Pyrometry  and  dreometry,  8cc.  5 *3 
conftru&ed  on  this  plan.  It  will  be  then  a fpirit  of  wine, 
which,  in  the  aforefaid  temperature,  being  effayed  by 
the  hydroftatic  balance,  will  weigh  fo  much  a cube 
foot : and  every  inftrument-maker,  who  fliall  undertake 
to  conftrua  fuch  Areometers,  will  be  obliged  to  begin  by 
eompofing  this  fixed  liquor  by  the  help  of  the  hydiu- 
ftatic  balance,  in  order  to  conftruft  his  ftandard.  And 
indeed  all  I have  farther  to  fay  upon  the  conftru&ion 
of  the  fcale  of  this  inftrument,  relates  merely  to  a ftan- 
dard,-to  which  the  Areometers  in  ufe  may  be  compared 
in  order  to  form  a fcale. 
For  this  purpofe  they  may  be  dipped  fuccefiively  in 
twoliquids  of  very  different  fpecificgravities,  and  fuch  that 
the  ftandard  may  indicate  thofe  fpecific  weights  by  whole 
numbers  of  degrees,  the  difference  of  which  may  admit 
of  a divifion  into  aliquot  parts:  it  will  be  very  eafy  fo  to 
modify 
par  cette  methode;  ce  fera  de  l’efprit  de  vin,  qui,  etant  a la  . M- 
dite  et  eprouve  a la  balance  hydroftatique,  pefera  tant  par  Fed  cube  Dcs  lora 
iout  faifeur  d’inftrumens  qui  voudra  centre 
ftatinue  Dour  confirm  re  fon  etalon*  Car  tou  ^ 
»•«-.  »,««!  to  Areomettes  d’uftge  feront  limpleinent 
«- 
tear  fpecifique  fort  differentes,  ct  wiles  que  1 etalon  in  rque  c p 
fanes  pa,  des  n.ntbte.  en.i.t.  de  degtes,  don.  la  diffi.enee  f« : ft* 
*f«e  en  patties  aliqnotes.  II  fa.  to,  ri*  * ~ *”  P“ 
Yol.  lxviii.  * Q.q  q 
