You can download these and bazillions more free digital images at Far, Far Hill. These are to be used for personal projects. Some large collections are available with unlimited use for $1.50.
I’m also thrilled to report that Dover Pictura is open for business! You can download whole collections of their images for about half the price of their books (especially when you figure in shipping.) Don’t want the whole collection? You can download indiviual pages (~1-20 images) for $.99-$1.99. When you sign up, you get three pages for free! You can also sign up for their free sample images that come by email every week. I’ve been gathering those for a couple of years, now.
I have to warn you, though, both sites are addictive!