| Reference number | NLB/70/469 |
| Alternative reference number | NLB/70 p246 |
| Level | Item |
| Title | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Chief; Engineering Library, the British Thomson-Houston Company Ltd., Rugby |
| Date | 12 April 1927 |
| Description | Thanks the Chief of the Engineering Library for showing the Tungsten Vapour Tube at the Conversazione held on 6 April, and asks if he would exhibit it again at the Soiree on 11 May. |
| Extent | 1p |
| Format | Carbon |
| Access status | Open |