% Scales.m4
.PS
gen_init
  SIdefaults
  psset_(arrows=c-c)

S: arrow thick 5/(1bp__) up 147 -> wid 11 ht 15
T: S.top
B: S.bot
H: S.top - (0,15)
  circle rad 11/2 at H-(0,1.4) fill_(0)
  circle rad 5 fill_(0) with .n at last circle.s
  circle rad 11/2 fill_(0) with .n at last circle.s-(0,4)
P: (0.5 between last circle.n and 2nd last circle.s)
  arrow wid 11 ht 15 down 15 from last circle-(0,1.4)
R: circle diam 9 fill_(0) at (P.x+56,P.y-16) 
L: circle diam 9 fill_(0) at (P.x-56,P.y-16) 
S1: (13,0)
  v = P.y-R.s.y
S2: S1+(25,-v)
S3: S1+(25, v)
S: spline 0.75 thick 5/(1bp__) \
  from L.s to P-S3 then to P-S1 \
  then to P+S1 then to P+S2 then to R.s 
  line thick 8/(1bp__) right 52 at B+(0,4)
  line thick 7/(1bp__) right 32 at B+(0,11.4)
  circle rad 11/2 fill_(0) at last line+(0,8)
  arrow wid 11 ht 15 up 15 from last circle+(0,1.4)

define pan {
  shade(0, F: line invis right 48 at $1+(0,-56)
    spline 0.55 down 4 left 1 then down 4 left 10 \
      then left 26 then up 4 left 10 then up 4 left 1 )
  line from $1 to F
  line from $1 to F.start
  line from $1 to F.end
  }
  linethick_(1.5/(1bp__))
  pan(S.start)
  pan(S.end)

.PE