The first articulator to be patented by McCollum in 1929, according to Charles E. Stuart, it was made in 1925 for the study group so that they could have some kind of instrument on which they could make a face bow transfer and check bites. Stuart stated that there were no instruments available at that time that would allow them to do that. They would then transfer the casts to a more appropriate instrument that would allow for the axis shift or laterotrusion.
This instrument was essentially a non-arcon, semi adjustable articulator with the adjustable intercondylar feature, adjustable incisal guide assembly, but only allowed for the progressive Bennett movement. Interestingly, it was initially named the “Gnathograph” but the name was changed to “Gnathoscope” for the more familiar commercial model. Later, Charles Stuart used the name, “Gnathograph” for his commercially available pantograph.
Stuart CE, Golden IB (ed): The History of Gnathology, (Memorial Edition), C.E. Stuart Gnathological Instruments, Ventura , California , 1984: p. 50.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.