1 66 The American Geologist. 
Maivh, 1905 
history • modified somewhat by glacial action in later times, 
and to a less degree by changes in the relations of land and 
sea; in a word they are simply partially submerged river- 
valleys." "According to the Scandinavian geologists, the 
cause of the rapid shallowing of the great sea-lochs, on ap- 
proaching their outlet in the North sea, is the piling up of 
enormous masses of morainic matter l:)y former glaciers 
which descended these valleys." Hull considers that the 
channels do exist, beneath the various sediments while the 
sea floor has l)een generally leveled over by tidal and other 
currents. While the Sognefjord reaches to a depth of 
nearly 4,000 feet, from the character of the continental 
slope Prof. Hull concludes that the late elevation was at 
least 6,000-7.000 feet. He cites Prof. Brogger as authority 
for the conclusion that the late elevation reached at least 
8.528 feet (luring the epoch of the greatest ice sheet; this 
conclusion l)eing derived from the occurrence of a bed of 
littoral shells at a depth of 2,600 metres. t Prof. Hull calls 
attention to the marine terraces of Trondhjem and Chris- 
tiania fjord to the hight of about 615 feet, while between 
these points nearer the coast the terraces are much lower. 
These show later changes of level. 
Prof. Hull's first paper was suggested by the evidence of 
great changes of level shown by Warren Upham and the 
reviewer before he had made his own classic researches. 
The subject was "Another Possible Cause of the Glacial 
Epoch."* which he attributed primarily to the great 
changes of level, afterwards shown in his own contribu- 
tions, the land having attained to the great elevation of at 
least 7,000 or 8,000 feet in ihe early Glacial period, although 
there was subsequently an interglacial or post-glacial sub- 
mergence of 1,200 feet in Britain. These contributions are 
new facts treated in a philosophical manner, and could now 
perhaps be put in a monographic form. They must be a 
foundation for all subsequent research in terrestrial move- 
ments and the consequences thereof. They also prove that 
a man's greatest work is not confined to his earlier years; 
and in spite of all he has done, the author considers this 
J Norges geologiske undersegelse, No. 31. p. 683. 
