Management of Light in Illumination. 135 



The use of this additional paper screen is so far from 

 impairing the illumination of objects placed on the 

 table that it improves it, and it never fails to render 

 vision much more distinct by preventing the eyes from 

 being fatigued and injured ; and although objects in 

 distant parts of the room will, in some places, be some- 

 what less illuminated, yet even there they will be seen 

 distinctly, for the eye will be better prepared to perceive 

 them. 



Most of the table illuminators that have been made 

 and sold at Paris have, in addition to their domes of 

 white gauze, been furnished with conical screens or 

 reflectors, made of tin, painted white and varnished 

 on the inside, and painted on the outside of the same 

 colour as the column ; but these painted reflectors 

 occasion so great a loss of light, and give so dismal a 

 tinge to the small quantity they reflect, that I never 

 make use of them, and certainly shall never recom- 

 mend them to others. Lamp-makers and dealers in 

 tin may wish to keep up their credit ; but I must say 

 that I think them perfectly useless, and it is evident 

 that they are often embarrassing. 



I cannot finish my account of this table illuminator 

 without recommending it in a very particular manner 

 to the studious, and to all those who are in the habit of 

 reading and writing by candlelight As it gives a great 

 deal of mild light, about six times as much as a good 

 wax candle, it illuminates sufficiently without being 

 near; and, as its stand is considerably higher than a 

 common candlestick, it may be so placed as not to be 

 seen by those who are reading, writing, or working by 

 its light, which circumstance renders the illumination 

 uncommonly mild and agreeable, and tends much to 

 the preservation of the eyes. 



