inventions-then-and-now

                                                        Ramps

Egyptians built pyramids around the year 2500 BC. Moreover, for around 3,800 years the tallest structure in the world was the Great Pyramid of Giza. It was built by cutting the big stones on the ground, then used ramps to push them up. However, the Great Pyramid took around twenty years to be built. Nowadays, we use cranes to lift building materials. Therefore, we are able to build skyscrapers in less than one year.  
 

Levers

In around 260 BC, lever was described by an ancient Greek mathematician called Archimedes. Levers are used to lift heavy objects. It is known that builders in ancient Egypt used levers to move and stand up stone pillars. Those days, many of the tools we use are levers, like hammers and scissors.

                                        Screws

In the first century, Greece was the first country to use screw. It was used to move heavy objects by rotating them around in a circle. Today we use screws to fix things in place. Example: light bulb.

Wheels and axles

In around 3200 BC, wheels were used for transportation in Iraq. It was a solid disk on an axle. It was used to move chariots. Nowadays, wheels are used in all the modern transportation like cars, bicycles, trains and airplanes.

references:

Gypsi Database. (2014). Retrieved from http://filippom.iics-k12.com/lever/

All-tech. (2012). Retrieved from http://www.all-techspecfast.com/fastener.html

Spadafora, R. R. (2011, June 25). Retrieved from http://www.education.com/reference/article/firefighter-exam-study-guide-wheel-pulley/

Pritchard, E. (2014). Oxford discover. Oxford: Oxford University Press.