IO2 Management of Light in Illumination. 



know how much room there was for improvement in 

 the art of illumination ; and since that time the subject 

 has frequently been the object of my meditations, and 

 of a variety of experimental researches. 



It was with a view to the prosecution of these in- 

 vestigations that I contrived the photometer for meas- 

 uring the relative intensities of the light emitted by 

 luminous bodies, which is described in the first volume 

 of my Philosophical Papers, page 270.* With the 

 assistance of that instrument I determined the relative 

 quantities of light that are emitted in the combustion 

 of the various inflammable substances most commonly 

 used in procuring light; viz., of beeswax, tallow, and 

 several of the fat oils. An account of the results of 

 these experiments was read before the Royal Society 

 the 6th February, 1794, and was afterwards published 

 in the Philosophical Transactions, and also in the first 

 volume of my Philosophical Papers. 



Having found, from the results of these and of other 

 experiments, that the purest light and most beautiful 

 illumination may be obtained by means of lamps prop- 

 erly constructed for less than one eighth part of the 

 price that the same quantity of light would cost if it 

 were furnished by wax candles, and consequently for 

 about half the sum it would cost when furnished by 

 tallow candles, I saw that very great advantages could 

 not fail to result to the public from such improvements 

 in lamps as should render them neat and elegant, and 

 prevent their being any longer liable to those disgust- 

 ing accidents to which they have hitherto been ex- 

 posed. 



Animated by a strong conviction of the importance 



See also page 7 of this volume. 



