English Title

Part of a Letter from Leonard Euler, Prof. Math. at Berlin, and F.R.S., to the Rev. Mr. Caspar Wetstein, Chaplain to his Royal Highness the Prince of Wales, concerning the gradual approach of the Earth to the Sun


Leonhard Euler

Enestrom Number


Fuss Index


Original Language


Archive Notes

It is likely that Euler wrote his letter in German, and that this publication is an English translation.

Content Summary

In this letter, Euler informs Wetstein that the astronomer le Monnier is about to publish a translation of an Arabic manuscript that he (le Monnier) found in Leiden. Euler expresses his impatience to see this work since it contains observations that he has used in determining why the years have gotten shorter in length. He goes on to explain that the shortening of the year is the result of the resistence of the æther, and this resistance entails the gradual approach of the Earth to the Sun. As a result, the system of planets had a beginning and must also have an end. (Based on Eric Aiton's introduction to Opera Omnia Series II, Volume 31.)

Published as

Published letter

Published Date


Written Date


Original Source Citation

Philosophical Transactions (London), Volume 1752, pp. 203-205.

Opera Omnia Citation

Series 2, Volume 31, pp.257-258.

Record Created


Included in

Mathematics Commons