m and fuse it in an iron kettle, then add 2 gallons of boiled
linseed oil, 1 lb. of litharge, 1/2 lb. of sulphate of zinc (add these
slowly, or the mixture will boil over), and boil them for about 3
hours. Then, add 1-1/2 lb. of dark gum amber, and boil for 2 hours
longer, or until the mass will become quite thick when cool. After
this it should be thinned with turpentine to the proper consistency.

VARNISHES FOR IRONWORK.

A reliable authority gives the following as a very good recipe for
ironwork varnish. Take 2 lb. of tar oil, 1/2 lb. of pounded resin, and
1/2 lb. of asphaltum, and dissolve together, and then mix while hot in
an iron kettle, taking all care to prevent the flames getting into
contact with the mixture. When cold the varnish is ready for
application to outdoor ironwork. Another recipe is to take 3 lb. of
powdered resin, place it in a tin or iron vessel, and add thereto
2-1/2 pints of spirits of turpentine, which well shake, and then let
it stand for a day or two, giving it an occasional shake. Then add to
it 5 quarts of boiled oil, shake it thoroughly well all together,
afterwards letting it stand in a warm room till it gets clear. The
clear portion can then be drawn off and used, or reduced with spirits
of turpentine till of the requisite consistency. For making a varnish
suitable for iron patterns, take sufficient oil of turpentine for the
purpose of the job in hand, and drop into it, drop by drop, some
strong commercial oil of vitriol, when the acid will cause a dark
syrupy precipitate in the oil of turpentine, and continue to add the
drops of vitriol till the precipitate ceases to act, after which pour
off the liquid and wash the syrupy mass with water, when it will be
ready for use. When the iron pattern is to be varnished, it must be
heated to a gentle degree, the syrupy product applied, and then the
article allowed to dry.

A fine black varnish suitable for the covering of broken places in
sewing machines and similar articles, where the japanned surface has
become injured or scratched, can be made by taking some fine
lamp-black or ivory-black, and thoroughly mixing it with copal
varnish. The black must be in a very fine powder, and to mix the more
readily it should be made into a pasty mass with turpentine. For the
ordinary repairing shop this will be found very handy.

The following is a simple way for tarring sheet-iron pipes to prevent
rusting. The sections as made should be coated with