502 BULLETIN OF THE BUREAU OF FISHERIES. 



the Sluice. The Sluice is estimated to be 8 miles from Upton Mills, following the river. 

 From the alder-tangle portion of the brook to the upper end of the pond produced by 

 the backed-up water above the dam it is a grassy meadow interspersed with clumps of 

 bushes and trees. Through this meadow the brook averages, perhaps, i6 or i8 feet in 

 width, much narrower in some places and considerably wider in others, especially in 

 the pools. The stream is everywhere very sinuous, the pools are very deep, and the bot- 

 tom mostly of sand. In many instances, especially on the deep side, the pools are over- 

 hung with alders, and each pool has its greatest depth at one side or the other, usually 

 on the short bend. The backwater above the Sluice extends as a moderately wide but 

 shallow pond for perhaps one-half of a mile above the dam. 



The Sluice is situated between two high and steep ridges or moraines, commonly 

 called horsebacks, which, diverging, extend some distance downstream, leaving a 

 narrow margin of meadow on the right-side part of the distance but wooded steep 

 shores on the other. The stream emerges from this region, the lower end of which bears 

 the local name of the Onion, into an extensive meadow, estimated to be 2 miles in 

 length and fully a mile in width. Through this meadow, which is covered with a prolific 

 growth of meadow grass and "Joe-Pye weed" (Eupatorium purpureum), the brook 

 pursues a very winding course to its junction with the Swift Cambridge. Throughout 

 its course there is no quick water, except a little just below the Sluice, and the bottom 

 is sandy or muddy, mostly sandy, all the way. From the Sluice to the meadow the 

 stream is generally deep, with frequent large, deep pools, but through the meadow it is 

 generally shoal with an extensive growth of pond weed (Potamogeton). 



From the junction of the Swift and Dead Cambridge branches, known as the Forks, 

 the Cambridge River is a slowly flowing stream perhaps 50 or 60 feet in general width 

 but varying considerably. The country is here low and wooded, with many lagoons 

 produced by spring freshets and the changing course of the stream. The banks and 

 bottom are mostly sandy and the stream varies in depth, having here and there wide 

 deep pools and shallow reaches covered with a profuse growth of water plants, con- 

 sisting of two kinds of yellow pond lilies, pond weed, etc. The water is dark red, almost 

 black in deep places. The foregoing conditions were those observed in July, August, 

 and September, but in the spring the river discharges a large volurrie of water and the 

 current of even the Dead Cambridge is far from mortal slowness. 



Upton Mills dam forms a pond of considerable extent, the bottom of which is 

 mainly muddy from deposits by the river and decaying vegetation. Power for a saw- 

 mill is furnished by this pond. 



Next in importance as a tributary of Umbagog is B Pond, situated in Upton, 

 formerly Township B, 3 miles in a direct line from Umbagog Lake but only about a 

 mile in a direct line from Rapid River about a mile below Pond-in-the-River. The 

 Maine Water Storage Commission report gives the area of B Pond as 0.90 of a square 

 mile. The pond is irregularly cycloid in shape, and there is a comparatively large 

 island near the southwestern shore. B Brook discharges its waters into Umbagog Lake 

 at B Brook Cove. Its course is very irregular, almost entirely through woodland and bogs. 



Sturtevants Brook is a small brook flowing into Sturtevants Cove. 



Sunday Brook flows from a small pond about i mile in a direct line from Sunday 

 Cove, into which it empties. 



