250-250A

Here, to the right, is a very early model of the conversion lamp 250A. Compared to the later 250 model. Though the model numbers are the same, there is a big difference in design of the generator and the burner. As most of you probably know, the burner is fitted into the hood on the later model. But the earlier on has a generator that is looking more like on Primus 1001 with the bell shaped top and using a "Tilley mantle".
The difference from 1001 burner is the air inlet. On this one a short tube is threaded over the generator, covering the inlet holes. So air in coming from beneath, not via separate tube like on Tilley and Primus burners.

3 images addes 14:t of April to show the difference in the text font Optimus between the two lamps. The earlier has concav O while the later has a convex.
A difference in style of filler caps is also shown.
Maybe a way to date old lamps.

 

Very nice indeed and very interesting burner.
I really like those globes.

 

Wow! I didn't knew that this kind of burner actually existed on any lamp.
I posted a patent from Tilley on behalf of Jeff a while ago, where this odd way of air supply was described.
Check it out https://classicpressurelamps.com/index.php?threads/1833

The patent from Tilley was applied for in 1933.
Does anyone know when this was first used on the Optimus? The 1932 catalogue shows a central positioned vaporiser like this, but you can't see what kind of burner it use.

 

Very very nice Bo. Now I'm extremely jealous.

Where did this one come from? Any guess at age? I'm pretty sure the 'new' one was being made by 1931, so it must be from before then.

How does the cleaning needle mechanism work? I've got lots of questions but I'll leave it at this for now.

 

Ah. That definately means that the similar patent Tilley applied for is later.

 

Hello Bo, that's a very interesting burner and in my opinion it warrants some research, Jeff.

 

Never mind the burner - that's a nice tank. Send it to me & I'll convert it to a stove!

 

You heretic, you!

 

Philistine stovie.

Tree, rope, branch - not necessarily in that order...

 

I think we can settle for the old tar and feather...

 

Great stuff!

 

That Tilley patent is an odd one. I had seen it before but as far as I am aware Tilley never used it in a lamp. You have to wonder why Fred bothered to patent something he did not subsequently use. It is a neat elegant way of making a burner as it does away with any protruding air intake tubes. Trouble is I guess it means finding another way of supporting a shade on a table lamp. Maybe a design solution too far for Tilley? ::Neil::

 

Using that burner would have meant investing in some new tooling to make the shade carriers, once the carriers had been designed that is.

 

are these globes still available?
I have a chance to purchase a primus lamp but without the glass its a sad thing