air route from New York to London passes over Iceland.
It is part of a great circle,
not a straight line.
A CAT scan
is based on the x-ray principle: as x-rays pass through
the body they are absorbed or weakened at differing levels
creating a matrix or profile
of x-ray beams of different strength. This
x-ray profile is registered on film, thus creating an
image. (CAT stands for Computerized Axial Tomography.)
often use a continuous colored line on the floor
to direct patients from place to place in the building.
sites use lines on the pavement to indicate the path of
self-guided tours. One example is the Freedom
Trail in Boston, Massachusetts.