NEIMME: Lamps
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No. 36. BIRAM LAMP. (Viewer's Pattern). Click to view image |
CONSTRUCTION.
Gauze. 22 mesh copper, at the lower front of the lamp for air inlet and
inside the top of the chimney.
Burner. 1/2 ins flat wick with a semi-cylindrical body 21/2 ins high 33/4 ins
diameter, fitted with a reflector.
Window. 21/2 x 33/4 ins.
Dismantling. The front of the lamp slides up.
Lock. Sliding ring and padlock.
Pricker. Inserted through the back of the lamp.
HISTORICAL NOTE.
This was designed by Mr. Biram in 1849. Mr. Biram, along with Dr. Clanny and others including Messrs. Nicholas Wood, T.E. Foster and Matthias Dunn from this district gave evidence before a Select Committee of the House of Lords in 1849 on safety lamps.
At that time the Davy was still the most popular lamp, the Stephenson next and the Clanny and similar types which gave better illumination but which had no gauze round the flame were less favoured.
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No. 37. BIRAM LAMP. Click to view image |
CONSTRUCTION.
Gauze. 22 mesh iron, covering the front 2? x 21/4 ins and a cap on top
of the chimney, 2 ins high.
Chimney. 31/4 ins high
11/4 ins diameter. With the gauze cap is a small extension to the
chimney with a solid top, the products of combustion escaping by holes in its sides.
Lock: Screw.
Dismantling. The top gauze unscrews.
The oil vessel slides in from below and is secured by a screw lock.
Burner. 1/4 ins round wick with silvered reflector.
HISTORICAL NOTE.
This is the normal pattern Biram lamp. Its candle power was similar to that of the Davy, but it has better protection from strong currents. It was not very commonly used