| 1950 CAIRNS ROBERT Blasting Cap Patent Print Art |
| 1950 PARR Separation Blasting Circuit Leads Art |
| 1950 JOSEPH Electric Blasting Device Patent |
| 1950 JAMES Safety Sheathed Blasting Explosive Cartridge |
| 1950 MARCEL GAUPILLAT ETS Delay Action Blasting Cap |
| 1950 BYERS Multiple Jet Blasting Charge Patent |
| 1950 CARDOX CORP Safety Release Blasting Shells |
| 1950 ARMSTRONG COALBREAK Gas Pressure Blasting |
| 1950 JACQUES Delay Action Blasting Cap Patent |
| 1950 HERCULES POWDER LTD Blasting Initiator Art |
| 1950 WILLIAMSON Safety Release Blasting Shells |
| 1950 HERCULES POWDER CO LTD Blasting Cap Patent |
| 1950 GIBSON Vibrator Type Multiple Shot Blasting Unit |
| 1950 CAIRNS ROBERT Blasting Initiator Patent |
| 1950 HERCULES POWDER LTD Blasting Cap Manufacture |
| 1950 OLIVE S PETTY Separation Blasting Circuit Leads |
| 1950 HERCULES POWDER LTD Electric Blasting Art |
| 1950 ARMSTRONG Gas Pressure Blasting Art Print |
| 1950 LEFREN Blasting Cap Manufacture Patent |
| 1950 LAUD STANLEY BYERS Multiple Jet Blasting Charge |