During the last years of his life, Christiaan Huygens worked on a “philosophical treatise”, addressed to his brother Constantijn, which contained his speculations on the construction of the universe and the habitability of the planets as deduced from his own observations and those of other astronomers of his time.
Although he first planned to write this work in French, he later decided to publish it in Latin instead. Christiaan Huygens finished his manuscript in January 1695 and wrote to Constantijn that he had also found a publisher. On 4 March he wrote to Constantijn that the first pages had already been printed but that the printer had not progressed any further.
However, Christiaan’s health was rapidly deteriorating and on 8 July he passed away. In his last will, drawn up on 23 March, he requested Constantijn to see to it that his book was published.
Unfortunately, Constantijn’s duties as secretary to the stadholder-king William III often necessitated his presence in London and the printing of the book progressed slowly. Constantijn too passed away (on 12 November 1697) before it was finished and the last stages of the printing were overseen by the Leiden professor of mathematics and physics Burchard de Volder.
Shortly after the Latin edition of the Cosmotheoros was published by the The Hague publisher Adriaan Moetjens, translations appeared in English (1698) and in Dutch (1699). In the following years, translations also appeared in French (1702), German (1703), Russian (1717) and in Swedish (1774).
This online edition is based on the English translation printed in 1698 by the London publisher Timothy Childe. The identity of the translator is unknown.
The spelling of this edition has been followed and has not been altered to suit modern taste or conventions. The pagination in this online edition is given in red numerals between square brackets.
The table of contents given at the begin of each book is not found in the original edition but was added in this online edition. It is largely based on the rubrics printed in the margins of the text.
The text of the Latin edition of 1698 is also available with a French translation and commentary in the Oeuvres Complètes de Christiaan Huygens [vol. 21, pp. 653-842].