"How to use a barometer to measure the height of a building."
1) mark the outside of the building in barometer tick marks. Height of building = no. Marks x barometer height.
2) find the building maintenance manager and say "I'll give you this nice barometer if you tell me how tall the building is."
3) (with stopwatch) swing barometer from top on a rope - time periodicity
4) (with stopwatch) drop barometer - Newton is your friend.
5) use barometer as a gnomon and scale the length of shadow up to extract height of building from it's shadow.
6) measure air pressure differential between ground and top of building.