DOI Page / Citation link:
https://doi.org/10.11588/diglit.19574#0456
420 H A R
HAR. Holbenius^ fignifies Holbenius of Harlem.
HARDENING, is the act of communicating a greater hard-
nefs to a body than it already has.
The Hardening and tempering iron and fteel makes a confr-
derable article in the mechanical arts.
There are divers ways of effecting it; as by the hammer,
quenching it when hot in cold water, cafe Hardening, he.
To harden and temper Englifh, Flemim, and Swedifh iron,
they give it a pretty high heat, then fuddenly quench it in wa-
ter to make it very hard. Spanifh and Venice fteel need only to
have a blood-red heat, and then be quenched.
The workmen fometimes grind indigo and fallad oil together,
and rub the mixture upon it with a woollen rag while it is
heating, and let it cool of itfelf.
If the fteel be too hard or brittle for an edge, fpring, or
pointed inftrument, it may be taken down or rendered fofter,
thus: Take a piece of grindftone or whetftone, and rub hard
on the work, to take the black fcurf off it, and to brighten it;
then let it heat in the fire, and, as it grows hotter, the colour
will change by degrees, coming firfl to a light goldifh colour,
then to a darkifh goldifh colour, and at laft to a blue colour.
Chufe which of thefe colours the work requires, and quench it
fuddenly in water.
Hammer Hardening, is moftly ufed on iron or fteel plates,
for faws, fprings, &c.
Cafe Hardening, is performed after the following manner:
Take cow horn or hoof, dry it well in an oven, pound it to
powder ; put as much bay-falt as-of this powder into ftale urine,
or white wine vinegar, and mix them well together; then cover
the iron or fteel all over with this mixture, and wrap it up in
loam or plate-iron, fo that the mixture may touch every part of
the work ; then put it in the fire and blow the coals to it, till
the whole lump has attained a blood-red heat, but no higher,
and then take it out and quench it.
HARMONY, in painting. Some mention a Harmony both
in the ordonnance and compofition, and in the colours of a pic-
ture.
In the ordonnance it fignifies the union or connection between
the figures, with relation to the fubje£f. of the piece.
In the colouring it denotes the union or agreeable mixture of
different colours.
HARPOCRATES, the god of filence, was reprefented by
the ancients in the form of a young child, holding one of his
fingers clofe to his lips, as a fign of taciturnity. Some again
portrayed him without any face at all, all covered with the fkin
of a wolf, painted full of eyes and ears.
HAR. Holbenius^ fignifies Holbenius of Harlem.
HARDENING, is the act of communicating a greater hard-
nefs to a body than it already has.
The Hardening and tempering iron and fteel makes a confr-
derable article in the mechanical arts.
There are divers ways of effecting it; as by the hammer,
quenching it when hot in cold water, cafe Hardening, he.
To harden and temper Englifh, Flemim, and Swedifh iron,
they give it a pretty high heat, then fuddenly quench it in wa-
ter to make it very hard. Spanifh and Venice fteel need only to
have a blood-red heat, and then be quenched.
The workmen fometimes grind indigo and fallad oil together,
and rub the mixture upon it with a woollen rag while it is
heating, and let it cool of itfelf.
If the fteel be too hard or brittle for an edge, fpring, or
pointed inftrument, it may be taken down or rendered fofter,
thus: Take a piece of grindftone or whetftone, and rub hard
on the work, to take the black fcurf off it, and to brighten it;
then let it heat in the fire, and, as it grows hotter, the colour
will change by degrees, coming firfl to a light goldifh colour,
then to a darkifh goldifh colour, and at laft to a blue colour.
Chufe which of thefe colours the work requires, and quench it
fuddenly in water.
Hammer Hardening, is moftly ufed on iron or fteel plates,
for faws, fprings, &c.
Cafe Hardening, is performed after the following manner:
Take cow horn or hoof, dry it well in an oven, pound it to
powder ; put as much bay-falt as-of this powder into ftale urine,
or white wine vinegar, and mix them well together; then cover
the iron or fteel all over with this mixture, and wrap it up in
loam or plate-iron, fo that the mixture may touch every part of
the work ; then put it in the fire and blow the coals to it, till
the whole lump has attained a blood-red heat, but no higher,
and then take it out and quench it.
HARMONY, in painting. Some mention a Harmony both
in the ordonnance and compofition, and in the colours of a pic-
ture.
In the ordonnance it fignifies the union or connection between
the figures, with relation to the fubje£f. of the piece.
In the colouring it denotes the union or agreeable mixture of
different colours.
HARPOCRATES, the god of filence, was reprefented by
the ancients in the form of a young child, holding one of his
fingers clofe to his lips, as a fign of taciturnity. Some again
portrayed him without any face at all, all covered with the fkin
of a wolf, painted full of eyes and ears.