One of Edison's invention - Does this article sound good in English?

I have translated this passage from Arabic into English, and I want to know if it sounds good in English, and if there are grammatical mistakes. Thanks in advance.

One of Edison's invention

When Edison was fourteen, he worked at a railway station. He worked only at night.

However, Edison used to spend the whole day working on his experiments. As a result, he

would usually fall asleep during his work time, and he was not able to answer any of the

telegraphs sent from the other stations. The inspector, however, warned him several times

and ordered him to transmit a special signal every thirty minutes to prove that he is awake. Edison did as he was told only for a few nights, then he got tired of that. Therefore, he

invented a small machine that transmits that special signal automatically every thirty minutes.

Yet, at one night, the inspector tried to call Edison but Edison did not reply. The inspector

found it so strange, as the signals were transmitted regularly every thirty minutes. So, he

went quickly to the station where Edison was working, and he looked through the window.

There he found him in a deep sleep, while the small machine was sending the required signals

regularly. In fact, the inspector was so pleased with Edison's work; however, he could not let

him continue working at the station and dismissed him.

A few small grammatical fixes:

"The inspector, however, warned him several times and ordered him to transmit a special signal every thirty minutes to prove that he was awake"

"Therefore, he invented a small machine that transmitted that special signal automatically every thirty minutes."

"The inspector found this very strange, as the signals were transmitted regularly every thirty minutes"

"In fact, the inspector was quite pleased with Edison's work

Sean took all the good corrections and left me with no corrections to make!

This is a cool story that I have never heard; thanks for sharing it here.

One little improvement I guess you could make is this:

...however, he could not let Edison continue working at the station, so Edison was dismissed.

I though of this:

When Edison was fourteen, he worked at a railway station only at night .

I think many short sentences make one's writing dull and jurky.