best known to foreigners, but. seen from 

 a distance, rising far above all surrounding peaks, with its crown 

 of glistening snow, the Indian name of Citlaltepetl, star mountain, 

 seems singularly appropriate. 



Popocatepetl, smoking mountain, and Ixtaccihuatl, woman in 

 white, rise from the plateau about 100 miles west of Citlaltepetl. 

 These old volcanoes, with Mount St. Ellas in Alaska, are the 

 culminating points of North America. 



rises considerably higher than its rivals further west. Dr. Franz 

 Kaska, using mercurial barometers, made the elevation 18,270 

 feet. Professor A. Heilprin, using an aneroid barometer, ad- 

 justed by a mercurial, and estimating his station as 120 feet below 

 the true summit, made the elevation 18,205 feet. My aneroid 

 made the elevation estimated at 120 feet only 86 feet. Making 

 this correction, the elevation would be 18,171 feet. Mr. O. G. 

 Bunsen, C.E., of the University of Texas, and the writer, using 

 railway levels to 8,313 feet, carried a line of spirit levels up to 

 14,000 feet, then using our aneroid barometer, made the elevation 

 18,179 feet. In April, 1892, by triangulatlon from the 13,000 

 feet level of Bunsen and Scovell, I made the total elevation 18,814 

 feet. These results, arrived at by different methods, seem closely 

 confirmatory. Popocatepetl is about 700 feet lower than Citlalte- 

 petl, and Ixtaccihuatl is about 700 feet lower than Popocatepetl. 

 In a paper before the National Geographical Society, Dr. Menden- 

 hall gave the elevation of Mt. St. Elia& as 18,010 ft., so that Mt. 

 Orizaba seems to be the highest elevation in North America. 



Climate of Glaciers. 

 In this region the summer is a wet season and the winter a dry 

 one. In the sunshine it is generally hot, summer or winter, even 

 on. the upper slopes, but in the shade or at night it is usually cool 



Fig. 1.— Southwestern slope of Citlaltepetl, taken Auz. 3, 1891, from the 13,800 ft. level, a. The 16,000 ft. level where the horses are left. See 

 moraine just above and to the left of a. Tree in foreground is just above the cave. 



Citlaltepetl, situated just within the northern boundary of the 

 torrid zone, rising from tropical waters to polar snows, presents 

 within narrow limits an epitome of the earth. On the slopes of 

 this mountain may be found every variety of surface and every 

 kind of climate, they produce all classes of vegetation and afford 

 a congenial home for all sorts of animal life. This region, with 

 its wonderful variety of scenery and its myriad forms of life, is 

 of special interest to the student of science, whatever his depart- 

 ment. 



In July, 1891, a party consisting of W. S. Blatchley of Terre 

 Haute, Ind., entomologist; Henry E. Seaton, now of Cambridge, 

 Mass., botanist; A. J. Woolman of South Bend, Ind., icthyolo- 

 gist; U. O. Cox of Mankato, Minn., ornithologist; and the writer, 

 visited the eastern slope of Citlaltepetl, making interesting collec- 

 tions of the varied forms of life which abound in that region. 

 We found some forms new to science, found some familiar forms 

 in unexpected localities, saw many interesting things, making 

 the trip an interesting and valuable one to us. The different 

 members of the party have published, or are preparing to publish, 

 accounts of the work done in their several departments. 



There is considerable discrepancy among observers as to the 

 elevation of these Mexican mountains, until recently Popocatepetl 

 has been considered the highest elevation, but determinations 

 made within the last three or four years show that Citlaltepetl 



and pleasant, anywhere between 4,000 feet and 10,000 feet. In 

 summer the northeasterly winds seem to prevail, as shown by the 

 fact that a tract of country, about 50 miles wide, to the southwest 

 of Citlaltepetl, was dry and dusty, receiving only an occasional 

 shower, while on either side of this region it rained almost every 

 afternoon. The explanation seems to be that the winds from 

 the northeast, losing their moisture on the mountain, flow over 

 the region to the southwest as dry winds. Above the elevation 

 of 12,500 feet, there were evidences of %vesterly winds, as leaning 

 trees, drifting sands, more abundant vegetation on the eastern 

 side of rocks, etc. But the winds most noticeable, summer and 

 winter, were cold winds down the mountain at night, and warmer 

 winds up the mountain by day. There is in general no rainfall 

 during the winter, during the summer it is scanty from the coast 

 up to 1,500 feet, then plenty of moisture to the summit, except 

 on the southwest above 8,000 feet. The rains on the lower 

 slopes are represented by snows on the upper slopes, but, while it 

 rains almost every afternoon below, the snows above are lees 

 frequent, sometimes eight or ten days passing without a storm. 

 But snow falls often enough during the summer to keep the peak 

 covered down to about the 14,000 feet level, forming a distinct 

 snow-line. If for a few days no snow falls, the old snow melts, 

 and the snow-line rises, while an exceptional storm may carry 

 the snow down to 11,000 feet or below, but 14,000 feet seems to 



