The  measurement  of  heights  by  means  of  the  barometer  being  inti-
mately connected  with  Meteorology,  it  was  thought  not  inappropriate  to
admit  into  this  collection  Hypsometrical  Tables,  destined  to  render  this  kind
of  calculations  more  easy  and  more  rapid,  and  thus  to  increase  the  taste  for
a  method  so  useful  in  physical  geography.  I  have  preferred  the  tables  of
Delcros,  as  uniting  in  the  greatest  degree  simplicity  and  accuracy.  Those
of  Gauss,  Bessel,  and  Baily  may  be  given  afterwards.
Every  table  contains  directions  for  its  use,  when  necessary ;  moreover,
the  indication  of  the  elements  used  in  its  calculation,  and  of  the  source
from  which  it  has  been  taken.  When  no  remark  is  made  as  to  this  last
point,  the  table  has  been  expressly  calculated  for  this  volume.
%

Very  respectfully,

Your  obedient  servant,

A.  GUYOT.
CAMBRIDGE,  MASS.,  December  15th)  1851.
PREFACE

i

TO    THE     SECOND     EDITION


To     PROF.     JOSEPH    HENRY,

Secretary  of  the  Smithsonian  Institution.
SIR,—

IN  sending  to  you  the  Meteorological  Tables  composing  the  first  edition  of
this  volume,  published  in  1852, 1  expressed  the  desire  that  they  be  consid-
ered as  a  first  collection,  containing  the  tables  most  needed  at  the  time  by
the  meteorological  observers  engaged  in  the  system  carried  on  under  the
supervision  of  the  Smithsonian  Institution,  but  destined  to  be  increased.
