ty. They are
remarkably resistant to corrosion by sea-water, and are well suited for
screw-propellers as well as for pump-plungers, pistons and glands.
Heated to a dull red delta metal becomes malleable and can be worked
under the hammer, press or stamps. By such treatment an ultimate tensile
strength of 30 tons per sq. in. may be obtained, with an elongation of
32% in 2 in. and a contraction of area of 30%.

In the arts brass is a most important and widely used alloy. As compared
with copper its superior hardness makes it wear better, while being more
fusible it can be cast with greater facility. It is readily drawn into
fine wire, and formed into rolled sheets and rods which are machined
into a huge number of useful and ornamental articles. It is susceptible
of a fine polish, but tarnishes with exposure to the air; the brilliancy
of the surface can, however, be preserved if the metal is thoroughly
cleansed by "dipping" in nitric acid and "lacquered" with a coating of
varnish consisting of seed-lac dissolved in spirit.

BRASSES, MONUMENTAL, a species of engraved sepulchral memorials which in
the early part of the 13th century began to take the place of tombs and
effigies carved in stone. Made of hard _latten_ or sheet brass, let into
the pavement, and thus forming no obstruction in the space required for
the services of the church, they speedily came into general use, and
continued to be a favourite style of sepulchral memorial for three
centuries. Besides their great value as historical monuments, they are
interesting as authentic contemporary evidence of the varieties of
armour and costume, or the peculiarities of palaeography and heraldic
designs, and they are often the only authoritative records of the
intricate details of family history. Although the intrinsic value of the
metal has unfortunately contributed to the wholesale spoliation of these
interesting monuments, they are still found in remarkable profusion in
England, and they were at one time equally common in France, Germany and
the Low Countries. In France, however, those that survived the troubles
of the 16th century were totally swept away during the reign of terror,
and almost the only evidence of their existence is now supplied by the
collection of drawings bequeathed by Gough to the Bodleian library. The
fine memorials of the royal house of Saxony in the cathedrals of Meissen
and Freiberg are the most artistic and striking brasses in Germany.
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