# Gabriel's Horn

Gabriel's Horn is the surface of revolution of *y* = 1/*x* for *x* greater than 1. Surprisingly
this has a finite volume, of π cubic units, but an infinitely large surface
area!

Gabriel's Horn is also known as **Torricelli's Trumpet** because
it was investigated by the Italian Evangelista Torricelli (1608–1647).
As a young man Torricelli studied in Galileo's home at Arcetri, near Florence, and then, upon Galileo's death, succeeded
his teacher as mathematician and philosopher for their good friend and patron,
the Grand Duke of Tuscany. Torricelli was amazed by the strange property
of his mathematical trumpet and tried various ways to avoid the conclusion
that a finite volume could be enclosed by a vessel with an infinite surface
area. Unfortunately, he lived before calculus came along to explain the apparent paradox in terms of infinitesimals.