Toward the end of the 19th century and through the early part of the 20th, the naturalist Robert Lloyd Praeger walked over Ireland, "stopping often, watching closely, listening carefully." In 1937 he published a wonderful natural history of the island, called "The Way That I Went." I dip into it often.
In the first chapter he thanks the "sturdy workers" of the Belfast Field Club, who shared with him their knowledge and enthusiasm: S. A. Stewart, trunk-maker, botanist and geologist; William Swanston, linen manufacturer and geologist; F. J. Bigger, solicitor and archeologist; Joseph Wright, grocer and specialist in the foraminifera; William Gray, Inspector for the Office of Works and a scientific jack-of-all-trades; Charles Bulla, commercial traveler and paleontologist; S. M. Malcolmson, physician and microscopist; Robert Bell, shipyard worker and geologist; R. J. Welch, photographer and crusader in the interest of Irish natural history; Canon Lett, clergyman and botanist; W. J. Knowles, insurance agent and prehistorian. These men, and others, says Praeger, "knew all there was to know about local birds and insects and flowers and rocks and fossils."
That's a world that has pretty much been surrendered to the professional scientists, but what a debt we owe to those gentlemen (and gentlewomen) amateur natural historians of yesteryear, who filled their infrequent "idle" hours with the love of learning.