IN the early days of fish culture, which for many years was only trout culture, the statement was often made that any farmer who had a small spring of cool water could, within a few years, realize enormous profits from it, and that an acre of water was worth more than an acre of land. Those of us who went into the business a quarter of a century ago found much to learn, and many dropped out discouraged. The writer bought a farm in Monroe County, New York, in 1868, and made ponds below a fine spring; and after some failures, due to ignorance for there was then no literature of the subject—he began to succeed in raising many fish, only to find, after raising them, that they had cost more than they were worth, because there was no available food near, and it required a man to drive fourteen miles to the city of Rochester twice or more per week for food. To-day we know that something more than a good spring of cool water of about 50 F. is necessary, and also that some acres of water may be worth more than some land, but that so many local and other conditions enter into the calculation that, as a general statement, the comparison is not true. To-day there are several successful trout farms where the fish are raised for market at a profit, and in all of them there are large, never-failing springs of cool water and cheap food, as well as intelligent management. There are other important considerations in choosing the location of a trout farm, such as a proper amount of fall to the water in order to control it and give it aeration between the ponds and a formation that will allow all surface water to be led aside and not to enter the ponds. A sudden thaw with frozen ground may destroy the work of years, and in summer the surface water brings leaves and trash, which clog screens and either burst or overflow them.
The first thing to be considered is whether the trout farmer wishes to merely hatch his fish and turn them into a suitable lake or pond where they will find their own food and where he can take a few for sport and market, and perhaps let anglers fish it for a fixed sum, or whether he prefers to raise his fish by hand in small pools.
The first method is the simplest, involving the least care, but, if the conditions are favorable, not so profitable as the other. One is like keeping a few fowls that pick up what they can, and the other like poultry breeding, with this exception: poultry will not eat their young, while trout will devour their fellows which are smaller. A trout under a year old feeds mainly on insects and their larvæ in a state of nature, but a large trout of two