Mr.  de  luc  on 
534 
with  this  point  that  its  bulk  at  the  temperature  15°  is 
compared.  Making  afterwards  equal  to  15  — 5 = 10  the 
number  of  the  equal  parts  which  meafure  the  augmen- 
tation of  the  bulk  of  water,  inftead  of  1,6  + 0, 4=2,  which 
was  the  number  in  the  firit  cafe  taken  from  the  experi- 
ment, I have  changed  all  thefe  terms  in  the  proportion 
of  2 to  10,  which  has  preferved  the  fame  proportions 
between  them.  After  this  the  expreffion  of  the 
Thermometer  continuing  the  fame,  that  is,  its  o or  x re- 
maining 5 0 lower  than  the  inferior  points  of  the  actual 
comparifon,  in  order  to  have,  without  calculation,  the 
deviations  within  and  without  thofe  points  of  compai'i- 
fon,  it  was  neceffary  to  add  5 to  all  the  firft  numbers 
which  exprefs  the  real  dilatations  of  the  water.  I might 
have  fubtradted  5 from  each  indication  of  the  Thermo- 
meter, which  would  have  come  to  the  fame.  It  will  be 
ealily 
Thermometre  de  mercure;  puifque  c’eft  avec  ce  point  que  fon  volume  a la 
temperature  I5°eft  compare.  Faifant  enfuite  egal  a 15  — 5=10  le  nombre  des 
parties  dgales  qui  mefure  l’augmentation  de  volume  de  l’eau,  aulieu  de  i56-J-o34 
= 2 qu’etoit  ce  nombre  dans  le  premier  cas  tire  de  l’experience,  j’ai  change  tons 
les  termes  dans  le  rapport  de  2 a 10 ; ce  qui  a conferve  les  memes  proportions 
entr’eux.  Apres  quoi,  Pexpreflion  du  Thermometre  reliant  la  meme,  c’eft  a 
dire  fon  zero  ouz  reliant  de  50  plus  bas  que  le  point  inferieur  de  comparaifon 
a&uelle ; pour  avoir  fans  calcul  les  deviations  au  dedans  et  au  dehors  de  ces  points 
de  comparaifon,  il  a fallu  ajouter  5 a tous  les  nombres  qui  expriment  les  dilata- 
tions reelles  de  Peau.  J’aurois  puretrancher  5 a chaque  indication  du  Thermo- 
metre, ce  qui  feroit  revenu  au  meme.  On  verra  aifement  je  crois  que  c’ell  la  la 
route 
