As a Biology teacher I have used microscopes for many years, possibly nearly every week. However, as many members will no doubt be only too aware of, teaching of the basics of microscopy and how to use the instrument properly is a rare thing in any basic or advanced Biology course. Certainly I never had any training myself, at Advanced, Degree or Postgraduate level. I suppose therefore, that all I was taught was how to use the instrument when I was about 12! Some six years ago this changed. In an attempt to service the microscopes we had at school I started reading up on the subject, learning a great deal as I went. The "bug" soon bit and now microscopy is my main hobby.
After borrowing instruments from work I decided this was to stop; my right arm was getting longer. I had joined the PMS and saw instruments for sale second-hand but was confused by all the names and detailed descriptions. Older members please forgive me but you have an advantage of years, I am too young to remember the enamelled instruments of the past. I sent for the Comrie and Mitchell catalogue and arranged to visit the home of Authur Mitchell in Nottingham. Arthur was most helpful and showed me old and new microscopes. Finally I bought a Biolam R21. This has given good service and has proved to be an excellent buy. Later on, I decided I would like an older British microscope and started to look around. I was tempted to buy a binocular head for the Biolam but was alarmed at the cost of this in relation to the microscope. A mechanical stage was also on my wants list. At this springs' Midland Quekett Meeting all these things came together as someone had a Baker IV BQ for sale. I looked it over. It had a binocular head and a mechanical stage, both features I was after, but best of all it was a lovely grey enamelled British microscope. Bound to be too pricey I thought to myself, but nevertheless I sought the vendor. He kindly demonstrated it and talked me around the features. He explained the sale, a recent Leitz acquisition, and also where he got it from. The price was very reasonable and my offer accepted, along with my cheque. I now owned a Baker IV BQ.
The microscope is in the original Baker case, though the handle has been replaced. Considering the weight of the instrument I am not surprised. The case contained a vertical tube suitable for photography, which is adjustable for tube-length. There are padded holes for additional condensers (not present) and clips to hold eyepieces and objectives. On the subject of optics, the objectives comprise Baker x10 and x40, interestingly also marked with the older style 2/3" and 1/6" in addition. The eyepieces were a little disappointing, being rather old and dirty beck high power. However. the previous owner sent me another pair of un-named lower power ones. I have since acquired a pair of x8 baker eyepieces from elsewhere, which are much better. The nosepiece is a triple type and I have placed a Russian x20 in the vacant position.
The microscope was also equipped with a small lamp and transformer unit with brightness control. This is a Baker lamp, called the Lamplux, which has a collector lens, diffuser and field iris. There is also a recess for colour filters in the top of the housing. This has been modified, a conclusion I have only been able to come to by looking in Baker catalogues of the late fifties. I should thank three people here in providing these. Firstly, Roy Winsby who I initially asked about the Baker IV, and Don Bruce who provided a catalogue for Roy to copy for me. Also, Barry Ellam for taking the trouble to copy his catalogue and price list. Back to the lamp, the original came with a 6 volt, 18 watt bulb, which seems to have been replaced with a small halogen bulb. Also, the rheostat unit is home-made. The lamp fits in place of the mirror (which I don't have anyway) on a small bracket. It provides even illumination and with the halogen bulb in place is quite powerful. In fact, I now use my excellent Prior (I think) lamp for Kohler illumination, the lamp is actually under my work bench which has a square hole cut in it. Don't worry, nobody was in when i cut the hole in the bench!in when I cut the hole in the bench!
The Baker is described in the old catalogue as a modern research microscope with coarse and fine adjustments below stage level. The control knobs are conveniently placed in close proximity to each other, and the controls are all silky smooth. especially the mechanical stage which is a joy to use. Like many things in life, once tried you wonder how you ever did without it. the limb and foot are massive, or in the words of the catalogue "especially robust". Quite. The focus adjustments both act on the stage bracket, the body tube being clamped into dovetails on the limb. the body can also be moved upwards and fixed in a position allowing greater clearance between the nosepiece and the stage. The body itself is wider than most.
I spent much time studying the catalogues to learn of the Baker coding system, ie. what the BQ meant. The first letter of the code refers to the stage, not the binocular head as I first thought. There were two types of mechanical stage, stage 'A' which was a rotating stage, and stage 'B', a 4.2" square stage. There were also nonmechanical stages, 'C' and 'E', rotating and square respectively. The second letter refers to the type of substage. Mine is the 'Q', which is a swing out type with centring screws. Later models had the 'W', which was the modified Akehurst type. In this each condenser was mounted on its own separate plate, allowing it to slide into position easily.
The catalogue shows quite an array of accessories for the Series IV. This includes dark-field condensers, phase contrast kit, lamps, and numerous objectives and eyepieces. Worthy of mention is the Projectolux illuminating base which provides Kohler illumination. It was designed to allow micro-projection, drawing attachments and a specially designed camera. There was also a special condenser, the Trilux, which provides light-field, dark-field and phase-contrast. Unfortunately for me, even if I did come across this item it is of the type 'W' substage only.
I also have a price list, dated 1956, and this makes interesting reading. I reckon that my instrument would have cost about 175. I shudder to think what that is equivalent to today! I only know that it brings me much pleasure and is a joy to use. I recently visited someone with a similar model but with many more additional items so there is always the hope of adding such items to mine. Certainly if any readers out there have any Baker series IV items surplus to requirements then I should be most grateful to hear from them.
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