VALUE OF NORWEGIAN LAKES FOR FISH CULTURE. 583 



crawfish. Young trout were purchased from a hatching establishment 

 in Paris ; but even the results reached in a few months determined the 

 marquis to give his apparatus the full extent intended. In the month 

 of October, 18G4, therefore, a multitude of workmen engaged in digging 

 the rest of the 12 kilometers of canal ; in April, 1865, the water began 

 to traverse the whole length. The expenses of the scheme (the digging, 

 locks and bridges, buildings, purchase of eggs, fish, crawfish) amounted 

 to fully 150,000 francs, and the exj)enses of maintaining, for food, watch- 

 ing, repairs, instruments, &c., must be estimated at about 12,000 francs 

 per year. 



According to the report the establishment was partly three and one-half 

 years old, and the rearing of crawfish was carried on for the same length 

 of time. Unfortunately, crawfish grow slowly; it requires eight to 

 ten years before they can be offered in the market of Paris. In order 

 to shorten tliis time, 325,000 crawfish of three to four years old were 

 gradually purchased and liberated in the canal. These have thrived 

 wonderfully, and will admit of comparison, so far as flavor and size are 

 concerned, with the best crawfish from Maas Eiver or from Germany.* 

 They have multiplied^^nd are found of all sizes from one to three years. 

 The Marquis de Selve estimates the number at 8,000,000 to 10,000,000, 

 which by no means appears overdrawn. Last year already he sold 

 many thousand francs worth ; this year he expects to sell over 20,000 

 francs worth. Since Paris is supplied for the greatest part from Hol- 

 land and Germany, an interruption may easily occur in the shipping, 

 and a cessation of nearly twenty-four hours brings up the price to double 

 or triple what it was. The marquis, who is close by and can obtain in- 

 stant information, can take advantage of these accidental pauses, and 

 has therefore constantly a reserve on hand for such fiivorable opportu- 

 nities. The marquis, however, cherishes no illusions ; as soon as autumn 

 approaches various sacrifices must still be made. To insure the ability 

 to deliver a uniform supply he must still for three or four years stock 

 his canals with crawfish to the amount of 25,000 francs yearly, in order 

 to be properly furnished with spawners. The profit on these purchased 

 crabs is only 12 to 15 centimes (2.2 to 2.7 cents) apiece ; when those 

 born in the establishment are grown, the case becomes entirely different. 

 There are sold now about 1,000 crawfish daily. 



Besides crawfish are cultivated also trout and other salmonoids. The 

 first planting is nearly three years old. On the 18th of August, 1866, 

 was caught a splendid trout; it was not weighed to avoid injuring it, 

 but from its appearance it must have weighed between 2 and 2^ kilo- 

 grams at the age of 27 to 28 months ; it was sent away living as a pre- 

 sent because of its size and beauty. Trout 20 to 24 months old weigh 

 from 500 to 750 grams. 



The hatching apparatus is placed in a separate building in connection 



* Crabs are almost as necessary a constituent part of a French dinner as meat or 

 fish ; if not as a dish proper, then as a means of decoration. 



