Management of Light in Illumination. 139 



CHAPTER II. 



Description of a Portable Lamp. 



AS vegetable oils, purified by means of the sul- 

 phuric acid, burn without either smoke or smell 

 and give a great abundance of pure white light in their 

 combustion, and as they cost considerably less than 

 tallow by the pound and give more light, great advan- 

 tages would be derived from the general use of them 

 for domestic illumination ; but, to render this possible, 

 lamps must be made portable. As they have hitherto 

 been constructed, the danger of spilling the oil is so 

 great, and that accident is so very disagreeable, that 

 nobody who can avoid it will make use of them, 

 except in cases where they can be stationary. Where a 

 light is wanted that must be continually moved about 

 from place to place, candles are universally preferred, 

 though many inconveniences attend the use of them. 



Perceiving that great advantages could not fail to be 

 derived from the introduction of a good portable lamp 

 for common use, to supply the place of tallow candles, 

 I have taken a good deal of pains to contrive such a 

 lamp, and after many experiments I have at length 

 succeeded in this undertaking. 



This lamp, which is not inelegant in its appearance, 

 is liable to none of those disagreeable accidents to 

 which lamps in general are exposed. It is so perfectly 

 neat and cleanly that it never spills a drop of oil nor 

 even lets it come into view; and, when properly ar- 

 ranged, it never smokes or diffuses any disagreeable 

 smell, not even when it is extinguished. Its flame, 



