In Prague is a lot of remarkable buildings. One of that is doubtless the church Na Karlove. The church was built in the 14th century by Karel IV government, which led in person the all charges of the whole building. The object of our interest was the vault over the central dome. The church's vault over the dome, which has average 22.8 m, was in the 14th century very daring. Master builder is unknown and to his person attach different legends. It's right he was the master of his branch. Measurement of the vault was made for using statics, which would know with modern static's methods, how was built the value. The church Na Karlove is with the grandiose vault the most memorable building of this kind in the all-central Europe.