Theory of the Pneumatic Paradox. 299 
attempted to explain the phenomenon, with the exception of Mr. 
Allies, to seek some other cause of it. This gentleman, unwil- 
ling to relinquish the idea of rarefaction, regards the adhesion of 
the disks as a particular case of a general principle which he de- 
duces from it, but which, as has been shown, may be demonstra- 
ted to be false. There still remains, therefore, the principal diffi- 
culty, of which I now proceed to offer a solution. 
_ For the leading ideas contained in it, I am indebted to the late 
Samuel Abbot, Esq., of Wilton, N. H. The experiment was de- 
scribed to him in June, 1828, by O. W. B. Peabody, Esq., now 
of this city, during the session of the Legislature of the State of 
New Hampshire, of which they were then both members. After 
alittle reflection, he suggested to Mr. Peabody, and subsequently 
to me, substantially the following explanation. 
Fig. 1. 
Let the accompanying figure represent the space between the 
two disks, O its centre, AAN the circumference of a circle of the _ 
same diameter as the tube to which the fixed disk is adapted, 
and corresponding to the tube when the two disks are applied to 
each other. Let the distance of the two circles AA, BB from 
each other, be equal to that of the two, BB, CC. On blowing 
through the tube, the air radiates in all directions from the circle 
AAN. As any portion of air recedes from the centre, that, for 
instance, which at oné moment occupies the space AA, BB, it 
