96 OF A NEW STATICAL LAM! 1 . 



Defcrlptlon of a have fallen but two or three lines, whilfl the flame will not b4 

 new^ftatical materially injured by a fall of four or five. By admitting a 

 larger interval between de and fg, the lamp will hold more 

 oil and burn longer. To raife the oil to its proper height on 

 thefe occafions, it will be necefTary to add more weights ; for 

 example, one ounce for each line of the height required. 



The method of filling and ufing the lamp will naturally be 

 underflood from the foregoing defcription. I (hall only add, 

 that the quantity of mercury required will be about a pound, 

 and that when once put into the lamp it need not be removed 

 from thence, unlefs it mould be thought proper to clean the 

 infide of the lamp at intervals. lathis cafe the oil and mer- 

 cury may be poured together into a glafs or earthen veilel, and 

 the mercury afterwards feparated from the oil by a paper 

 ilrainer. The inflrument may be cleaned with warm water 

 and a feather, it may then be filled again, and when the proper 

 weights are placed, the rife of the oil mufl be produced by a 

 gentle fhaking of the lamp, any unufual prefiure for this pur- 

 pofe mufl be avoided. The oil will not rife to its proper and 

 conftant height till a few moments after being lighted. The 

 length of the lower current of air requires high chimneys to 

 produce a clear light. Thefe mufl be taken off when the 

 lamp is extinguished. To remove it with fafety, the column 

 or upper part of it mufl be taken off, and the inflrument be 

 carried carefully by its focket. 



It will eafily appear, that various ornamental and elegant 

 forms may be given to this lamp, the determination of which 

 will remain with the manufacturing artifl. Our prefent defign 

 reprefents a truncated column, on a fquare bafe, ornamented 

 with four balls, which alfo ferve for the counterpoifing 

 weights. 



I have thought proper to call this inflrument a flatical lamp, 

 as depending on the equilibrium of three different bodies, 

 two of them fluid, and one folid. 



Pa 



