Joseph Guyton
1862, 3 November
Cloud formation as seen in Thebes, November 3rd 1862. (Glass negative of a sketch)

Photograph
Wellcome Collection
Wellcome Library, Creative Commons Attribution (CC BY 4.0), xgc5ud6s
 
A.Alpha particle strikes helium nucleus and they part at right angles. B. Alpha particle enters nitrogen which ejects proton and becomes nitrogen. Experiments by Blackett in a Wilson Cloud Chamber.
 
LL/92924