- Cart
The origins of the cart are inextricably linked to the invention of the wheel. In fact, one theory of how the wheel was invented suggests that the cart and the wheel were developed simultaneously, inspired by earlier bladed sledges that were dragged across logs.
The earliest sources of life evidence for wheeled vehicles are Mesopotamian tablets. Although the dating methods used for these artifacts are not exact, the tablets are known to be from the middle of the fourth millennium B.C.E. Around the same time there is also evidence for wheeled vehicles in Europe, including wheel tracks at a long barrow near Kiel, Germany, and wagon picto-graphs found on a beaker a Bronocice Poland. This has led archeologists to debate whether wheeled vehicles were developed in multiple places simulta-neously or whether the technology quickly diffused out of Mesopotamia.
Carts have been in continuous use since their inception, evolving over time to incorpo-rate wheels with spokes and suspension springs for added comfort. However, the invention of the automobile, and to some extent the railroad, has undoubtedly led to the cart's decline as a mode of transport.
Today carts take all l sorts or shapes and functions, from traditional horse-drawn carts, through l rickshaws and tuk tuks to the electric powered golf cart. And we must not forget the ubiquitous shopping cart (or trolley), invented in 1937 in Oklahoma, United States, by Sylvan Goldman, who wanted to make it easier for his customers to buy more groceries from his chain of Piggly-Wiggly supermarkets.
SEE ALSO: LOG-LAID ROAD, WHEEL AND AXLE, LUBRICATING GREASE, SPOKED-WHEEL CHARIOT, MACADAM
- Catapult
The word catapult came from two Greek words: kata, meaning "downward”, and pultos, which refers to a small circular shield. Katapultos was taken to mean “shield piercer”. The weapon was said to have been invented in 399 B.C.E. in the Sicilian city of Syracuse and, according to Archimedes, was derived from a compo-site bow, which was similar to the crossbow.
Early catapults had a central lever with a counterweight at the opposite end to the projectile basket. Torsion powered catapults entered into common use in Greece and Macedon around 330 B.C.E.
Alexander the Great used them to provide cover on the battlefield as well as during sieges.
The Chinese, Greeks, and Romans used various types of catapults. The ballista, built for Philip of Macedon, was similar to a giant crossbow and, using tension provided by twisted skeins of rope, it could aim heavy bolts, darts, or spears. The trebuchet consisted of a lever and a sling and could be used to hurl large stones. The mangonel, credited to the Romans, fired heavy objects from a bowl-shaped bucket at the end of its single giant arm.
Catapults used as siege weapons were usually constructed on the spot because they were too cumbersome to move around. Sometimes beehives or carcasses of dead animals were catapulted over castle walls to infect those inside. The weapon reached Europe during medieval times and the French used them during their siege of Dover Castle in 1216 C.E. Cannons replaced catapults as the standard European siege weapon in the fourteenth century C.E.
SEE ALSO: SPEAR, SLING, BOW AND ARROW, FORT, LEVER, CROSSBOW, CANNON, BALLISTIC MISSILE