Sri Ramalingam’s piece of work during 19^th century on “how rain forms” is an extra-ordinary scientific work considering the time he had written without even having a primary school education. May be this piece of work is to clarify the doubt among the people on “how rain comes?”, as people had a wrong belief (according to him) that “Cloud consumes ocean water to form rain” 

Here is the rough translation of his work

• Due to the energy from sun (Solar insolation), the water content from vegetation, water and land is sent to troposphere as water vapor (vaayu mandal), (due to evaporation/evapo-transpiration)
• As the vapor content moves up and stays as a warm layer in troposphere, the water vapor contents gets condensed and forms as water droplets (clouds).
• Due to the wind movement (seasonal varying winds), the thickness of the warm troposphere layer loosens (may be due to density of water droplets and also the gravity), then lightning comes, followed to that thunderstorm comes, then cloud condenses (also affected by wind movement), then rain comes to the land.

Highlights

I do not know when the physical mechanism behind the rain is identified, may be 20^th century or even before? Whereas, the importance of land atmosphere interaction is getting more attention among the climate scientist for past 2 or 3 decades. It is astonishing to note that he has recognized the importance of biosphere (vegetation, land and water) in the process of rain formation during 19^th century.

At present, we know about wind movement and tropospheric layers through satellite observations, and also how the seasonal wind pattern changes during different months. It is really a mystery, how he could say this line “seasonal varying winds movement in the troposphere layer”

His information on role of solar insolation, troposphere, condensation, evaporation/evapo-transpiration, clouds, lightning, thunderstorm etc., are great scientific contribution to that time. I am not sure, how many has recognized his scientific aspects in his work during late 19^th or even early 20^th century. Many of his works are not so easy to understand, as he is not just a poet, he is more than that (for me, he is a great scientist).

Original version in Tamil

“இதுபோல் சூரியகிரண (Sun rays) உஷ்ண ஆவியாகிய புகை ஓஷதிகளிலும் (Vegetation) நீரிலும் பாரிலும் பொருப்பிலுமுள்ள திரவசக்தியைக் (Water content) கிரகித்து, வாயுமண்டலத்தில் (Troposphere) சேர்த்து, மேலுங்கீழும் உஷ்ணம் நிரம்ப, மத்தியிலுள்ள திரவ (vapor content) அணுக்கள் புழுங்கி நீராய் (condensed water vapor or clouds), காலபேத வண்ணம் (seasonal varying) வாயுவால் (wind) பிரேரிக்கப்பட்டு அசைக்கும்போது, கீழுமேலுமுள்ள உஷ்ணவாயு தடிப்பு (warm pressure layer thickness) விலகும்போது, மின்னலாகிய பிரகாசமும், நெருங்கி யொன்றுபடும்போது சத்தமாகிய இடியும், அத்தொனியால் படலம்போல மூடியிருந்த காராகிய மேகம் விலகி வாயுவால் கலங்கிய போது மழையும் உண்டாகும். இதன்றி, மேகம் கடல் ஜலத்தை உண்டு மழைபெய்வ தென்பது பொய்.”

–    Sri Ramalingam (Most of his works are done between 1853 – 1874)