Only a century ago,it was virtually impossible to build a structure more than five or six stories high.
In 19th century stone or brick buildings,each floor put more and more weight on it from the floor above.
This weight limited how high engineers could build.
Today ,different building techniques and technologies are used.
But why don't very tall skyscrapers collapse under their own immense weight?
Elevator technology.
The most recessary invention to make a tall building was the elevator shaft.
In the mid 1800s,the first passenger elevator was installed in a New York Department store.
At the time,it was very difficul to conveniently move thousands of people up and down a building that was over 20 stories tall.
Without elevators,tall buildings might never have been built.
Foundations and steel skeletons.
The first step to constructing a skyscraper is digging a big foundation hole.