| Year | 1939 |
| Date | 29-Jun |
| Volume | 80 |
| Issue | 1,990 |
| Page | 753 |
| Category | General |
| Part | |
| Title | Cheap Apparatus. A Few Hints for the Experimental Engineer |
| Author | B.C.J. |
| Notes | Valve-box for air or vacuum pump, mercurial gauge for low pressure or vacuum, an inexpensive diaphragm device for converting pressure to motion, a simple valve-grid, a simple adjusting device, a device to restrict valve lift, a tool to remove a ball valve |