Cities and Construction The requirements for city-building, trade and warfare led to the development of more efficient mechanisms with which to fell and dress timber and unearth/quarry, move and lift the material for walls and buildings constituting the city. The acceleration of commerce brought larger warehouses, docks and machinery to lift and move large pieces and amounts of goods. Burgeoning commerce led to the building of barges and ships, the raising of sails and the construction of roads and canals. Avarice brought warfare and the constant seesawing of ascendancy - the counterbalance of offense and defense and the special skills required. Beyond all this activity was the ego of hierarchies seeking long remembrance, or passage to eternal life. The erection of the "wonders of the world" included monuments worshipping a panoply of gods. The construction skills were consequently honed in cathedral engineering and construction, sites worshipping the One God. Some were to be the highest structures in the world. This preoccupation with construction led to a continual creation and improvement in combinations of gear types, pulleys, cranes, windlasses, counterbalances, clever leverage, blocks and tackles, and last but not least, improvement in the ropes, chains, cables and belting that expended the power of muscle, running water and wind.