Upon numerous occasions, Peter and his father worked together guiding climbers. For example, on August 17, 1886, they led P. Levenson (Calverley, Leeds, West Yorkshire, England) to the summit of the Schreckhorn (13,378 ft.). Mr. Levenson commented in Kaufmann's Führerbuch that the snow was bad and we only reached the summit at 12:00. A snowstorm began at 11:30 and lasted for 24 hours, forcing us to spend the night on a narrow snow ledge on the lower arête. We reached the hut at 12 noon on August 18, having been absent 34 hours. Kaufmann was very careful & attentive & nobly assisted his father in the descent, which was very difficult owing to the fresh snow.