Daltons observations of the atom

John Dalton, son of a poor weaver, began his career as a village school teacher at the age of 12 years He became the principal of the school seven years later. In 1793, he moved to Manchester to teach physics, chemistry and mathematics in a college. 

Dalton proposed his atomic theory in 1803. He published a table of atomic masses. The errors (due to errors in his assumptions) in his first table were corrected in 1858. 

Dalton was the first to put the atomic theory on a quantitative basis. 

From his youth to his death, Dalton carefully recorded each day the temperature, pressure, amount of rainfall. He was a meticulous meteorologist Dalton could not see red colour due to protonopia. This visual defect is known as daltonism. 

Till recently, people believed that atoms could not be seen. But now, under powerful microscopes, atoms can be seen and photographed  

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