Note 2 — Letters from Father Mateo Gisbert to the Reverend Fathers and Brothers of Veruela
Reading edition
The volcano of Apo is located on the highest summit of the Philippines, which is 10,311 ft. high. The first to attempt its ascent was José Oyangúren in 1859, but he failed. It was first ascended in 1880 by Montano, Joaquin Rajal, and Mateo Gisbert, S. J. See Census of Philippines, i, pp. 202–204.