 Cranes were used for construction work and possibly to load and unload ships at their ports, although for the latter use there is according to the “present state of knowledge” still no evidence.Most cranes were capable of lifting about 6–7 tons of cargo, and according to a relief shown on Trajan's column were worked by treadwheel.The Romans designed the Pantheon thinking about the concepts of beauty, symmetry, and perfection.