first Arbor Day in 1872. Arbor Day
became a legal state holiday in 1885.
The holiday later spread across the
United States as well as to other
countries.
Archaeology
Archaeology is the study of things that
people made, used, and left behind. The
goal of archaeology is to understand
what people of the past were like and
how they lived. Scientists who study
archaeology are called archaeologists.
An archaeologists works begins with
finding a site to study. Some sites, such
as ancient cities, are visible on the surface.
Other sites are buried. Special
devices can be used to sense structures
that are underground or underwater.
After finding a site, an archaeologist digs
slowly and carefully. This work is called
excavation, or a dig. Archaeologists use
spoons, knives, picks, brushes, and other
tools in their work. They try to uncover
buildings, tools, weapons, art, and anything
else that people made. These items
are called artifacts.
Then archaeologists study the objects.
They want to know when an artifact was
made, what it was made from, and what
it was used for. Archaeologists have several
methods for figuring out an artifacts
age. One method is called
carbon-14 dating. Carbon-14 is a
chemical found in all organisms, or living
things. After an organism dies, the
amount of carbon-14 decreases at a certain
rate. An archaeologist measures this
decrease to find out how long ago the
organism died.
Archaeologists uncovered life-size figures of soldiers in an ancient tomb in China.
BRITANNICA STUDENT ENCYCLOPEDIA Archaeology 163
Archaeologists also try to understand the
culture from which artifacts came. For
example, tools such as arrow tips, knives,
and grinding stones can tell an archaeologist
how people got and prepared
their food.
An archaeologist sometimes works with
experts from other fields of study. Botanists,
zoologists, and geologists can help
to identify plants, animals, soils, and
rocks found along with artifacts.
#More to explore
Botany Geology Zoology
Archaeopteryx
A prehistoric bird, Archaeopteryx is best
described as a feathered dinosaur with
wings. Archaeopteryx is considered proof
that birds developed from dinosaurs,
because it had the traits of both.
When and Where
Archaeopteryx Lived
Archaeopteryx lived about 159 to 144
million years ago. All known Archaeopteryx
remains have been found in southern
Germany.
Physical Features
Archaeopteryx reached 2 feet (60 centimeters)
in length and had a wingspan of
2 feet (60 centimeters). It had wing
feathers like those of modern pigeons.
Archaeopteryx also shared several features
with a group of small, meat-eating dinosaurs,
however. It had well-developed
teeth and a long, slender and flexible
neck. It had long leg and foot bones,
and it had claws on its hands.
Behavior
Some scientists believe that Archaeopteryx
took off by running along the
ground and leaping into the air, flapping
its wings. However, other experts believe
that Archaeopteryx most likely spent a lot
of time perched in low-growing trees.
The animal could simply launch itself
from atop the branches and glide out on
short flights. When it was not in the
A team of archaeologists works
on a dig, or excavation, in
Peru.
Archaeopteryx
164 Archaeopteryx BRITANNICA STUDENT ENCYCLOPEDIA
trees it is possible that Archaeopteryx
swam and fished in the lagoons surrounding
the islands on which it lived.
Archaeopteryx, like both dinosaurs and
modern birds, reproduced by laying
eggs.
..More to explore
Bird Dinosaur
Archery
The sport of shooting arrows with a bow
at a target is called archery. But archery
is not just a sport. For thousands of
years people used the skills of archery
mostly for war and for hunting. Even
today bow hunting is a popular activity.
Bows and Arrows
Bows allow people to shoot arrows farther
and with greater force than is possible
by simply throwing them. At its
most basic, a bow is a long, thin piece of
wood with a string stretched tightly
from one end to the other. The string
holds the wood in a curved position.
People competing in archery contests
today often use more complex bows
made of wood, plastic, or fiberglass.
An arrow is a long, thin piece of wood,
metal, or other material. It ends in a
pointed tip. Near the other end of the
arrow is a tail of feathers or plastic fins.
The tail helps the arrow fly straight.
The tail end of the arrow fits onto the
string of the bow. To shoot the arrow, an
archer pulls the string back and lets it
go. A lot of energy is stored up by the
string being stretched. When the string
is released, this energy is also released.
This sends the arrow flying with great
force.
Archery Competitions
There are many kinds of archery events.
In most kinds the archers shoot arrows
at round targets. Each target is marked
with a circle surrounded by several rings.
Archers earn a set number of points for
hitting the various areas on the target
with their arrows. They earn the most
points for hitting the circle in the center
and the least points for hitting the outer
ring.
The most common types of archery
used in contests are target archery and
field archery. In target archery archers
shoot a set number of arrows at targets
at set distances. For example, an archer
Modern archers shoot at targets up to 295
feet (90 meters) away.
BRITANNICA STUDENT ENCYCLOPEDIA Archery 165
may have to shoot 18 arrows at a target
that is 230 feet (70 meters) away. In
field archery the archer shoots arrows at
several targets on a course set up to imitate
hunting conditions.
World championships are held regularly
in target, field, and other kinds of
archery. The Summer Olympic Games
feature target archery events for men
and women, individually and in teams.
History
In prehistoric and ancient times many
peoples in Europe, Asia, Africa, and the
Americas made bows and arrows. The
bow was one of the main weapons of
war and hunting. The ancient Egyptians,
Greeks, and Chinese also practiced
archery as a sport.
The Huns, the Turks, the Mongols, and
other groups used the bow and arrow for
warfare while riding on horseback. Their
skills as archers helped them conquer
large parts of Asia.
English soldiers began using a large bow
called the longbow in the 1300s. It
helped them win great military victories
against France. The leading bow in other
parts of Europe at the time was the
crossbow. It was a small, powerful bow
attached crosswise to a piece of wood. It
had a groove to guide the arrow across
the wood and a lever to pull and release
the string.
In Europe guns replaced the bow and
arrow as the major military weapon in
the 1500s. Today soldiers in most parts
of the world use firearms. However,
many people still use a bow and arrow
to hunt. Archery has also grown popular
as a sport. In the 1900s archery became
an Olympic event.
#More to explore
Olympic Games War Weapon
Hundreds of years ago warriors used bows and arrows to fight battles.
166 Archery BRITANNICA STUDENT ENCYCLOPEDIA
Architecture
The science and art of designing buildings