There where portable (or at least smaller) 35 m.m. projectors. They camed with one when I was in kindergarten. And I've seen somwehere a manual for one.
Here are images with 35 m.m. portable film (movie) projectors:
http://www.film-tech.com/warehouse/p...860&category=1
http://www.hallucine.fr/en/rental-sa...nema-material/