A cathedral is a large
A cable is made of twisted strands of
Which of these is a heating device?
In history, a landmark is
What might a farmer use to convey milk products?
Which of these is a structure?
Plastic-covered cables are used to carry
Which of these carries freight?
In a motor or machine, what is a shaft?
Which of these is a San Francisco landmark?
How might someone convey good wishes?
A coal shaft is a
Which of these are cooking methods?
Which of these usually has a rod to hold it up?
Which of these has a shaft?
The subway and the elevator are two inventions that changed cities forever. Both_________________people quickly and safely to where they want to go.
Elisha Otis built the first elevator in 1857. His invention made the skyscraper possible and is a____________________in human history.
The world's tallest building, completed in 2010, is the 2,717-foot Burj Khalifa, in the United Arab Emirates. For hundreds of years, the record was held by the 528-foot____________________in Ulm, Germany
Before 1857, the only way to get to a building's upper stories was by climbing stairs. Otis'_________________________was less tiring and could carry people to any height.
The idea caught on, and soon skyscrapers were shooting up like mushrooms. Otis' elevator was the perfect______________________________for moving people up and down quickly and safely
Otis was working in a factory that made beds when he got his idea. He saw how a hanging cage used for moving______________between floors could be made accident-proof.
The idea behind Otis' invention is quite simple, If the_________________holding the elevator car breaks , then there should be some means of keeping it from dropping like a stone.
Before the skyscraper, tall buildings like the one at Ulm were made of stone, The use of steel girders made possible_________________________Like Burj Khalifa
It was unlikely that such a thing would happen. However, if it did, then steel___________________in the side of the elevator car would spring out to hold it in place.
There were two rods, and they caught in slots designed to hold them and prevent further movement. The slots ran the whole length of the elevator_________________