The Laws of Motion of a Cylinder, &e. 983 
From this it is evident, without further confidera- 
tion, that when y is a minimum, that is, when y=1, 
the whole time of performing the procefs — ms +. 
ath Vo 
which is the fame with the expref- 
fion for the minimum found in the preceding Corol- 
lary, and the value of x i in both cafes. But 
if x is fuppofed infinitely little, y will be infinitely 
great, and the time will be infinite alfo; it cannot, 
therefore, be compared with the minimum as in the 
former cafe, 
Scuottum. Though x may be taken infinitely 
little both in this and the preceding Cox. with the 
firideit propriety, yet it cannot be fuppofed to be 
abfolutely equal nothing, without committing an 
error in mechanics. Becaufe, while the Block de- 
fcends through the leaft fpace imaginable, fome 
motion will be generated, which will produce a 
proportionate impreffion on the Obftacle; but, if it 
actually reft on the top of the column, the fyftem 
will only act on the plane that fupports it by fimple 
preflure; and, if its weight be lefs than the force 
required to overcome the cohefion of the particles . 
which are to be removed, no change will take place. 
For want of attending to this circumftance, fome 
who have attempted to folve the Problem contain- 
ed in the laft Corollary, find x —= nothing, when 
the time is a minimum. The foregoing conclu- 
Nne fions 
