Comments and guided tour

This selection of texts and historical documents is not meant as an exhaustive history of Venus transits. The main goal is rather to present to the reader a set of genuine texts, which might be difficult to access or read. The comments that come along with these texts should help the reader to navigate in the CD-Rom, by providing complementary explanations and information, as well as highlighting the most important or relevant documents.

The chronology of transits can be summarized in three steps :

a) 1631 and 1639 : confirmation of the heliocentric model of Copernic, and of the model of elliptical orbits of Kepler,

b) 1761 and 1769 : starting of the Halley method for the Sun parallax determination (method completed by Delisle). This determination was difficult to perform due to inaccuracies in astronomical tables, longitudes, clocks, and due to the “black drop” effect,

c) 1874 and 1882 : photography and electrical telegraph allow some real improvements but do not fill all expectations.

Acronyms used for texts references :

- HMARS : Histoire et Mémoires de l'Académie royale des Sciences (History and Records of the Royal Science Academy)

- JdS : Journal des Sçavans

- CRhAS : Comptes rendus hebdomadaires des séances de l'Académie des sciences (Weekly reports of the Science Academy sessions)

- Ph. tr. : Philosophical transactions of the Royal Society of London

- Proc.R.S : Proceedings of the Royal Society

- MNRAS : Monthly Notices of the Royal Astronomical Society

Navigation map :

- Venus 1631 (December 7)

- Venus 1639 (December 4)

- Venus 1761 (June 6)

- Venus 1769 (June 3-4)

- Venus 1874 (December 9)

- Venus 1882 (December 6)

- Venus 2004 (June 8) and 2012 (June 6)