At this time of year I tend to do a lot of background research, since most of our wildlife is under the snow hibernating. During the summer, I bought a copy of "A Practical Guide to Nature Study" by J.H.Crabtree. It was published in 1924, so the material is at least 90 years old. The book deals with tools and techniques that assist with the task of studying our wildlife, and much of it is still relevant today. Having said that, as a keen photographer (he wrote books on photography, too), I'm sure he'd be astonished with our progress from film to digital.
J.H. shares his wealth of experience in collection, preservation and examination of plants, fungi and insects as you might expect, but his narrative is also peppered with references to the contemporary lack of education and awareness of the wildlife around us. He seems surprised that even in the early 20th century most school pupils couldn't identify many of our most common birds, trees or flowers. Given that I recently showed a photograph of a Bullfinch to a class of 11 year olds and was given a universal reply of 'Robin', I'm not sure that we've made a lot of progress.