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Since the average lunar month is 29.5 days, over 12 months this would produce a total of only 354 days as against a solar year of 365.25 days.
To keep the calendar aligned to the seasons they added seven extra months in each period of 19 years, equivalent to the way we add an extra day in leap years.
The Mesopotamians thus introduced the 60-minute hour, the 60-second minute and the 360-degree circle with each angular degree consisting of 60 seconds.
The calendar adopted by the Sumerians, Babylonians and Assyrians was based 12 lunar months and seven-day weeks with 24-hour days.
It seems Tesla's explanation was appropriately named. Also called magnetite, lodestone is a magnetic oxide of iron (Fe) which was mined in the province of Magnesia in Thessaly from where the magnet gets its name.
Lodestone was also known in China at that time where it was known as "love stone" and is in fact quite common throughout the world.
Initially inspired by the development of batteries, it covers technology in general and includes some interesting little known, or long forgotten, facts as well as a few myths about the development of technology, the science behind it, the context in which it occurred and the deeds of the many personalities, eccentrics and charlatans involved.
The clay subsequently hardened in the Sun or was baked to form permanent tablets. For the first time news and ideas could be carried to distant places without having to rely on a messenger's memory and integrity.Produced from the freshwater papyrus reed, the papyrus scrolls were fragile and susceptible to decay from both moisture and excessive dryness and many of them have thus been lost, whereas the older, more durable clay cuneiform tablets from Mesopotamia have survived. Sumerian mathematics and science used a base 60 sexagesimal numeral system.Historians seem to agree that the wheel and axle were invented around 3500 B. 60 is divisible by 1,2,3,4,5,6,10,12,15,20,30 and 60 making it more convenient than using a base 10 decimal system when working with fractions.In recent years batteries have changed out of all recognition. Today the cells are components in battery systems, incorporating electronics and software, power management and control systems, monitoring and protection circuits, communications interfaces and thermal management. Mesopotamia, incorporating Sumer, Babylonia and Assyria, known in the West as the Cradle of Civilisation was located between the Tigris and Euphrates rivers (The name means "land between the rivers") in the so called Fertile Crescent stretching from the current Gulf of Iran up to modern day Turkey. the Sumerians of ancient Mesopotamia developed the World's first written language.(See Map of Mesopotamia) Unfortunately this accolade ignores the contributions of the Chinese people and the Harappans of the Indus Valley, (Modern day Pakistan) who were equally "civilised" during this period practicing metallurgy (copper, bronze, lead, and tin) and urban planning, with civic buildings, baked brick houses, and water supply and drainage systems. Called Cuneiform Writing from the Latin "cuneus", meaning "wedge", it was developed as a vehicle for commercial accounting transactions and record keeping.
Despite decimalisation, we still use these sexagesimal measures today.