DESCRIPTION  AND  USE
384
For  the  afternoon  hours,  turn  the  quadrant  of
altitude  round  the  zenith,  until  it  comes  to  the
degree  in  the  horizon,  opposite  to  that  where  it
was  placed  before,  namely,  as  far  from  the  west
towards  the  south,  and  turn  the  globe  eastward;
and  as  the  hours  I,  II,  III,  &c.  pass  under  the
strong  brazen  meridian,  the  first  meridian  will  cut
on  the  quadrant  of  altitude  the  number  of  degrees
from  the  zenith,  that  each  of  the  hours  is  from
XII  on  the  dial.
When  the  first  meridian  goes  off  the  quadrant
at  the  horizon,  in  the  forenoon,  the  hour  index
will  ſhew  the  time  when  the  sun  comes  upon  this
dial;  and  when  it  goes  off  the  quadrant  in  the
afternoon,  it  points  to  the  time  when  the  sun
leaves  the  dial.
Having  thus  found  all  the  hour  distances  from
XII,  lay  them  down  upon  your  dial  plane,  either
by  dividing  a  semicircle  into  two  quadrants,  or
by  the  line  of  chords.
In  all  declining  dials,  the  line  on  which  the
gnomon  stands  makes  an  angle  with  the  twelve
o'clock  line,  and  falls  among  the  forenoon  hour
lines,  if  the  dial  declines  towards  the  east;  and
among  the  afternoon  hour  lines,  when  the  dial
declines