Wolf's Dahlmann Lamp

The Friemann & Wolf Company of Zwickau, Germany made many unusual styles of safety lamps prior to 1900.  One of the more unusual lamps, and short lived, was a lamp  known as the Dahlmann.  Wolf must of thought a lot of the lamp, because it appeared as a centerpiece in some pre-1900 advertisements.  But the lamp disappeared from the advertisements and Wolf's catalogues going into the 20th century.  In fact, very few have survived.

The Dahlmann was first patented on May 23, 1894 and was designed for gas testing/measuring. Basically, the design is a Museler chimney system with a damping system to control the air intake.  The damper consists of a brass sheet metal cylinder with a wire gauze top.  It works by sliding the cylinder up or down, which adjusted the amount of intake gauze area that is exposed to the atmosphere. A device on one of the standards  gages the adjustment of the damper.  There are essentially three positions for the damper: 1) fully open, 2) half open, and 3) fully closed (lamp will extinguish).  Mounted on two of the lower standards is a sighting device for measuring the flame.

 The example pictured has an early 1893 spring loaded type striker.  The serial number is 194,442, which puts the lamp circa 1895 or 1896.  Another example exists in the German Mining Museum in Bochum.  Interestingly, the one at Bochum is only ten (10) serial numbers off th example shown.