Chimneys for Burners with Small Flame Disc

At the invention and improvement of Argand's burners, it was discovered very early on that a glass chimney tapered at the approximate height of the flame with a kink-like shoulder produced a brighter flame. This invention is generally attributed to the Frenchman L'Ange (or Lange), who at the time, together with a pharmacist named Quinquet, tried to steal Ami Argand's invention. This principle of kink-like tapering was then retained for a very long time. The later, optimised oil lamps such as Moderator lamps also had this type of chimney, which is self-evidently called a shoulder chimney.

These chimneys do not have a designated fitter part. The lower part of the chimney, which is strictly cylindrical up to the height of the flame, is also the fitter, as its diameter corresponds exactly to the gallery of the burner. At the height of the flame, this chimney immediately tapers in a step, and goes up again strictly cylindrically, but with a smaller diameter than at the bottom.

Shoulder chimneys for Moderator oil lamps and for kerosene/paraffin burners with small flame disc (shown in their correct size ratio to each other - Top row: marks of the chimneys shown)
From left: Shoulder chimney for Moderator oil lamps
Shoulder chimney for 14‘‘‘ Victoria burner, Stobwasser
Shoulder chimney for 15‘‘‘ Sonnenbrenner, R. Ditmar
Shoulder chimney for 16‘‘‘ Perfect burner, Kindermann
Shoulder chimney for 18‘‘‘ Sonnenbrenner, R. Ditmar
Shoulder chimney for 20‘‘‘ Odin burner, Carl Holy

The shoulder chimneys for Moderator oil lamps can be distinguished quite easily from the other shoulder chimneys because their lower cylindrical part from the bottom edge up to the shoulder is much longer.

Another innovative step in early burners was the invention of the flame disc in the 1840's in Great Britain. These first flame discs had a rather small disc on their pin. The primary purpose of this small disc was not to widen the flame considerably (which was done with the later, larger flame discs), but to reduce the air gap between the flame and the wall of the glass chimney. Combined with the strong reduction of the chimney diameter in shoulder chimneys, the flame disc causes a considerable narrowing of this gap, which fulfils two important functions (see also the main chapter Glass Chimneys – Effect of the Glass Chimney).

Firstly, the air flow upwards experiences a considerable acceleration at this point, because the same air volume coming from below now suddenly has to flow through a much narrower gap. The higher speed of the air flow upwards inevitably pulls the flame upwards with it; the flame is "extended" upwards.

Secondly, the two air streams, i.e. the inner and outer drafts, are pressed much harder against the inner and outer flanks of the flame at this significantly constricted point. This results in intensive air contact of the flame with the result that the flame brightness increases here accordingly.

A burner with small flame disc with its shoulder chimney
From left: 16‘‘‘ Odin burner of Carl Holy, with shoulder chimney
Schematic representation of the air flows and the flame
The flame of the burner

With the advent of kerosene/paraffin lamps with round burners, this principle was initially adopted unchanged. The first round burners with a flame disc had this small flame disc described above and were operated together with the corresponding shoulder chimneys. A prominent example of this is the famous Sonnenbrenner (Sun burner) made by the R. Ditmar company in Vienna. But other, more or less well-known burners from German production also belong to this class, such as Rex burner by Ehrich & Graetz, Odin burner by Carl Holy, Diamant burner (Mitrailleuse type) by Schwintzer & Gräff, Victoria burner by Stobwasser (all in Berlin), to name but a few. These burners only need a suitable shoulder chimney.

If you now look for the matching shoulder chimney for a burner with the small flame disc, you will be disillusioned to find that these chimneys are very rare. They are no longer manufactured. If, for example, you want to fit your 15- or 18-line Sonnenbrenner with the matching shoulder chimney, you either have to be very lucky and find the chimney somewhere, or have a glassblower produce a new one to scale. Another option is to order the chimney from the US online shop of Miles Stair (Miles Stair's Wick Shop; see Literature and Sources). The owner has chimneys for both Sonnenbrenner sizes made from borosilicate glass absolutely true to scale.

Chimney Sizes

In the following table I have compiled the relevant dimensions of the shoulder chimneys. I have based this on the chimneys that I have in my collection.

Table: Shoulder chimneys

* The line size of Schwintzer & Gräff’s Diamant burners differs from the line size of other burners with a comparable chimney.