402 WISCONSIN STATE AGRICULTURAL SOCIETY . 
into the clean trough. The trough thus made empty is cleaned 
and filled from the next, etc. The only advantage of this plan is 
that it economizes room and enables the eggs to be more easily 
looked over. But for all purposes of accurate hatching, the old 
gravel beds are preferred. 
Experiments to be made .—Accurate experiments should be made 
by those having means and leisure in the following directions: 
As to weight of food given and increase in weight of fish in 
one year. 
As to kind of food which will give best results. 
As to their relative increase in weight at different periods of 
their lives. 
As to the average age of a trout and average period of maturity. 
As to the best age for spawning purposes, etc. 
Some eight years ago, we believe, Seth Green’s was the only 
establishment in the United States making a business of raising 
and selling fish stock. Now there are about a dozen widely 
known farms, and some hundreds of smaller ones which have at¬ 
tained only a local reputation. Of these establishments, Pennsyl- 
via has the most in number, although not the largest, Massachus¬ 
etts is probably next, wdrile New York boasts the largest and most 
complete. A remarkable fact is the increase of trout-breeding in 
the more western states. Ponds, etc., for this purpose are now to 
be found in Ohio, Wisconsin, Michigan, Illinois, Indiana, Ken¬ 
tucky, Tennessee, Minnesota, and California. In fact, there is 
scarcely a state in the Union into which of late years we have not 
sent trout fry or eggs. This increase of those practicing the art 
shows that the practice must be successful to a degree wonderful 
for an art so new. Trout-culture has now been in use for a num¬ 
ber of years, and though there is still very much to learn, yet 
great and successful progress has been made. 
A few words may be in place as to present aspect of trout farm¬ 
ing as a business. There are now, so far as a matter of this kind 
can be ascertained, a great many paying establishments. At any 
rate, many have gone into the business and still remain in the bus¬ 
iness, which they would not be likely to do unless they found it 
profitable. Their income is derived from the sale of eggs, live 
