praxinoscope

the praxinoscope was the first device to overcome the distortion that was caused by viewing the moving images through a slot. because of this, the device quickly became more popular then the zoetrope. as the praxinoscope continued to grow in popularity, Emile reynaud discovered a way of projecting these images. this allowed more people to view the animations and also allowed the animations to be longer. this device was called the Theatre optique. if you want to learn more about the theatre optique you can find more information on my timeline 'History of animation'

sources
http://www.earlycinema.com/technology/praxinoscope.html