Glancing through the recent additions to Project Gutenberg, I encountered this nice little book which details some of the pioneering scientists in the field of astronomy. It even has some nice illustrations which might be useful, such as the one on the right of Newton's first reflecting telescope.
I've been interested in 3D printing for quite some time. It's a technology that seems poised for a break through. One of the things that it really needs is an inexpensive medium to create objects from. I've seen printers which use sugar which is carmelized by hot air, corn starch which is glued together, and various plastics. This link on the Make blog links to an article which includes a recipe (awesome) for a ceramic medium for 3D printing, which is very inexpensive. I have no immediate use for this information, but who knows what the future may be.