Vyrometry  and  Areometry , 8cc.  443 
gradually  diminifhed  the  heat  of  the  water,  this  point 
rofe  little  by  little ; that  is  to  fay,  the  lamella  of  brafs  pre- 
ferved  a part  of  its  lengthening,  whilft  the  rod  of  glafs 
conrradted  itfelf  to  the  fame  point  at  which  it  was  at  the 
beginning  of  the  experiments.  After  a number  of  fimi- 
lar  trials,  which  always  ended  in  the  fame  manner,  I 
went  to  work  another  way : when  no  change  had  been 
produced  in  the  heighth  of  the  point,  by  the  fudden 
change  of  water  of  the  fame  temperature  as  the  air 
into  warm  water,  I immediately  put,  in  the  place  of 
that  warm  water,  water  of  the  fame  temperature  as 
the  air,  and  in  that  cafe  the  point  did  not  change  nei- 
ther. 
It  will  not  be  ufelefs  to  mention  here,  that  I had 
in  my  bottle  a fyphon  with  a cock,  by  which  I drew 
out  the  water  without  motion;  and  that  I poured  it 
in 
chaleur  de  l’eau,  ce  point  s’elevoit  peu  a peu ; c’eft  a dire  que  la  lame  de  leton  con- 
fervoit  une  partie  de  fon  allongement,  tandis  que  la  branche  de  verre  fe  contrac- 
tor au  ineme  point  ou  elle  l’etoit  au  commencement  de  Pexperience. 
Apres  nombre  de  tentatives  de  meme  efpece,  dont  les  refultats  furent  tou- 
jours  femblables,  jeprocedai  d’une  autre  maniere.  Lorfque,  par  le  changement 
fubitde  l’eau  qui  etoit  a la  temperature  de  Pair,  en  eau  chaude,  il  ne  s’etoit  fait 
aucun  changement  dans  la  hauteur  du  point,  je  fubilituois,  fubitement  auffi,  a 
cette  eau  chaude,  de  l’eau  a la  temperature  de  Pair;  et  alors  le  point  ne  changeoit 
pas  non  plus. 
ILne  fera  pas  inutile  de  dire  ici,  que  j’avois  un  fyphon  a robinet  dans  ma  bou- 
teill^  .par  lequel  je  retirois  Peau  fans  mouvement;  et  que  je  Py  yerfois  au  travers 
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