Humberstone arrived at the Peruvian port of Pisagua on January 6, 1875, where he commenced working as a chemist and engineer.
Pisagua was founded in 1611 after an edict by the Viceroy of Peru which established a base from which it could be possible to stem the illegal traffic of gold and silver flowing from the important mines of Potosí and Oruro, in the Highlands of the "Audiencia of Charcas", to the British and Dutch pirates operating in the Corregimiento de Arica.
After checking the terrain and weeks of preparations the high command decided to strike at Pisagua, a small port with a suitable bay for unloading the army contingent and supplies.
On November 2, 1879, Condell participated in the assault and takeover of the port of Pisagua, the blockade of Arica, and afterwards, the combat against the fortresses of the same city and the ship Manco Capac.
Right after Pisagua, two Allied squadrons were slightly outnumbered and crushed at Pampa Germania on November 6, and Col. Emilio Sotomayor held off a 7,400 men Allied attack on November 19 at Dolores dwell, near San Francisco.