The Chesneau Lamp

The Chesneau lamp was introduced in 1892 by M. Chesneau, president of the French Fire Damp Commission.  Essentially, Chesneau's invention was a Pieler lamp with many improvements to overcome the weaknesses and hazards of Pieler's design. 

 Chesneau's lamp is made heavier duty for rough service, and has a fixed bonnet that allows it to perform safely in air currents up to 2000 ft. per minute.  Like the Pieler, the lamp burns alcohol and has a tall gauze surrounding the burner.  Instead of using a conical shield around the burner, the Chesneau use a cylinder as a standard for adjusting the flame.  Unlike a Pieler, the Chesneau has a shutter to control the underflow of air to the burner. (Click here for assembly drawing of Arras Chesneau)

 

 

Gas measuring is identical to the Pieler. The elongation of the flame while in a firedamp atmosphere is observed through a mica window, and measured with scale attached to the bonnet.  The lamp is also fixed with a sliding shield that can be adjusted to the exact height of the cap, which permits a more accurate reading.  To more easily read the caps, copper nitrate and ethylene chloride are dissolved in the wood alcohol to give the flame a greenish tint.

In the Chesneau, as in the PieIer, the accuracy of the test result is depended on the condition of the cotton being the same as when the lamp was standardized.  A great improvement  is that the Chesneau only requires 30 to 90 seconds to cool down between tests, where the Pieler requires 20 to 30 minutes to eliminate the artificial  atmosphere of alcohol vapor.

Click on the thumbnail below to view a Chesneau from my collection!!