Leaning Tower of Pisa: The Construction
by Prof. Piero Pierotti
The Construction
A circular ditch was dig out, 7 meters and 55 wide, with a depth of little less
than 3 meters, and a diameter of 19 meters and 60. The layers of earth on
which the bell-tower is constructed had different characteristics; the surface
is accumulated fluvium from the River Arno, while underneath there is a
resistant layer of clay, with fine sand and saltish shells.
The interior of the structure is of stones and mortar of the best quality lime,
such that the porous wall structure is elastic and able to resist the
tremendous pressure and continuous movements. The covering is made of
marble perfectly connected and smoothed, that are 40 to 60 cm thick on
the exterior part and a little bit less on the inside of the wall. The stairs
are lighter in weight; a spiral of 293 steps, one meter wide, constructed
between the inner and outer walls.
Description provided by Professor Piero Pierotti
Member of the Commission for the Restoration of the Tower
and Professor of Medieval Architecture at the University of Pisa
http://www.cisiau.unipi.it/~pierotti/Torre/lavori-en.html
Personal e-mail to:
gary@endex.com
