Telescopium: sive ars perficiendi novum illud Galilaei visorium instrumentum ad sydera

Girolamo Sirtori

Frankfurt: Luca Jennis

1618

The volume collates 4°: [2], 3–75, 78–81, [1] p. and has ten quarto gatherings signed )( and A–I. Pages are misnumbered after p. 75. The book appears to be in a contemporary vellum binding, warped as is common for old vellum bindings. This is the only edition of the text. On the front paste-down is the signature “De La Reynie,” which is that of Gabriel Nicolas de La Reynie (1625–1709), the well-known collector of books and manuscripts.

For a book collector with a focus on the historical development of optical instruments, Sirtori’s text — the first book published on the telescope — is important. It is a primary source of information about the early telescope. Provided for the first time is a description of a refracting telescope — the type of telescope used and made by Galileo — and instructions how to make one. The text and the illustrations focus on the design of the instrument and the working of glass to make lenses. The preparation of iron tools to shape lenses is described and illustrated. Sirtori’s book appeared nine years after the first demonstration of a refracting telescope by its Dutch inventor. No significant information about Sirtori’s life other than that he was a Milanese Jesuit scholar seems to be known. In his book he says that he traveled in Europe to see examples of telescopes.

The book by Sirtori is a part of my collection of books that document the technical history of scientific instruments in general. This collection includes books published from the date of Sirtori’s book into the early 20th century. In addition, an extensive modern reference collection on the subject, including numerous museum catalogs that describe instruments in collections, is present in my library.

Ronald K. Smeltzer