Units of time in Ancient Tamil history:

• 1 kuzhi(kuRRuzhi)= 6.66 millisecond-the time taken by the Pleiades stars(aRumin) to glitter once.
• 12(base 8) or 10 kuzhigaL= 1 miy= 66.6666 millisecond-the time taken by the young human eyes to flap once.
• 6(base 8) or 6 miygaL= 1 siRRuzhi(nodi)= 0.40 second-the time taken for a bubble (created by blowing air through a bamboo tube into a vessel 1 saaN high, full of water) to travel a distance of one saaN .
• 2(base 8) or 2 nodigaL= 1 vinaadi= 0.80 second-the time for the adult human heart to beat once
• 12(base 8) or 10 nodigaL= 1 aNu= 4 seconds
• 6(base 8) or 6 aNukkaL= 1 thuLi= 24 seconds
• 12(base 8) or 10 thuLigaL= 1 kaNam= 4 minutes
• 6(base 8) or 6 kaNangaL= 1 naazhigai= 24 minutes
• 12(base 8) or 10 naazhigaigaL= 1 siRupozhuthu= 240 minutes= 4 hours
• 6(base 8) or 6 siRu-pozhuthugaL= 1 naaL(1 day)= 24 hours
• 7 naaTkaL= 1 kizhamai(1 week)
• 15 naaTkaL= 1 azhuvam(1 fortnight )
• 29.5 naaTkaL= 1 thingaL(1 lunar month)
• 2 thingaL= 1 perum-pozhuthu(1 season)
• 6 perum-pozhuthugaL= 1 AaNdu(1 year)
• 3600(=10*6*10*6) AaNdugaL= 1 Oozhi(1 epoch)

Units of Ancient trade: Volume

• 1 kuNam= smallest unit of volume
• 1 mummi= 9 kuNam
• 1 aNu= 11 mummi
• 1 immi= 7 aNu
• 1 umi= 7 immi
• 1 sittigai= 7 umi
• 1 aazhaakku= 320 umi
• 1 padi= 13 aazhaakku
• 1 veesai= 16 padi
• 1 moodai= 19 veesai

Length

• 1 izhai= 30.303 micron
• 1 aNu= 11 izhaigaL= 333.3333 micrometre
• 1 immi= 7 aNukkaL= 2.3333 millimetre
• 1 saaN= 100 immi= 23.3333 centimetre
• 1 muzham= 2 saaN= 46.6666 centimetre
• 1 kaadham= 5000 saaN= 1166.66 metres= 1.1167 kilometre

Numbers

Image File history File links Oldtamilcharactersold. ...

• 1= "ondru"
• 10= paththu
• 100= noorru
• 1000= aayiram
• 100,000= nooru aayiram
• 1000,000= meiyiram
• 10^9= thoLLunn
• 10^12= eegiyam
• 10^15= neLai .

Currency

• 1 pal(wooden discs/sea shellots)= (approximately) 0.9 grain
• 8 (or 10 base 8) paRkaL =1 senkaaNi (copper/bronze) = 7.2 grains(misinterpretted by Roman accounts as 10 base 10=9 grains)
• 1/4 senkaaNi =1 kaalkaaNi (copper) =1.8 grains(misinterpretted by Roman accounts as 2.25 grains)
• 64 (or 100 base 8) paRkaL = 1 KaaNap-pon a.k.a. Kaasu panam(gold) = 57.6 grains
• 1 Roman dinarium was traded on par with 2 KaaNappon plus 1 SenkaaNi(=124 grains).

References:

• [1] Mu.Varadharasanaar's "Brief history of Tamil and their literature"
• [2] Ancient trade routes -map
• [3] Contacts with West
• [4] Ancient trade sea routes