m of
his own. To be of greatest value, such sheets should show on their
face the method by which the "spread" departments are handled, and
how revenue and suspense departments are segregated. When too much
detail is presented, it is but a waste of accounting and consequent
expense. Where to draw the line in this regard is, however, a matter
of great difficulty. No cost sheet is entirely satisfactory. The
appended sheet is in use at a number of mines. It is no more perfect
than many others. It will be noticed that the effect of this system
is to throw the general expenses into the revenue expenditures,
and as little as possible into the "suspense" account.

GENERAL TECHNICAL DATA.

For the purposes of efficient management, the information gathered
under this head is of equal, if not superior, importance to that
under "working costs." Such data fall generally under the following
heads:--

LABOR.--Returns of the shifts worked in the various departments
for each day and for the month; worked out on a monthly basis of
footage progress, tonnage produced or tons handled per man; also
where possible the footage of holes drilled, worked out per man
and per machine.

SUPPLIES.--Daily returns of supplies used; the principal items
worked out monthly in quantity per foot of progress, or per ton
of ore produced.

POWER.--Fuel, lubricant, etc., consumed in steam production, worked
out into units of steam produced, and this production allocated to
the various engines. Where electrical power is used, the consumption
of the various motors is set out.

SURVEYS.--The need of accurate plans requires no discussion. Aside
from these, the survey-office furnishes the returns of development
footage, measurements under contracts, and the like.

SAMPLING AND ASSAYING.--Mine sampling and assaying fall under two
heads,--the determination of the value of standing ore, and of
products from the mine. The sampling and assaying on a going mine
call for the same care and method as in cases of valuation of the
mine for purchase,--the details of which have been presented under
"Mine Valuation,"--for through it, guidance must not only be had to
the value of the mine and for reports to owners, but the detailed
development and ore extraction depend on an absolute knowledge of
where the values lie.

CHAPTER XVIII.

ADMINISTRATION (_Concluded_).

ADMINISTRATIVE REPORTS.

In addition to financial returns showing the monthly receipts,
expen