TPO 25 reading:
In 1938 an archaeologist in Iraq acquired a set of clay jars that had been excavated two years earlier by villagers constructing a railroad line. The vessel was about 2,200 years old. Each clay jay contained a copper cylinder surrounding an iron rod. The archaeologist proposed that vessel were ancient electric batteries and even demonstrated that they can produce a small electric current when filled with some liquids. However, it is not likely that the vessels were actually used as electric batteries in ancient times.
First of all, if the vessels were used as batteries, they would probably have been attached to some electricity conductors suchas metal wires. But there is no evidence that any metal wires were located near the vessels. All that has been excavated are the vessels themselves.
Second, the copper cylinders inside the jarslook exactly like copper cylinders discovered in the ruins of Seleucia, an ancientcity located nearby. We know that the copper cylinders from Seleucia were used for holding scrolls of sacred texts, not for generating electricity. Since the cylinders found with the jars have the same shape, it is very likely they were used for holding scrolls as well. That no scrolls were found inside the jars can be explained by the fact that the scrolls simply disintegrated over the centuries.
Finally, what could ancient people have done with the electricity that the vessels were supposed to have generated? They had no devices that replied on electricity. As batteries, the vessels would have been completely useless to them.
The writer and the professor discuss whether the vessels were used as batteries. The writer contends three reasons to argue that they are unlikely to be used as batteries, which are rejected by the professor respectively. The professor thinks that they could be used for electricity.
The first statement offered by the writer is that metal wires were not found near the vessels which served as electricity conductors. However, the professor challenges this view by saying that these vessels were initially found by local people who lacked training. Maybe there were metal wires around the vessels, but local people overlooked their importance and threw away metal wires which appeared around the vessels. No one exactly knew the situation at that time.
Secondly, according to the passage, the copper cylinders inside the jarslook was similar to those found in the ruins of Seleucia which were proved to be used for holding scrolls. On the contrary, the professor considers that although they were similar, it could prove nothing. It was true that copper cylinders could preserve things, but it was also found that they could be used to generate electricity when filled with liquids, according to the first battery discovered. So it is reasonable to believe that the copper cylinders could be used for one purpose originally and adapted to another purpose with time.
Finally, generating electricity like this seemed useless for ancient people, argued by the writer. Unfortunately, the professor feels that this explanation does not hold water, for the reason that the vessels could generate a mild shock which might be seen as an invisible power. Besides, ancient people could use it to show that they hold magical power. Moreover, they could use electricity currents for healing, such as doctors.
(A lecture from an American History class | TOEFL Lectures | english.best)