no longer connect with the lake. The principal outlet is the United States 

 Ship Canal. Reighard, in an iinpublished report, liointed out that all of the 

 streams along this shore have wide and deep channels near their mouths, and 

 that the current in River Raisin undergoes frequent reversals. On August ll;, 

 1920, the direction of the current changed five times between 3:00 A.M. and 

 5:l5 P.M. Reversals were noted during the present investigation also, but 

 observations were not made over long enough periods to determine their fre- 

 quency. The discharge of River Raisin has not been measured, but McNaraee 

 (1930, p. 56) estimated the mean annual rate of discharge at O.6O cubic feet 

 per second per square mile, which, with the drainage area of 1,125 square 

 miles (2,9lU square kilometers), would give a mean annual discharge of 675 

 cubic feet (19.1 cubic meters) per second. 



Huron River empties into the lake at the northern boundary of the west 

 shore. The mean annual discharge at Flat Rock, seven miles from the mouth, 

 for the six-year period, 1905-1909, was 670 cubic feet (19. cubic meters) 

 per second (Sherzer, 1913, page 117). 



Detroit River is Ii.25 miles (6.8 kilometers) wide at the mouth. Its 

 length from Windmill Point to Bar Point Lightship is about 28 miles (Ii5 

 kilometers). Near its head the river is divided by Peach Island and Belle 

 Isle. Below Belle Isle the channel is deep, the banks are steep, and the 

 current velocity is about 1.5 miles (2.U kilometers) per hour. At the head 

 of Fighting Island, the river broadens and becomes shallower. There are a 

 number of islands in the lower river; the largest is Grosse Isle, near the 

 United States shore. Bois Blanc Island, much smaller than Grosse Isle is 

 near the Canadian shore opposite Amherstburg. A short distance above this 

 island the mean current velocity is 3 miles (I1.8 kilometers) per hour, -and 

 the maximum is about 6 miles (9.7 kilometers) per hour. The discharge of St. 

 Clair River is 20li,000 cubic feet (5,777 cubic meters) per second at the 

 mean stage of Lake Huron and Lake Erie, with an increase of 19,700 cubic 

 feet (558 cubic meters) per second per foot rise of Lake Huron, without change 

 in Lake Erie. The discharge of Detroit River is only slightly greater than 

 that of St. Clair River on the average. The amount discharged into Niagara 

 River from Lake Erie is almost the same; it is 206,00 cubic feet (5,S3ii cubic 

 meters) per second at mean stage, with an increa^of 22,100 cubic feet (626 

 cubic meters) per second per foot of rise of lake level. 



Lower Detroit River has been deepened artificially to permit the passage 

 of large vessels. At the level of Bois Blanc Island there are two channels, 

 but these join at Bar Point Lightship and continue as one to Detroit River 

 Light (Fig. 1). Here the channel divides to form a west or downbound, and 

 an east or upboimd, channel. The former extends in a 5. by W. direction 3.9 

 miles (6.3 kilometers), and the latter extends in a S. by E. 3/8 E. direction 

 2.25 miles (3.6 kilometers). 



The north shore of Western Lake Erie is almost free from irregularities. 

 The beaches are generally sandy, and in a few places there are high bluffs of 

 glacial material back from the beach. Ihere are few tributary streams and 



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