Frontispiece table from Jabez Hogg'' textbook "The Microscope", 1st edition, 1854. On a monument's base we find a contemporary small microscope (left) by the splendid Ross Company, U.K. and an older "Screw Barrel" microscope (right) dating back to the 18th century.
In this book and in others we come across a wide range of possible technical solutions for microscope micro aquaria. We will look at them in order to find one that might be suited for our special task. Some of the devices might look a little bit crude at the first sight but we should by no means underestimate the creativity our our ancestors!
Aquarium microscope, ca. 1860.
The above figure represents a small microscope dipping directly into the water and being protected by a glass container looking like an ordinary test tube. It can be moved all over the surface area by a positioning device working in a similar way as the mechanical stage of a microscope. As a consequence, a really big water volume can be studied and a large fraction of the volume is accessible for the microscope. The big water volume has its well-known advantages: the physico-chemical properties of the water will change only slowly and there is no danger that it might suddenly dry out like a droplet of water on our microscopy glass slides. On the other hand, after some time this ingenious machinery will certainly cause some back-ache and you will certainly know what you have done after some hours of study. Last but not least when being transferred to the water bear topic it becomes clear that the water bears will run away out of sight and will get lost somewhere within the big volume, so we will not be able to study them in a continuous manner and we will not be able to find certain individuals again a few days later.
Our ancestors therefore tried very soon to reduce the dimensions of the aquaria and by this facilitated the study with optical devices. A good example for a moderate solution is the following "portrait" orientation aquarium with attached loupe.
"Portrait" orientation aquarium for the
study of water animalcules at an approximate 10x magnification.
A very practical approach came from a female Irish microscope amateur, The Honourable Mrs. Ward  (1827-1869). It might possibly be a solution for a more comfortable long time observation and doesn't need any additional investment:
"Arrangement of Microscope for viewing minute Water Animals" (after WARD)
But do not think that Mrs. Ward might have been a primitive person. As many other microscopists of her time she owned a so-called "Live-box" which she did in fact use for her water bear investigations.
Schematic diagram showing a so-called "Live-Box" (top view
and cross section).
Fine microscope by the Ross company, ca. 1850, with
A modern, mechanically less sophisticated variation of the Live-box is the washer-type design made out of modern materials:
Simple micro aquarium. The ring can be made out of glued plexi glass, or, even more primitive, consist of a water-proof washer. Some people use a simple thread layed down in form a ring. All those containers can be closed by means of a normal cover glass.
For higher magnifications and smaller organisms (bacteria) the principle of the hanging droplet can be used:
The small droplet hanging down from the cover glass
into a glass slide with a cavity allows the observation of very small
organisms in constant humidity. And, of course, there are variations, e.g.
with paraffine as an addional sealing material in order to prevent
Left: simple compressorium. The screw is used
to adjust the distance between the bottom glass and the cover glass.
In practice you will soon notice that a micro
aquarium can cause problems, e.g. in servicing, when you want to change
a fraction of the water. There might be deposits of unwanted materials
in the edges, there might be unwanted evaporation ...
The construction of the capillary cage allows
the water volume to be confined between a bottom glass and a cover glass
without being confined mechanically by side walls. It can be perfectly sealed,
opened and re-closed easily without any problems. Water can be taken out or
added without major disturbances or losses.
We will come up with a surprising suggestion and a solution to meet
all the above requirements of the capillary cage design: you will find it
here, in our next issue (December) which will be on-line by end of November.
And you will not be asked to send 100 US $ to us. The advice will be free,
the material needed will be surprisingly cheap and you will not need a degree
in engineering in order to get a working micro aquarium.
We would like to add an urgent request to all amateur microscopists:
please be aware of what is usual called human superiority and character
and therefore do not simply use the compressoria in order to squeeze or
squash the water bears.
© Text, images and video clips by
Martin Mach (email@example.com).