The so called Dark Ages occurred when Rome fell. Things improved when the Holy Roman Empire formed.
I have no idea how they were able to build the aqueducts without computers. The level had to be a gradual descent sometimes for hundreds of miles. Too steep or not steep enough and it would not work.
They also built incredible bridges so their enemies could not hide on the other side of the river. The army could quickly build these incredible bridges. Waterproof or underwater cement was one of the most important inventions. The roads were incredible and straight. Just amazing stuff.
Ping.
An awesome find. The Romans were definitely COOL.
Between Sevilla and Granada, in Andalusia, Spain, runs a two-lane highway which crosses over a river call Rio Frio (Cold River).
There exists there today three bridges at that river crossing; Roman, Medieval (both no longer used), and modern. The Roman bridge still looks great, the Medieval looks crude by comparison to the Roman, and modern one everyone uses has no personality at all.
They used a level and plumb bob. The Romans seemed to have perfected it. I'm pretty sure it was worked out before the Romans...
The angle of decline on the aquiduct if I remember was very tiny per mile