| Year | 1914 |
| Date | 19-Mar |
| Volume | 30 |
| Issue | 673 |
| Page | 267 |
| Category | General |
| Part | |
| Title | An Apparatus for Filling Vacuum Tubes: How Made and Used |
| Author | F.J.Kettel |
| Notes | Trap, three-way tap & mercury trough, apparatus for producing helium, showing reverse side of helium-producing apparatus, removing gas tube from mercury trough, filling gas tube with mercury, gas tube & crucible |