98 Mr. Genet’s Vindicator. 
talents to discredit @ronautism, and to deprive their country 
_of the additional honor of having subdued the air by the im- 
provement of that science, after having subdued the waters. 
by the power of steam? 
But I forget, Sir, that I am not writing now in support of 
zerostation, and only answering the Boston reviewers. Re- 
turning, then, to those gentlemen, I find that, having con- 
demned me, they triumphantly undertake to show that their 
mathematical science is in no way inferior to their cosmologi- 
cal knowledge. They take hold, for that purpose, of the de- 
scription of my erostatic elevator, and magisterially observe, 
that I give to the large wheel of that machine a diameter of 
30 feet and a circumference of 90, “ while, in the time of 
Metius, every thing, of 30 feet in diameter, had a circumfe- 
rence of 94 feet.”—I could reply to this charge, that Metius 
has never said that every thing, let the figure be what it would, 
had those proportions, and that he has restri them e 
circles only, which being similar figures, have a eircumfer- 
ence p ionate to their radii, or to their diameters. I 
could also represent that, in common mechanical practice, 
when a rigid mathematical ealcalation is not requisite, it is 
are not yet precisely known. Archimedes thought that a cir- 
cle, having 7 feet diameter, would have 22 feet circumference. 
Adrien Metius, on the contrary, who professed mathematics 
at Calmar, in the sixteenth century, was of opinion that the 
proportion of the diameter of a circle to its circumference, 
was that of 113to 355. While Bezout, professor of mathe- 
matics in France, and member of the Academy of Sciences 
of Paris, has proved, in his Cours de Mathematiques, pub- 
lished in 1770, that Metius was incorrect, and that, by fol- 
lowing his proportions, if the diameter of a circle weré 
3,000,000 feet, there would be an error of one foot on the 
circumference, and that the surest proportion was 1 to 
