“Why are clouds like jockeys?”/“When they hold the rains.”

A “rains/reins” pun from 1878 is:
 
“When are the clouds like jockeys? When they hold the rains.”
 
The joke was repopularized (or reinvented) in the 2000s. “Why are clouds like jockeys? Because the hold the reins” was cited in 2002.
 
 
13 September 1878, Titusville (PA) Morning Herald, “Varieties,” pg. 3, col. 1:
When are the clouds like jockeys? When they hold the rains.
 
Chronicling America
10 October 1878, Belmont Chronicle (St. Clairsville, OH), “Wit and Humor,” pg. 1, col. 8:
When are the clouds like jockeys? When they hold the rains.
   
Google Books
March 1879, Frank Leslie’s Popular Monthly, pg. 383, col. 2:
ENTERTAINING COLUMN.
When are the clouds like jockeys ? When they hold the rains.
 
8 March 1976, Wichita Falls (TX) Times, “Wizard Word,” pg. 14A, col. 5:
JOCKEYS ARE LIKE CLOUDS BECAUSE THEY HOLD THE _____.
 
Google Groups: rec.humor.jewish
“Puns of the Weak” 07/12/02
Stan Kegel
7/13/02
(...)
Why are clouds like jockeys?
Because the hold the reins.  (Lederer & Ertner)
 
26 August 2003, Roswell (NM) Daily Record, “Riddle Card,” pg. B6, col. 1:
2. Why are clouds like jockeys?
Because they hold the rains (reins),
 
Google Books
The Mammoth Book of Really Silly Jokes
By Geoff Tibballs
London: Constable & Robinson Ltd.
2011
Pg. 444:
Why are clouds like jockeys?
Because they hold the reins.
 
Twitter
Kim
‏@Brigette_5149
Why are clouds like jockeys? Because they hold the reins! Ha
10:28 PM - 22 May 2015