N.B.

From Zenit news service:

This month, the crowning glory of St. Peter's is preparing to get a face-lift. The lantern, bronze orb and cross surmounting the great dome will be cleaned and restored. Visitors this summer will see the gleaming bronze ball trapped in a sort of giant bird cage. The Fabbrica di San Pietro -- the workshop of St. Peter's -- is directing this project which will send workers to a platform 436 feet in the air. There they will clean the columns of the graffiti left by tourists and polish the gilded ball and cross. As St. Peter's dome is the tallest structure in Rome, storms have taken quite a toll since the last restoration in1975. Some extensive repairs will be undertaken to fix damage caused by lightening as well as installing a new lightening rod. The elegant lantern was built by Giacomo della Porta and Domenico Fontana, the architects who brought Michelangelo's dome project to its conclusion in 1590. The immense globe was added in 1593. While the sphere looks tiny from the square, it can actually fit 14 people inside.

Now how did they get a statistic like that?