In 1855, Johann Nepomuk Czermak's published an article about his Stereophoroskop and other experiments aimed at stereoscopic moving images. He mentioned a method of sticking needles in a stroboscopic disc, so that they would appear as if moving in and out of the cardboard when animated. He supposed that this principle provided endless possibilities to make different 3D animations. He then introduced two methods to animate stereoscopic pairs of images, one was basically a stereo viewer using two stroboscopic discs and the other was more or less similar to the later zoetrope (but in a vertical position with horizontal slits). Czermak explained how suitable stereoscopic photographs could be made by recording a series of models, with an example of a growing pyramid.