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18 ANNUAL REPORT 
This failure seems to imply one of two things, either that ancient 
concrete was very superior in toughness to anything we now construct, 
or else, that the Latin race lacks much of the vigor and persistency which 
the Yankees possess ; for, elsewhere in this paper an account is given of the 
successful removal of a solid concrete monolith of great toughness in pre- 
paring the foundations of the new post office building in Chicago. : 
The dome of the Pantheon, which was erected at the beginning of the 
Christian era, is of concrete supported in a frame work of brick arches. 
It has an internal diameter of 142 feet. For 2,000 years nature has been 
expending her energies upon the structure, but it still survives to tell the 
story of the durability of concrete. Figure 1 shows this remarkable 
building. 
Fig. 1.—View of the Pantheon at Rome. 
“The Pantheon at Rome is the most perfect existing classical building in that fa- 
mous old city. It was built by Agrippa, 27 B. C., nearly 2,000 years ago. The circular 
walls are about 20 feet in thickness, and the roof is a hemispherical cement concrete 
dome with a thirty-foot opening in the top and spanning in the clear 142 feet 6 inches. 
This is the most remarkable instance in the world’s history showing the great 
strength, durability and permanence in cement concrete construction. It has baffled 
the destructive elements of time for nineteen centuries and shows not a single crack 
to-day.’”’ 
Cummings says that in Mexico and Peru, natural rock cement was 
used so long ago in stone masonry that the stone has worn away leaving 
the projecting mortar joints. 
