VALUE OF NORWEGIAN LAKES FOE FISH CULTURE. 585 



its temperature is nearly constant, 46.4° Fabr. The water of the Iser, 

 which is brought in by a Httle canal, has on the contrary a very varia- 

 ble temperature, and just as variable clearness, as a natural conse- 

 quence of the extremely changeable climate of Bayern and the river's 

 risiug in a high, partly snow-clad mountain region, and its course through 

 easily soluble strata of earth. 



The establishment is constructed on a field with little inclination, and 

 occupies a surface of not over 150 square meters (IJ Ar. =0.15 Maal). 

 Highest, but lower than the spring, are placed a series of stone troughs 

 for the salmonoids of different ages, and for the small fishes which are 

 required for their support, in a series along the wall and covered with a 

 movable screen, to prevent the light from shining down upon them, and 

 at the same time to protect the fish against thieves or beasts of prey. 

 Somewhat lower, different basins are dug out in the bottom for other 

 salmonoids from two to four years old ; however, with the excei^tion of 

 one which is intended for the small fry. These water-reservoirs are 

 constructed in the simplest manner possible. The sides are formed of 

 planks driven down into the ground; a gate for entrance and exit keeps 

 the fish confined; and some holes made in the bottom for shelter, 

 constitute the whole of the internal structure, while the arrangement 

 is completed by some boards, which partially cover the basins to pro- 

 duce a little shade and darkness in them. These basins or bowls hare 

 a size of 18 to 20 square meters and a depth of 45 to 50 centime- 

 ters. The height of the water varies between 30 and 40 centimeters. 

 Immediately above the basin intended for the young is a little larger 

 basin, likewise dug out in the ground, which has been constructed 

 for a variety of salmon peculiar to the waters of Bayern, the Donau 

 salmon.* This basin is so constructed that about half of it is under a 

 httle house, and is there covered by a floor, which can be lifted at 

 pleasure, to observe the fishes, catch them, or distribute food to them. 

 In this basin are found only individuals from one to three years old. 

 The above-mentioned basin for the young differs from the rest only in 

 having a supply of water-plants as shelter or cover for the young fish. 

 The bottom in all the rest of the basins is covered with larger and 

 smaller stones, and care is taken to remove all vegetation as soon as it 

 shows itself. 



All these troughs and reservoirs are filled from the spring. The 

 troughs receive the spring-water first, and from these it flows down in 

 the lower basins. The basin for the young is fed, however, directly from 

 the spring with i:)erfectly pure water, which has not been used before. 

 The narrowness of the space has made Mr. Kiiffer attempt fish culture 

 in a manner which comes the closest to stall-feeding. To show this it 



* This; tbe liuclio, Salmo hucho, is a variety, wliicli like the Veneru salmou, Salmc 

 ogla, never leaves fresh water ; it has white flesh and reaches the enormous 8ii:e of 50 

 kilograms and upwards. It has been attempted to transplant it in this country, but 

 without success. 



