Here we go again

[philjay]

A hobby of mine is restoring antiques and my favourite bit is antique scopes. I restore, play with and then sell at auction or antiques fairs or direct to dealers to fund the next. So earlier this year I had the brass 3" Franks refractor which sold at auction earlier this month. Which allowed me to fund this next one 🙂

 

I thought you might like a butchers at the latest project which has me scratching my head a little

 

Just spent 2 days fettling it as it had a few issues.

 

Its a 3.25" F16 (yes its loooonnnngggg) Refractor. Tube is embossed James Smith London which dates it to before 1847 as Smith merged with Beck after that date to form Smith and Beck.

 

However, the objective elements are signed M Pillischer London on the glass edge. Moritz Pillischer was a instrument maker from 1849 to 1887 when Richard Pillischer took over.

 

So theres a conundrum, the dates dont match.

 

Therefore I reckon its a pre 1847 scope that was retrofitted with a Pillischer lens post 1849 but pre 1887. Perhaps that is when the tube was painted with the crinkle paint which I always thought to be a late 19th early 20c technique to cover poor quality tubes. Hmm

 

Most of it is fettled now but collimation is slightly out and its a non collimateable cell, so thats another puzzle for me to sort. Thats all part of the fun 🙂

It came with a homemade accessory box containing 5 RAS eyepieces and a Prism diagonal. Someone really cherished this scope

Edited September 27, 2023 by philjay

[+Glafnazur]

It's a beautiful looking scope Phil.

[+Bino-viewer]

Looks a fascinating project Phil, with a very interesting history.

Some thoughts :

 

1. Did James Smith make the optics himself (when the scope was built) or did he source them from elsewhere ?

2. Perhaps the original optic 'had issues' or was damaged, so a replacement or 'upgrade' was deemed necessary.

3 Have you had chance to try it out and give it a star test or anything ?

4. I can't see a focuser as such : are all the RAS eyepieces parfocal ?

 

[philjay]

I agree with your point 2, thats my thinking.

Point 1, the dates dont match so far as I can find out. So this isnt the original lens.

 

The focuser is rack and pinion internal, the big brass wheel on the side is the focus wheel. Most refractors of that era had these. Separate focusers are arelatively modern thing, when i say that I mean 1900 on 🙂

 

3 Only tested terrestrially so far. I dont star test till i have sorted collimation, waste of time and effort otherwise.

 

4 I havent yet found any parfocal RAS eyepieces but thats not to say there werent any. I tend not to use these eyepieces as they arent very user friendly, i have an adapter in which i chuck my televues or vixens in.

But collectors always like  a set of ras accessories.

Put a modern 1.25" in there and they wont want to know.

[philjay]

The dust cap is the best (and heaviest) I have ever come across. Its very heavy as its made from one piece of brass turned town. Normally they are fabricated and silver soldered but this is a belter.

 

Plus the OTA is solid brass in the thickest gauge I have seen so far. Therefore it weighs "a lot" far more than if it were late victorian/edwardian.

 

[Clive]

11 hours ago, Bino-viewer said:

... are all the RAS eyepieces parfocal ?

 

My first set of eyepieces were RAS Ramsdems bought from Charles Frank in Glasgow and they were certainly not parfocal!

[+Bino-viewer]

Do the RAS standard eyepieces of that era have the .965" sizing ? 

Or am i mixing that up with something else.....?

[Clive]

RAS eyepieces had a 1.25 inch diameter thread.

[philjay]

RAS is Royal Astronomical Society standard thread, it was used into the 70s still by some manufacturers.

 

I Have cut many RAS on my lathe. The threads are 1" x 1/16 pitch.

There is a lot of misunderstanding over the thread size some even try to force 1" bsp threads on them which just chews things up.

Edited September 28, 2023 by philjay

[Clive]

1 hour ago, philjay said:

RAS is Royal Astronomical Society standard thread, it was used into the 70s still by some manufacturers.

 

I Have cut many RAS on my lathe. The threads are 1" x 1/16 pitch.

There is a lot of misunderstanding over the thread size some even try to force 1" bsp threads on them which just chews things up.

A 1" BSP thread has an OD  of 1.309" and 11 TPI whereas the RAS thread has a OD of 1.250" and 16 TPI so I guess they could engage about 1 turn of the threads before it all went pear-shaped  😁

[philjay]

30 minutes ago, Clive said:

A 1" BSP thread has an OD  of 1.309" and 11 TPI whereas the RAS thread has a OD of 1.250" and 16 TPI so I guess they could engage about 1 turn of the threads before it all went pear-shaped  😁

Ive seen a few pear shaped threads Clive, where people have forced eyepieces in.

 

The ras eyepieces in longer fl are quite useable but eyerelief is a bit strained. The Comet eyepiece was the one to look for. Never maged to get one myself though.

They were 1 1/4" (35mm) fl, well the BC ones were, and were much sought after

Edited September 28, 2023 by philjay

[philjay]

Heres the scope on the field tripod. This isnt original with the scope. Some enterprising owner made a good quality but very strange one to act as a platform for the library stand.

I spent a couple of hours making a brass spindle which goes through the tripod head so you can unscrew the cabriole legs off the pillar and screw it on the field tripod as it should be. I then cut the odd wings off the tripod head and removed some very odd ali feet.

Still got to sort a spreader or chain, not made my mind up yet as to which way i will go. Plus stain the wood where ive had to cut and sand.

A handsome beast.

[+Glafnazur]

It is handsome indeed Phil, looking at the tube I can almost sense what it feels like 👍