14(5 TALLOW LAMP. 



Pcfcriptlon of a to the pipe : But this method occafioned a wafte from the 

 {*Jj'Pj°'' ''"'"'"« evaporation of the melted tallow, and befides, required much 

 attendance to regulate the cock and keep the tallow veflTel at a 

 proper diftance from the flame ; for the alteration of the tem- 

 perature of the melted tallow, which was very frequent from 

 many caufes, continually changing its degree of fluidity, 

 caufed it to vary in its fupply through the pipe propor- 

 tionally. 



It occurred to me fome time after I faw this lamp, that one 

 might be contrived in which the tallow ftiould only be melted 

 as it was confumed, and other of the inconveniences be re- 

 moved to which the firft was fubjecl; and X made then a 

 rough drawing of a lamp for this purpofe, but other more 

 interefling matters prevented my having one made on that 

 plan before laft December : It confifted of a trough fupported 

 in an inclination of about 45 degrees, fimilar to the one in the 

 figure, which held a fquare prifm of tallow ; under this was 

 placed a little oblong veflel of tin, formed fo as to move for- 

 wards and backwards like a drawer, in front of which was 

 placed a burner : a couple of wires placed acrofs the lower 

 pcirt of the trough, prevented the tallow from Aiding down 

 beyond them, as it otherwife would from the obliquity of its 

 fupport; but as it melted by the heat from the burner, it 

 fell in drops into the little drawer, fo as to fupply the flame, 

 while the degree of this fupply was regulated by moving the 

 drawer in or out, fo as to bring the burner nearer to, or fur- 

 ther from the tallow. In this Hate, though it formed a very 

 , ufeful lamp, it was not fo perfect as I could wifli ; every al- 



teration of temperature of the apartment (which in cold wea- 

 ther happens frequently) required a proportional alteration in 

 the diftance of tlie burner from the tallow, to prevent the 

 little drawer being either overflowed by a fuperabundance of 

 V melted tallow, or the flame cealing from a deficiency of fup- 

 ply. The attendance this circumftance requh-ed induced me 

 to contrive the prefent lamp, or rather to improve the former, 

 in manner following. 



I conceived that if the little pan, which held the melted 

 tallow and the burner, was placed on the arm of a balance 

 inclined from 30 to 45 degrees from the perpendicular, and 

 its weight corapenfated by a counterpoife at the extremity of 

 the; other arm, that when more than a certain quantity of tal- 



lovr 



