In the 1860s, mechanisms for producing two-dimensional drawings in motion were demonstrated with devices such as the zoetrope, mutoscope and praxinoscope. These machines were outgrowths of simple optical devices (las vegas hotel) and would display sequences of still pictures at sufficient speed for the images on the pictures to appear to be moving, a phenomenon called persistence of vision. Naturally the images needed to be carefully designed to achieve the desired effect, and the underlying principle became the basis for the development of film animation. With the development of orlando hotel celluloid film for still photography, it became possible to directly capture objects in motion in real time. An 1878 experiment by Eadweard Muybridge in the United States using 24 cameras produced a series of stereoscopic images of a galloping horse, arguably the first "motion picture," though it was not called by this name. This technology required a person to look into a viewing machine to see the pictures which were separate paper prints attached to a drum turned by a handcrank new york hotel. The pictures were shown at a variable speed of about 5 to 10 pictures per second, depending on how rapidly the crank was turned. Commercial versions of these machines were coin operated.