42 OF LIGHT AFFORDED BY CANDLES. 



in tbe fame experiment, but the exact, quantity being fmall, I 

 did not afcertain by calculation. 



3. The mould candle in the 4th experiment, loft more of 

 its weight in three hours, than in the preceding experiments. 

 This was owing to the current of air in the room in which the 

 experiments were made, being greater than ufual, occafioned 

 by a frefh gale of wind. 



GENERAL LAWS. 



General law as at From the experiments contained in the table, it appears to 



nrft Gated; ^ an e ft a biifl iec i ] aw> where combuflion is complete, that the 



quantities of light produced by tallow candles, are in the 



complicate ratio of their times of burning and weights of 



matter con fumed. 



For if their quantities of matter be equal, and times of 

 burning the fame, they will give equal quantities of light, by 

 the experiments. 



And if the times of burning be equal, the quantities of light 

 will be diredly as their weights of matter expended, by expe- 

 dients 3 Sf 4. 



Therefore the light is univerfally in the compound ratio of 

 the time of burning and weight of matter confumed. 



STANDARD OF LIGHT. 



More ample If the law which I have endeavoured to prove, both by 



explanation re. reafon and experiment, be admitted, we have a ftandard by 

 fUndarf candle, which we may compare the lirength of any other light. 



Let a fmall mould candle, when lighted, be fo placed as 

 neither to produce fmoke nor require fnuffing, and it will lofe 

 an ounce of its weight in three hours. Let this quantity of 

 light produced under thefe circum fiances, be reprefented by 

 1.00. 



Then mould this candle at any other time, lofe more or lefs 

 of its weight in three hours than an ounce, the quantity of 

 light will be ftill known, becaufe the quantity of light in a 

 given time is direfily as the weight of the candle confumed, 

 by the gineral law. 



CONCLUSION. 



Advantages of A candle which is ufed'in the manner that I have pointed 

 the inclined ou t, gives more light than a candle of the fame dimenfions fet 

 4an c > 4 perpeudicularly 



