One of the latest books to be posted on their Flickr account is Mabel Osgood Wright's Birdcraft. First published in 1895 (with many subsequent printings), this book is notable as being one of the very first to promote bird watching and identification. Another was Birds through an Opera-Glass by Florence Merriam Bailey, published in 1898. (The significance of those two women in the history of field guides and birdwatching is covered in two books I reviewed, Of a Feather by Scott Weidensaul and Binocular Vision by Spencer Schaffner.) You can find the set of images from Birdcraft here, and the images on this page are linked to posts within that Flickr set.
Most of the birds on these plates are immediately recognizable, and many are posed as if engaging in characteristic behaviors. In the plate above, the nightjars are chasing after moths, and the swallows are building the nests characteristic to each species. However, the names are in a key a few pages away, and descriptive text resides somewhere else in the book. The birds are also somewhat oddly proportioned and often out of scale with their neighbors. Consider how huge the Brown Creeper two plates above looks compared to most of the other birds on the page! Field guides have clearly come a long way in their visual depictions and organization since then, but we can still enjoy and appreciate them.