ge amount of water, often exceeding in
weight that of the fibre itself, and to take the goods direct from the
preceding operations to the drying plant means that a considerable
amount of fuel must be expended to drive off this large amount of water.
It is therefore very desirable that the goods be freed from as much of
this water as possible before they are sent into any drying chambers,
and this may be done in three ways, by wringing, squeezing and
hydro-extracting. The first two methods have already been described (p.
239, etc.) and need not again be alluded to; the last needs some
account.

[Illustration: FIG. 39.--Hydro-extractor.]

Hydro-extractors are a most efficient means for extracting water out of
textile fabrics. They are made in a variety of forms by several makers.
Essentially they consist of a cylindrical vessel, or basket, as it is
called, with perforated sides so constructed that it can be revolved at
a high speed. This vessel is enclosed in an outer cage. The goods are
placed in the basket, as it is termed, and then this is caused to
revolve at high speed, when centrifugal action comes into play, and the
water contained in the goods finds its way to the outside of the basket
through the perforations, and so away from the goods. Hydro-extractors
are made in a variety of sizes and forms--in some the driving gear is
above, in others below the basket; in some the driving is done by
belt-gearing, in others a steam engine is directly connected with the
basket. Figs. 39 and 40 show two forms which are much in use in the
textile industry. They are very efficient, and extract water from
textile goods more completely than any other means, as will be obvious
from a study of the table below.

[Illustration: FIG. 40.--Hydro-extractor.]

The relative efficiency of the three systems of extracting the moisture
out of textile fabrics has been investigated by Grothe, who gives in his
_Appretur der Gewebe_, published in 1882, the following table showing
the percentage amount of water removed in fifteen minutes:--

Yarns. Wool. Silk. Cotton. Linen.

Wringing 44.5 45.4 45.3 50.3
Squeezing 60.0 71.4 60.0 73.6
Hydro-extracting 83.5 77.0 81.2 82.8

Pieces.

Wringing 33.4 44.5 44.5 54.6
Squeezing 64.0 69.7 72.2 83.0
Hydro-