1 Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone, brick, or concrete; the steeper the gradient, the faster the flow.
2 removing grime was accomplished by the application of oil. After the Romans took a bath, sometimes scented oils would be used to finish the job.
3 these engineering marvels used gravity to transport water along stone, lead and concrete pipelines and into city centers. Aqueducts liberated Roman cities from a reliance on nearby water supplies and proved priceless in promoting public health and sanitation.
