302 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



proper fresli-water fisli caught iu tbis part of the river or any part of 

 the bay, except a single specimen, caught in Yerona, of trout, {Sahno 

 fontinalis,) which is known to often run into salt water. 



The works of man have interfered less with the migration of salmon, 

 iu the Penobscot than in any other large river south of the Saint John. 

 Owing to its great volume and other favorable circumstances, dams, 

 quite impassable by salmon, have never been in existence many years 

 at a time. The four points on the lower part of the river at which dams 

 have been built are Veazie, Ayer's Falls, Great Works, and Oldtown. At 

 Old town thecenterof the river has never been closed, and saluion ascend 

 there with considerable ease. At Great Works two long wing-dams, 

 running from the mills on either side up the river nearly parallel with 

 the banks, are joined at their upper ends by a low cross-dam, which is 

 not a serious obstacle at the season of the year when the main body of 

 the salmon are ascending the river. At Ayer's Falls the dam that 

 crosses the river is low, and at its eastern end abuts upon a ledge, over 

 which the water runs down an irregular inclined plane to the level of the 

 main channel below. This assisted the salmon in surmounting the dam, 

 and was, to a certain extent, an abatement of the evil, but at best the 

 structure was so serious an impediment that it was necessary to con- 

 struct a fish-way, an inexpensive affair, made by merely enlarging a 

 crevice in the ledge at the east end of the dam. The dam at Veazie, 

 built in 1834 or 1835, Avas at first quite impassable, and so remained for 

 several years. Since then, however, the water has wasted away the 

 bank at the east end of the dam, and disclosed a large crevice in the 

 ledge, through which so large an amount of water is generally flowing 

 that sabnon have little difficulty in passing the dam. 



Above Oldtown the main Penobscot is entirely free from artificial ob- 

 structions for 70 miles ; the Mattagamon, or East Branch, for nearly 

 100 miles ; theMattawamkeag, for 45 miles ; the Piscataquis, for 50 miles. 

 Of the tributaries, the lower ones are nearly all effectually closed against 

 salmon by dams, and have been in that condition for many years; in 

 few of them, however, if in any, was the species ever abundant. In the 

 upper tributaries there are comparatively few obstructions, and there 

 the salmon have access to their original spawning-grounds. The dams 

 built therefor service iu floating timber, or, in the vernacular, "driving" 

 it to the mills below, are generally of such a character that they do not 

 prevent the passage of salmon, and hinder it only for short periods 

 in the spring and early summer. The dam at the outlet of North 

 Twin Lake is of this character. It serves to raise the surface of Am- 

 bojegis, Pamedumcook, and the Twin Lakes to a point some thirteen 

 feet above their ordinary level, both for the purpose of facilitating the 

 passage of the "drives '' of logs across the lakes, and to store water, to 

 be let out when wanted to float them over the shallow rapids below. 

 The gates of the dam are closed iu June, and kept shut for several 

 weeks, while the lakes are filliug up. Buriiig this time no salmon can 



