84-1908.
-zinc ores, enrichment.
Lenses.
Levels.
intervals.
of Broken Hill.
protection.
Life, in sight.
of mine.
Locomotives, compressed-air.
Lode mines, valuation.
Lodes.
Long-wall stope.

Machine-drill, performance.
drilling.
_vs_. hand-drilling.
Management, mine.
Matte.
Mechanical efficiency of drainage machinery.
equipment.
Men for underground transport.
Metal content, determining.
contents, differences.
demand for.
mine, value.
price.
Mines compared to other commercial enterprises.
equipment.
expenditures.
Mines--_continued._
life of.
metal, value of.
of moderate depths.
to be worked to great depths.
valuation.
Mining engineering profession.
Mt. Cenis tunnel.
Morgan gold mine.

Normal price.

Obligations of engineering profession.
Openings, position in relation to secondary alteration.
Ore, average width in block.
blocked-out.
-bodies.
shapes.
-breaking, methods.
calculation of quantities of.
-chutes in shrinkage-stoping.
-deposits, classes.
determination of average metal contents.
developed.
developing.
expectant.
in sight.
sight, classification.
-pillars.
support in narrow stopes.
-shoots.
weight of a cubic foot.
width for one sample.
Origin of deposit.
Outcrop mines.
Output, factors limiting.
giving least production cost.
maximum, determination.
Overhand stapes.
Overproduction of base metal.
Oxidation.

Patchwork plant, mechanical inefficiency of.
Pay areas, formation.
Pillars, artificial.
Positive ore.
value of metal mine.
Possible ore.
Power conditions.
general technical data.
sources.
transmission.
Preliminary inspection.
Previous yield.
Price of metals.
Probable ore.
Producing stage of mine.
Production, cost.
Profit and loss account.
factors determining.
in sight.
Proportional charges.
Prospecting stage of mine.
Prospective ore.
value.
Protection of levels.
Proved ore.
Pumping systems.
Pumps, compressed-air.
electrical.
hydraulic.
rod-driven.

Ratio of output to mine.
Recoverable percentage of gross assay value.
Recovery of ore.
Rectangular shaft.
Redemption of capital and interest.
Reduction of output.
Regularity of deposit.
Reliability of drainage system.
Replacement.
Reports.
administrative.
Resuing.
Revenue account.
Rill-cut overhand stope.
method of incline cuts.
-stopes.
filled with waste.
-stoping.
Rises.