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Broadstone, Dorset.

April 15th. 1903

Prof. George H. Darwin

Dear Mr. Darwin

I dare say you have seen that I have been trespassing on the Astronomer's preserve, & have been warned off accordingly. However I am preparing myself for the fray by writing a book, which will give my critics more solid matter to deal with. I also very much want to clear up my own ideas on the subject, and nothing does that so well as trying to put them so that others can understand them.

There are certain mathematical points known that I much want to have cleared up, and I as suppose that either you or others

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must have considered them, as they involve only applications of the laws of gravitation, I venture to send you a few queries, which I shall be much obliged if you will answer as briefly as possible,—or if they have not yet been answered, yet, let me know.

Pray excuse me for troubling you with my ignorant difficulties, but I know no one as likely as yourself to be able to answer them.

Believe me

Yours very truly

Alfred R. Wallace.

P.S. Do you know any young mathematical astronomers who would look over my proofs for error?

Queries.

1. Can a ring of discrete matter (like Saturn's rings or the Milky Way) revolve, if there is no central body, or only one much less massive than itself?

1.a Without such central attracting body would the ring be stable?

2. In a roughly globular star-cluster, must all the stars revolve round the common centre of gravity to ensure stability?

2.a. Must not their orbits be at all angles of inclination?

2.8. In such a system will the tendency be towards condensation or dispersal? Or may it be either?

3. It has been suggested that some stars revolve round the Milky Way at rt. angles to its course or nearly so. Is this possible or probable?

4. Prof. Newcomb states that many stars have proper motions so rapid that they must escape altogether from the Stellar Universe! Have you formed any opinion on this?