A Spectral located is not a Spectral completed. Physical manifestation requires a witness. One researcher is going to Roma to find these four. Whether they take physical form depends on who commits to their existence first.
Each Vestigium will be delivered by hand in Roma in early May. Estimated physical form: paper, approximately postcard-sized, colorful, blank back.
The blank back is intentional. Kircher filled every margin of everything he studied. His best observations lived in the space around the published work, not inside it. The back of each Vestigium is that space. What did you find in Roma? A theory, an image, a date, a question. Whatever it is, it belongs there. The research continues through whoever carries it.