No. XV. GEOLOGY. 341 



of fresh -water and instantaneously is converted into ice, and 

 forms a solid wall from the bottom of the sea upwards and 

 increasing in height as the snow falls. 



When the ' season floe,' or young ice, is first formed there 

 is little difference in the level of the floe and that of the ice- 

 foot, but as the latter is constantly increasing in height, 

 while the former is daily oscillating with movement of the 

 tides, a junction of the two 'never takes place ; for the height 

 of the surface of the ice-foot above the level of high-water is 

 mainly dependent on the amount of snow-fall, while its 

 depth below that level is dependent upon the slope of the 

 sea-bottom anji the vertical range of the tides. 



Like the beaches of more temperate regions, the ice-foot 

 is absent on exposed and projecting headlands, and it is best 

 developed in the sweeping curves and deeper bays of the 

 coast-line. Its typical aspect in Smith Sound is a flat 

 terrace 50 to 100 yards in breadth, stretching from the base 

 of the ' scree ' to the sea-margin, its width, varying with the 

 slope of the sea-bottom, decreasing in direct proportion to 

 the increase of the land slope. 



When the solar rays exert their force, the snow forming the 

 upper layer of the ice-foot lying nearest to the ' scree ' is first 

 melted, owing to the dark surface of the talus absorbing heat, 

 and a deep trench is formed, which becomes filled with water, 

 received from the cliffs above, and derived from the melting 

 of the snow below ; these united streams soon cut deep 

 channels in the ice, and make their way to the sea through 

 transverse gullies, often exposing the rock beneath, which at 

 low-water become dry, but filled with sea-water on the 

 return of the tide, which rushing through the apertures 

 with great violence, sweeps right and left, occupies the 

 ditch at the face of the talus, and reasserts its materials. 

 These fall to the bottom, and form the old sea margins, 

 which, through the gradual rise of the land, form a cha- 

 racteristic series of successive terraces at various elevations up 

 to 200 or 300 feet, especially in sheltered bays and inlets, 

 and occasionally in positions where wave-action was impossible. 



