The New Family Receipts ©1810 has this to say about fly fishing.
Rules for Fly Fishing.
A fishing fly is a bait used in angling for various kinds of fish. Thefly iseither natural or artificial. The chief of the natural flies are the *' stone fly," found under hollow stones at the sides of rivers, between April and July; it is brown, with yellow streaks, and has large wings. The " green-drake,'' found among stones by river sides i it has a yellow body ribbed with green; it is long and slender, with wings like a butterfly, and is common in the spring. The "' oak fly," found on the body of an oak or ash, is of a brown colour, and common during the summer months. Hie "palmer fly or worm," found on the leaves of plants, when it assumes the fly state from that of the caterpillar; it is much used in trout fishing. The " ant fly," found on ant hills from June to September. The •* May fly," is to be found playing at the river side, especially before rain. And the " black fly," which is to be found upon every hawthorn after the buds are off. There are two ways to fish with natural flies, either on the surface of the water, or a little underneath it. In angling for roach, dace, &c. the fly should be allowed to glide down the stream to the fish, but in very still water the bait may be drawn by the fish, which will make him eagerly pursue it.
There are many sorts of artificial flies to be had at the shops ; they are made in imitation of natural flies, and the rules for using them are as follow: Keep as far from the water's edge as may be, and fish down the stream with the sun at your back) the line must not touch the water. In clear river* the angler must use small flies with slender wings, but in muddy waters a larger fly may be used. After rain, when the waters are muddy, an orangecoloured fly may be used with advantage; in a clear day the fly must be light coloured, and in dark water the fly must be dark. The line should in general be twice as long as the rod ; but, after all, much will depend upon a quick eye and active hand. Flies made for catching salmon must have their wings standing one behind the other. Thii fish is said to be attracted by the gaudiest colours that can be obtained ; the wings and tail should be long and spreading.