Copyright-free clip art
You're right to be careful about making sure that sources of clip art are genuinely free to use, and copyright-free, as the term "clip art" could be said to cover all types of images.
One complication is that the ways in which you're allowed to use these images can vary:
- Some are totally free to use
- Some are licensed only for a particular form of use, such as educational or personal (i.e. not for commercial gain)
- Some are free to use in any way you choose.
So, my first piece of advice is that, if you see an image online that you think you'd like to use, it's well worth contacting the website owner to check if you can do so before going ahead.
(Copyright law varies between countries and so it's difficult to give you more than the most basic advice on this, however.)
My second piece of advice is that whether you are allowed to use an image free-of-charge will often depend on what you want to use it for: Whether commercially, or purely for personal use.
This isn't clear from your question - so I'll assume you want images of teapots and Victorian ladies for your own use in the rest of my answer.
Many companies have built up libraries of clip art, which they then charge a fee (or royalty payment) for using - but as you wanted images that are totally free-to-use, I've done a quick search and come up with these:
1. Images of teapots
From The Graphics Fairy Blog, which is a good source of restored vintage images, which are free to use.
2. Victorian ladies
I've used the same source as above for these pictures of Victorian ladies, as the blogger makes it clear that all the images on her blog are copyright-free:
Finally, if you need a lot of images, say for ongoing decoupage projects or something similar, then it might be worth joining one of the websites, such as Dreamstime.
These sites will allow you access to hundreds, if not thousands of images, which are either royalty-free, or completely free to use.
I'd also suggest you check out Flickr, where you'll be able to see at a glance whether an artist or photographer is happy for you to use their images, and for what purpose.