Padlock
Contemporary with the Scandinavian padlock, were the "cast heart" locks, so called because of their shape. A significantly stronger lock than the smokehouse and much more resistant to corrosion than the Scandinavian, the hearts had a lock body sand cast from brass or bronze and a more secure lever mechanism.
Arun Thomas
Mechanical calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically. Most mechanical calculators were comparable in size to small desktop computers and have been rendered obsolete by the advent of the electronic calculator.
Metronome
A metronome is a practice tool that produces a steady pulse (or beat) to help musicians play rhythms accurately. The pulses are measured in beats-per-minute (BPM). Most metronomes are capable of playing beats from 35 to 250 BPM.
Flintlock
The basic goal of the flintlock is simple: to create a spark that can light the gunpowder stored in the barrel of the gun. To create this spark, the flintlock uses the "flint and steel" approach. ... The sparks that you see are the hot specks of iron burning! If these sparks come near gunpowder, they will ignite it.
Mercury Thermometer
Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it's used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures.
Lens of Glass
a piece of glass or other transparent material with curved sides for concentrating or dispersing light rays, used singly (as in a magnifying glass) or with other lenses (as in a telescope).
Scythe
The word "scythe" derives from Old English siðe. In Middle English and after it was usually spelt sithe or sythe. However, in the 15th century some writers began to use the sc- spelling as they thought (wrongly) the word was related to the Latin scindere (meaning "to cut"). Nevertheless, the sithe spelling lingered and notably appears in Noah Webster's dictionaries
Flying Kite
A kite is a tethered heavier-than-air craft with wing surfaces that react against the air to create lift and drag. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the face of the kite so the wind can lift it
Archimedes Screw
The water screw, popularly known as the Archimedes' screw and also known as the screw pump, Archimedean screw, or Egyptian screw, is a machine used for transferring water from a low-lying body of water into irrigation ditches. Water is pumped by turning a screw-shaped surface inside a pipe.
Pulley
A pulley is a wheel with a groove along its edge, that holds a rope or cable. Usually, two or more pulleys are used together. When pulleys are used together in this way, they reduce the amount of force needed to lift a load. A crane uses pulleys to help it lift heavy loads.
Crossbow
A crossbow is a type of elastic ranged weapon in similar principle to a bow, consisting of a bow-like assembly called a prod, mounted horizontally on a main frame called a tiller, which is handheld in a similar fashion to the stock of a long gun. It shoots arrow-like projectiles called bolts or quarrels. The medieval European crossbow was called by many other names including crossbow itself, most of which were derived from the word ballista, an ancient Greek torsion siege engine similar in appearance
Abacus
Abacus is a simple tool or a hardware used for performing rapid arithmetic calculations. Calculations based on abacus was invented at ancient times and now widely used a brain development programme. It consists of a rectangular frame holding a number of vertically arranged rods, on which beads slides up and down.