C 431 ) 



No. LXVI. 



An account of a Kettle for boiling lyjflammabk Fluids, — In 

 a letter from Thomas P. Smith, to Robert Patter- 

 son. 



Philadelphia^ fune 14, 1798. 

 Sir, 

 Read, June "T X THEN wc conficlcr the many unhappy acci- 

 14, 1798- V V dents that occur from veflels containing 

 inflammable fluids boiling over and fetting fire to the 

 buildings in which manufaftories of them are carried on, 

 it mufl fti-ike us as a matter of importance to form a veflel 

 which fhould be fo conftrudled as to prevent any of thofe 

 accidents, and yet of fo fimple a form as to render it fit for 

 general ufe. Imprefled with thefe ideas, I take the liberty 

 of offering for your approbation the following plan. 



Let A B C D {/ee figure^ reprefent a large kettle, D E, a 

 fpout running out to the diftance of three or four feet, com- 

 mencing at D, four or five inches from the brim of the ket- 

 tle, and the termination of it E, juft as high as the brim 



C. Let the bottom of this fpout be covered with wet fponges 

 or rags. Now fuppofe the kettle to be filled up to D with 

 any fluid, then as loon as it commenced boiling it would 

 rife in the kettle, and in rifing but a fmall perpendicular 

 height, would pafs a confiderable diftance up the fpout 

 D E : here the liquor would foon cool and of confequence 

 fall back into the kettle, and the whole fubfide to its origin- 

 al height. This would occur as often as the fluid rofe above 



D, as the evaporation from the wet fponges or rags, would 

 keep D E conftantly cool. 



k would perhaps be heft to pafs the fpout through the 

 fide of the bui'ding into the open air, as thereby the evapo- 

 ration would be increafed, and confequently the fpout kept 

 at a lower temperature ; in this cafe it might be covered. 



In 



