'2* Ofi the Cojl of Illumination ly different Kinds of Candles, 



Feet Inch. Lints. 

 \ The tallow candle of Experiment II. gave - - 1126 



The ditto ditto III. - - - 11 5 o 



The drawn candle of Experiment IV. - » - 12 2 3 



- - 12 9 o 



n 30 



- - - 990 



- . 12 6 o 



- 12 4 6 

 - - 12 <S o 



- 12 9 o 

 If thefe diftances be compared with each other, and If the intenfity of illumination (hewn 



by the wax candle be taken as the ftandard unity, the following Intenfities of light, as pro- 

 duced by the feveral candles, will be the refult by calculation. 



If the illumination, effeded by the burning of the wax candle according to Experiment I, 

 be •---...^ 1,000 



then that of Experiment II. will be - - - - - 1,107 



1,127 



1,203 



- - - - - 1,260 



----- - i»io4 



0,963 

 1,234 

 1,234 

 1,234 



- - - I|20(S 



From this it follows, that, in general, tallow candles burn with a brighter flame than 

 thofe made of wax ; notwithftanding that the refults of thefe experiments do not feem to 

 fucceed each other in a perfeftly regular order. On this account I do not yet venture to 

 infer from thefe refults any decided opinion concerning the ftrength of light ; but fball poft- 

 pone the fuller inveftigation of this point to a future time and more leifure *. 



* It is hoped the author will then likewife take notice of the tliicknefs of the wicks, as well as of the 

 temperatures, fize, and other circuraftances of the rooms where his experiments were made, which on one 

 fide will make his inquiry more complete, while on the other it will afford a means to form by calculation 

 a reafonable eftiraate of the probable quantity of fuch kind of fuel wafted by combuftlon in a given time, 

 place, and temperature. There is alfo reafon to conclude, that a greater degree of accuracy would have 

 been obtained if the relative illuminations had been determined from the fliadows of the fame book when 

 equally dark upon an oppofite wall, as the intenfities of light are then univcrfally as the diftances of the 

 candles from the wall — Tranflator. 



Short 



