http://www.archive.org/details/story_of_television


early promo for color television

There are many more films on early television online:

http://www.earlytelevision.org/online_films.html

Check out the Alexandra Palace Television Society channel on Youtube,

http://www.youtube.com/user/aptsarchive#p/p

And "Television comes to London" (part II is on the side),

http://www.youtube.com/watch?v=pps6aWcvReA