I think it would be reasonable to store a fixed-focus compound microscope as part of your archive. That's basically a tube and a couple of lenses, and it gets y

I think it would be reasonable to store a fixed-focus compound microscope as part of your archive. That's basically a tube and a couple of lenses, and it gets you to 500x right off the bat. But if you want to be doubly sure, include instructions for making a hand lens at 1x, and instructions for making a microscope at 5x.