Home
Back
"A-Z" INDEX
DAC Logo

Morphometry Tools

Many measurements have to be made repeatedly on large numbers of bees. These can be taken in a simple way with the aid of specific tools.

The tomenta hair eyeglass...
has it's own built in measuring wire. This particular version was made with materials that were to hand and is a little more robust than others I have seen.

There are several parts... the eyeglass itself was made of bakelite and had a 100 mm focal length, the electrical connector came from my junk box and the copper wire was a strand pulled from some thick cable I had lying around.
Electrical Connector Block
EyeglassThe left hand illustration shows the basic eyeglass that I started with.

The electrical connector block shown right is stripped down to obtain the brass centre piece and the screws.

Modified Eyeglass
A series of 1 mm diameter holes was drilled in the side of the body (note the stagger in the bottom row of holes).

The end of some 1 mm copper wire was soldered to the brass connector and the wire fed through the holes, soldering each time the wire passed over the front of the brass block.

Even pulling the wire tight each time, the result was still a little loose so a dollop of superglue was used to firm everything up.


Guage Wire

The guage wire shown in the illustration left is fitted into the bore of the connector and the screws tightened to hold the wire so that the flattened measuring tip is in focus.



The enlarged view shows how the wire is flattened at the end. The flattening is achieved using a pair of pliers, not the jaws themselves but the root nearest the pivot so that adequate leverage is obtained. The tab so formed is measured using a micrometer and the squeezing repeated until the tip is exactly 0.40 mm thick.


Note... Plenty of illumination is required.

There are two modifications I will perform some time in the future:-

The first is to fit another connector on the opposite side the eyeglass body so that another wire can be fitted to act as a stop so that my thumb is in a repeatable position.

The spring removed from an old alarm clock will be my second modification and this will be fitted so that the curl of the spring holds the eyeglass in place in my eyesocket (I have seen jewellers use this method in the past).

A further possible modification may be needed in future to correct for the astigmatic component of my eyesight defects... This would entail cutting a circular portion from an old plastic spectacle lens and gluing it inside the body of the eyeglass. Link to Herold drawing

Herold fan...
This enables rapid assessment of Cubital index using the 35 mm projection method. (click on thumbnail image for full size printable versions)

This may look complex at first sight but it is quite easy once you have done two or three.

When using the projector ensure that the axis of the lens is exactly perpendicular to the wall both horizontally and vertically.

Herold Use detail
The diagram left was drawn from a BIBBA original.

The Herold Fan is held flat on the wall so that vein "AB" is parallel to the "rungs" of the right hand ladder. The exteme right side of this "ladder" should pass through the centre of point "A". The line that forms the left of this "ladder" should pass through point "B".

The line that then passes through point"C" then represents the Cubital Index. Joint "C" is a broad traingle, the actual measuring point should be the centriod of this triangle.

I had some difficulty drawing the full sized versions of the Herold fan... There were some minor errors in the original printed sheet that I have. I have corrected these and provided both left and right hand versions which can be printed via your browser. There are still some minor errors but they are very small (less than 0.17 mm). I have used colour to aid those that are, like me, challenged in the eyesight department.

Link to drawing
Discoidal card...

Can be used with the projection method for discoidal shift measurement. (click on small image at right for full size printable version)

Glossimeter...

Is the technical term for the device that measures tongue length (or more precisely tongue reach).
unfinished drawing



Home Back Top