DESCRIPTION: Signed on the nickel-plated brass turntable itself: E.H. GRIFFITH.PAT.AP'D.FOR, FAIRPORT N.Y.. This is a heavy turntable mounted on a traditional black painted cast iron tripod. It has a removable wrist rest which overhangs the slide to give the user the advantage of holding their brush closer to the center of slide for added stability. The edge of the turntable itself is knurled, but there is also a smaller diameter knurled knob underneath for turning. Concentric rings are engraved on the table to assist in centering. The turntable rests on an axle or spindle with a sharp point on top to minimize friction, and this works amazingly well. There are two knobs underneath the table, R being a knob which lowers or raises one of the fixed pins (E, below) and the T-shaped knob (T) is used to lock the small accessory disk with a single pin in place(F below).
The unusual mechanism allows one to center a slide easily. It was patented December 14, 1886, so the inscription of patent applied for, dates it to earlier than that. There are two fixed pins(D & E, two pins(B & C) on a rotating center plate(A) and a fifth pin(F) which rides on a small disk. The latter can be locked by a control on the bottom. One of the fixed pins(E) is screwed in from under the table, and can be lowered beneath the turntable to accomodate longer slides. It is controlled with a small kurled knob. The knobs and the table are all nickel-plated brass.
The central ring on the table with the 2 pins, 180o from each other as noted above, is moveable. Originally it was sprung so that the spring would pull it clockwise when it was turned counterclockwise to allow a slide to be attached , but the spring is now missing. Nevertheless, the mechanism still works well manually to center a slide. A series of images on this site illustrates how this works.
HISTORY:
Ezra Griffith received a patent for his turntable on December 14, 1886. It was sold individually as seen on this page, but was also integrated into the bottom of the foot of his famous Club Microscope. The Club Microscope was first reported by Griffith in 1879, and the description of the first version was published in 1880. But the original version of the Griffith turntable, including the one on the foot of the Club microscope, changed over the years.
The early Griffith turntable models, presumably starting in 1879, had three triangular fittings to hold the slide, and although the slide holding mechanism automatically centered the slide, the mechanism was not as smooth or sophisticated as in the newer turntable mechanism as featured on this web page. In addition, the three spokes with balls were not originally present on the foot of the Club microscope. Then sometime between the time the Griffith Club microscope was introduced, and 1883, the spokes with balls were added. This gave the Club Microscope turntable more momentum once spinning; this intermediate design(right) still used the triangular fittings to hold the slide.
Later, the final design using the patented mechanism, was used on the foot of the club microscope. In use, it made use of a spindle integrated into the inside of the case for the microscope. For more about Ezra Griffith and his life and work, please see the history section of the Griffith Club Microscope Page
CONDITION:
When I received this turntable it was in very poor condition and nearly all of the nickel-plating was gone. In addition the paint had severe losses and the iron tripod had several large areas of rust. Some prior owner had fitted stage clips to two of the pins and the centering mechanism was frozen. I removed the clips, resurfaced and re-painted the black tripod and partially restored the nickel plating. I did not want it to look new so the plating was restored in a way that was consistent with its age. The knobs underneath were also cleaned and replated.
The centering mechanism was removed and cleaned and refinished. The spring was missing and I was unable to find a suitable replacement. Nevertheless, the centering mechanism works perfectly though it has to be manually rotated back to the centering position after a slide has been placed on the table.
Signed on the nickel-plated brass turntable itself: 
The early Griffith turntable models, presumably starting in 1879, had three triangular fittings to hold the slide, and although the slide holding mechanism automatically centered the slide, the mechanism was not as smooth or sophisticated as in the newer turntable mechanism as featured on this web page. In addition, the three spokes with balls were not originally present on the foot of the Club microscope. Then sometime between the time the Griffith Club microscope was introduced, and 1883, the spokes with balls were added. This gave the Club Microscope turntable more momentum once spinning; this intermediate design(right) still used the triangular fittings to hold the slide.
Later, the final design using the patented mechanism, was used on the foot of the club microscope. In use, it made use of a spindle integrated into the inside of the case for the microscope. For more about Ezra Griffith and his life and work, please see the history section of the Griffith Club Microscope Page