Management of Light in Illumination. 157 



sive vapour which is diffused by lamps with metallic 

 burners, when they are made to burn with very small 

 flames, is quite evident. 



Conceiving that the evil might be remedied by pre- 

 venting the flame from coming into contact with the 

 burner, I attempted to do this by giving to the burner 

 a projecting brim, in the form of an inverted truncated 

 cone, and about one tenth of an inch in width ; and 

 this contrivance has completely answered the purpose 

 for which it was designed. As the current of air which 

 keeps the flame alive passes upwards in the chimney, 

 it is thrown outwards by the projecting brim of the 

 burner, from whence it returns and falls into the flame 

 in an oblique direction, which prevents the flame from 

 descending so low as to come into contact with the 

 burner. 



Since this improvement has been introduced in the 

 construction of the burners of the portable lamps, they 

 have ceased to diffuse a disagreeable smell on being 

 made to burn with a very small flame; and they are 

 now frequently employed as night-lamps {veilleuses) in 

 bed-rooms. 



They are the better adapted for that use, as they are 

 not liable to be deranged by the wind, or by any other 

 accident, and can always be made to give a very bright 

 light in a moment, as often as such a light is wanted 

 during the night. 



For those who have the bad habit of reading in bed, 

 they will be very convenient, and much less dangerous 

 than candles or common lamps. They will likewise be 

 found to be very useful in ante-rooms in great houses, 

 where several of them may be lighted and kept con- 

 stantly burning with reduced flames, for a very small 



