A Leitz 'Edinger Apparatus' photomicrography system ca. 1910: Notes on progress in its restoration.   by Bruce Allen, USA

 

Micscape readers might be interested in a Leitz photomicrography system I found in a damp warehouse (Richmond, Virginia) in January 2002. I would appreciate any information on the apparatus as I plan to restore and USE it. I describe below the restoration so far and some background information I've gleaned to date.

It's called an "Edinger Apparatus" (serial number #121) and is used vertically as seen in the attached photos. However, it can be rotated 90 degrees for projection purposes. It can be configured three ways; 1) as a magic lantern slide projector using an attachable holder (missing), 2) as a microscope slide projector, or 3) for photomicrography with the addition of the 11x14 inch plate camera (the set-up shown in this article).

The only literature that I have on this apparatus was kindly sent to me by John Field in California. It is in German and has no date. I have passed on a copy of the brochure and photos to Herr Rolf Beck at Leica Microsystems who maintains the Leica archives. Herr Beck tells me in a letter that the 'Edinger Apparatus' was first produced in 1910.

So far all I have done is replate all the obvious nickel parts, polished the brass ones and cleaned up the original paint which is in remarkably good condition. I've left alone any parts which I could not identify the correct finish and I have not started on the camera portion as yet.

I'm debating the merits of replacing the bellows; do I leave it original and not be able to use the camera or do I replace it with a replica so that the camera is functional? I have found someone who can make an exact copy and can reproduce the missing film holders. (The ground glass screen is present and perfect). I found a table similar to the one in the brochure and mounted the rail correctly. As far as it goes, once I replaced the wiring with modern reproduction braided wiring, the carbon arc lamp works beautifully and is BRIGHT. As a microscope slide projector it works perfectly.

Thank you for looking. If anyone has information leading  to restoration of similar equipment or can provide further information on the unit or its history, please e-mail me, Bruce Allen.

 

Acknowledgements:

Many thanks to John Field, California for providing an extract of the E. Leitz Wetzlar brochure (the section is entitled Zeichen -und Projektions apparat IV). The black and white drawings below are scanned from this brochure. I would like to particularly thank him for sending me three boxes of the correct arc lamp rods (50 to a box!).

Also thanks to Rolf Beck, Leica Microsystems who provided very useful information in his correspondence, including the manufacturing date. The photo of Dr. Edinger below was scanned from an article written by Herr Beck and which he kindly included a copy of in his letter. This German article doesn't cover the Edinger apparatus described below, but an earlier (?) smaller gas light version. (The article is Projecktions- und Zeichenapparat nach Edinger by R. Beck in Mitteilungen für Wissenschaft und Technik, June 1991, p. 30-31. The article has seven refs. to further information.)

Editor's note: Bruce possesses a range of  interesting apparatus including a Bausch & Lomb carbon arc lamp from 1935, a clockwork driven arc lamp and other early electric microscope lamps. The author hopes to illustrate some of these in a later article.
 
 

Image gallery
Click each image to see a larger ca. 600x800 pixel image (ca. 70 kbytes each in size).
Images of the restored apparatus are copyright of the author and
are not to be used without permission.

E. Leitz ‘Edinger’ apparatus ca. 1910.
Set up for photomicrographic use in 2002 (with a table found of similar design to that in the brochure). Dimensions: The focussing rail is 90 cm long. Total length to the top of the arc lamp is 115 cm. Overall width is about 34cm (including camera). From the back edge of rail to far edge of camera is 55 cm.  Click the upper right image for an 600x800 pixel image, or click here for the master 1422x1922 image (184 kbytes).	Name plate detail.
With camera attached to auxiliary rail.
Another view of camera configuration.
Carbon arc lamp in relation to the microscope stage. The large red knob is used to adjust the carbon rods. Two nickel plated knobs below and to the left of the red knob adjust the rods left and right, forward and back inside the lamp housing, centering the light onto the ellipsoidal lenses below.  The small window is a sight glass made of dense, dark blue glass so you can look at the rods without going blind in the process of adjusting them. The large brass handle is for moving the entire lamp up or down, which concentrates the light onto the iris and condenser assembly.
View showing iris, condensers, microscope stage with slide, objective and shutter. The iris is a leaf type diaphragm which opens and closes in order to dim the light  passing through to the two swing-out condensers below. The condensers are used to further concentrate the light onto the specimen slide.  The microscope objective is below the stage, facing up and is adjustable via the two brass knobs. The large one is coarse focus and the small one is spring-loaded and is for fine focus.
Another view showing the microscope stage and camera shutter. The nipple on the side of the shutter is for a rubber squeeze bulb used to remotely open (and close) the shutter, thereby minimizing vibration. The shutter may also be opened or closed manually with the knob on the top of the assembly.
Camera with hinged bellows opened to show the ground glass plate used for focusing an image. You lift the bellows up and peek at the image formed on the ground glass. Once you are satisfied with the image you close the bellows and lock it down with the small brass slide tabs, then pull out the ground glass plate and replace it with a film holder plate.
As found when brought home from a damp warehouse in Richmond, Virginia January 2002.
E.Leitz Edinger Apparatus after phase 1 of restoration March 2002. Phase 2 includes: Replacement of the bellows and constructing the missing film plates and control rod for the carbon arc lamp as well as manufacturing the auxiliary rail assembly.
Carbon arc lamp in operation. The carbon arc lamp operates on 110 volts, wired through a 4 amp rheostat. Reproduction wiring is used to keep the house from burning down! A rheostat acts as a heat sink and glows red-hot after the lamp has been in operation for any significant period of time. The arc lamp itself gets very hot too. You have to wonder how many laboratories burned to the ground at the beginning of the 20th century!
Ludwig Edinger (1855 - 1918). See the 'Founders of neurology' web site of the University of Illinois for a brief biography.