Next page Previous page

machine operator

See:machine miner

machine rating

a. The amount of power a machine can deliver without overheating.
Crispin
b. Also, work capacity of a machine.

machine runner

See:machine miner

machine screw

A very commonly used type of screw with clear-cut threads and of a variety
of head shapes. It may be used either with or without a nut.
Crispin

machine set

See:mechanical set

machine sumper

See:sumper

machine tool

Any machine used for cutting metal, such as a boring machine, drill,
grinder, planing machine, hobber, shaper, or lathe. Hammond

machine wall

The face at which a coal-cutting machine works. Fay

machinist

Aust. The person in charge of a coal cutter. Fay

mackintoshite

See:thorogummite

Mac-Lane system

This system consists essentially of an inclined rail track with the
haulage gear and the loading station at the base. The haulage rope passes
round a return sheave in the extending frame at the top of the heap. The
tipping gear may consist of a carriage with a portable tippler that
conveys a tub of dirt to the top of the heap, where a trigger operates the
tippler, thus discharging the tub. For a greater quantity, the carriage
incorporates a revolving frame carrying two or three tubs; this gives a
broader top to the heap. The main disadvantages of this system are the
unsightly conical heaps produced and the tendency to segregation of
material, with the large pieces at the base of the heap, which increases
the danger of spontaneous combustion. Sinclair, 5

macle

a. A twin crystal; esp. octahedral diamond twins flattened parallel to the
twin plane. Also spelled maacle, maccle, mackle.
b. A variety of andalusite with tessellated cross section resulting from
segregation of carbonaceous impurities. Syn:chiastolite

Maclean separator

A revolving disk-type magnetic separator widely used for the separation of
large quantities of ilmenite from tin ore. Harrison

macled

a. Twinned.
b. See:tessellated
c. Spotted. Also spelled mackled.

macro-

A prefix meaning large, long; visibly large, e.g., macrocrystalline.
CF:micro-

macro-axis

In the orthorhombic and triclinic systems, an obsolete term for the longer
lateral crystallographic axis, the b axis in orthorhombic and mostly the b
axis in triclinic minerals.

macrocrystalline

Said of the texture of a rock consisting of or having crystals that are
large enough to be distinctly visible to the unaided eye or with the use
of a simple lens; also, said of a rock with such a texture.
Syn:eucrystalline

macrodiagonal

In crystallography, the longer lateral axis in the orthorhombic and
triclinic systems. Standard, 2

macrodome

a. In crystallography, a dome parallel to the macrodiagonal. CF:dome
Standard, 2
b. In the orthorhombic system, an obsolete term for a form of four faces
parallel to the macro-axis, but intercepting the other two.
Syn:horizontal prism
c. In the triclinic system, an obsolete term for a form of two faces
parallel to the macro-axis, but intercepting the other two.

macroetch

Etching of a metal surface for accentuation of gross structural details
and defects for observation by the unaided eye or at magnifications not
exceeding 10 diameters. ASM, 1

macrograph

A graphic reproduction of the surface of a prepared specimen at a
magnification not exceeding 10 diameters. When photographed, the
reproduction is known as a photomacrograph. ASM, 1