Where did the name Midlothian come from?

Originally Midlothian was called Barker after C. H. Barker who had this first post office on his farm. It appears according to Brian Bennett from Waxahachie that

"By January of 1881 a railroad line had been surveyed through Barker and a depot "on the square" was expected. The company had purchased from G.W. Hawkins six hundred acres of land, his residence and spring for the depot ground. Barker residents felt that the railroad would make Barker a large city. By June, Barker was referred to as Midlothian (the first instance of this name appearing in the Waxahachie Enterprise was June 3, 1881)."

So apparently Barker name change to Midlothian happened June 1881. The Post Office was still named Charles Barker ,then

"by May of 1882 citizens had sent a petition to Washington to seek a change in the name of their post office from Barker to Midlothian (it is undetermined when this change became effective)."

I have heard and believe that Midlothian, Texas was named by a Scottish train engineer who thought the town reminded of his home county Midlothian, Scotland. It may have been another Scottish man, maybe a guy who worked on building the rail line, because according to Brian Bennett's article the railroad wasn't completed or completely running until

"between November and January"

Then

"the tracks had been completed to Cleburne and passenger trains were running."

I wonder if 6 months was enough time to get a train running to Midlothian. Because the survey for the lines were completed in January of 1881 and the name Midlothian appeared in a paper in June of 1881 that is according Brian Bennett.

If you have ever looked into how Texas towns get named it usually comes about by Native American names, Settlers names, Mexican names,Politicians names, War hero names, or whatever the Post Office or Rail Road decided to call the area.