... the rock in theinterior of the tunnel (luring the period of construction are sufficient. I n Fig. 2 are shown, by mean6 of curves, the depths for whichthetemperature increases 1' C. in the Mont Cenis, the Gothard and the Arlberg Tunnels, so that it might be possible t o confirm thetemperaturespredicted...

... selection for purely commercial purposes. The road over the Arlberg pass, though not crossing the main Alpinechain,is of considerableimportance in affordingdirect communication between Switzerland and the Tyrol (Plate 6, Figs. 1, 2, 5 and 8). The summit of the pass, 5,902 feet above sea-level, lies onthe...