French Inventions TOM MAYE

INTRODUCTION I have put together five of my favourite objects invented by the French.  The bicycle  The Cassegrain telescope  The battery  The parachute  The hot air balloon

THE BICYCLE  The earliest bicycle was a wooden scooter-like contraption called a celerifere; it was invented about 1790 by Comte Mede de Sivrac of France. In 1816, Baron Karl von Drais de Sauerbrun, of Germany, invented a model with a steering bar attached to the front wheel. It has two wheels (of the same size), and the rider sat between the two wheels in the middle of the bike. Such as this one.

THE CASSEGRAIN TELESCOPE  A Cassegrain telescope is a wide-angle reflecting telescope. It was developed in 1672 by the French sculptor called Cassegrain. A correcting plate (a lens) was added in 1930 with a concave mirror that receives light and focuses an image. A second mirror reflects the light through a gap in the primary mirror, allowing the eyepiece or camera to be mounted at the back end of the tube. The Cassegrain telescope was improved by the Estonian astronomer and lens-maker Bernard Schmidt, creating the Schmidt-Cassegrain telescope.Schmidt-Cassegrain telescope  It looks like this.

THE BATTERY  A battery is a device that converts chemical energy into electrical energy. An electrical circuit runs between two electrodes, going through a chemical called an electrolyte (which can be either liquid or solid). This unit is called a cell. Batteries are used to power many devices and make the spark that starts a petrol engine. Volta was an Italian physicist and invented the first chemical battery in 1800.Volta  Storage batteries are lead-based batteries that can be recharged. In 1859, a battery made from two lead plates joined by a wire and immersed in a acid electrolyte was developed; this was the first storage battery.  The dry cell is a an improved cell with a cylindrical zinc shell that is lined with the electrolyte (in the form of a paste). The dry cell battery was developed in France in the 1870s.  Edison batteries (also called alkaline batteries) are an improved type of storage battery developed by Thomas Edison. These batteries have an alkaline electrolyte, and not an acid.  It looks something like this.

THE PARACHUTE  Parachutes are used to skydive from airplanes, to jump from very high places, and to help slow down the descent of spacecraft. Parachutes are also used to slow down some race cars. The early parachutes were made from canvas (a strong cotton cloth). Light-weight (but very strong) silk cloth was then introduced for parachutes. Modern-day parachutes use nylon fabric. The idea of using a parachute to fall gently to the ground was written about by Leonardo da Vinci. The first person to jump from a flying airplane using a parachute (and survive the fall) was Captain Albert Berry, who jumped from a U.S. Army plane in Parachutes were first used in World War 1.Leonardo da Vinci  Here you can see that the parachute is quite large.

THE HOT-AIR BALLOON  A hot-air balloon is a balloon that is filled with hot air; it rises because hot air is less dense (lighter) than the rest of the air. The Montgolfier brothers made the first successful hot-air balloon. Their first balloon was launched in December, 1782, and ascended to an altitude of 300 m. This type of hot-air balloon was called the Montgolfiére; it was made of paper and used air heated by burning wool and straw. The first passengers in a hot-air balloon were a chicken, a sheep, and a duck, whom the Montgolfier brothers sent up to an altitude of 500 m. On September 19 th, 1783 (the trip lasted for 8 minutes); the animals survived the landing. This event was observed by King Louis XVI and Queen Marie Antoinette of France. Montgolfier  Here people are setting up for a flight.

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