| Reference number | NLB/56/504 |
| Alternative reference number | NLB/56 p293 |
| Level | Item |
| Title | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Lewis Simons Esquire |
| Date | 25 February 1919 |
| Description | Refers to Mr. Lewis Simons' paper, 'The velocities of two distinc groups of secondary corpuscular rays produced by a homogeneous Rongten radiation and their absorption coefficients in gases'. |
| Extent | 1p |
| Format | Carbon |
| Access status | Open |