264 THE ESSEX NATURALIST.
Charring of timber to prevent decay has been practised
from antiquity. An experiment was made with the Dauntless
launched in 1808. When examined in 1814 some of the timbers
and planks which has been charred were in a state of decom-
position with fungus growing on them.
The use of mineral and vegetable oil was also brought forward.
Lukin's proposal to impregnate timber with oleaginous matter
was tried out on a large scale in 1812. The method was to
stack timber in kilns and to allow the liquid resulting from
heating pine sawdust with train oil or pit-coal in retorts, to drip
on to it. The experiments were put an end to by an explosion
which killed six men and wounded fourteen others, some of
them being struck sixty feet away, and threw down a house
in an adjoining field. The treated wood was also a failure.
The holds of ships were difficult to ventilate and many
realised that herein lay part, at least, of the cause of decay.
Murray in 1665 proposed to effect ventilation by means of metal
pipes from the fire in the galley to the hold. A similar method
was recommended by Sutton in 1748 and used until 1757 in
all new ships. They were ousted by wind-sails, first generally
introduced in the British Navy in 1740 and used by all European
powers until well on into the nineteenth century. The pneu-
matic machines of Hales and others, and bellows were also
introduced and from 1783 four of Brodie's airing stoves were
supplied to all ships of the line to ventilate the holds and between
decks.
One obvious improvement was the introduction of permanent
roofs over the docks and slips to protect the ships while being
built or repaired : the first ship of the line launched in England
from under a permanent roof was the Wellington in 1816.
Time and again it was suggested that ships should be sunk
for their preservation. In 1816 this method was practised for
the cure of dry rot owing to Seppings having observed that the
Resistance and the St. Fiorenzo, both of which had been sunk,
were sound. The Eden built in 1814 and much injured by
fungal attack was deliberately sunk in 1816 and refloated after
five months. When twelve months afterwards she was opened
up a considerable quantity of fungus was found in her but
none in a growing state. Bowden claimed the merit for having
discovered this "simple, easy, cheap and effectual remedy