ein, and Schleswig.
The loss of the two last, the fairest and most fertile districts of the
kingdom, was indeed grievous. The Danish king now ruled only over a land
consisting largely of moor, marsh, and dunes, apparently worthless for
any purpose. But the Danes, with admirable courage, entered upon a
second struggle, this time with nature. They made roads and railways,
dug irrigation ditches, and planted forest trees; and so gradually
turned large tracts of what had been useless country into valuable
possessions. Agriculture being much depressed, owing to the low price of
corn, they next gave their attention to the improvement of dairy
farming. Labour-saving machinery of all kinds was introduced, none more
important than the device for separating the fatty from the watery
constituents of milk. It would not be too much to say that the separator
is largely responsible for the present prosperity of Denmark.

[Illustration: FIG. 191.--Section of a Cream Separator.]

How does it work? asks the reader. Centrifugal force[37] is the
governing principle. To explain its application we append a sectional
illustration (Fig. 191) of Messrs. Burmeister and Wain's hand-power
separator, which may be taken as generally representative of this class
of machines. Inside a circular casing is a cylindrical bowl, D, mounted
on a shaft which can be revolved 5,000 times a minute by means of the
cog-wheels and the screw thread chased on it near the bottom extremity.
Milk flows from the reservoir R (supported on a stout arm) through tap A
into a little distributer on the top of the separator, and from it drops
into the central tube C of the bowl. Falling to the bottom, it is flung
outwards by centrifugal force, finds an escape upwards through the holes
_a a_, and climbs up the perforated grid _e_, the surface of which is a
series of pyramidical excrescences, and finally reaches the inner
surface of the drum proper. The velocity of rotation is so tremendous
that the heavier portions of the milk--that is, the watery--crowd
towards the point furthest from the centre, and keep the lighter fatty
elements away from contact with the sides of the drum. In the diagram
the water is represented by small circles, the cream by small crosses.

As more milk enters the drum it forces upwards what is already there.
The cap of the drum has an inner jacket, F, which at the bottom _all but
touches_ the side of the drum. The distance between them is the merest
sli