THE GEOLOGIST. 



Punchbowl. Porndon is a cone of very light cinder. Leura is a broken 

 crater on the edge of the rises, while Purrumbete is a beautiful sheet of water, 

 a few miles distant, which once, as a crater, discharged vast quantities of ash. 

 The other principal volcanos of Western Victoria are Buninyong, Blowhard, 

 Noorat, Gellibrand, Napier, Franklin, Cavern, Shad well, Lower Hill, Clay, 

 Elephant, Eckersley. No adequate impression can be formed as to the period 

 of the activity of these cones and craters. There is a freshness in most of 

 them, indicative of a comparatively modern date, and the natives have tradi- 

 tions of the eruptions of several of them. 



GLACIAL MOVEMENTS OX THE NORTH- WE ST COAST OF AMERICA. 



By Sir E. Belcher, F.G.S. 



Sir E. Belcher said that early in September, 1837, his expedition ran down 

 the coast of North America, between Ports Etches and Mulgrave, in order to 

 fix the po3ition and determine the heights of Mount St. Elias. The icebergs 

 which hung about the coast w r ere much larger than those which he had seen in 

 Bearing's Strait, or off the mouth of the fiords in the vicinity of Port Etches. 

 He believed that in Icy Bay the lower bodies of the ice were subject to slide, 

 and that the entire substratum, as frequently found within the Arctic Circle, 

 was composed of slippery mud. In Icy Bay the apparently descending ice 

 from the mountains to the base was in irregular broken masses, which tumbled 

 in confusion. The motion was clearly continuous. As to the causes which 

 operated in producing the constant displacements of the glacier, and the pro- 

 tusion of the bergs seaward, many theories had been proposed. His impression 

 was that, whatever w T as the intensity of cold under which congelation had 

 taken place, the actual temperature clue to the ice was merely that of 32 

 degrees Fahrenheit, and that self-registering thermometers, properly buried in 

 ice or snow, subject even to the very low temperature of 62 degrees, 5 below 

 zero, on the external skin, only indicated the proper temperature of freezing- 

 water. In the very high latitudes of 63 degrees to 76 degrees North, the 

 snow on the surface of the snow-clad elevations furnished sufficient water to 

 undermine the lower beds of snow-ice, and bore a passage to the sea. How- 

 ever firm the crust might be in certain positions, a furious torrent had been at 

 work beneath. Was the conclusion to be that the temperature of the earth must aid 

 in keeping up a temperature sufficiently high to prevent the water hidden from 

 light from congealing ? The advance of vegetation was another proof; the 

 ground-willow, saxifrages, and many other plants producing their shoots before 

 light caused the immediate expansion and colouring of the leaf. The earth's 

 temperature, acting on the lower portions next to the soil, aided in facilitating 

 the travel of the slip of the snow-ice of which these glaciers were composed 

 to lower levels. In all ice-formations there might be noticed, at the season 

 which followed the period of day-frost or preceded the spring, a peculiar dry- 

 ness, the result of evaporation of the superfluous water, attended by dense 

 fogs. An ominous cracking was then experienced, which had been misrepre- 

 sented by some of the first Arctic explorers as the breaking of the bolts of 

 their vessels : no bolt was ever traced to have been so broken. He imagined 

 that the soil on which masses of eternally-shifting ice reposed, must be, from 

 never being exposed to the sun's rays, of a loose, boggy, or muddy nature, 

 which facilitated slipping. The undermining facilitated "cracking, and'the very 

 action of alternate freezing and thawing between the exposed surfaces, serving 



