POSTGLACIAL DEVELOPMENT OP CONNECTING EIVEES OP GEEAT LAKES. 471 



Erie. He called the outlet river in the Trent Valley the Algonquin River. 1 He was the first 

 to trace the Iroquois and Algonquin beaches for long distances and to measure accurately their 

 northward rise. In his later papers, however, he abandons these views and interpretations and 

 appears to regard all the ancestral waters of the Great Lakes as marine with open connection 

 with the sea. He combats the idea of continental ice sheets and ice clams and rejects all of 

 the earlier glacial lake outlets, although he was first to describe two of them — the Trent River 

 outlet at Kirkfield, Ontario, and the Imlay channel in Michigan — attributing the first discharge 

 from Lake Huron to Lake Erie to the uplifting of the land in the region of Lake Nipissing 

 northeast of Georgian Bay, and admitting no earlier activity for the Port Huron outlet. In 

 1891 Spencer rejected the Mohawk River outlet for Lake Iroquois and the Trent River outlet 

 for Lake Algonquin and calculated the Algonquin beach to pass 20 feet below the present lake 

 level at Port Huron, thus allowing for no southward outlet of Lake Algonquin at that place, 

 nor for any eastward outlet at Kirkfield. 2 In 1894 he reaffirmed that the first discharge of the 

 upper lakes southward to Lake Erie was due to uplift at Lake Nipissing. 3 In the first publi- 

 cation of his papers he repeatedly used the word "lake" in designating these early waters, 

 but in a reprint in book form in 1895 he generally substituted the word "gulf." 4 In this volume 

 he reaffirms his rejection of the Mohawk and Trent Valley outlets, the assumed submergence 

 of the Algonquin beach at Port Huron, and the recent first opening of the southward outlet. 



In a recent, more elaborate volume 5 he repeats the same views respecting the southward 

 outlet for Lake Algonquin, although more than 10 years had intervened since his last publi- 

 cation on that subject and the investigations of others had in the meantime brought out new 

 facts that point clearly to a different history. His earlier conjecture that the Algonquin beach 

 passes 20 feet under Lake Huron at its south end was disproved in 1896 by the finding of the 

 beach strongly developed 25 feet above the lake at Port Huron and Sarnia. But although 

 he recognizes this fact in his recent report, Spencer reaffirms his belief that Lake Algonquin 

 had no southward outlet. 6 



In the same work he discusses St. Clair River and the delta and puts forth views that are 

 novel and in harmony with his hypotheses of Lake Algonquin and Niagara Falls, but not in 

 accord with either the lake history or the features of the connecting river district as set forth 

 in this monograph. He makes the first river in the St. Clair Valley a local stream — necessarily 

 relatively small — and flowing nortbward. He makes it rise in the south part of the bed of 

 Lake St. Clair, the many tributaries uniting at Algonac and flowing northward to Lake 

 Algonquin, the shore of which, he says, was then 17 miles north of Point Edward and 110 

 feet below the present level of Lake Huron, or 90 feet deeper than by his earlier estimate. 

 On the elevation of the land at Lake Nipissing, Ontario, he says the discharge of Lake Huron 

 shifted south and for the first time passed to Lake Erie. The. coming of the great river hi a 

 reverse direction into the bed of the previous small local river caused the drowning of the 

 tributaries of St. Clair River. 7 (See, further, pp. 499-500.) 



In discussing the relations between Niagara Falls and the upper Great Lakes, the fact 

 that these lakes had two periods during which they discharged their overflow eastward was 

 first distinctly recognized by Gilbert 8 in 1889, when he showed two hypothetical maps intended 

 to represent the conditions at these periods. He states that during both periods the discharge 

 of the upper lakes abandoned the southward course through St. Clair and Detroit rivers which 

 it had previously taken and that these rivers ran dry. He states also that the gradual uplifting 



1 Spencer, J. W., Notes on the origin and history of the Great Lakes of North America: Proc. Am. Assoc. Adv. Sci., vol. 37, 1SSS, pp. 19S-199. 



2 Deformation of the Algonquin beach and birth of Lake Huron: Am. Jour. Sci., 3d ser., vol. 41, 1891, pp. IS, 19. 



3 Duration of Niagara Falls: Am. Jour. Sci., 3d ser., vol. 48, 1S94, pp. 463, 466. 



< The duration of Niagara Falls, Humboldt Pub. Co., New York, 1S95, pp. 69-71, 73, 10S. 111. 



s Evolution of Niagara Falls, Geol. Survey Canada, 1907, pp. xxxi, 490. 



« Idem, pp. 299, 303. 



» Since this monograph was written, Spencer claims to have changed Ms views, accepting the idea of the land ice sheet and its function as a 

 dam retaining lakes of great extent. But on the Niagara excursion connected with the Twelfth International Geological Congress at Toronto 

 in August, 1913, he ignored the land ice sheet and reaffirmed the explanations given in his report of 1907. The intimate connection between 

 the history of Niagara and the history of the Great Lakes as presented in this monograph is set forth briefly in the Niagara folio (No. 190, Geol. 

 Atlas U. S., U. S. Geol. Survey, 1913). 



» Gilbert, G. K., The history of the Niagara River: Sixth Ann. Rept. Commissioners State Reservation at Niagara, 1890, pp. 72-73, Pis IV, V. 



