Rio Hingador ┤ │Mean 879.9 │ ... │ ... └ No. 1363│ 949.94│ ... │ ... Camp on Hingador │ 788.6 │814.32│- 25.72 Dividing Ridge │ 948.5 │947.44│+ 1.06 Rio Chupepe │ 240.24│241.35│- 1.11 Rio Totumia, below Dos Bocas │ 40.6 │ 45.3 │ 5.24 ─────────────────────────────────────┴───────────┴──────┴─────────── These hypsometric determinations differ from the true levels at the points of observation from two to forty-five feet. These figures fall considerably within the limit of error considered as probable by Baron Humboldt. This distinguished observer states that the barometer may be trusted to determine heights to within from seventy-five or ninety feet of the truth. FOOTNOTES: [7] The Caledonia Canal is 25 miles long, and 122 feet wide at water surface. Dimensions of locks, 178½ by 39 feet. Lockage, 95 feet. [8] An announcement in the Cincinnati Commercial declares that the exploring party now at Darien have failed to find a practicable route at that point.—{May 11, 1870.} [9] At this station the difference in the readings of the barometers was so great that the height was computed from the mean of the readings of each instrument separately. In other cases the united mean of both was used. The height given in the table was computed from the readings of the barometer which was used as a standard. CHAPTER VII. Physico-Geographical Features—Deficiency of Information—Barometer—Colonel Williamson—Lieutenants Gibbon, Herndon and Maury—Señor Moro—Popagayos—Influence of the Andes—Climate—Rainy Season—Colonel Hughes —Statistics—Population—Indians—Vegetation—Building Materials—Woods—Geology. The present chapter includes certain physico-geographical features subsidiary to the duties of the engineer and explorer. The object of this paper excludes all matter, not possessing practical value for this purpose, and admits of little more than mere mention. The previous chapters indicate a deficiency in information in regard to the following routes: 1. Nicaragua—The practicability of a route between Monkey Point and the Lake Nicaragua, or San Juan River. 2. Chiriqui—No information extant. 3. Panama route, and improvement of the harbors. 4. San Blas and Chepo—A better line may be practicable. 5. Caledonia Bay, or the Gulf of Urabà to the Gulf of San Miguel, by way of the Savana or Lara Rivers. 6. Examination of the depression noticed by Gen. Michler. 7. The line proposed by Sr. Gorgoza.