Semi-adjustable articulator with mounted casts. An articulator is a mechanical device used in dentistry to which casts of the maxillary (upper) and mandibular (lower) teeth are fixed, reproducing recorded positions of the mandible in relation to the maxilla.
The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century AD during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604â618), who had one installed for his royal library.
Actually, Elwood Haynes built the first automobile made in the United States. It was first driven in 1894, two years before the Quadicycle.Duryea's automobile was a horse drawn carriage adapted to use an internal combustion engine but still could be horse drawn. Haynes car was built as an automobile from the ground up.ctually, Elwood Haynes built the first automobile made in the United States. It was first driven in 1894, two years before the Quadicycle.