"The largest number of high peaks and the greatest average elevations occur upon the eastern Andes, or Cordillera Oriental, whilst the western or Occidental is distinguished by having the highest individual elevations. The altitudes given by various authorities of these peaks differ somewhat, and the measurements of later investigators vary considerably from those of Humboldt in some cases. Humboldt was the first to study and measure the Ecuadorian volcanoes, and La Condamine measured them in 1742. The more modern investigators were Drs. Reiss and Stübel, who spent four years, from 1870 to 1874, in the study, and in 1880 they were the subject of Edward Whymper's famous travels. The alleged remarkable condition of the sinking or rising of various of these summits and localities may account, it has been stated, for the variation found in measurements made at different times. It has been estimated that a considerable decrease in the elevation of the Ecuadorian Andes in the region took place during last century. Quito has sunk, it is stated, 26 feet in 122 years, and Pichincha 218 feet in the same period. The farm at Antisana, where Humboldt lived for some time, has sunk 165 feet in sixty-four years. On the other hand, two of the active volcanoes, those of Cotopaxi and Sangay, have increased in altitude since they were measured by La Condamine, it is asserted. Underlying seismic disturbances have doubtless been the cause of these movements."[24] [24] _Ecuador_, loc. cit. The highest of these peaks is Chimborazo, 20,498 feet, followed by Cotopaxi, 19,613 feet, Antisana and Cayambe, both over 19,000 feet, with others ranging downwards to about 14,000 feet.