These were 70 in number. They were constructed of blocks of red
granite and of a very hard stone. These were of extraordinary size,
and their transportation and adjustment indicates a surprising degree
of mechanical skill. The Great Pyramid was supposed to have been
erected about 3,800 years B. C., and is of the enormous size of 746
square feet at its base, covering about 12 acres of ground, and is
over 450 feet high. It was probably erected as a burial place for the
rulers of Egypt.