Set Of 3 Grenet Batteries

Set of three Grenet batteries of different sizes: 18cm, 20cm and 21cm in height, 7.5cm in diameter, 7.8cm in diameter and 9.5cm in diameter. They are not signed. "The Grenet potassium dichromate battery, also called a bottle battery because of its shape, was invented by the French electrical engineer Eugène Grenet in 1850. His invention is based on the Poggendorf battery designed in 1842. The Grenet battery was highly appreciated for its ease of use. It provides a voltage of 2 volts per element and operates for 9 to 10 hours. Its applications are numerous until 1910 in medical practice, telegraph or electroplating. Manufacturers offered batteries of 3 to 12 elements placed side by side in a wooden frame equipped with a winch for lifting the electrodes." (see website of the French Society of Radiology). Fairly good condition.