Hindu temple Kalasam (pot) - Some captivating facts

Kalasam on Thanjavur Big temple, TN. outline.aminus3.com
Srikanteswara temple,Nanjangud, Karnataka  dreamstime.com
Kalasam is like an inverted  pot made of an alloy of five metals (iyympon) normally you will find atop the Hindu temple Tower/ Gopuram. Metals including  gold, silver, copper and tin are used in right proportion to make kalasams. These metals  are believed to give these kalasams an electro-magnetic property.  There is no Hindu temple  across the world that does not have kalasams atop the Vimana. The number of kalasams depends on the structure  and choice and the total number of kalasams comes in odd number. Fixing kalasam on top of the temple has been in practise for centuriesand it is done on an auspicious day.  In India there are  countless 1000 plus year old  historical temples that have metal kalasam(s). According to an ancient Tamil wheeze: ''Don't live in a place where there is no temple'' (in Tamil: ''kovil illatha ooril kudiyerrukka vendam''). This is the reason why Tamil Nadu, in particular, has tens of thousands of Hindu temples. Invariably almost all kalasams are well decorated
Cross section of a Vishnu temple. North Indian style  .quora.com

The following are the interesting facts associated with Temple Kalasams: 

01. Worshipping of Gopuram /Temple Tower (Gopura dharsanam) is one of the important rituals of Hindu  temple worship. One should view the tower  along with  Kodimaram (Temple flag mast). It also goes by the name of Dwajasthambam.

02. In  ancient time no building was allowed to build taller than the temple tower within the specified perimeter, considering the deity's exalted status. No body is above the almighty.

03. Each Kalasam is filled with various dhanyams  (grains) like millet (Kambu), rice (paddy) etc and the quantity will be not less than 50 kg.  In case of a deluge or some kind of powerful natural disaster that might wipe out the plants, crops, etc,  sustenance or survival of humans will become questionable. To avoid food shortage, the dhanyams -will be taken out of kalasams for cultivation purpose, making room for prolification in the future.  The belief is in case of vast flooding, the water level won't touch the kalasams  at higher elevation and the grains will be safe. The grains  in the kalasams on top of these towers will be protected and dry and they could be used for sowing.

04. The kalasams are filled with grains like rice, salt, ragi, millet, corn, maize and sesame. Millet, especially, is used in huge quantities as it is claimed that it could conduct electro-magnetic waves.
Lingaraj Mandir, Bhubaneswar, Indiain.pinterest.com

05.  Kalasams are kept on the top of the tower where the flow of cosmic energy is maximum and from there they conduct it to the interior parts  right below. In the case of Srikovil or Garbagriha  (sanctum) where the main deity is kept, it is filled with positive energy. A priest has old me that the sanctum does not have a window on the walls  so that the positive energy will be retained within sanctum. So,  Kalasam - Vimana  improves the flow of cosmic energy and helps focus on the interior of the temple. 
06. Yet another fact is these Dhanyam/ pulses in the metal kalasam minimize the impact of  lightning on the structure and avoid damage to it.

Jambukeshwarar (Shiva) Temple, Thiruvanaikaval, Trichy, Tamilnaduin.pinterest.com

07. Periodic renovation of the temple is called Kumbabishekam / Samprokshanam (in Tamil: “Kudamuzhugu Vilzha”). that is done every 12 years;  reason being after 12 long years, the grains lose their power to  absorb the electro-magnetic waves and conductivity and productivity.
Meenakshi Amman Temple at Madurai in Tamil Naduin.pinterest.com
Srirangam Ranganathar temple, TN. in.pinterest.com
08. In this elaborate ritual lasting few days, puja is done to the kalasams replacing the old dhanyams/pulses with fresh ones. In some temples, new kalasams are made and ceremoniously fixed atop the tower. This is mostly done by  priests who are well- versed in temple Agama sastras. On the day of kumbabishekam, holy Thertham is poured on the metal pots on the tower

09. The artisans  do not begin their work on the temple kalasam without doing elaborate puja/prayer. Besides, they choose only auspicious day and time to begin their work. The artisans specialized in making idols, kalasams, puja articles and other related items for the temples have a good knowledge of Agama sastras and do their work accordingly.