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.
The electronics, computers and communications industries, power engineering and much of the chemical industry of today were founded on discoveries made possible by the battery.
He travelled to Egypt and the city state of Babylon in Mesopotamia (now modern day Iraq) and is said to have brought Babylonian mathematics back to Greece.
The following rules are attributed to him: Using the concept of similar triangles he was able to calculate the height of pyramids by comparing the size of their shadows with smaller, similar triangles of known dimensions.
The writing was in the form of a series of wedge-shaped signs pressed into soft clay by means of a reed stylus to create simple pictures, or pictograms, each representing an object. the script progressively evolved to encompass more abstract concepts as well as phonetic functions (representing sounds, just like the modern Western alphabet) enabling the recording of messages and ideas.
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.
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.
Surprisingly although they were aware of its magnetic properties, neither the Greeks nor the Romans seem to have discovered its directive property. D., the somewhat unscientific Roman chronicler of science Pliny the Elder, completed his celebrated series of books entitled "Natural History". The Greek philosopher and scientist, Thales of Miletus (624-546 B.