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              Ross 6 x 28 and 12 x 28 with an unconventional construction - 1908

1.  Introduction

2.  Ross 6 x model

3. The markings of our binocular

4. The binocular body

5. Internal construction

6. Summary

 1. Introduction
The binocular is in many ways unusual. As far as today, we have not found any information with reference to our particular model.
The shape of our binocular looks as model 6 x which was produced in 1907 by Ross, Ltd., Optical Works, 3, North Side, Clapham Common; London.
Dr Simon Tomlinson, English collector, has kindly found an advertisement which was published in the 1907 British Journal Photographic Almanac. In advertisement was illustrated a new model – Ross 6 x magnification.

                                                             RossBJPAadvert1907; 45%

                              Advertisement in the 1907 British Journal Photographic Almanac; the picture sent by Dr Simon Tomlinson

 The date of the production as a new binocular on the market would be correct, if it was the first year of publication, in 1907 British Journal Photographic Almanac. The submission of any advertisement for print was expensive, and often a publisher was holding a printing block with a complex text for a possible re-publishing next year. 
The advertisement described the binocular as ‘a prism glass of large aperture specially suitable for marine use’.
In Ross Catalogue - “Ross’ Optical List” published in April 1908, the binocular is described as:
  -   Ross’ Extra large Aperture Prism Binocular Glasses - objective 1 and 3/16 inch (30,1625mm); power 6.
Afterwards we read:
  - “This binocular allows of the passage  of a large amount of light, so that it is not only useful for marine purpose, but also makes an excellent Night Glass”
In April 1908 the binocular was priced 7, 10, 0.
The picture of the catalogue was kindly sent by German collector Ulrich Zeun -

Ross.1908.Optical.List.;20 %
                                              Ross Catalogue – “Ross’ Optical List” page 4; the picture courtesy of Ulrich Zeun 

2. Ross 6 x model
Let’s look closer at Ross 6 x model. The binocular body is made from alloy aluminium and covered with black leather.

Ross6x 28 No206171 from Simon coll; 35%

6 x from Dr Simon Tomlinson collection, No production 20617; Copyright picture Dr Simon Tomlinson

Ross6x206171 from Simon coll; 35%

6 x from Dr Simon Tomlinson collection, No production 20617; Copyright picture Dr Simon Tomlinson

Looking at other description on the binocular, it appeared that this model was sold in a shop in Calcutta. Many shops around the world made markings on the binoculars, which were sold at their shops: look at the articles:
           - “Zeiss 3x Teleplast...” Unusual – page 4;
“Marine Revolver 5 & 10 magnification” – Unusual page 7.
We do not have any catalogue of the shops, which were selling Ross binoculars at that time.
However, the marking on the bottom plate of the Ross binocular pictured above shows the name of the owner of that binocular; he was a  horse race enthusiast . 
The secret of that description resolved Dr Simon Tomlinson: “G.B. Deakin - he
was a race horse owner. In 1907 he was listed as a Steward of the Royal Calcutta Turf Club.” 
The lists of the former Stewards found by Dr S. Tomlinson:
Ross6x 28 No206171 from Simon coll;eye lenses 35%
                                      6 x from DR Simon Tomlinson collection, No production 20617; Copyright picture Dr Simon Tomlinson

We have asked Simon Tomlinson to take all measurements of his Ross model 6 x:

“Approximate measurements of Ross 6 x; Production No 20617:

Weight 742g
Total length 14.5cm
Width at widest point 14.1cm
Length of body including prism covers 9.3cm
Visible objective diameter: 28mm (actual objective diameter advertised as 30mm, which is probably the actual diameter of the lens, I haven't taken it apart to measure)”

It appears as we have found the appropriate information about our model.

           Ross 6 x 28-unconventional constr-KO; back15%   Ross 6 x 28-unconventional constr-KO; fr15%
Ross in our collection; Copyrights pictures Anna Vacani

3. The markings of our binocular
The binocular did not have a visible description of a manufacturer.   The top and bottom plates were painted by previous owner.

                             Ross 6 x 28-unconventional constr-lenses plate;20%       
Ross in our collection before paint was removed; Copyrights picture Anna Vacani

The only marking – KO and number 8, was on the hinge interconnector.

                                                                                      Ross 6 x 28-unconventional constr-KO;80%
                                                                                   Ross binocular with ‘KO’ markings; Copyrights picture Anna Vacani

William Reid in his book “Barr and Stroud Binoculars and The Royal Navy”, page 91 explains the meaning of these two letters – KO. We are reading:
“[...] manufactured binocular field-glasses, Britain’s measurement standards were set and monitored by the National Physical Laboratory (NPL) whose routine tasks embraced the quality control of observation instruments submitted by the Admiralty.  The laboratory began life at Richmond Surrey [...] came to be known as Kew Observatory. [...] it became a more broadly based scientific establishment where instrument accuracy was verified under the aegis, successively, of the British Association for the Advancement of Science, the Royal Society and finally the NPL.
Further we are reading interesting information:
[...] binoculars are listed among the scientific instruments increased in 1889 when the laboratory contracted with the Admiralty to test telescopes and binoculars bought for the Royal Navy.

[...] Not every glass satisfied its examiners. In 1897, when the test fee for ‘superior binoculars’ was 2s.6d [2s.6d – in old British money it is 2 shillings and 6 pence = a half crown; 8 half crowns it is equal of 1- added by Anna Vacani]; 661 passed [test] and 21 were rejected. [...] each binocular that reached the required standard was engraved with the observatory monogram ‘KO’ and the serial number of the document attesting to its quality and accuracy.”
In a view of the above information we can assume that our Ross model was bought for the Royal Navy or was considered as one for using in Royal Navy. 
Presumably, in the Science Museum Library is a test document of that Ross model, provided by Kew Observatory. 

It had looked as our binocular manufacturer and all specification were - Ross 6x.

After removing the paint from top plates, it proved that it is binocular produced by Ross, London however not 6 magnification but 12 magnification.
Ross 6 x 28-unconventional constr-lenses plate(2);20%
                                                         Ross in our collection - paint was removed; Copyrights picture Anna Vacani

Subsequent to measuring the exit pupil, which is approximately – 2.33 mm diameter, it confirms that it is 12 x magnifications (28mm objective: 2.33mm exit pupil=12x).
Left plate shows description- Ross, London No 21161- :       Ross 12x28 KO; top cover left 80%

The right plate description is Prismatic Binocular Power 12:            Ross 12x28 KO; top cover right 80%

4. The binocular body
We have applied all possible methods for testing our Ross model 12 x 28. The first we have made a comparison to the model 6 x.
Our binoculars’ body and both plates are built from aluminium alloy and covered with black leather. Other parts of the binocular are produced from brass: eye lenses and objectives tubs, the top hinge interconnector, washer and neck strap retaining brackets.

As far to that point our binocular 12 x 28 appeared to be the same construction and shapes of prism house and the plate covers, as Ross 6 x 28 with alloy aluminium plate covers from Dr Simon Tomlinson collection.
The difference is measurements of the eye lenses and eye cups.

             Ross6x No206173 -50%                                             KO Kew Observarory, prisms; 30%
        Ross 6 x from Dr Simon Tomlinson collection                                                                             Ross 12 x in our collection

The bigger eye lenses have an impact on the total weight of the binocular. The 6 x model weight is 742 g and our Ross 12 x weights only 682g. It is only difference between these two models.
length of body, including prism covers, is the same - 9.3cm.

The most unusual characteristic of our binocular is the internal body constructions.

5. Internal Construction
This kind of binoculars internal construction has not been seen before.  
When the top cover of the prism was removed, it appeared a strange construction.  The prisms seats in the metal recess in the body without any retaining spring clip on the top.

Ross 6 x 28-unconventional constr-lenses plate;16%

The top cover plate with the lenses is removed; Copyrights picture Anna Vacani

The prisms are held in place by cork pads.

Ross 12x28 KO; top cover 15%

The top cover plate; Copyrights picture Anna Vacani

Next the binocular objective was unscrewed and odd construction became visible in the prism housing.

Ross 6 x 28-unconventional construction-objective rod;25%

The objective is removed; Copyrights picture Anna Vacani

The compartment is divided into two sections with a separating wall.

Ross 6 x 28-unconventional constr-objectives hole;20%

Two section of the prism house; Copyrights picture Anna Vacani

 The division in the bottom prism housing is to stop stray light affecting the bottom prism.
Subsequently, to see complete interior construction the bottom plate was taken off.

Ross 12 x 28-unconventional constr-interior from obj side;16%

The interior from objectives side and the bottom plate; Copyrights picture Anna Vacani

                      KO Kew Observarory, objectives site -prisms supports; 15%   KO Kew Observarory, prisms supports; 15%          
The bottom covers construction; Copyrights picture Anna Vacani

Into the bottom cover are mounted the rods with a circular plates with cork pads on the top. The plates are adjustable.

Ross 6 x 28-unconventional construction-objective rod;36%

                                                                                  The rod with adjustable plate; Copyrights picture Anna Vacani
The function of the rod is to keep the prism tightly, in the proper position.
6. Summary
Analyzing that unconventional construction we conclude that it was design in this way, because at that time was in force the Zeiss patent for ‘a wider separation of the doublet objective lenses thereby resulting in markedly improved depth perception. This patent remained in force until 1908. ‘ 
As we are reading in
Carl Zeiss - A History of a Most Respected Name in Optics’:

“Ernst Abbe by 1893 he had created and patented (back dated to July 9 at the German Imperial Patent Office) an 8x 20mm "binocular telescope with increased objective separation". The significant improvements over then competing designs being that he employed the improved glass prisms in an air spaced fashion in the form of the now traditional Porro binocular permitting a wider separation of the doublet objective lenses thereby resulting in markedly improved depth perception. This patent remained in force until 1908. The mass production of prism binoculars by Zeiss then began in 1894.”

Dr Simon Tomlinson analysis all information on Ross models we have been exchanged:
The 6x version of this model is scarce but I haven't seen any other examples of a 12x model, nor is it mentioned in any adverts or catalogues that I've seen. Ross did offer a 12x version of both the previous model and the subsequent Stereo Prism Binocular, so I suppose it's logical that they would have experimented with this magnification on other models. Zeiss introduced the 12x Telefort at this time so maybe Ross considered trying to offer an equivalent British glass. Another possibility is that the military requested a small batch of binoculars with this specification for trials.”
Comparing those two Ross models described in previous chapters; 6 x 28 and our model 12 x 28, we can see that only eye lenses and eye cups are different.
                  Ross 12 x 28-unconventional constr-lenses eyecup;30%                                                                       6x28 Simon eyecups;80%
              Ross 12 x in our collection              
                                           Ross 6 x from Dr S. Tomlinson collection

In this way the total lengths of our Ross 12 x 28 binocular are:
                                            -  with eyepieces lowered to minimum – 124mm ( 137 mm – 6 x 28);
with eyepieces raised as far as possible – 130mm (148 mm – 6 x 28)
Our binocular is shorter than Ross 6 x 28. 
The body are exactly the same in the shape and the measurements.
Presumably, it was not produced for a wet environment because all body was built from aluminium.
We can presume that our model was manufactured after the model 6 x 28, if the order of production numbers were continued. The production number of Ross 6 x 28 from Simon Tomlinson collection is – 20617; our Ross 12 x 28 is 21161.
It could be a prototype as well. The binocular could be produced as a prototype, because Ross expected an extension of Zeiss patent (?).  

The internal construction of the binocular is very cheap and in a poor workmanship standard. 
Other collectors of the binoculars have never seen a similar type of internal construction. In this way this model of binocular is a kind of curiosity and rarity.

Other model 6 x manufactured by Ross was produced from brass for use in a damp surroundings.
                    RossMarine brass Simon;30%    RossMarine brass;30%
6 x brass model from Dr Simon Tomlinson collection; No production number; Copyright picture Dr Simon Tomlinson

 If any collector s posses the Ross 12 x 28 model, or a binocular with the similar interior construction, we will be happy to hear about. 






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