05086

Title: 
Photographs of heading before and after block shot is fired into coal seam
Keywords: 
Coal mines and mining; Underground mining; Explosives;
Added Entries: 
sl_006; sl_007; sl_008; sl_009
Notes: 
"Permissible explosive, heading after firing breaker shot"; Large blocks of shot coal show cleavage; Coal Section file sl_006, sl_007, sl_008, sl_009' 4 photographs