| Year | 1929 |
| Date | 16-May |
| Volume | 60 |
| Issue | 1,462 |
| Page | 459 |
| Category | Electrical Work |
| Part | |
| Title | Sludge Pumps in General and Battery Cleaning in Particular |
| Author | |
| Notes | Diagram of air ejector pump, glass laboratory ejector air suction pump, sand and gravel pump, aerated jet pump for sludge removal, sludge pump to use aerated water jet |