Broadhurst clarkson &co Telescope

[Bucko1975]

Hello, I have come across an old telescope after my dads brother passed away.

seems to be missing eye piece 

can any one help with where I would get one so I could have a go.

also not that I would consider selling but are they of any value these days.

[Cosmic Geoff]

You should first check what size of eyepiece is required.  If the bore of the eyepiece holder is exactly 1.25 inches, you are in luck as any modern eyepiece will fit.  It might be what is called 'RAS thread' (q.v.) and those eyepieces have an overall diameter (over the threads) of 1.25 inch.  You can find old eyepieces of this type on ebay.  The thread is the same as on old fashioned gas pipe fittings IIRC. 🙂

I actually have a vintage brass telescope with an original eyepiece the diameter of which is a shade over 1.25".  So modern eyepieces and diagonals will fit with the aid of a piece of card to wedge them in place. 🙂

If the eyepiece holder is an odd size, or some part of the focuser is also missing, your chances of finding original parts are exceedingly dim.  You should then think of how you intend to use the scope - purely for display, for terrestrial viewing, or for astronomical viewing, and think about having an adaptor made.  At a guess, the original eyepiece had a focal length of up to 50mm and a narrow field of view, but you will probably find that it will work with higher powered eyepieces for astro use. 

The value? As a named vintage brand, with original tripod, it could be worth several hundred pounds.

Do check out this video of a similar scope: 

 

Edited May 8 by Cosmic Geoff
Video added

[Bucko1975]

Thank you so much for the info!

will watch video later and see if I can acquire a eyepiece from eBay. 
will probably post again if I get stuck🤣

thanks again for the kind and prompt advice.

it is very much appreciated as a complete novice in this field.👍

[Bucko1975]

Is it possible to clean the inside of the scope?

as you can see from the picture it is quite dirty.

Also is there definitely eyepiece missing.

I wouldn’t know TBH.🤔

[dweller25]

Please DO NOT attempt to clean the scope, the optics are easily damaged, any patina on an old scope is in keeping 👍

There could be fungus on the optics, you may want to try killing it by pointing the front lens up to the sky for an hour, over a couple of days, **but behind the path of the Sun**

It does look like you may have an eyepiece threaded into the drawtube 🙂

Edited May 8 by dweller25

[Bucko1975]

Thanks

[John]

If the objective lens is 3 inches in diameter the scope looks very much like the Broadhurst Clarkson "Starboy" model. Sir Patrick Moore's first scope was the same model.

I recently acquired one of the last batch made at 63 Farringdon Road in 1992. Yours will be much older than that - 1930's perhaps ?

Here is a tidied up one:

Vintage Telescope, Tripod, Broadhurst Clarkson, London, Starboy, Astro – London Fine Antiques

 

[Peter Drew]

I think this may well be a terrestrial version   There is no provision for a finder and the male threading on the rearmost end will not accept an eyepiece but possibly a camera.  its also possible that the last component is actually an eyepiece. I have a few of around that vintage and they have a very small exit aperture that defines the exit pupil to improve terrestrial contrast.  Finally there could be yet another tube to screw on to the end thread, terrestrial erecting systems of the period had a number of translation lenses that gave a lot of back focus.  Have you tried a look through it?      🙂 

[Bucko1975]

Hi, going to try tonight.👍

[Bucko1975]

[Bucko1975]

Seems really small area to look through but will give it ago!

[Peter Drew]

Be prepared to pull the drawtube out a long way!   Why wait until tonight, much easier to try it out in daylight.     🙂

[Bucko1975]

I have tried in daylight and I can’t see anything really! It just seems blurry.

[Peter Drew]

Unscrew the final piece that has the external thread on it and see if there is any glass in it.     🙂

[Bucko1975]

It’s hollow I 🤔 is this what you mean

[John]

Here is another video of a different (though very similar) B&C refractor being taken apart. This one shows what should be in the tube at the opposite end to the objective lens. I think it's called an erecting or terrestrial eyepiece:

 

 

[Cosmic Geoff]

The object screwed into the small (drawtube) end of the telescope does look like a high-powered eyepiece.

I can't tell what the picture from Bucko above is showing. If that is the small end of the telescope, of course it's hollow. We would be interested in a picture of the inner side of the 'eyepiece'.

And watch the videos!  I don't advise dismantling the scope if you don't know anything about telescopes.

Edited May 8 by Cosmic Geoff

[Albir phil]

2 hours ago, Bucko1975 said:

Seems really small area to look through but will give it ago!

As Peter mentioned it will probably have another lens ,you should be able to see some glass in the small hole.I had one with the first reflector I built years ago   im sure it's the old RAS thread 

[Peter Drew]

If there is no glass in the component that I suggested removing then the small hole is what defines the field stop of a system of lenses nearer the prime objective.  There would then be another tube screwed to the threaded portion that also contains a set of lenses, this is what creates the image erection, the furthest end of this last tube will include a female thread to accept a RAS fit eyepiece.  It appears that this tube and an eyepiece may be missing.      🙂

[Bucko1975]

I tried to look through it and nothing! There’s definitely something missing , do I try and get one through eBay and what size would I be looking for?

[Cosmic Geoff]

Did you try adjusting the focus knob?

Even if you can identify the missing part, the chances of finding it on ebay are very low.  You should take the telescope to a competent person who can tell you what is missing and suggest a fix.  If you are willing to pay, I can look out the details of a telescope repairer I used in the past who put a new lens in a vintage brass telescope.