when was it invented?
1865
Secchi disk
The Secchi disk (or Secchi disc), as created in 1865 by Angelo Secchi,
what is uranus's atmosphere made out of Hydrogen and helium describe corona of hydrogen? The exosphere is unusually extended, reaching as far as several Uranian radii from the planet. It is made mainly of hydrogen atoms and is often called the hydrogen corona of Uranus how is it explored? UNANSWERABLE who discovered the planet? The first spectra of Uranus were observed through a prism in 1869 and 1871 by Angelo Secchi and William Huggins mention a few of his technical works? He invented the Secchi disk what does the disk do? It measures water transparency or turbidity in bodies of water
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Secchi disk [SEP] Introduction
The Secchi disk (or Secchi disc), as created in 1865 by Angelo Secchi, is a plain white, circular disk in diameter used to measure water transparency or turbidity in bodies of water. The disc is mounted on a pole or line, and lowered slowly down in the water. The depth at which the disk is no longer visible is taken as a measure of the transparency of the water. This measure is known as the Secchi depth and is related to water turbidity. Since its invention, the disk has also been used in a modified, smaller diameter, black and white design to measure freshwater transparency.