In 1899, George Snow and DeWitt Gritman were issued a landmark patent for the Gritman articulator and Snow facebow. The Gritman articulator was a fixed condylar guide instrument. The Snow facebow was the first device that related the maxilla anatomically to the condylar.
The Snow "New Century" is the next generation Gritman and embodied adjustable condylar guides with fixed "Bennett" (inward) path. It was the 4th articulator to be patent for such a feature.
The Snow "Acme" was the next generation of the "New Century" but embodied two significant improvements : incisal pin and guide assembly and a condylar horizontal "side shift". The "Acme" was the 5th articulator patented with an incisal pin and guide. The Snow "Acme” was a practical articulator and was widely accepted by the profession.
JP Article V.9, No.4, December 2600: pp217-22
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.