1 64 MOTION of Small Lighted WICKS 



(landing up through a pun(flure in the middle to ferve as a 

 wick ; and the phenomena, in queftion, are certain motions 

 which fuch minikin lamps acquire, when lighted and made to 

 fwim in very pure falad oil. 



A SHALLOW glafs bafon, with fides rifing nearly perpendicu- 

 lar, or a common glafs falver, will conveniently contain the oil 

 for thefe experiments. As foon as the lamp is lighted, it will 

 immediately fail briflcly forward, in fome direcflion, till it meets 

 the fide of the vefTel, and afterwards will take a circular courfe, 

 always bearing up to the fides, and fo will perform many revo- 

 lutions. 



Sometimes the circulation is from right to left, and fome- 

 times in the contrary dire(flion, according as that point of the 

 paper bafe, which in the diredl failing kept always foremoft, 

 turns away from the fide of the glafs a little to the right or to 

 the left hand of that which comes to be the point of contadl. 

 This turning away, of what may be called the Leading Point 

 of the bafe, is diflindlly obfervable by a partial rotation of the 

 lamp round the wick as an axis, as foon as it arrives at the fide 

 of the vefTel. Sometimes, though rarely, the leading point itfelf 

 attaches to the fide, and forms the vinculum^ in confequence of 

 the well known corpufcular attradlion between the elevation of 

 oil around the bafe, and that belonging to the fides of the glafs ; 

 and when the vinculum fo correfponds to the leading point, the 

 lamp will be found to fland ftill, without any tendency to cir- 

 culate. 



When the little wick has any fenfible excentricity upon the 

 circular paper bafe, the lamp will fail fo as to make that part 

 of the bafe which lies nearefl to the wick the Jlern ; and if 

 the bafe of the lamp be clipped of an oval form, and the wick 

 placed in the longer axis excentric'al, that end of the bafe, 

 nearefl the wick, will alfo keep hindmofl, when the lamp 

 fails acrofs the falver. In the fame manner, if the bafe be 



an 



