WCP1834

[1]

Frith Hill, Godalming

July 18th. 1886

Prof A. Schuster¹

Dear Sir

I am desirous of obtaining evidence as to the size and weight of dust-particles which can be carried great distances through the atmosphere, and I see in the Report of the Meteor[ologica]^l Dust Comm. of the Brit. Ass. for 1883 a reference to "magnetic" dust of ferruginous rocks brought by the wind to "high Himalayan Passes". Can you be so good as to furnish me with any [2] particulars of the dust as regards distance carried or size of particles. My object is to obtain evidence that small seeds may be carried over considerable width of ocean by violent winds, & the only method available is to show that mineral particles of equal or greater specific gravity are then carried.

If you could spare me any specimens of the largest particles of dust known to be carried great distances [3] I should be much obliged.

I have some of the Krakaloa dust, but there was ^{(I believe)} no gale sufficiently strong at that time to carry more than the finest dust for considerable distances.

Believe me | yours faithfully | Alfred R. Wallace [signature]