Antiquarian science books are original historical works (e.g., books or technical papers) concerning science, mathematics and sometimes engineering.
These books are important primary references for the study of the history of science and technology, they can provide valuable insights into the historical development of the various fields of scientific inquiry (History of science, History of mathematics, etc.)
The landmark are significant first (or early) editions typically worth hundreds or thousands of dollars (prices may vary widely based on condition, etc.).
Incunabula are extremely rare and valuable, but as the "scientific revolution" is only taken to have started around the 1540s, such works of Renaissance literature (including alchemy, Renaissance magic, etc.)
Nicolaus Copernicus' De revolutionibus orbium coelestium of 1543 sold for more than US$2 million at auctions.