Coventional ideas of an Hour arises by splitting Earth's 360 degrees rotation around its own axis into 15 degree segments. Ancient Indians split the 360 degree rotation into 6 degree units instead which corresponds to a time measure of 24 minutes. A 24 minute unit is a Naazigai (நாழிகை) in Tamil language. The use of Naazigai dates centuries before the start of the common era. Measuring instruments to track time in Naazigai units were often made of copper. A very old Sangam text mentions a Kannal (கன்னல்) instrument and qualifies it with the phrase "of narrow water passage" (குறுநீர்). Using these instruments and announcing the passage of time in units of Naazigai was a profession in itself (Naazigai Kanakkar நாழிகை கணக்கர்). Those who measured the movement of stars and planets in the sky took the tile "the one who observes" (பார்ப்பனர்) an astronomer.
|Full and Half size Naazigai pots|
Temple builders were familiar with the Naazigai units and may have also been experts in assembling special stones to serve as a clock. They set two special stones in the inner ceiling of the Shiva temple in the town of Thittai in Tamil Nadu. Water vapor condenses on the carved surface of one of them during the night. It condenses on the surface of the other during day time. These two stones gather enough water to create a drop of water every 24 minutes. A drop of water falls on the Lingam in this temple every one Naazigai. The knowledge of condensation and the use of it as a time measure may have originated in temples in moist caves.
Half Naazigai is 3 degrees of rotation of the earth around its own axis. Was this the smallest convenient measure of time in ancient times? Tamil folk are still familiar with a time measure which is called a Jaamam (ஜாமம்). Seven and a half Naazigais make one Jaamam. Eight Jaamam Pujas are offered daily in old Shiva temples to this day. Astronomy texts in Sanskrit also convert Naazigais into the Hora or Hour units. A Hora contains two and half Naazigais. The Vinaadi unit is smaller than the Naazigai unit. There are 60 Vinaadis in a Naazigai. It is too small a unit to be measured with instruments. Traditionally the smaller units were based on phenomenon such as a blink or the time taken to pronounce a syllable.