William Lewis Herndon, Lieutenant, U.S.N., Exploration of the Valley of the Amazon… (1853)
“ The Madeira is by far the largest tributary of the Amazon. Once past its cascades, which are about four hundred and fifty miles from its mouth, and occupy a space of three hundred and fifty miles in length, it is navigable for large vessels by its great tributaries — the Beni and Mamoré — into the heart of Bolivia; and by the Guaporé or Itenes, quite through the rich Brazilian province of Matto Grosso. ”
