Such a line is therefore called a meridian, or noon line.
b. If this line be extended to the poles, all places under it (that
is, all places exactly North and South of each other) will have
noon at the same moment.
If this line be drawn round the Earth on the opposite side, it
will pass through the places which have midnight at that time.
c. As the Earth turns from West to East, the Sun appeal's to
move round it from East to West.
d. Therefore, if a number of meridians be drawn on the Earth,
the Sun will first pass over the most eastern, and afterward over
those which are most western.
Thus it is noon in Europe, after it is noon in Asia, and before
it is noon in America*

Of coarse when it is noon in Europe, it is afternoon in Asia,
%uA forenoon in America.
To illustrate this, lei the pupil place his finger, to represent
the Sun, over the map of the world, and draw the map from



LONGITUDE AND TIMB. 35

West to East as the Earth moves. He will then see, that the
Sun will first pass over places to the eastward, as Asia, and
4ifierwards over those to the west, as Europe and America,

Only a few meridians are drawn upon maps ; but every place
on the Earth, however small, has its own meridian.
e. Distance East or West, from any meridian, has been called
longitude^ because the aucients supposed the Earth to be longest
from East to West.
f. Longitude is generally reckoned from the meridian of
Greenwich or London, and is counted 180 degrees, or half round
the globe^ each way.
Of course the longitude of a place cannot be more than 180
degrees.
