T.G. Lewis and George Snow may have collaborated on more than one articulator during the 1860's. This one was produced well into the 1900's.
Articulators of this kind were very popular with most dentists of the time because the emphasis of design was high adjustability to correct common clinical errors. This articulator had vertical, horizontal and lateral adjustment capabilities. Set screws prevented loss of the selected positions. Lewis continued to produce articulators of this type while George Snow pursued another course designing articulators based on information recorded from the patient.
Morrison Brothers illustrated Dental Catalog, 1897, Nashville, TN.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.