30 On the prefent State of A'erojlatmn, 



quantity of the number in the firft column, whether reckoned 

 as inches, feet, or yards, mufl: be the fame in each lateral co- 

 lumn ; as fquare inches, feet, or yards, in furface — and cu- 

 bical inches, feet, or yards, in capacity *. 



• 1 have omitted to particularize the method of cutting the pieces com- 

 po!ing a balloon, which will vary according to the width of the ftufF; as 

 the fmallert ingenuity will enable any one to deferibe a pattern, only 

 recollecting the length in circumference of the machine required, to- 

 gether with its propofcd fhape. Alfo the heights of the barometer arc 

 omitted (as requiring corrcftions for temperature too nice for any but phi- 

 loiophical amateurs, who may, with propriety, be fuppoftd to be already 

 matters of this ellential branch of the fcience) forthe preftnt purpofe — only 

 recollecting that, without regard to the difference of temperature, an ele- 

 vation of 16 fathoms, 01 96 feet, is ufually allowed for the fall of every 

 tenth of an inch of the mercury. 



POSTSCRIPT, 



