These questions may never be adequately answered to satisfy all who ask. However, one thing is for sure; there was apparently a presentation, and it was with a Tachyscope, likely that of the Edison labs, made by Dickson.
Chronicler Gordon Hendricks in his exhaustive work The Edison Motion Picture Myth has presented some impressive details, but as he himself points out, “Since an exhaustive search has discovered no other reference to this projection . . . we can assume that such a projection occurred." (p92). The presentation is said to be the sponsored work of Edison, at the Lenox Lyceum, which was at one time the Panoramic Building on Madison Avenue, New York City.
It is also reported to have been a public motion picture projection, although as it turned out only reporters saw the pictures move. The event was certainly well documented, having made it’s way into several daily newspapers including the New York Herald, Sun and World, as well as other magazines and weekly newspapers. Hendricks documents a report from a writer of the Western Electrician published on April 12;
"The effects produced are indeed wonderful, and in splendor outrank anything ever seen in this country. A magic lantern of almost unimaginable power casts upon the ceiling from the top of the tower such pictures as seen to be the actual performances of living persons.â€
Could this have been only a preview for the press as Hendricks suggests? The strong suggestion has also been made that the photographs of Muybridge could have been what were shown that day. Photographs made and shown in the Edison lab to this time, where well known as being microscopic and not suitable for full projection in any projector he had. This bides well then for the hint that Muybridge may have provided such photos for the event at the Lenox Lyceum.
Interestingly, The General Magazine and Historical Chronicle, published through the University of Pennsylvania where Muybridge had worked earlier, reported regarding the photographs of Muybridge, that Thomas Edison had used, “Muybridge’s motion photographs of running horses . . . [as] his first continuous movie on a strip film.†We have not come upon any other references either, regarding this event, and must conclude from what evidence does exist, that this presentation did in fact take place.