On Printing Presses and their Theory. 315 
the bottom. (16) is a bar check, which limits the revolu- 
tion of the bar to a precise are. e carrt 
The operation of the mechanism will now, it is believed, 
be sufficiently apparent. When the bar BA is brought 
ler i 
eminently adapted to effect that rapid increase owe! 
near the end of the pull, which has been already mentioned 
as the great desideratum in the construction of this part of 
the printing press. ‘To determine the actual gain of power 
at the beginning and at the end of the pull, measures have 
been taken from an individual press, of the lines necessary 
for the computation. When the bar was thrown back, the 
angle ACD (of the triangle ADC formed by joining the 
three centres of motion with straight lines) was found to be 
=113° 52’, CDA=7° 12’, and the distance of the centre of 
‘ives a total of 20 to 1. 3 ge nee gee 
“At the end of the pull, the angle ACD=172°, the angle 
CDA=1° 3’, and the distance of the vertical levers from a 
straight line, according to the specification of the inventor, 
strai 
which was found nearly exact, = half an ineh. it 
i yer wil 1 by compoundin ding the follo 
Srna? BA to 32, Cos. 1° 3! to Sin. 172°, 15 to 2x4, sna 
763 to 1. 
