Latitude, 6 deg. 4' 45" south; longitude, 75 deg. 1' west of Greenwich; magnetic variation, 7 deg. 22' 10" east; thermometer, 79 deg.; elevation above sea-level, 377 feet; distance from the Atlantic, 2482 miles; current, 3 miles per hour. SARAYOCU. Latitude, 6 deg. 35' 15" south; longitude, 74 deg. 58' 30" west of Greenwich; magnetic variation, 7 deg. 52' 8" east; thermometer, 79 deg.; elevation above sea-level, 410 feet; distance from the Atlantic, 2578 miles; current, 3 miles per hour; depth of water, 20 feet. The town of Sarayacu is situated on a small creek, about three miles from the place on the river which is called the Puerto del Sarayacu. Between Pucacura and Sarayacu is Esquina, a small settlement built on high land, which extends along the river for a mile or more. This place (Esquina) and Pucacura are about the only places on the banks of the Ucayali, below Sarayacu, that are not overflowed at high water. The floods of the Ucayali, which regularly recur every year at certain seasons, render the banks of the river an undesirable, perhaps even an impracticable, location for an agricultural population. It is possible that a crop might be raised and gathered during the dry season, but the farms would have to be abandoned whenever the river rose to its maximum height. At Paca, about twelve miles above Sarayacu, the banks on both sides of the river are high; such places are much more frequently met with above than below Sarayacu, but still they are the exception to the general character of the country near the river, which continues to be low and subject to overflow until the highlands are reached near the confluence of the Tambo and Urubamba. PACAMASHI. Latitude, 7 deg. 53' 15" south; longitude, 74 deg. 40' 45" west of Greenwich; magnetic variation, 7 deg. 51' 38" east; thermometer, 77 deg.; elevation above sea-level, 435 feet; distance from the Atlantic, 2733 miles; current, 3 miles per hour; width of the river, 600 yards. YARINACOCHA. Latitude, 8 deg. 15' south; longitude, 74 deg. 31' 30" west of Greenwich; magnetic variation, 7 deg. 38' 30" east; thermometer, 79 deg.; elevation above sea-level, 447 feet; distance from the Atlantic, 2800 miles; current, 3 miles per hour; width of river, 1200 yards. MOUTH OF THE PACHITEA RIVER. Latitude, 8 deg. 43' 30" south; longitude, 74 deg. 32' 30" west of Greenwich; magnetic variation, 8 deg. 45' 40" east; thermometer, 75 deg.; elevation above sea-level, 508 feet; distance from the Atlantic, 2891 miles; current, 3 miles per hour; width of the river, 600 yards. VUELTA DEL DIABLO. Distance from the Atlantic, 3091 miles. This strait is the first serious difficulty encountered in ascending the Ucayali; the current dashes with much violence against the trunks of large trees which lodge in, and almost block up, the passage. CONFLUENCE OF THE TAMBO AND URABAMBA RIVERS.