Finding and using images in our creative endeavours can be fraught with concern over copyright and attribution of images, so it’s really great when you find a cache of images that you know are fine to use. The British Library have released over 1,000,000 into the electronic domain for public use. The images were generously digitised by Microsoft enabling them to be free to use.
The images are taken from 17th, 18th and 19th century books! and cover a wide variety of topics.
British Library public  images

I discovered the news of the images from a website called Open Culture which appears to be full of interesting stuff like free movies, books and links to other public domain image collections. Their catch call is ” the best free cultural and educational media on the web”.
I’ll certainly be looking at it in more detail.
Open Culture’s article about the images with links to more.