Kuthiraikkaran vilakku - some Science - some Maths !!

 

Sure, you have been to many temples – observed people pouring Oil in lamps hanging from high ceiling … one often wonders, how they hang in good balance – Symmetry, distribution of mass, and some more Scientific reasons come to mind.  

Starting with calculating the weight - there are few things more frustrating than weighing an item twice only to receive two radically different results. One seeks a  precise measurement, and one cannot  trust  digital scale too.

 

Here is a photo of lamp (background edited and colour enriched)  and some Science behind the surprising design – the parts are not symmetric – and it defies imagination on how equilibrium and the mass distribution are designed – how artisans were so Scientific  -  “Kuthiraikkaran Vilakku” (Horseman’s lamp) seen at Padmanabhapuram Palace. 

A lamp hanging on chains stays up because the chain is in tension, and the lamp’s  weight is pulled downward by gravity while the chain pulls upward with an equal and opposite force. When those forces balance, the lamp is in static equilibrium and remains suspended without accelerating.

The important idea is the center of mass. The lamp hangs stably when the vertical line through its center of mass falls below the suspension point, so gravity does not create a turning effect that would make it tip over.

 

If the lamp is shaped like the one in this  photo, the decorative body and the tray are to be precisely arranged  so the whole assembly balances around the hanging point. 

In hanging lamps, the chain is flexible, so each link carries tension along its own direction, and the chain naturally settles into the shape needed to support the load. The hanging shape of a chain is called a catenary (the curve formed by a flexible chain or cable hanging freely under its own weight between two fixed points. Its name derives from catena, the Latin word for "chain"), and its geometry helps distribute force smoothly from the lamp to the ceiling. This is why chains are often used instead of rigid hooks when the design needs some swing or slight adjustment.

 

Catenary pic – Wikipedia By Geek3 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7728690

 

When the hanging lamp is nudged, it may sway like a pendulum, but if the center of mass is low enough and the suspension is properly aligned, gravity tends to pull it back toward the resting position.   

The lamp hangs in balance because its center of mass is arranged so the vertical line of gravity falls through the support point, and the turning effects on either side cancel out. In physics terms, it is in static equilibrium: the net force is zero and the net torque is zero. 

The heavy decorative horse and the lamp tray are not just ornamentation; they are positioned to shift the combined center of mass to a stable point below the chain attachment. When the center of mass hangs directly under the suspension point, gravity creates no twisting tendency, so the lamp does not tip.  When you observe the photo,   the chain is attached above the horse figure, and the lamp bowl is offset but still balanced by the mass distribution of the full hanging assembly. The support point, the horse body, and the tray together form a system where clockwise and counterclockwise torques balance each other. 

It is beautifully positioned as though it is a seesaw that has been carefully weighted so both sides match. Even if the parts look uneven, the object can remain steady as long as the overall center of mass is below the hanging point.  It takes care of both Static equilibrium as also dynamic stability – meaning it is firm at rest and does not fall even when disturbed and is moving.  Only a  well-designed hanging object can be in static equilibrium and also be dynamically stable, because gravity pulls its center of mass back under the suspension point. 

“Kuthiraikkaran vilakku” at  Padmanabhapuram Palace is a  horse-shaped hanging lamp, hailed for its balance and physics.   In this horseman-style lamp, the decorative horse is not just ornamentation; it is part of the mass distribution that helps position the center of gravity correctly. Even though the bowl and horse look visually uneven, the total weight is arranged so the system hangs in static equilibrium.   The lamp’s geometry works like a carefully weighted hanging system.   The horse body acts like a counterweight and also moves the mass distribution away from the bowl. The tray-like lamp part adds weight low down, which helps keep the overall center of gravity beneath the chain attachment, making the system stable. 

Imagine drawing a vertical line straight down from the chain hook. If that line passes through the combined center of mass of the horse, hook, and tray, the lamp stays balanced. If it were to move outside that support region, the lamp would rotate until balance is restored. So the geometry is really a weighted balance problem: the shape is designed so that the center of mass stays under the support point, and that is why the lamp can hang neatly without toppling. 

Padmanabhapuram Palace is a magnificent 16th-century wooden palace located in Thuckalay, Kanyakumari district, Tamil Nadu. Notably, while the palace is physically situated in Tamil Nadu, it is owned, controlled, and maintained by the Government of Kerala as it served as the ancient capital of the erstwhile Kingdom of Travancore. It is widely celebrated as one of Asia's largest and finest surviving examples of traditional wooden architecture

 
Interesting !
 
Regards – S Sampathkumar
24.5.2026