After browsing the web for images that feature the interiors of buildings from the 1920s to the 1930s in which schoolhouse fixtures are installed, I have noticed that in some cases, there were schoolhouse fixtures that had their own pull chains instead of having multiple wired to one switch in a single room. Why were some schoolhouse fixtures manufactured with integral pull chains?
Here is an example of a building with schoolhouse fixtures with their own individual pull chains:
https://fineartamerica.com/featured/1-1920s-office-scene-underwood-archives.html
I do not remember any school house classroom lights with pull chains. Those would be in other areas were teachers and other personel worked because they were turned on only as necessary. Further, school systems did not want kids fiddling around with turning lights on-and-off, so they were in restricted areas. The old classroom fixtures as I recall (with milk-glass globes) hung on chains were placed over student seating and controlled by multiple switches. Some had a special key to prevent kids tampering with them :-) As I recall there were three lights in a row with three rows in each regular-sized classroom (nine-total), going front-to-back. I think they had 200W lamps inside them. Each row was controlled by an individual switch (that was typically I assume rated around 660W), so three switches; and they were on the wall near the entry door as I also recall.
