O que significa electric lights kept factories go around the work ?

See a translation

This a part of an old TOEFL listening material,and the unchanged sentence is:Watches became fairly inexpensive.Furthermore,electric lights kept factories going around the clock.

In the late 1700's, people didn't know the exact time unless they were near a clock. Those delightful
clocks in the squares of European towns were built for the public --- after all, most citizens simply
couldn't afford a personal timepiece. Well into the 1800's --- in European and the United States --- the
main purpose of a watch, which, by the way, was often on a gold chain, was to show others how
wealthy you were.

The word "wristwatch" didn't even enter the English language until nearly 1900. By then the rapid
pace of industrialization in the Unites States meant that measuring time had become essential.

How could the factory worker get to work on time unless he or she knew exactly what time it was?
Since efficiency was now measured by how fast a job was done, everyone was interested in time. And
since industrialization made possible the manufacture of large quantities of goods, watches became
fairly inexpensive. Furthermore, electric lights kept factories going around the clock. Being on time
had entered the language --- and life --- of every citizen.

Oh,thank you.I typed in a wrong word,and I understand it now