when it appeared as well as possible, and pecked
about." The Lowtans which roll when filliped
are reckoned higher caste than those which
require to be shaken.

The explanation of all these facts is easy, if
we remember that all tumblers are pigeons
artificially stunted, whose centre of gravity has
been disturbed. When their heads are filliped,
rubbed, or heated, the cranial gases are dilated,
and the light-headed bird loses its balance.
The Lowtans have long pointed wings, and yet
they can barely fly, not from any deficiency of
wing surface, or of gaseous lightness, but for
want of such a distribution of the gases as will
enable them to keep their balance, and regulate
their movements.

Spiders fly without wings. Some spiders
wrap themselves up in silken bags and float
through the air in great numbers. There is a
tiny black spider, very common on the Sussex
coast, which flies about floated by a filament, as
a boy swims floated by a string of bladders.
Wings, therefore, are not essential to flying;
but a certain proportional lightness is essential.
A boy does not need bladders to float in water,
he only needs to know how to maintain his
balance; but a spider seems to require its
thread, as a bird requires a gaseous structure and
wing surface.

The wings and the tails of birds have their
shares in flying; but they are not essential to
the act. Ducks fly, as we have seen, in saucy
contradiction to Smeaton's rule of Atmospheric
Resistances; the area is generally proportional
to the weight—a square foot to a pound weight
—and, moreover, the contour of many flying
birds comes near to the contour of Newton's
solid of least resistance. A man and a parachute
properly poised, and weighing one hundred and
forty-three pounds may descend safely. Birds
and insects can at will expand or contract their
resisting surfaces. They can also, by exercise and
rest, warm or cool, weight or lighten their gases.
The Cingalese hornbills in flying strike the
air several strokes with their wings, and then
stretching them out, sail for several yards,
throwing their heads as far forward as their
long necks permit. The hornbills have gas
stowed away everywhere; and the screamers, or
kamichi, are similarly gaseous, although for a
different purpose. The kamichi walk upon the
broad leaves of aquatic plants. Long ago,
naturalists and physiologists have shown that
the birds of strongest and swiftest flight have
the longest and narrowest wings. Yet this fact
is by some folks spoken of as a new discovery!
Wings spread wide to sustain weight, on the
principle of snow-shoes and broad wheels; wings
have hard front edges to catch hold of successive
wingfuls of air, as oars catch hold of water;
wings have some breadth to push, like paddles;
wings are often rather narrow, and it is found
that two blades one-sixth of the circle each make
the best screw-propellers for ships; wings are
smooth, and the smoothness adapts them, like
skates on ice, to glide along upon the layers
of air. Two qualities of the air must not be
overlooked by students of flight. The globules
of the air are elastic. When struck by the
downward stroke of the elastic wing, the elastic
air pulses up again. Air, never still, being
composed of heavier or lighter globules, always
seeking their level, and varying their pressure,
has such variations as currents, breezes, gales,
hurricanes. Observers of the arrivals and
departures of birds know the winds which will
bring them or take them. Prior to leaving for
warmer climes, our summer visitants assemble
in flocks on the coast of Sussex, just as, fifty
years ago, tourists used to collect and wait at
Dover for a favourable wind to waft the
packet across to Calais. The wings of a pelican,
as I before stated, weighing twenty-one pounds
may be ten feet from tip to tip; the wings of
the albatross are only eight and a half inches
broad, although fifteen feet long. The albatross
moves these wings so little that it is said to
sleep in the storm. But it is not necessary
to try to explain this buoyancy by the lifting
power of these machines. By rapid motions
of his wings, the lark sustains himself above his
mate in her nest; by rapid motions of his wings,
the humming-bird can sustain himself in one
spot until he darts out his tongue and catches
an insect, or the humming-bird moth until its
trump snatches pollen from the flower, and
their increased activity of wing measures the
greater muscular force necessary to maintain a
stationary as compared with a gliding position.
Light screws rapidly moved can mount short
distances for brief spaces in the air. But the
pelican and the albatross require not, and make
not, any such rapid motions with their wings;
for they have, in addition to gas in their osseous
frame, gas in interclavicular cells, gas in thoracic
cells, gas in abdominal cells, gas in pelvic cells,
gas in intermuscular cells; and these cells
communicate with subcutaneous cells of gas all over
the surface of their bodies.

To resume. Flying, we have seen, can be
done without wings, and without mechanical
force. Flight consists of two things, buoyancy
and waftage; and without saying that wings
have nothing to do with buoyancy, and lightness
nothing to do with waftage, it may be submitted
that buoyancy (like that of a balloon) depends
on gaseous structure, and waftage on the
mechanism of wings; flying being the combination
of the two as guided by the instinct or will
of a bird.

ANCIENT GUIDES TO SERVICE.

POLITENESS among our ancestors was
handsomely defined in all its departments by a
variety of little books of etiquette, written in
verse, for the use of children generally, pages
in great men's houses, chamberlains of royal
households, and others who were expected to
do things precisely as they should be done. A
bundle of such books has been reprinted for the
Early English Text Society—a busy printing-club
which is laying down, with good metal, a
broad and easy highway of communication
between us and our forefathers.