ting. By an oversight a stereo of the penny value was dropped into
the fourpenny plate and a fourpenny into the penny plate.
Consequently, each sheet printed in the required red ink from the
penny plate yielded a fourpenny wrongly printed in red instead of
blue, its proper colour; and every sheet of the fourpenny likewise
yielded a penny stamp printed in blue instead of red. These errors are
highly prized by collectors, and are now extremely scarce, even poor
specimens fetching from L50 to L60. At the time, copies were sold by
dealers for a few shillings each. Similar errors are known in the
stamps of other countries.

Now and again the sheets of a particular value have, by some
extraordinary oversight, been printed and issued in the wrong colour.
In 1869 copies of the 1s. of Western Australia were printed in bistre
instead of in green, and a few years later the twopence was discovered
in lilac instead of yellow. In 1863 a supply of shilling stamps was
sent out to Barbados printed in blue instead of black; but this latter
error was, according to Messrs. Hardy and Bacon, so promptly
discovered, that it is doubtful if any of the wrong colour were issued
for postal use. In 1896 the fastidiously careful firm of De la Rue and
Co. printed off and despatched to Tobago a supply of 6,000 one
shilling stamps in the colour of the sixpenny, _i.e._ in orange-brown
instead of olive-yellow. Several are said to have been issued to the
public before the error had been noticed. Indeed, the firm at home is
credited with having first discovered the mistake, and is said to
have telegraphed to the colony in time to prevent their issue in any
quantity.

Another and much more common error in the early days of stamp
production was the careless placing of one stamp on a plate upside
down. Stamps so placed are termed _tete-beche_. They have to be
collected in pairs to show the error. The early stamps of France
furnish many examples of this class of error. They are also to be
found on the 6d. and 1s. values of the first design of the stamps of
the Transvaal, on the early issues of Roumania, on some of the stamps
of the Colombian Republic, and other countries.

Stamps requiring two separate printings--_i.e._ stamps printed in two
colours--have given rise to many curious errors in printing. A sheet
passed through the press upside down after one colour has been printed
results in one portion of the design being inverted. In the 1869 issue
of the