“What is the difference between an engineer and a school teacher?” (riddle)

A popular pun was cited in many newspapers in 1850:
 
“What is the difference between a schoolmaster and an engine driver?—One trains the mind, and the other minds the train!”
 
“Schoolmaster” is often replaced with “schoolteacher” and “engine driver” is often replaced with “locomotive driver” or “locomotive engineer.”
 
 
27 November 1850, The Nonconformist (London), “Gleanings,” pg. 966:
What is the difference between a schoolmaster and an engine driver?—One trains the mind, and the other minds the train!
 
5 December 1850, Boston (MA) Daily Bee “The Pen and Scissors Department,” pg. 2, col. 3:
Why is a schoolmaster like an engine-driver? One trains the mind, the other minds the train.
     
Chronicling America
16 October 1852, Daily American Telegraph (Washington, DC), “Items,” pg. 2, col. 4:
What is the difference between a schoolmaster and an engine-driver? One trains the mind, the other minds the train.
 
Chronicling America
14 February 1856, Lancaster (OH) Gazette, pg. 4, col. 1:
The difference between a schoolmaster and an engine driver is, that one minds the train, and the other trains the mind.
 
Google Books
The World of Wit and Humour
Edited by George manville Fenn
London: Cassell, Petter & Galpin
1872
Pg. 303:
WHAT is the difference between a locomotive driver and a schoolmaster?—One minds the train, the other trains the mind.
 
Google Books
November 1892, Donahoe’s Monthly Magazine, pg. 466:
What is the difference between an engineer and a school teacher? One trains the mind and the other minds the train.
 
Chicago (IL) Tribune
PLAYING AROUND.
What’s the difference between a railway guard and a…
October 24, 1995
What’s the difference between a railway guard and a teacher?
- One minds the train and the other trains the mind.
 
Google Books
Riddles, Riddles, Riddles
By Darwin Alexander Hindman
Mineola, NY: Dover Publications
1997
Pg. 57:
What is the difference between a locomotive engineer and a schoolmaster?
ANS: One minds the train, the other trains the mind.
 
Google Books
A Tribute to Teachers:
Wit and Wisdom, Information and Inspiration about Those Who Change Our Lives
By Richard Lederer
Portland, OR: Marion Street Press
2011
Pg. ?:
What’s the difference between a conductor and a teacher?
The conductor minds the train and a teacher trains the mind.
What’s the difference between a train and a teacher?
A train goes “choo choo,” and a teacher says, “Spit out your gum!”
 
Google Books
Riddledom:
101 Riddles and Their Stories
By David Astle
Crows Nest NSW (Australia): Allen & Unwin
2015
Pg. 5:
“What is the difference between an engineer and a school teacher?”
(...)
One minds the train, the other trains the mind.