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ditch drain

A gutter excavated in the floor of a gangway or airway to carry the water
to the sump, or out to the surface.

ditcher

a. A mobile tracked machine fitted with an endless chain of buckets used
for shallow vertically sided trenching. Nelson
b. A drill mounted on a frame that rotates about a central axis. It is
used to cut circular trenches for the production of large grindstones.
Also called circle cutting drill. Fay

ditching

The digging or making of a ditch by the use of explosives.
See also:propagated blast

ditching dynamite

A nitroglycerin type explosive esp. designed to propagate sympathetically
from hole to hole in ditch blasting.

ditch water

The stale or stagnant water collected in a ditch.

ditch wiring

The method of connecting electric blasting caps in such a way that the two
free ends can be connected at one end of the line of holes. Fay

dithiocarbamate

A flotation collector agent of the general formula X2 N.CS.SM , X
being hydrogen, aryl, or alkyl radical. Pryor, 3

dithionate process

A process for extracting manganese from low-grade oxide ores. The
manganese ore is leached with dilute sulfur dioxide gas in the presence of
calcium dithionate solution, the manganese being recovered from solution
by precipitation with slaked lime and then nodulized or sintered.
Osborne

dithiophosphates

In mineral processing, flotation collector agents, marketed as Aerofloats
by the American Cyanamid Co.

dithizone

Diphenylthiocarbazone. Used in geochemical prospecting to detect traces of
certain metals. Pryor, 3

diurnal fluctuations

Variations occurring within a 24-h period and related to the rotation of
the earth. Hy

diurnal inequality

a. The departure easterly or westerly from the mean value of the
declination for the day. Mason
b. In tides, the difference in height and/or time of the two high waters
or of the two low waters of each day; also, the difference in velocity of
either of the two flood currents or of the two ebb currents of each day.
Hy

diurnal variation

a. The daily variation in the earth's magnetic field. AGI
b. In tides, having a period or cycle of approx. 1 lunar day (24.84 solar
hours). The tides and tidal currents are said to be diurnal when a single
flood and single ebb occur each lunar day. Hy

diver

Small plummet, so adjusted as to density that by rising or falling it can
be used to show whether specific gravity of pulp is above or below a
desired control point. If pulp is opaque, diver can initiate magnetic
signal, or in a pulp containing magnetic material can carry radioactive
marking material. Pryor, 3

diversion valve

A valve that permits flow to be directed into any one of two or more
pipes. Nichols, 1

diversity factor

The ratio of the sum of the individual maximum loads during a period to
the simultaneous maximum loads of all the same units during the same
period. Always unity or more. Strock, 2

divided cell

A cell containing a diaphragm or other means for physically separating the
anolyte and catholyte. Lowenheim

divider

Cross-steel or timber piece in a circular or rectangular shaft. Such
pieces serve to divide the shaft into compartments and may also carry the
cage guides, etc. See also:bunton

diviner

Dowser. AGI

diving bell

A watertight, bell-shaped steel chamber that can be lowered to or raised
from a freshwater or seawater bed by a crane. It is open at the bottom and
filled with compressed air, so that persons can prepare foundations and
undertake similar construction work underwater. Hammond

divining

A method of searching for water or minerals by holding a hazel fork (or
other device) in the hands, and the free end is said to bend downward when
a discovery is made. In the Middle Ages, the divining rod was closely
associated with the mine surveying profession. The water diviner has not
succeeded when submitted to impartial scientific tests. Nelson