1918.] The N.Z. Journal of Science and Technology. 
179 
-Plan of Mine Workings — 
«~j5eep Creek Section — 
1R0NBRIDGE COLLIERY 
— DENN1ST0N — 
— Showing Locality of — 
■Small Coaldust Explosion- 
24*-April 1917. 
-—- Reference - 
Position of blown-through shot drilled south-eastward A 
Place where miners - sheltered unhurt ___ g 
.Direction of flame and small force ___ — 
Zone of explosion _ 253 
— Scale — 
LINKS 1 00 50 0 _I_2_3_4_5_6_ 
METRES 10 5 0 50 100 METRES 
7 CHAINS 
1 • 1584 
,G.Ert. 
