| Year | 1955 |
| Date | 24-Nov |
| Volume | 113 |
| Issue | 2,844 |
| Page | 788 |
| Category | General |
| Part | |
| Title | Refrigeration in reverse |
| Author | Charles Tunstall |
| Notes | The principle of the heat pump first propounded by Lord Kelvin. How does it work? Norwich Electricity offices, diagram showing the principle |