45 that he and Ekblaw entered the open arch or grotto thus formed in 1915. They could stand upright in it. Four could easily have stood there then. He took photos. Note on Perret camera - Speed 6 seems to be about the same as speed 4 of Graflex ... aperture 4 cm speed 6 of Perret gives ca 1/25 sec. exposure 7 1/2 = ca u.s. 10 ; (7 1/6 = 16) ; 18 = 20 ; (20 = 24) ; 7 2/5 = ca u.s. 39 ; (32 = 64) ; 36 = 84 ; (128 = 45) 7 5/0 = " " 160 The latest exposures of 12 1/2 / 4/16 (= 10/25") on Penker Snow Point and of 18/4/16 (= 20/25") on Ekblaw glacier nearer on 11. VIII. 1915 gave very good results. We were only three or four miles distant (perhaps less) when these views were taken. Film exposures of same diaphragms and times on more distant mountains and ice masses a month previously were too great. Approximate table (compared with Graflex) 1 cm 2 cm 4 cm Tension 6 | 1/95- | 1/75 | 1/25- " 9 1/295-| 1/90 | 1/35-