EUTACE^E 415
The ecuelle process, which is employed in the North of Italy and the(^1) 3outh of France, depends on the preliminary breaking of the oil globules
by means of spikes or knives, and varies in detail, according to the quan-
iity to be operated upon. A simple ecuelle is a saucer-shaped vessel,
about 8 to 10 ins. in diameter, usually made of copper, tinned inside,
and covered inside with short spikes, about J to J in. long. In the
bottom of the saucer is a hole about •£ to ^ in. in diameter, leading to a
hollow tube about 4 or 5 ins. long. A fruit is placed in the vessel,
and, by means of a rapid rotary motion, the oil cells are broken by the
spikes. The escaping oil flows into the hollow tube, which is periodically
emptied.
Various purely mechanical appliances have been devised for obviating
the necessity of hand labour, but most of these have proved of little
value.
An apparatus, known as the thermopneumatic extractor, has been
PIG. 38.
invented by Montfalcone for the extraction of all varieties of citrus oils.
The inventor claims that a far higher yield of oil of equal quality is
•obtained by the use of his apparatus, which is described as follows:—
1 is a hollow cylinder of sheet iron, the interior surface of which is
studded with a large number of metallic knife-points. This cylinder
revolves on two axles, attached to it at diagonally opposite points. Its
^capacity is such that, when charged, it is capable of holding 1200 or 1500
lemons. The cylinder having been properly charged, say with the above-
mentioned number of lemons, together with a small quantity of water, it
is set in motion by aid of the shafting and pulleys, driven by the small
steam engine. The fruits are thereby made to come in contact with the
metallic lancets, and their whole surface gradually becomes punctured
sufficiently to cut or rupture the cells containing the essential oil, which
escapes. The cylinder, 1, has double walls, the space between them
being intended for the circulation of a current of steam, which is admitted
to heat the water and to facilitate the extraction of the oil, while, at the
same time, the vapours are rarefied or aspirated by the vacuum-pump, 2,
The axles of the cylinder on both sides are hollow : that on the side look-