Basically, Hermes was the Greek messenger god. The Romans identified their gods with Greek ones, and Mercury is the Roman version of Hermes.
The use of two spaces was taught when typewriters were used. With a typewriter, all characters were all the same size, and the extra space helped the reader distinguish the sentences. With today's word processors, the characters are different sizes, ...
back when we used typewriters we all knew that it was stewardesses and hokeypokey on the right, because that was part of the typing test, just like the quick brown fox jumps over the lazy red dog. there were also word for the top and middle, rows, bu...