242 Prof. Barnard on a modification of the Ericsson Engine. 
The total of i’ and ii’, for the Ericsson engine, is, (¢ and ¢’ being 
eliminated, ) 
P=1ba [ F+t—-2m)—21—m) | (V) 
The similar total for the other is, 
l-m _mn—l a ; 
P=16a [ min 72 ent 1)-2 }> 
Comparing these, as before, we have, 
’) =-—5a=—110500 lbs. 
(1) =-5a=—110500 * 
(il) =+4a=+88400 . 
(2’) =+6286a= 138920 “ 
l’} =-—a= — 22100 ‘ 
[Il] =+1:286a=+28420 « 
It thus appears, that, at the point of minimum pressure, engines 
constructed in the proposed form would have a considerable bal- 
ance of positive power, even were their action directed in the 
same straight line, which it is not. In point of fact, arranged as 
they are, Ericsson’s engines, with a cut-off at two-thirds’ stroke, 
always preserve a balance of positive power at the point of great- 
est exigency ; but for the same reason, the balance is much more 
in favor of the form now proposed, hardly descending at any time 
no immediate interest in a discussion like that just now in hand. — 
