Pyrometry  and  Areometry , See.  42  g 
I did  was,  to  mount  it  in  the  manner  of  a table,  with  four 
deal  legs,  each  a foot  long,  and  an  inch  and  a half  fquare, 
very  folidly  fitted  near  its  four  angles,  and  kept  together 
at  the  other  ends  by  four  crofs  pieces,  likewife  very  folid. 
Ifhall  always  confider  this  final!  table  as  hung  to  a ftand,, 
capable  of  being  tranfported  to  whatever  part  there  is 
moft  light  in;  the  board  being  in  a vertical  fituation  in  the 
direction  of  its  grain,  and  bearing  its  legs  forward  in  fuch. 
a manner  as  that  the  crofs  pieces  which  join  them  may 
form  a frame,  likewife  placed  vertically  facing  the  ob- 
ferver. 
This  frame  fuftains  the  Microicope,  which  is  firmly 
fixed  in  another  frame  that  moves  in  the  former  by 
means  of  grooves;  but  with  fuch  a degree  of  tightnefs  as 
to  render  it  neceflary  to  ufe  fmall  ftrokes  of  a hammer  ir. 
order  to  make  it  Hide.  The  preffure  of  four  ferews 
will 
que  font  attaehees  toutes  les  autres  parties.  Je  1’ai  montee  d’abord  comme  une 
petite  table,  ayant  quatre  jambes  de  fapin  d’un  pied  de  long  et  d’l  j pouce  en 
quarre,  pofeesbien  folidement  pres  de  fes  quatre  angles,  et  reunies  al’autre  extre- 
mite  par  quatre  traverfes  auffi  tres  folides.  Je  fuppoferai  toujours  cette  petite 
table  fufpendue  a un  fupport  propre  a etre  tranfporte  la  ou  l’on  aura  le  plus  de 
lumiere,  fa  planche  etant  dans  une  fituation  verticale  dans  la  dire&ion  de  fes 
fibres,  et  portant  fes  quatre  jambes  en  avant,  de  maniere  que  les  traverfes  qui 
les  reunifient  forment  un  cadre,  fitue  aufii  verticalbment  en  face  de  i’obfervateur. 
C’eft  a ce  eadre  qu’efi;  folidement  adapte  le  Microfcope,  dans  un  chafiis 
qui  monte  et  defeend  a coulifie,  et  avec  alfez  de  juftefle,  pour  qu’il  faille 
employer  de  petits  coups  de  marteau  pour  le  faire  mouvoir:  la  predion  de 
quatre. 
