Found 2 items, similar to Black lead.
English → English
Definition: black lead
n : used as a lubricant and as a moderator in nuclear reactors
English → English
Definition: Black lead
(l[e^]d), n. [OE. led, leed, lead, AS. le['a]d; akin
to D. lood, MHG. l[=o]t, G. loth plummet, sounding lead,
small weight, Sw. & Dan. lod. [root]123.]
1. (Chem.) One of the elements, a heavy, pliable, inelastic
metal, having a bright, bluish color, but easily
tarnished. It is both malleable and ductile, though with
little tenacity, and is used for tubes, sheets, bullets,
etc. Its specific gravity is 11.37. It is easily fusible
(melting point 327.5[deg] C), forms alloys with other
metals, and is an ingredient of solder and type metal.
Atomic number 82. Atomic weight, 207.2. Symbol Pb (L.
Plumbum). It is chiefly obtained from the mineral galena,
2. An article made of lead or an alloy of lead; as:
(a) A plummet or mass of lead, used in sounding at sea.
(b) (Print.) A thin strip of type metal, used to separate
lines of type in printing.
(c) Sheets or plates of lead used as a covering for roofs;
hence, pl., a roof covered with lead sheets or terne
I would have the tower two stories, and goodly
leads upon the top. --Bacon
3. A small cylinder of black lead or graphite, used in
, graphite or plumbago; -- so called from its
leadlike appearance and streak. [Colloq.]
, a sounding lead intermediate in weight
between a hand lead and deep-sea lead.
, the heaviest of sounding leads, used in
water exceeding a hundred fathoms in depth. --Ham. Nav.
, a small lead use for sounding in shallow water.
, Kremnitz lead
[so called from Krems or
Kremnitz, in Austria], a pure variety of white lead,
formed into tablets, and called also Krems white
, and Vienna white
, tallow put in the hollow of a sounding lead.
See To arm the lead
. See under Colic
, a deep bluish gray color, like tarnished lead.
. (Min.) Same as Galena
(a) (Med.) A dark line along the gums produced by a
deposit of metallic lead, due to lead poisoning.
(b) (Naut.) A sounding line.
, a leaden polishing wheel, used by lapidaries.
(Min.), a massive sulphur-yellow oxide of lead.
Same as Massicot
, a pencil of which the marking material is
graphite (black lead).
(Bot.), a low leguminous plant, genus Amorpha
), found in the Northwestern United
States, where its presence is supposed to indicate lead
(a) (Bot.) A West Indian name for the tropical, leguminous
tree, Leuc[ae]na glauca
; -- probably so called from
the glaucous color of the foliage.
(b) (Chem.) Lead crystallized in arborescent forms from a
solution of some lead salt, as by suspending a strip
of zinc in lead acetate.
, a miner's term for blende.
, a scarlet, crystalline, granular powder,
consisting of minium when pure, but commonly containing
several of the oxides of lead. It is used as a paint or
cement and also as an ingredient of flint glass.
Red lead ore
Sugar of lead
, acetate of lead.
To arm the lead
, to fill the hollow in the bottom of a
sounding lead with tallow in order to discover the nature
of the bottom by the substances adhering. --Ham. Nav.
To cast the lead
, or To heave the lead
, to cast the
sounding lead for ascertaining the depth of water.
, hydrated carbonate of lead, obtained as a
white, amorphous powder, and much used as an ingredient of
Black lead \Black` lead"\
Plumbago; graphite. It leaves a blackish mark somewhat like
lead. See Graphite