Scalpels are basically medical knives composed of two parts, a handle and a blade. An ancient Greek scalpel was used in the same manner and fashion as they are in the present day: that is, to create incisions in the body. Ancient models recovered at archaeological digs are almost identical in shape to the scalpels found in today's hospitals and clinics. Produced from steel, bronze, or a combination of both, these tools came in a wide variety of sizes depending on the medical condition and surgical needs of the physician.
An astrolabe uses the position of the sun and stars to help determine sunrise, sunset and the timing of moon phases and other astronomical events. It shows how the sky will look at a certain location and time. It is often confused with a mariner's astrolabe, a navigation instrument used by early explorers to determine a ship's position. Astrolabs were refined and advanced by the Islamic empires after 800 A.D., but are believed to have initially originated in ancient Greece.
The Archimedes Screw raises water from lower to higher levels. Archimedes, a Greek who lived from 287-212 B.C., developed this technology to help irrigate crops and to siphon ships to prevent capsizing. The tool's shape resembles a modern screw, with a shaft covered with spiral threading from bottom to top. Water is lifted from the lower threads, moving up the threads as the screw is turned, eventually making its way to the top. People actively used this technology as a way of extracting water until the 19th century.
A catapult is a machine used to increase the power of a projectile. A catapult originally used arrows and was carried by soldiers on the battle field. It resembles today's modern compound archery bow. With an increased in strength, called torsion, and a resulting increase in size, the catapult became a weapon able to send large projectiles far into enemy territory, without having to send troops. The principles of the catapult have not changed over the centuries. Only the materials with which the instrument is made have advanced.