John Dalton, a British scientist, is probably best known for his groundbreaking research and contributions to two completely different fields- atomic theory and colorblindness.
It was discovered in 1995 that Dalton actually had a very rare form of color blindness- he was only able to see one colour, yellow.
So, he studied the problem in great detail and concluded that colorblindness was a genetic feature, as his brother was also colour blind.
Dalton was also very influential in the study of meteorology, specifically barometric pressure. This led to his publication of a series of papers called experimental essays in which he discussed the makeup of mixed gases.
The most important of all Dalton’s investigations are those concerned with the atomic theory in chemistry. The research had a great impact on atomic theory. He created a listing of atomic weights for six different elements – hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorous.
Dalton’s interpretation of atomic theory maintained that atoms are combined in chemical reactions, but also that they can be separated and rearranged. Without doubt, it was John Dalton’s atomic theory that laid the foundations of modern chemistry.
Below a certain depth all the porous spaces are saturated with water. This upper limit of the ground water is called the water table.
Water cycle or hydrological cycle is the natural evaluations of water through biosphere. Water is lost from earth’s surface to the atmosphere by evaporation from rivers, oceans, and seas etc. This atmospheric water forms clouds and creates rainfall. The water that collects on land, again flows to oceans, seas and rivers etc., and completes the cycle. 
Rain, snow, rivers, streams, brooks, lakes, ponds, wells, springs, underground water, ice sheets, etc. are the main sources of water. 
Pure water is colourless, odourless and tasteless. It can exist as solid (ice), liquid (water) and gas (steam). Water freezes at 0°C or 32° F and boils at 100°C or 212°F. It is a peculiar liquid in that it expands when it freezes. That is why ice floats on water.