ECONOMICAL LAMP. £11 



lloti;, any longer to defer communicating an observation, which 

 I hope will be of real utility in the discrimination of bodies that 

 differ so essentially in their composition. 



IX. 



Account of an Ecofiornlcal Lamp for producing Heat, with a con- 

 siderable saving of Oil. In a Letter from a Correspondent, 

 L. O. C. 



To Mr. Nicholson. 

 SIR, 



ira"F yon should not think the following experiments too tri- Introduction. 



JL fling for insertion in your excellent Journal, it is probable, ^^""'^stTone 



that such of your readers as are in the habit of using an Argand tenth of an Ar- 



lamp in their chemical researches may feel interested in them. ^^ ""^ "^"^P' 



•^ •' _ and saves one 



They certainly have some claim to attention in an economical third of the 



point of view : and this, I think, no one will deny, when he °'^' 



is informed, that he may procure a lamp at one tenth of the 



price of the clu^apest Argand lamp 3 which will produce an 



equal, if not a greater degree of heat ; and effect a saving of at 



least one third of the quantity of -t)il consumed. 



Experiment 1, a. An Argand lamoj, which is supplied by a Exp. l, Ar- 

 r ■ . t M rr / gand stamp 



fountam, so that the oil can never become very hot, was made consumed 447 

 to burn as bright and strong as possible, without smoke : and g". of oil per 

 r J x^ . 7- r M • t. rr hour,andboiI" 



was found t6 consume 44/ grs. of oil, m an hour. Iwo ^j goooors.of 



thousand grains of rain water were exposed to the heat of this water In 7 m, 

 lamp in a glass matrass ; they boiled in seven minutes. 



b. As I suspected that the lamp did not produce its greatest Same lamp, 

 effect, on account of the wick having been in the oil for a length "^ ^^ ^d^m d 

 of time, I caused a new one to be put to it, and every precau- consumed 500 

 tion was taken to make it burn as powerfully as possible. It S^'^- P^f j^V'^' 

 now consumed 500 grs. of oil in the hour, and made 20©0 grs, water in 6^. 

 of water to boil in 6§ m. min, 



Exp. 2. I caused a small tin lamp to be made, with four Exp.2. Alamp 



burners : and having a tube in the centre, to convey air to theni: with <f separate 



' ir> ^ J 7 small wicks, 



each of the burners containing eight threads of cotton, of the &c, consumed 



diameter of .-V of an inch. This lamp, when burning as only 200 grs. 

 ^^ 1 , . , of oil per hour. 



Strongly as possible without smoke, consumed m one hour and boiled the 

 200 grs. of oil, and made 2000 grs. of water boil in 10 m. (See water in ten 

 plate 5, fig. 3 and 4 j and the description at the end of this 

 letter.) 



P2 We 



