Chimneys for Kosmos Burners

The idea of narrowing the air gap just at the height of the flame, as described above for the shoulder chimneys, was also achieved with another design. In conventional oil burners without a flame disc, the local narrowing was achieved by a narrow inward crease in the wall of the glass chimney again at the height of the flame. These chimneys with the specific inward crease, like a constriction, were invented by two Germans, Ruhl and Benkler from Wiesbaden, around 1840 and are called, again self-evidently, chimneys with crease.

These chimneys are a further development of the shoulder chimneys. Visually, both chimney types look almost the same, with the only difference that the chimneys with crease have an inward constriction in addition to the stepped shoulder of shoulder chimneys to create the same effect of constricting and accelerating the airflow at this point, but without the aid of a flame disc.

This is why they were exactly the right chimneys for Kosmos burners, which, as is well known, do not have a flame disc. With the triumphant advance and worldwide distribution of the Kosmos burner, the matching chimney with crease also landed an unimagined market success. The exclusive use of this chimney type with the Kosmos burner has led to this glass chimney being generally and internationally called the Kosmos chimney. I will stick to this second and much better known name, as it makes it quite clear which chimney is the right one for Kosmos burners. There are 7 different sizes of Kosmos burners from 6 to 18 lines; consequently the Kosmos chimney comes in 7 corresponding sizes.

Chimneys for Kosmos burners (shown in their correct size ratio to each other - Top row: marks of the chimneys shown)
From left: Chimney for 6 – 8 – 10 – 12 – 14 – 16 – 18‘‘‘ Kosmos burner

A Kosmos burner with its Kosmos chimney
From left: 14‘‘‘ Kosmos burner of Wild & Wessel, with Kosmos chimney
Schematic representation of the air flows and the flame
The flame of the burner with Kosmos chimney
The flame of the burner with Phénomène chimney (see below)

Kosmos chimneys are still produced in the usual sizes from 6 to 14 lines and are offered in the online trade. So there is no shortage here. It is more difficult to find the much rarer sizes for 16- and 18-line Kosmos burners. These are neither available as new items in the trade nor in antique shops. You have to be patient and lucky if you have Kosmos burners in these sizes and want to find the right chimneys.

Modified Chimneys for Kosmos Burners

The great market success of the Kosmos chimney has led to modified versions of this chimney being developed over time with the aim of further improving flame height and brightness. These modifications include, for example, the German Kalthoff and Culinan chimneys, the French Phénomène and Avenir chimneys, the so-called X-beam chimneys, and possibly a few other types, but they are very rare and are not newly manufactured.

The next picture shows some modifications of the Kosmos chimney that were marketed in France, with their French designations (picture taken from the 1911 catalogue of the French company S.V.E.).

Kosmos chimney and its special shapes (from S.V.E. catalogue 1911)
From left: 1) „Etranglée“ (usual Kosmos chimney)
2) „Hygiénique“ (Kalthoff chimney)
3) „Japonaise“ (Culinan chimney or equivalent)
4) „Avenir“
5) „Miracle“ (Phénomène chimney)

The best-known further development of the classic Kosmos chimney in Germany is the so-called Kalthoff chimney (named after the German inventor Kalthoff). Sometimes it is also called "Reform" chimney. It has no extra constriction at the narrow point at the height of the flame, as it is designed to be quite narrow at this point anyway. Its special feature is that it pretty much maintains this narrowness towards the top as well. The chimney only gradually widens again towards the top, so that at the upper end it has the diameter of a normal Kosmos chimney. The purpose of this shape is - as is easy to understand - to constrict the airflow upwards within the chimney even longer, which benefits the flame height and brightness. Compared to the ordinary Kosmos chimneys, these chimneys have a higher height (see table).

Correction by Ara Kebapcioglu, Paris: Based on the sporadic designation "Reform", I had previously described this type of chimney as the correct type for the Reform Kosmos burner, which was not correct. Ara brought this error to my attention. The modified Kosmos chimneys by Kalthoff are not primarily intended for use with the Reform Kosmos burners. They are an independent further development of the classic Kosmos chimney and can be used with any suitable Kosmos burner. Consequently, the Reform Kosmos burners with the triple air supply do not need a special Kalthoff chimney; they can be used just as well with the normal Kosmos chimneys. Because of this erroneous assumption, I have consistently equipped my Reform Kosmos burners with Kalthoff chimneys, which was just not necessary. Nevertheless, these chimneys remain with the lamps where I had used them.

Kalthoff and Phénomène chimneys for Kosmos burners (shown in their correct size ratio to each other - Top row: marks of the chimneys shown)
From left: 6 – 10 – 12 – 14 – 16‘‘‘ Kalthoff chimneys and 8 - 14’’’ Phénomène chimneys

A Reform Kosmos burner with a Kalthoff chimney
From left: 16‘‘‘ Reform Kosmos burner of Schuster & Baer, Kalthoff chimney
Schematic representation of the air flows and the flame
The flame of the burner

Chimney Sizes

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

Table: Kosmos and Kalthoff chimneys

* For railway lamps: 140 mm