Ifl  tbi)  town,  according  to  Stnbo,  a  well  was  sunk,
which  ma^ed  tbe  Bununer  eoUtice,  and  the  day  was
known  whMi  tbe  style  of  tbe  aundial  eaat  no  abade  at
noon :  at  that  inaunt  tbe  vertical  sun  darted  hia  raya
to  ^  bottoin  of  tbe  well. The  obaervationa  of  ttie
Fnneb  astronomera  place  Atnum  in  34°  6*  XS"  of
north  latitude. If  this  was  foraieriy  situsted  under  the
tropic,  the  position  of  the  earth  must  be  a  tittle  alter-
ed, and  tbe  obliquity  of  the  ecliptic  diminiihod. Bat
we  shonld  be  awan  of  tbe  vogoeneaa  of  obaervationo
made  by  tbe  ancients,  which  nave  conferred  so  muob
cokbrity  on  tbeao  plaeea. The  phenomenon  of  tba
eninetion  of  tbe  shadow,  trbether  within  a  deep  pit  or
round  a,  perpendicular  ^^wnon,  ia  not  confined  to  one
exact  mubematical  position  of  tht  sun,  hot  is  eomnoa
to  a  certain  extent  of  aKttude,  correapondit^  to  the  viai-
ble  diameter  of  that  luminanr,  which  is  men  than  half
a  degree. It  would  be  aufficiont,  therefore,  that  tba
northern  margin  of  tbe  aon*e  diak  alioaU  icneb  tbe  len*
ith  of  Syene  on  the  day  of  tbe  summer  solstke,  toab(4>
ish  all  lateral  shadow  of  a  perpendiootar  object. Now,
in  the  second  centnry,  the  obliqoily  of  the  ecliptic,
reckMed  from  the  obeervationa  of  Hif^rchna;  was
S8°  49'  3&". If  we  add  the  semldiameter  of  the  snn,
which  ia  IV  &7",  we  find  for  the  northern  margin  34°  fi*
Sf  ,  which  ia  within  a  aecond  of  the  eetnal  latitado  irf
Syana. At  |Meeent,  when  the  (diliqn  tty  of  tbe  ecliptic  ia
39°  SS*,  the  nonhem  limb  of  tbe  snn  comes  no  neem
the  latitude  of  Syene  than  31'  8",  yet  tbe  shadow  is
scarcely  perceptible. We  have,  therefore,  no  imper»<
oos  reason  for  admitting  a  greater  diminution  in  tbo
obliquity  oi  tbe  ecliptic  than  tbat  which  ia  shown  by
nil  ■atmwmicalobMmtien  of  tba  mo«  aBibantic  tmi

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MMt  kiol. Hiftt  of  lU  mil  ^rane  i»  not  Mnoof
ttw  wukbor  of  Umm  hut,  and  ou  give  m  do  — jmiiBo
M  uGMHiBing  the  poMtion  of  iIn  trapic  thii^  ccntn-
riea  ago,  m  •one  leaptcuble  own  of  •ctenee  moo  (0
heve  believed. — Netuie  pieeeoU  «  peculiar  spectacle
aiound  Syene. 