Note 13 — Chapter XI · THE MUISCA TRAIL
Reading edition
Notwithstanding the statements, frequently made by travelers, about their mules climbing roads inclined at angles varying from 30° to 45°, it can safely be affirmed that the maximum angle is but little, if any more than 20°, as actual measurement will show. When the inclination becomes greater than this the mule will always take a zigzag course, so as to reduce the grade as much as possible. ↑