Some of my favourite reference books are those with many useful diagrams.
A few of these books are purely informative — the basic underlying structures of trees, for example. For art, this is directly useful as a reference and identification, while for writing they’re useful for descriptive shorthand (do those branches reach out like hands or curl up like beckoning fingers…). At bottom right are the endpapers for The Ladybird Book of Trees.
Often diagrams are more useful than photographic evidence. They not only confirm and explain it, but show at least one way that people who understand such things have chosen to reduce the information (in pleasing form) for reproduction. They are also a little less idiosyncratic than individual photos, for better or worse — for better, mostly, as long as I remember that fact. Shown at top left is The Observer’s Book of Wild Flowers.
These sorts of guides are particularly useful for working out the commonly-agreed distinguishing details of a thing (here, a plant) — which in turn helps me understand what’s going on in reference photos (or reality!) and how a particular example might have more personality than “the perfect specimen that’s figured in my book”. (If you know who wrote the poem that line is from, please tell me! It’s about an apple tree and I cannot find it online).
But the diagrams that are the most fun appear in old illustrated books of advice. Now, old unillustrated books of advice are also fascinating in and of themselves.
But when they are illustrated! First, there are the styles particular to an era of art and print technology. Then there’s the aesthetic pleasure of purely communicative art. And then again, they are full not only of intriguing devices and useful plans, but also of people and animals going about their work. A whole dictionary of visual vocabulary. For art, they present all sorts of ways people have communicated textures and movements and physical interactions, unexpected ways to solve problems, telling details to add to a setting.
And for writing — well, of course they’re very useful for research for a particular point in time (the movie Babe, for example, brilliantly captures a certain farming attitude to life embodied in these types of books). But beyond that, they are a catalogue of ingenuity and invention that can suggest all sorts of details for inventing or adding texture to world — from the need of an expert to name all the main points of an animal to the misappropriation of almost any human invention to serve some unanticipated purpose, to the apparently eternal human drive to automate everything.
The book with the blue ink is Handy Farm and Home Devices and How to Make Them. The one with the squatter at extreme ease in a squatter’s chair is Ron Edwards’ Australian Traditional Bush Crafts. These were my parents’, but I am saving up for a complete set of Edwards’ Bushcraft books, because the illustrations are jaunty and detailed and IN QUANTITY and very informative.