WCP97

[1]

Broadstone, Wimborne.

Sept^r 25^th. 1904

My dear Will¹

I have just been reading an address to the B. Ass. [British Association] at Cambridge (in last week’s "Nature") on Radiation in the Solar System.² It is the most interesting to me of all the lectures &c. at the B.A. this year. First it ^states a law connecting the amount of radiation of the Sun with the temperature produced in block bodies at various distances. It shows that the Surface of Venus w^d. be 87 C. (= 188F.) while Mars would be -30 C. (= -54 degrees of [illeg.] F.) That, making all allowances, is in favour of the total uninhabitability of the planets. But even more interesting is the discovery that radiation does actually produce motion; and its amount predicted by Clerck[sic]-Maxwell,³ [2] has now been definitely measured. It is thus a force opposed to gravitation but is almost infinitesimal in large bodies like the planets. But it becomes proportionally greater in small bodies because it decreases as the sq. of the surface ^diameter while gravity decreases as the cube; so that very small bodies have their gravity perceptibly reduced. He works out a number of most curious results from this, at the end of his paper, which are well worth reading.

Violet⁴ has now got the boy from London — 9 years old — to look after. His father, Mr. Squires, brought him down last Thursday. He seems nothing remarkable but has been greatly neglected and badly managed by his mother, can hardly read [3] and yet seems bright enough and quite contented. His mother stopped[?] in bed all day when he went, and has now gone to Hastings to recruit. Mr. Squires has written to F Violet that if Mrs. S — comes to see him, she is on no account to allow them to walk out alone together, being evidently afraid that ^she is contemplating an abduction! So we may have quite a little domestic comedy (or tragedy.) Mr. S — also sent Violet the doctor’s letter saying that the boy requires to be away from his home, — that is away from his mother.

We are now gathering our apples and shall have enough to last us I hope till gooseberries [4] come in. I have just begun fires in the study all day as it is getting quite chilly in the morning as well as in the evenings, and Violet’s mania for open windows is almost too much & wants counteracting. I⁵ have also been listing the doors to veranda to keep out draughts in winter. I forget whether I sent you a copy of the new Appendix with the argument from Evolution. If not I will do so. The cheap edition is out with a red cover, and looks very well. I sent an answer to R. Blatchford’s⁶ last week’s War article in the Clarion, but as it was rather late they did not print it this week, but will probably next, Look out for it.

Your affectionate Pa | Alfred R. Wallace [signature]