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>IFT   OF 


POPULAR    ASTRONOMY. 


A  DESCRIPTION 


OF  THE 


PEINCIPAL  PHENOMENA 


ASTRONOMY: 


.   INCLUDING 

THE  SUN;  THE  SOLAR  SYSTEM;  PLANETS;  THE  EARTH  AND 
ITS  ATMOSPHERE;  THE  SEASONS;  THE  MOON  AND  ITS 
PHASES;  DAY  AND  NIGHT;  ECLIPSES;  "TIDES  j  STARS; 
NEBULAE  &c. 


LONDON: 
PUBLISHED  BY   JAMES  REYNOLDS,  174,  STRAND. 


I   $ 

POPULAR  ASTRONOMY. 


IN  giving  a  brief  sketch  of  the  principal  phenomena  of  Aslroauiny,  it  will  be  de- 
sirable to  commence  with  a  description  of  the  Solar  System. 

^THE  SOLAR  SYSTEM  comprises  the  sun,  eight  principal  planets,  and  thirty-five 
minor  planets ;  all  of  -which  revolve  round  the  sun  as  their  centre,  and  are  termed 
primary  planets ;  in  addition  to  these,  it  also  comprises  a  number  of  secondary 
planets  or  moons,  which  revolve  round  some  of  the  primary  planets ;  and  an  unknown 
number  ot  bodies  called  comets. 

THE  SUN. 

The  Sun  forms  the  centre  of  the  planetary  system,  and  is  a  round  opaque  body, 
surrounded  by  a  luminous  atmosphere,  adapted  to  supply  heat  and  light  to  all  the 
planets.  The  sun  is  distant  from  the  earth  about  ninety-five  million  miles  ;  his  dia- 
meter is  882,000  miles ;  and  Jus  vojume«or  bulk.  1,?QO,QOO  times  greater  than  that  of 
the  earth.  The  sun  rotates  updn/his  axJ§  ifl  IJwOqty-fivf  days  eight  hours. 

Upon  looking  at  the  sun  thrbugh'a  telescope; h^vnig* coloured  glasses,  a  number 
of  dark  spots  are  usually  seen  upon  its  surface.  If  these  spotsbe  repeatedly  watched, 
they  will  be  found  not  to  b»  slatiorjaay^o"^  ttte!  sun's  ."dis£  fot'*any  long  period  of  time, 
nor  to  remain  of  the  sasae  shap'ei  haf  fc>  vary'tlleir  pogitipn,  to  contract  or  enlarge^ 
and  at  times  suddenly  to  *dfsap*pfeaf ; '  while  'otters*  brea*k*  out  in  places  where  none 
beforeexisted.  The  size  of  some  of  the  spots  is  immense;  in  the  year  1758,  one 
was  observed  which  measured  45,000  miles  across :  indeed,  the  least  possible  spot 
which  can  be  seen  by  our  best  glasses,  cannot  be  less  than  465  miles  in  diameter. 
The  result  of  the  investigations  into  this  subject  is,  that  the  solar  spots  are  believed 
to  be  spaces  or  openings  through  the  luminous  matter,  exposing  to  view  portions  of 
the  solid  body  of  the  sun.  By  an  attentive  observer  it  will  be  remarked,  that  such 
of  the  spots  as  remain  stationary  for  a  considerable  time,  have  a  gradual  motion, 
apparently  across  the  sun's  disk.  This  motion  of  the  spots  can  only  arise  from  the 
rotation  of  the  sun  on  his  axis;  and  they  serve  to  mark  the  time  of  this  rotation. 
These  spots  also  prove  that  the  sun  is  a  spherical  body  ;  for  a  spot  makes  its  appear- 
ance on  the  western  edge  of  the  sun  as  a  fine  line,  which  gradually  increases  n 
breadth  tiil  it  approaches  the  centre.  As  it  passes  on  to  the  eastern  edge,  its  dia- 
meter gradually  lessens  into  a  fine  line,  before  it  entirely  vanishes  from  view. 

With  regard  to  the  question,  whether  or  not  the  sun  is  inhabited,  astronomers  are 
undecided.  Sir  William  Hershel,  from  what  he  had  observed  in  that  luminary, 
states  as  follows  :  "  The  sun  appears  to  be  nothing  else  than  a  very  eminent,  large,. 
and  lucid  planet ;  evidently  the  first,  or  rather,  the  only  primary  one  of  our  system, 
all  the  rest  being  secondary  to  it.  Its  similarity  to  the  other  globes  of  the  solar 
system,  with  regard  to  its  solidity,  its  atmosphere,  and  its  diversified  surface,  leads 
us  to  suppose  that  it  is  most  probably  also  inhabited,  like  the  rest  of  the  planets,  by 
beings  whose  organs  are  adapted  to  the  peculiar  circumstances  of  that  vast  globe." 

Owinj*  to  the  great  difference  in  the  distances  of  the  various  planets  from  toe  sun 
and  which  will  be  described  presently,  it  will  be  evident  that  he  must  present  to  their 
various  inhabitants  different  degrees  of  magnitude.  Thus,  to  Mercury,  he  appears 
as  a  globe  far  larger  than  he  does  to  us,  while  to  the  inhabitants  of  Neptune,  he 
must  appear  little  larger  than  a  star  point.  The  former  planet  being  only  37  mil 
lions  of  miles  distant  from  him,  while  the  latter  view  him  from  the  enormous  distance 
of  2,800  millions. 

THE  PLANETS 

Round  the  sun  revolve  tne  planets,  in  orbits  not  circular,  but  more  or  less  ellip- 
tical or  oval.  The  planets  are  opaque,  solid,  globular  bodies,  which  receive  their 
light  and  heat  from  the  sun ;  they  all  rotate  upon  their  axis,  and  consequently,  all 
enjoy  the  alternations  of  day  and  night.  Their  axis  is  also  more  or  less  inclined  to 
the  plane  of  their  orbit ;  they  therefore  experience,  to  a  greater  or  less  degree,  the 


vicissitudes  of  the  seasons.  The  planets  are  retained  in  their  orbits  by  the  com- 
pound action  of  two  mutually  opposing  forces  : —first,  the  centrijieial  force,  or  «ra- 
vitation,  by  which  a  body  is  attracted  towards  the  centre  of  gravity,  which,  in  the 
case  of  the  planets,  is  the  sun  ;  and,  secondly,  the  centrifugal  f<>rce,  by  which  a  body 
in  motion  tends  to  proceed  in  a  straight  line.  Thus,  if  a  body  be  acted  upon  by 
two  forces  impelling  it  in  different  directions,  the  body  will  obey  neither,  but  take  a 
direction  compounded  of  both,  or  between  the  two.  It  is  the  action  then  of  this 
universal  law  which  retains  the  planetary  bodies  in  their  appointed  orbits. 

Several  of  the  planets  are  accompanied  by  satellites  or  moons,  which  supply  light, 
by  reflection  from  the  sun  during  his  nightly  absence,  to  their  primaries.  The 
sa;ellites  revolve  round  their  primaries,  and  accompany  them  in  their  revolution  round 
the  sun.  Between  the  orbits  of  Mars  and  Jupiter  have  been  discovered  a  number  of 
small  planets,  which  are  all  classed  under  the  term  MINOR  PLANETS.  Their  exis- 
tence was  unknown  before  the  commencement  of  the  present  century ;  but  at  this 
time  we  are  acquainted  with  thirty-five,  and  probably  more  may  yet  be  discovered. 

MERCURY.  This  planet  is,  with  the  exception  of  the  minor  planets,  the  smallest 
in  the  system,  at  the  same  time  he  is  the  most  compact  celestial  body  with  which  we 
are  acquainted.  His  density  is  about  fourteen  times  that  of  water,  or  more  than 
equal  to  that  of  lead.  On  account  of  his  small  size  and  proximity  to  the  sun,  Mer- 
cury is  seldom  distinctly  seen,  but  with  a  good  telescope  he  may  sometimes  be  dis- 
covered a  little  before  sunrise  and  after  sunset.  The  telescopic  appearance  of 
Mercury  is  that  of  a  planet  having  phases,  or  assuming  that  alternate  increase  and 
decrease  of  form  under  which  we  see  the  moon,  except  that  Mercury  does  not  appear 
quite  full  to  us.  The  powerful  telescopes  of  modern  times  have  discovered  to  us 
spots  on  the  surface  of  this  planet  by  means  of  which  his  axial  motion  has  been 
ascertained,  and  found  to  be  24  hours  5  minutes  and  28  seconds;  thus  his  day  is 
nearly  the  same  length  as  our  own.  His  year,  however,  consists  only  of  88  days, 
being  the  period  in  which  he  completes  his  revolution  round  the  sun,  so  that  bis 
seasons  will  each  consist  of  only  three  or  four  weeks. 

VENUS.  This  is  the  brightest  of  the  planets,  and  as  she  is  usually  visible  at  the 
time  of  sunrise  and  sunset,  she  has  received  the  name  of  the  morning  and  evening 
star.  Venus  would  appear  to  be  the  sister  globe  to  the  earth  ;  her  diameter  differs 
only  by  200  miles  from  that  of  our  own  planet;  her  day  only  by  a  few  minutes  ; 
she  is  surrounded,  like  the  earth,  with  an  atmosphere,  through  which  clouds  and 
vapours  float,  indicating  the  existence  of  water  beneath,  from  which  they  derive  their 
origin  ;  her  surface  is  also  diversified  by  mountains  of  vast  height.  The  matter  of 
this  planet  is  supposed  to  be  somewhat  denser  than  that  of  the  earth. 

The  phenomena  of  the  seasons,  which  depend  (as  we  shall  hereafter  explain)  upon 
the  inclination  of  the  axis  of  a  planet  to  the  plane  of  its  orbit,  are  peculiar  in  the 
case  of  Venus.  Her  axis  is  inclined  about  75  degrees  to  her  orbit,  and  as  the  decli- 
nation of  the  sun  on  each  side  of  the  equator  is  equal  to  the  inclination  of  her  axia, 
her  tropics  are  only  15  degrees  from  her  poles,  and  her  polar  circles  at  the  same 
distance  from  her  equator.  The  variations  of  her  seasons  is  so  frequent  that  she 
has  two  winters,  springs,  summers,  and  autumns  in  each  of  her  annual  revolutions. 

Venus  exhibits  the  various  lunar  phases,  except  that  she  never  appears  quite  full ; 
for  when  the  whole  of  her  enlightened  side  is  turned  towards  us,  in  her  superior 
conjunction,  the  solar  rays  interfere  with  her  splendour.  Her  course  is  as  follows: — 
Soon  after  her  inferior  conjunction,  when  she  passes  between  the  sun  and  the  earth, 
we  behold  Venus  as  a  morning  star,  rising  a  little  before  the  sun,  exhibiting  a  fine 
silver  crescent.  She  gradually  gains  upon  the  luminary,  rises  more  and  more  before 
him,  till  her  greatest  angular  distance  westward  is  attained,  when  she  appears  a 
semi- circle.  Proceeding  to  her  superior  conjunction,  she  apparently  returns  to  the 
sun,  rises  later  and  later,  appears  gibbous,  and  then  nearly  full.  On  the  east  of  the 
sun  Venus  becomes  an  evening  star,  visible  for  a  short  time  after  his  setting. 
Passing  to  her  eastern  elongation,  she  sets  later  every  night,  and  her  appearance  is 
gradually  reduced  to  a  semi-circle  j  after  which,  returning  to  the  sun,  she  becomes 
a  crescent,  sets  with  him,  and  is  invisible,  the  unenlightened  half  of  the  orb  being 
towards  us.  In  a  few  days  the  phenomena  of  the  morning  star  are  repeated. 

Deferring  for  the  present  the  description  of  the  earth,  we  will  pass  on  to  ^the  next 
planet  in  order  of  distance  from  the  sun. 

MARS.  This  planet,  which  has  its  orbit  exterior  to  that  of  the  earth,  is  about 
one  half  the  diameter  of  the  latter.  He  sometimes  presents  a  gibbous,  and,  at 
other  times,  a  circular  appearance.  He  possesses  an  atmosphere  which  is  very 
dense,  and  of  considerable  extent.  From  the  nature  of  this  atmosphere  arises,  in 
part,  perhaps,  the  red  colour  which  distinguishes  this  planet;  tuough  this  may  be 

M97533 


caused  by  the  ochry  tinge  of  the  soil  beneath.  Clear  indications  of  continents  and 
seas  are  disclosed  by  the  telescope,  the  seas  presenting  a  greenish  hue.  A  brilliant 
white  district  from  time  to  time  is  observed  in  the  neighbourhood  of  his  north 
pole,  which  decreases  in  size  when  it  is  turned  towards  the  sun.  It  is  highly  pro- 
1  bable  that  this  is  the  accumulations  of  snow  and  ice  formed  during  his  long  polar 
winters  of  twelve  months  duration,  which  melt  before  the  sun  as  the  summer 
season  returns.  The  axis  of  Mars  is  inclined  to  the  ecliptic  about  30  degrees  18 
minutes;  hence  his  seasons  must  be  very  similar  to  those  of  the  earth,  but  of 
different  length ;  he  has  also  nearly  the  same  intervals  of  day  and  night  as  we 
have. 

THE  MINOR  PLANETS.  Next  in  order  of  distance,  we  come  to  the  group  of 
minor  planets,  or  asteroids.  They  are  exclusively  telescopic  objects,  and  require 
very  powerful  instruments  to  be  discerned.  The  brightest  in  the  group  is  Vesta, 
which  appears  like  a  star  of  the  fifth  magnitude.  The  dimensions  of  these  planets, 
although  not  accurately  ascertained,  is  comparatively  small ;  Vesta  is  computed  to 
be  only  250  miles  in  diameter,  and  Pallas  is  supposed  to  be  much  smaller.  Their 
orbits  are  much  more  eccentric  than  those  of  the  other  planets. 

JUPITER.  We  now  come  to  the  first  of  a  group  of  planets  distinguished  for 
their  vast  magnitudes,  their  rapidity  of  rotation,  their  comparative  lightness,  and 
the  enormous  extent  of  their  circuits. 

Next  to  the  sun,  the  planet  Jupiter  forms  the  most  magnificent  body  in  our 
system.  His  great  size,  being  nearly  1,300  times  the  volume  of  the  earth,  the 
clearness  of  his  light,  and  his  accompaniment  of  moons,  render  him  a  most  agree- 
able object  for  telescopic  observation.  The  density  of  Jupiter  is  little  more  than 
that  of  water,  so  that  the  quantity  of  matter  contained  in  his  enormous  volume  is 
only  equal  to  about  331  times  that  of  the  earth;  and  it  is  computed  that  a  liquid 
on  Jupiter,  which  would  be  analogous  to  our  oceans,  would  be  three  times  lighter 
than  sulphuric  aether,  and  would  be  such  that  cork  would  scarcely  float  on  it.  The 
axis  of  Jupiter  being  nearly  perpendicular  to  the  plane  of  his  orbit,  there  is  no 
change  in  the  seasons,  but  perpetual  summer  at  his  equator,  and  winter  at  the  poles. 
The  velocity  of  his  rotary  motion  is  enormous,  being  at  the  rate  of  28,000  miles 
an  hour.  His  day  is  less  than  ten  hours ;  but  his  year  is  equal  to  nearly  twelve 
of  ours. 

The  belts  of  Jupiter  are  certain  streaks  across  his  disk,  running  parallel  to  his 
equator  ;  they  are  not  fixed  or  regular  either  in  size  or  number,  but  are  observed  to 
vary,  to  run  into  each  other,  and  sometimes  suddenly  to  disappear.  They  are 
supposed  to  be  clouds  floating  in  the  atmosphere  of  the  planet ;  or  rather,  perhaps, 
the  darker  body  of  the  planet  appearing  through  the  atmosphere. 

The  distinguishing  feature  of  the  planet  Jupiter  is  his  being  accompanied  by 
four  moons,  which  revolve  round  him  in  periods  of  time  varying  from  1  day  18 
hours,  to  16  days.  The  moons  of  Jupiter  form,  with  the  planet  as  a  central  body, 
a  planetary  systam  in  miniature  ;  the  first  and  fourth  are  about  the  siz.e  of  Mercury; 
the  second  and  third  about  the  size  of  our  moon. 

SATURN.  This  planet,  the  most  remarkable  body  in  the  system  in  point  of 
architecture,  is  nearly  twice  the  distance  of  Jupiter  from  the  sun  ;  or,  at  the  mean 
distance  of  900,000,000  miles. 

Saturn  rotates  upon  his  axis  in  10  hours  29  minutes,  forming  his  day  ;  and  com- 
pletes his  revolution  round  the  sun  in  29g  of  our  years,  forming  one  of  his.  Next 
to  Jupiter,  he  is  by  far  the  largest  of  the  planets,  having  a  diameter  of  76,000 
miles,  and  a  bulk  equal  to  nearly  a  thousand  times  that  of  the  earth.  The  density 
of  Saturn  is  little  more  than  that  of  cork.  Although  never  seen  by  us  at  a  point 
nearer  than  800,000,000  miles,  Saturn  shines  to  the  naked  eye,  with  a  pale,  feeble, 
jet  steady  light ;  but  becomes  one  of  the  most  fascinating  objects  in  the  heavens 
as  seen  with  the  telescope.  The  body  of  this  planet  is  encompassed  with  an  inner 
and  outer  ring,  resembling  the  horizon  round  a  globe,  but  at  a  greater  comparative 
distance.  The  width  of  the  double  ring  is  computed  at  30,000  miles ;  and  the 
space  between  the  inner  ring  and  the  body  of  the  planet  19,000  miles.  The  figure 
of  Saturn  is  the  flattest  of  all  the  planets  at  the  poles,  for  in  addition  to  the  cen- 
trifugal force  generated  by  his  rapid  rotation,  the  attraction  of  the  rings  over  the 
equator  has  aided  the  accumulation  of  matter  in  that  region. 

Saturn  exhibits  belts  like  Jupiter,  indicating  an  atmosphere ;  his  seasons,  zones, 
find  climates,  ure  similar  to  those  of  the  earth,  and  the  tropical  and  polar  pheno- 
mena are  the  same.  Of  his  satellites  little  is  known,  they  require  very  powerful 
telescopes  to  reach  them. 


URANUS.  Since  the  time  of  the  discovery  of  this  planet  by  the  illustrious  Her- 
tehel,  little  has  been  added  to  our  knowledge  of  him.  He  is  certainly  attended  by 
»t  least  four  satellites,  possibly  more,  and  their  revolutions  are  performed  iti  a 
direction  contrary  to  the  general  movements  of  the  planetary  system,  from  west  to 
east;  while  the  inclination  of  their  paths  to  the  ecliptic,-  one  oi  "which  forms  an 
angle  of  only  11  deg.  2  min.  with  a  perpendicular  to  it-s  plane,  is  another  deviation 
from  what  would  seem  to  be  the  existing  arrangement  with  all  the  other  planets, 
except  Neptune. 

NEPTUNE.  This,  the  most  distant  of  the  known  planets  in  the  solar  system,  was 
discovered  by  Messrs.  Adams  and  Le  Verrier,  in  1846.  He  revolves  at  tue  vast 
distance  of  2,862  millions  of  miles  from  the  sun,  and  occupies  164  years  in  per- 
forming his  vast  circuit  round  that  luminary,  although  he  travels  at  the  rate  of 
12,500  miles  an  hour.  The  discovery  of  a  satellite  to  this  remote  planet  is  due  to 
Mr.  Lassel,  of  Liverpool ;  and  it  is  found  to  travel  in  the  same  retrograde  order  as  the 
satellites  of  Uranus. 

COMETS 

Besides  the  planets  already  described,  there  is  an  unknown,  number  of  other 
bodies,  called  COMETS,  which  revolve  round  the  sun  in  very  elliptical  orbits.  Their 
period  of  revolution  is  so  long  that  very  little  is  known  respecting  them.  They 
are  only  seen  by  us  when  they  are  in  that  part  ot  their  orbits  which  is  nearest  the 
sun,  and  then  they  move  with  such  vast  rapidity  that  they  soon  become  again  in- 
visible to  us.  They  are  not  all  alike  in  appearance ;  some  appear  like  a  faint 
vapour,  while  others  have  a  solid  part  in  the  middle.  When  they  approach  the  sun, 
they  have  a  tail  of  luminous  matter,  which  is  sometimes  of  astonishing  length, 
and  always  directed  from  the  sun. 

The  conjectures  of  many  eminent  astronomers  respecting  the  nature  and  causes 
of  the  tails  of  comets,  show  that  they  are  not  yet  understood.  Some  have  thought 
that  it  was  the  atmosphere  of  the  comet  driven  behind  it  by  the  force  of  the  solar 
rays.  Sir  Isaac  Newton  considered  that  the  tail  is  a  thin  vapour  raised  by  the  heat 
of  the  sun  from  the  comet.  Probably  neither  of  these  conjectures  is  right ;  and 
the  nature,  uses,  and  laws  of  comets  are  left  for  future  discovery. 

THE  EARTH, 

Having  described  the  solar  system,  and  the  planets  which  compose  it,  with  the 
exception  of  the  Earth,  we  have  reserved  the  latter,  on  account  of  its  importance 
to  us  rendering  it  desirable  to  describe  it  in  connection  with  the  celestial  phenomena 
with  which  it  is  associated. 

The  diameter  of  the  Earth  is  7,912  miles;  its  circumference  at  the  equator 
24,900  miles;  and  its  mean  distance  from  the  sun  95,000,000  miles.  The  Earth 
performs  its  revolution  round  the  sun  in  365  days  6  hours,  forming  our  year ;  and 
turns  upon  its  axis  in  about  24  hours,  producing  the  phenomena  of  day  and  nigh*. 

The  ancients  considered  that  the  Earth  was  a  large  flat  plain,  surrounded  by 
water  ;  but  what  there  was  beyond  this  mass  of  land  and  water,  or  what  there  was 
below  it,  or  how  the  Earth  was  supported,  were  problems  they  were  unable  to  solve. 
At  length  men  became  more  enquiring,  and  it  was  discovered  that  the  earth  is 
globular,  or  round ;  but  it  has  been  only  within  the  last  th-ree  hundred  years  that 
the  true  figure  of  the  earth  has  been  ascertained. 

THE  ATMOSPHERE. 

The  earth  is  surrounded  on  all  sides  by  the  atmosphere,  which  extends  to  the 
height  of  about  forty-five  miles,  decreasing  in  density  in  proportion  to  the  altitude. 
Among  its  important  properties,  it  possesses  that  of  REFRACTION  ;  that  is,  a  ray 
of  light  from  any  celestial  object,  in  passing  through  the  atmosphere  becomes  re- 
fracted, or  bent  out  of  a  straight  line,  and  is  deflected  towards  the  earth.  This 
occurs  to  the  greatest  extent  when  the  celestial  object  is  near  the  horizon  ;  and,  as 
a  consequence,  it  appears  to  us  higher  than  it  really  is,  because  we  see  all  things  in 
the  direction  in  which  their  rays  last  approach  the  eye.  It  is  owing  to  this  that 
the  sun  is  seen  some  minutes  before  it  rises  above  the  horizon  and  after  it  has 
sunk  below  it. 

DAY  AND  NIGHT 

In  order  that  this  phenomena  may  be  clearly  understood,  it  must  be  borne  in 
mind,  first,  that  the  earth  is  round  ;  secondly,  that  it  receives  its  light  from  the 
sun  ;  thirdly,  that  a  globe  cannot  be  illuminatejd  on  both  sides  at  the  same  time  by 
one  luminary  ;  fourthly,  that  if  both  sides  are  to  enjoy  the  light,  it  must  be  in  suc- 
cession ;  thus,  while  one  sidi  is  enlightened,  the  other  side  must  be  in  darkness 


and  vice  versa.  Now,  the  earth  has  always  one  side  dark  and  the  other  side  light  'T 
and  that  both  sides  may  enjoy  the  cheering  rays  of  the  sun,  the  earth  is  constantly 
revolving  upon  its  axis,  thus  bringing  every  part  of  its  surface,  once  in  every 
twenty-four  hours,  under  the  influence  of  the  meridian  sunlight,  and  once  into  the 
position  immediately  opposite.  Accordingly,  while  it  is  mid-  day  in  England,  it  is 
mid-night  on  the  opposite  side  of  the  globe,  or  in  New  Zealand. 

THE  SEASONS 

The  grand  cause  of  the  seasons  is  the  inclination  of  the  axis  of  the  earth  to  the 
plane  of  its  orbit,  during  the  revolution  of  the  globe  round  the  sun.  This  inclina- 
tion is  to  the  extent  of  23^  degrees,  and  is  always  preserved  ;  the  north  pole  of  the 
earth  being  constantly  directed  to  the  same  point  in  the  heavens.  In  consequence 
of  this,  the  north  and  south  poles  of  the  earth  are  alternately  presented  to  the  in- 
fluence of  the  sun's  light  and  heat ;  so  that,  when  it  is  summer  in  the  northern 
hemisphere,  it  is  v*  inter  in  the  southern,  and  vice  versa.  We  will  briefly  follow  the 
earth's  progress  in  its  orbit  during  the  different  seasons. 

On  the  20th  March  the  sun  is  vertical  on  the  equator,  his  rays  fall  equally  on 
the  northern  and  southern  hemispheres,  and  the  days  and  nights  are  equal  in 
length  all  over  the  world.  This  is  the  SPRING  EQUINOX.  The  earth  proceeds  in 
its  orbit,  gradually  the  north  pole  comes  more  under  the  influence  of  the  sun's  ray&, 
which  fall  more  and  more  perpendicularly  ;  and  the  length  of  the  days  exceeds 
that  of  the  nights,  in  proportion  to  the  distance  from  the  equator,  until  the  21=t 
June,  when  the  sun  becomes  vertical  at  the  tropic  of  Cancer,  and  we  reach  the 
SUMMER  SOLSTICE.  After  this,  the  earth  proceeding  in  its  course,  the  north  pole 
gradually  recedes  from  the  sun,  the  days  shorten,  the  sun's  rays  become  more 
oblique,  and  on  the  23rd  September  the  sun  is  again  vertical  at  the  equator,  and 
we  arrive  at  the  AUTUMNAL  EQ.UINOX.  The  earth  speeds  onward,  the  days  be- 
come shorter  than  the  nights,  the  sun's  rays  fall  more  and  more  obliquely  on  the 
northern  hemisphere  until  the  21st  December,  when  we  reach  the  WINTER  SOL- 
STICE. The  north  pole  is  now  furthest  inverted  from  the  sun,  which  has  become 
vertical  at  the  tropic  of  Capricorn.  The  earth  hastens  on  its  way  ;  our  days  be- 
gin to  lengthen  ;  and  the  sun's  rays  gradually  increase  in  power.  On  the  20th 
March  the  sun  is  again  vertical  on  the  equator,  and  we  rejoice  in  the  return  of 
spring. 

THE    MOON    AND  ITS    PHASES. 

Our  satellite  the  Moon  is  a  globe  2,160  miles  in  diameter,  and  revolves  round  the 
earth  at  a  distance  of  240,000  miles,  in  27  days  7  hours  43  minutes  and  11 
seconds. 

When  viewed  through  a  telescope  her  surface  appears  very  bright  and  extremely 
rugged,  presenting  numerous  mountains  and  deep  excavations  or  hollows.  There 
are  no  traces  of  water  nor  of  an  atmosphere. 

The  Phases  of  the  Moon  arise  from  the  different  positions  which  it  assumes  in  rela- 
tion to  the  sun  and  the  earth  during  its  revolution  round  the  latter.  When  the  moon 
is  between  the  sun  and  the  earth,  its  dark  side  is  presented  to  us,  and  it  is  conse- 
quently invisible  ;  in  this  position  it  is  called  the  NEW  MOON.  Four  days  after  the 
time  of  new  moon  it  has  receded  45  degrees  from  the  sun,  and  now  a  portion  of  its 
illuminated  surface  is  seen  in  the  form  of  a  crescent.  After  eight  days  it  has  de- 
parted 90  degrees  from  the  sun,  and  shows  a  bright  semi-circular  disk  ;  the  moon 
is  now  said  to  be  in  its  FIRST  QUARTER.  Gradually  showing  more  of  i'S  illuminated 
surface,  it  becomes  gibbous  ;  and  about  fifteen  days  after  the  time  of  new  moon,  it 
stands  directly  opposite  the  sun,  presenting  a  complete  circular  disk  ;  this  is  the 
FULL  MOON,  rising  when  the  sun  sets,  and  shining  through  the  whole  night.  Pro- 
ceeding in  its  course,  its  illuminated  surface  gradually  decreases ;  approaching  the 
BUII  it  becomes  a  second  time  gibbous  ;  a  half- moon  at  its  LAST  QUARTER  ;  assumes 
a  crescent  form  ;  and  completing  its  orbit,  disappears  ;  becoming  a  ntw  moon 
again  as  at  first. 

ECLIPSES. 

When  an  heavenly  body  is  darkened  by  the  shadow  of  another  heavenly  body 
falling  upon  it,  that  heavenly  body  is  said  to  be  eclipsed. 

ECLIPSE  OF  THE  MOON.  An  eclipse  of  the  moon  is  caused  by  the  earth  so  com- 
ing between  the  sun  and  moon  as  to  prevent  the  sun's  rays  falling  upon  the  latter; 
this  can  only  happen  at  the  time  of  full  moon.  If  the  moon's  orbit  were  parallel  to 
the  plane  of  the  ecliptic,  we  should  have  an  eclipse  of  the  moon  every  month,  at  the 
lime  of  full  moon,  and  one  of  the  sun  at  the  time  of  every  new  moon ;  but  this  does 


not  happen  because  the  two  orbits  cut  or  intersect  each  other,  and  the  moon's  orbfr 
is  inclined  5  degrees  8  minutes  to  the  plane  of  the  ecliptic.  Those  two  places  where 
the  intersection  takes  place  are  called  the  nodes  ;  and  an  eclipse  can  only  take  place 
when  the  sun,  earth,  and  moon,  are  in  conjunction  (or  in  a  line;  at  the  time  when 
the  moon  is  in  one  of  the  nodes. 

ECLIPSE  OF  THE  SUN.  An  eclipse  of  the  sun  is  caused  by  the  moon  so  coming 
between  the  sun  and  the  earth  as  to  prevent  the  rays  of  the  former  from  falling  on 
certain  portions  of  the  latter.  This  occurrence  can  only  happen  at  the  time  of  new 
moon,  and  when  she  is  at  or  near  one  of  her  nodes. 

There  is  a  great  difference  between  an  eclipse  of  the  sun  and  eclipses  of  the  moon 
The  light  which  the  moon'  supplies  is  borrowed  from  the  sun,  and  when  she  is 
eclipsed  it  is  because  the  earth  intercepts  the  sun's  rays,  and  she  is  in  darkness ;  but 
when  the  sun  is  eclipsed,  he  is  still  shining  in  all  his  splendour  ;  so  that  what  is 
termed  an  eclipse  of  the  sun,  is  in  reality  an  eclipse  of  the  earth,  caused  by  the  moon 
passing  over  the  sun's  disk,  and  thereby  preventing  his  rays  of  light  falling  on  a  por- 
tion of  the  earth.  The  moon  being  smaller  than  the  sun,  casts  a  shadow  which  eucla 
in  a  point ;  and,  therefore,  solar  eclipses  can  only  be  s^en  by  those  who  are  withia 
the  shadow  of  the  moon  at  the  time  the  solar  eclipse  takes  place. 

THE  TIDES 

The  tides  are  certain  movements  produced  in  the  waters  which  in  part  surround 
the  earth,  by  the  attraction  of  the  sun  and  moon,  particularly  the  latter,  upon 
them. 

The  waters  immediately  beneath  the  moon  being  attracted  by  her,  are  elevated  into 
a  swell,  or  wave  of  high  water ;  at  the  same  time,  the  waters  on  the  opposite  side 
of  the  globe  are  also  raised  into  a  similar  swell,  owing  to  the  attraction  of  the  moon 
upon  the  solid  mass  of  the  earth,  tending  to  draw  it  away  from  the  waters  on  the 
opposite  side.  Simultaneously,  also,  the  waters  between  toe  tide  swells  are  corre- 
spondingly depressed,  that  is,  it  is  there  low  water.  Now,  as  the  moon  is  constantly 
revolving  round  the  earth,  so  the  waters  follow  her  attractive  influence  ;  and  thus 
we  have  two  tides  daily,  at  intervals  of  about  12^  hours. 

Tides  are  distinguished  into  neap  tides  and  spring  tides ;  the  difference  may  be 
thus  explained  :  sometimes  the  sun  and  moon  are  acting  in  conjunction,  at  other 
times  in  opposition.  Thus,  at  the  time  of  new  moon  and  full  moon,  the  sun  and 
moon  are  in  conjunction,  when  their  combined  attraction  causes  the  waters  to  be  mere 
elevated,  and  we  have  what  are  c  died  spring  tides.  Again,  at  the  times  of  half-moon, 
the  sun  and  moon  are  in  opposition,  when  we  have  but  a  slight  elevation  of  the  waters, 
termed  neap  tides. 

THE  FIXED  STARS, 

Vast  as  the  solar  system  we  have  been  considering  may  appear,  it  is  but  a  mere 
point  in  the  map  of  creation.  When  we  pass  from  the  planetary  system  to  the 
other  regions  of  creation,  we  have  to  traverse  in  imagination  a  space  so  immense, 
that  it  has  hitherto  baffled  all  the  efforts  of  science  to  determine  its  extent.  In  these 
remote  and  immeasureable  spaces  are  placed  those  beautiful  luminous  bodies,  the 
Fixed  Stars,  each  of  which  is  equal  or  superior  in  magnitude  and  brilliancy  to  our 
sun.  The  grandeur  of  the  universe  thus  disclosed  overwhelms  the  mind,  and  its 
powers  fail  to  comprehend  the  immensity  of  space,  filled  as  it  is  with  system  after 
system  in  apparently  endless  succession. 

The  stars  are  divided  into  classes,  according  to  their  apparent  magnitude,  ranging 
from  the  first  to  the  sixteenth ;  but  all  after  the  sixth  magnitude  are  invisible  to  the 
naked  eye.  The  stars  have,  however,  no  appreciable  magnitude  at  all,  remaining 
mere  points  of  light  under  the  greatest  telescopic  power.  They  vary  simply  in 
brightness.  To  facilitate  reference  to  the  heavens,  the  stars  havr  been  arranged  into 
groups,  or  constellations,  of  which  there  are  35  in  the  northerr  hemisphere,  and  46 
in  the  southern.  Ursa  major  is  the  most  conspicuous  and  well  known  of  the  northern 
constellations.  Ursa  minor  is  important  from  including  the  uorth  polar  star.  Of 
the  southern  constellations,  Orion,  with  the  groups  in  his  vicinity,  constitute  the 
richest  part  of  the  visible  heavens ;  Canis  major,  an  the  souih-east  of  Orion,  con- 
tains the  beautiful  star  Sirius.  The  constellation  of  the  Cross,  not  visible  in  our 
latitude,  is  important  to  the  mariner  as  indicating  the  direction  of  the  south  pole. 

Astronomers  have  endeavoured  to  ascertain  the  approximate  distance  of  the  fixed 
stars.  Professor  Bessel  made  very  carefuJ  observations  of  a  star  in  the  constellation 
of  the  Swan,  and  the  result  was,  that  although  the  earth  is  distant  in  July  190  mil- 
lions of  mil'es  from  the  place  it  occupied  in  January,  yet  the  difference  in  the  angu- 
lar bearing  of  the  same  star,  observed  at  the  two  periods,  was  somewhat  less  tha;> 


8 

one-third  of  a  second.  Its  distance,  consequently,  could  not  be  less  than  sixty-two 
billions,  four  hundred  and  eightly  one  thousand,  five  hundred  millions  of  miles ;  a 
space  which  light,  that  flies  to  us  in  eight  minutes-  from  the  sun,  would  require  more 
than  ten  years  to  traverse. 

In  a  number  of  instances,  stars,  whose  places  have  been  registered  in  the  cata- 
logues, have  subsequently  disappeared.  Some  stars,  on  the  other  hand,  appear  to 
be  new,  as  no  entry  of  them  is  found  in  the  catalogues  of  former  observers.  There 
are  also  temporary  stars,  which  appear,  and  after  shining  with  more  or  less  lustre 
for  a  time,  vanish.  Lost,  new,  and  temporary  stars,  are  among  the  mysteries  of 
nature.  Some  astronomers  suppose  that  these  stars  are  subject  to  a  periodical  trans- 
lation from  the  depths  of  space,  moving  in  vast  elliptical  orbits,  at  one  extremity  of 
which  they  become  visible  to  us,  and  then  retire  from  view. 

Versatile  stars  are  such  as  undergo  periodical  mutations,  regularly  waxing  and 
waning.  These  singular  appearances  are  accounted  for  by  supposing  a  rotating 
body  to  have  one  of  its  hemispheres  less  luminous  than  the  other,  and  which,  being 
presented  to  us  in  the  course  of  rotation,  produces  the  periodical  changes  observed. 

Multiple  stars  are  also  observed  ;  that  is,  stars  which  appear  to  the  naked  eye  to 
be  single  objects,  are  found  by  the  telescope  to  be  compound,  consisting  of  two  or 
more  individuals.  They  appear  to  be  suns  revolving  round  a  common  centre,  each 
having  probably  its  system  of  planets  and  satellites  ;  but  which,  owing  to  their 
enormous  distance  from  us,  are  crowded  into  a  space  which  a  grain  of  sand  would 
cover. 

NEBULAE.  Under  tnis  term  are  comprised  a  class  of  objects  which  seem  to  the 
naked  eye  patches  of  luminous  matter,  but  which  are  resolved  by  powerful  telescopes 
into  clusters  of  stars,  the  individuals  of  which  may  be  reckoned  by  thousands.  Of 
such  clusters  of  stars,  there  are  hundreds  of  various  shapes,  each  constituting  as 
rich  a  firmament  as  that  immediately  around  us. 

The  Milky  Way,  which  stretches  across  the  heavens,  is  a  wonderful  system  of 
nebulae,  or  stars,  of  which  our  sun  is  considered  to  form  an  individual  member.  Of 
this  remarkable  belt,  Sir  William  Hershel  says,  "  when  examined  through  powerful 
telescopes,  it  is  found  to  consist  entirely  of  stars,  scattered  by  millions,  like  glitter- 
ing dust,  on  the  black  ground  of  the  general  heavens." 

In  concluding  our  rapid  sketch  of  popular  Astronomy  we  would  strongly  recom- 
mend to  all  the  study  of  this  great  science,  tending  as  it  does  to  elevate  the  mind 
and  impress  it  with  more  exalted  ideas  of  the  glorious  Creator  of  all  things.  In  the 
sacred  writings  we  find  frequent  allusions  to  this  sublime  subject.  "  The  heavens," 
says  the  Psalmist,  "  declare  the  glory  of  God,  and  the  firmament  showeth  his  handy- 
work."  "  Lift  up  your  eyes  on  high,  and  behold,  who  hath  created  all  these  things 
— the  everlasting  God,  the  Creator  of  the  ends  of  the  earth,  who  fainteth  not,  neither 
is  weary  ;  there  is  no  searching  of  His  understanding.  He  bringeth  out  their  host 
by  number,  and  calleth  them  all  by  names,  by  the  greatness  of  His  might,  for  He  is 
strong  in  power.  It  is  He  that  sitteth  upon  the  circle  of  the  earth,  and  the  inhabi- 
tants thereof  are  as  grasshoppers  j  all  nations  before  Him  are  as  nothing  ;  and  they 
are  counted  unto  Him  less  than  nothing  and  vanity." 

We  should  not  only  study  God  in  the  revelation  he  has  made  of  himself  in  the 
Scriptures  ;  but  we  should  also  study  him  as  he  unfolds  his  glorious  attributes  in 
the  works  of  creation.  They  are  both  revelations  of  the  same  almighty  and  benevo- 
lent being ;  both  are  in  perfect  harmony  with  each  other  ;  both  display  His  power, 
His  wisdom,  and  His  love. 


NEPTUNE 


THE  SC 


URANUS 


PRINCIPAL  PLANETS, 

end  their  Mean  Distance 
from  the  Sun  in 
Millions  of  Milea. 

Period  of 
Revolution 
In  Days. 

Hourly 
Motion, 
Miles. 

MINOR      PLANETS 
Date  of  Discovery,  and 
Discoverer. 

Period 
of 
Revn. 
Days. 

88 

110  000 

Ceres  1801  Piazzi 

1  680 

VENUS  69 

225 

80000 

Pallas   1802  Olbers  

1,686 

EARTH     95 

365 

68  000 

1  592 

MARS             .   .           .      145 

687 

55  000 

Vesta,  1807  Olbers    ... 

1  326 

4  332 

30  000 

Astrea  1845  Hencke 

I  511 

10,759 

22,000 

Hebe,  1847,  Hencke  

1,380 

URANUS   1,828 

30,687 

16,000 

Iris,  1847,  Hind  

1,346 

NEPTUNE  .'.  2,S6'4 

1     60,126 

12,500 

Flora,  1847,  Hind     . 

1  193 

Metis,  1848,  Graham  

L.347 

LONDON:   PUBLISHED 


&NETS, 

rery,  and 
rer 

Period 
of 
Revn. 
Days. 

MINOR    PLANETS, 

Date  of  Discovery,  and 
Discoverer. 

Period 
of 
Revn. 
Days. 

MINOR    PLANETS, 

Date  of  Discovery,  and 
Discoverer. 

Period. 
of 
Revn. 
Days. 

sparis   .... 
>,  Gasparig.. 
ind.  

2,041 
1,402 
1,300 
1,512 
1,518 
1,570 
1,825 
1,421 
1,271 

Fortuna,  1852  Hind. 

1,395 
1,364 
1,388 
1,817 
1,554 
2,037 
1,359 
1,581 
1.311 

Bellona,  1854,  Luther  
Amphitrite,  1854,  Marth..  .. 
Urania,  1854,  Hind  

1,689 
1,491 
1,350' 
2,047 
1,512 
1,787 

Massilia,  1852,  Gasparis  ..  . 
Lutetia,  1852,  Goldschmidt 
Calliope,  1852,  Hind  

sparis  

Euphrosyne,  1854,  Ferguson 

Thalia,  1852,  Hind  
Themis,  1853,  Gasparis.... 
Phocea,  1853,  Chacornac.. 
Prosperine,  1853?  Luther.. 
Euterpe,  1853,  Hind  

jasparis...  .. 
sparis  
ther  
„  Hind 

Polyhymnia,  1854,Chacornac 
A  Planet,  1855,  Chacornac.. 
I.encothea,  1855,  Luther..  .. 

EYNOLDS,  174,  STRAND. 


Thomas 


Drawn  aiLiEiigravedljy  JohnEmalie. 

^ 

The  Earth  />  ?4.91?nulcs  in  circumference,  and  7.9WmHes  in  diameter  at  the  equater.  Its  si/rr<'s<  v  • ,  <  >ntu 
greaJjjj,  tlie  uu  v//////////  ttfite  bed  being  ruJLy  as  great  as  die  inruiitilitii  »r'Hif  snrfajxofthflaruL.  < 

71i,'  \tirn  >u/i,lm;i  Jlnit  >*/>//<'/>'  t:\it7itls  fri/in  t/ie  surtiiiY  t>r' the  Earth  ,  whav  ItismoGt  dmse,  t^tii 
/V.v  //////// v/v/.v  <>////•/•  iniiitvluiit  t/n<(litii's,it  /h'.w.w.v  the ]hn\\T iit'iri'mctiiVi.UIustriilit'iis  i>rwhuh  are  duni 
>'///f-r  the  rei'raeli\  v  e/'/'eiis  </i  .v/v/  in,particular  states  i>r't/ie  atmosphere. 


EFFECT  OF  REFRACTION 


Dundas 


Jaju.es  Reynolds 074  Strana.lCarckl0^i84S 

V 

is  of  square  miles  t'f  water, and  49mOKong  t>r*xtju<nr  miL-s  pftini  land.  17itf  depth &r*tfit*  <  wan  varies 
/'/////•  Earth, beyond,  a  r't'u'  /tiuiifi<-J  r'i-t't  th'in  it\  »orfacefn&thing  is  foum-fi 
nit  4Jnii/i's.  At  tfehetffkt  <'/""</ r'l'tv  thousand  fiW  rt/>t\'i  v/^'.v  A  v  nirerii'J  A'^v//y/ v/  ////'* .  ///  itJJititm  te 

/'/r  ///<    luvi ;<->n,thi> 


O  I  A  C  R  A  I 


/fir    ttmtntti  re  ^ 

<•/'  the 

ijf  X.'i  hour.* 

h     imniit**.<f        tut/i 


<  1, 



•ins  >t 

so   ftiUt-J     hecnit.te    in 
fhiit    time    tilt-   .fttir.f   lift 
jH'tir    to    complete  one  re- 
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Rut    < 

/V//V.v   iii>on    its    <:.rix .  it    is    1110 
iijitf    in    its    or  I >it     roianl      the 
siut  .   It     if///     require     -?-/    lumrs 
tifoii     0.11     in'ertttfc       throuffll       the 
)<•<//•  ,     t'oi      the     .vitti      to     jniss    Troni 
tin-      ineritliiiii      at      u      pltiee      to        liie        ^ 
fume     meridian     110,11111  .     Tins     twins    it 
.s',>/,//-    ,/</v. 

'The     nnniitil       resolution       of'        the        earth 
rouiu!       tlie        sun       o,-fii/'i<'S       n       />eri<></        o/ 
.>!>.'>     </,/r.v    ,    5     hours  .     -If'   iiiiinit 


s  ^ 


proce* 

o     O       ^     sn'/i     01     our     pla 
net  ,  in    { >tts.fina  from 

7"      ^      the    ti'rst     point 
Aries      /,.      the      some 


*.      point 

77ie  diameter  or' the 
orbit    i.f    I'.'i  >,  ( '('( •',  /  •< 
miles,    an</    /"/.<•    linear     >:r 
*          o        ii-nt    near    ^(^'.(^(^('.('tfl*  miles. 
Tin's    enormous   distance    is    Ira- 
o  versed     at      the    rate    <>.'     (.>H.O(~)O 

^  tni/e.v    a/i     hour ,   or    I'>    ?/i/7e.- 

x  .In     ita    iinniiiil     revolution     li>- 

^      ^  '      the    earth  ,     inclined     '23^ rrom    ,i     Inn-    />er 

pendiriilar    to    the    plane    at'  the    orhit . 
\^  V-         tains    iinnriahh     llie    s<une    position  .    ciin.«iiia     t/ie 

\>          phenomena     or     the    ^<ia,\~ons. 


x^ 


v-\  ,» 

A  && 
>>  ** 


EQ"'»o 


•    <?.      ^      >>    -^ 


''////  ///////. A/// 

" 


/I 


The  comparative  diameter  of  the  Sun 
upon  this  scale  will  be  two  feet  four  inches. 


COMPA: 


SAT 


JUPITER 


JUPITER  89,000.  SATURN  76,000. 


DIAMETER  OF  TI 
NEPTUNE  75.500.  URANUS  35,OC 


PHASES  OF  SATURN. 


The  planet  Saturn  presents  various  appearances  to  the  earth,  consequent  upon  the 
relative  positions  of  the  two  bodies.  Thus,  while  the  planet  traverses  one  part  of  its 
orbit,  the  southern  side  is  presented  to  us,  and  during  its  passage  through  another 
portion  of  its  orbit,  the  northern  side  is  seen.  Twice  in  every  revolution,  or  once 
in  every  fifteen  years,  the  plane  of  the  ring  intersects  the  ecliptic,  and  its  edge  is 
then  seen  as  a  fine  line  across  the  body  of  the  planet;  at  other  parts  of  the  orbit 
the  ring  becomes  more  or  less  open  as  the  planet  recedes  from,  or  approaches,  the  points 
of  intersection. 


LONDON:  PUBLISHED  B? 


E  MAGNITUDES  OF  THE  PLANETS. 


URANUS 


MTH  VENUS 


,V*ARS       MERCURY 


MILES. 


EARTH  7,912.  VENUS  7,800.  MARS  4189.  MERCURY  3,140. 


PHASES  OF   VENUS. 

Superior  Conjunction. 

oooo 


Inferior  Conjunction. 

'he  brilliant  and  beautiful  planet  Venus,  during  its  annual  revolution  round  ~  the 
presents  to  us  phases  similar  to  those  of  the  moon,  as  represented  in  the  diagram, 
ing  her  conjunction  she  is  generally  invisible;  but  after  passing  ner  inferior  con- 
Stion,  she  appears  west  of  the  sun  as  a  morning  star;  and  after  passing  her  superior 
'unction,  she  is  seen  east  of  the  sun  as  an  evening  star.  Her  apparent  magnitude 
«s  according  to  her  distance  from  the  earth,  winch  at  her  inferior  conjunction  is  only 
million  miles,  but  at  her  superior  conjunction  160  millions. 


NOLDS,  174,  STEAND. 


The  Phases  of  the 

Moon  arise  from  the 
different  positions  it 
assumes  in  relation 
to  the  sun  and  the 
earth,  during  its  revo- 
lution round  the  lat- 
ter. When  the  Moon 
is  between  the  sun  and 
the  earth,  its  dark 
side  is  presented  to 
us,  it  is  then  invisible, 
and  is  called  the  NEW 
MOON;  proceeding  in 
its  orbit,  a  portion  of 
its  illumined  surface 
becomes  visible  in  the 
form  of  a  crescent; 


THE 

PEAS 


OF    THE 


M001 


Eclipse  of  the 

Moon.  An  eclipse 
of  the  moon  is  caused 
by  the  earth  coming 
between  the  sun  and 
the  moon,  so  as  to 
prevent  the  sun's  rays 
falling  upon  the  latter; 
this  can  only  happen 
at  the  'time  of  full 
moon,  and  when  the 
sun,  earth,  and  moon, 
are  in  conjunction, 
at  the  tune  when  the 
moon  is  in  one  of  the 
nodes. 


ECLIPSE   OF  THE   MOON 


E( 


The  Tides  are 

caused  by  the  attrac- 
tion of  the  sun  and 
moon  upon  the  waters 
of  the  earth.  NEAP 
TIDES  are  occasioned 
by  the  attraction  of 
the  moon  alone;  the 
waters  immediately 
beneath  the  moon 
being  elevated  into  a 
swell  or  tide  wave, 
follow  her  attractive 
influence,  as  she  re- 
volves round  th»e 
globe.  The  second 
tide  on  the  opposite 


LONDON:  PUBLISH! 


0' 


J[|  ALP 

'(i 


\ 


O    (I 


GIBBOUS 


MOON 


then  a  half  moon; 
three  quarters  full ; 
and,  lastly,  the  moon 
attaining  a  position 
opposite  to  the  sun, 
its  whole  illumined 
disk  is  presented  to 
the  earth,  when  it  is 
called  a  FULL  MOON; 
Advancing  onwards 
hi  its  orbit,  its  illu- 
mined surface  is  gra- 
dually inverted  from 
the  earth,  until  it 
entirely  disappears, 
and  the  Moon  hacomes 
invisible,  as  at  first. 


ECLIPSE  OF   THE    SUN 


Eclipse  of  the  Sun. 

An  eclipse  of  the  sun 
is  caused  by  the 
moon  so  coming  be- 
tween the  sun  and 
earth,  as  to  prevent 
the  rays  of  the  former 
from  falling  on  cer- 
tain portions  of  the 
latter.  This  pheno- 
menon can  only  hap- 
pen at  the  time  of 
new  moon,  and  when 
she  is  at,  or  near, 
one  of  her  nodes. 


ES 


SPRVNG      TIDES. 


side  of  the  globe  is 
caused  by  the  moon 
attracting  the  solid 
body  of  the  earth 
away  from  the  waters 
on  that  side,  causing 
them  to  be  elevated 
into  a  similar  swell. 
Thus  we  have  two 
daily  tides.  SPUING 
TIDES  occur  from  the 
combined  influence  of 
the  sun  and  moon 
when  they  are  in  con- 
junction, causing  the 
tides  to  be  more  ele- 
vated. 


IEYNOLD3,  174,  STRAND. 


COMETS,  AEROLITES 


THE  COMET   OF  1811 


Comets  are  heavenly  bodies  of  a  luminous  and  nebulous  appearance,  which  approach  to  a: 
recede  from  the  sun,  moving  in  very  elliptical  orbits;  they  usually  present  the  following  pi 
nomena.     A  faint  luminous  circle  is  first  seen  by  the  aid  of  good  telescopes,  after  a  short  tn 
a  nucleus  or  part  where  the  light  seems  more   concentrated  appears,  the  object   continues 
enlarge  and  a  tail  begins  to  form  which  looks  as  if  one  side  of  the  nucleus  were  projected  u 
stream  of  light  away  from  the  body  of  the  comet.     This  tail  increases  in  length,  so  as  sometii 
to  spread  across  the  whole  visible  heaven.     The  comet  approaches  the  sun,  and  passing  roui 
it  is  for  a  time  lost  to  view,  but  emerges  again  on  the  other  side  with  increased  brilliancy, 
phenomena  of  disappearance  are  then  in  the  inverse  order,  the  same  as  those  of  its  appearan< 


AEROLITES. 

Aerolites.  These  are  supposed  to  be  small  bodies 
moving  in  space,  and  which  are  occasionally  met  with 
and  attracted  by  the  earth.  Their  luminous  appearance 
is  owing  to  their  becoming  ignited  by  the  intense  heat 
acquired  by  their  great  velocity  and  the  compression  of 
the  air.  The  view  represents  a  shower  of  Aerolites  seen 
in  Europe  in  1835. 


ELLIPTICAL 

Cometary  Motion,    it 

about  the  sun  in  orbits  of  a 
meter  very  greatly  exceeds  t 
of  the  extremities  of  the  fig- 
form,  although  of  various  deg 
comet  in  its  orbit,  varies  wi1 
rapid  when  near  that  lumina 
from  him.  At  different  par 
passage,  showing  the  directio 
be  opposite  to  the  sun. 


LOIS'JXXN:  PUBLISHED 


ZODIACAL  LIGHT. 


ENCKE'S    COMET 


Diagram  represents  three  Comets  of  modem  times.  First,  the  celebrated  COMET  of  1811, 
i  had  a  tail  computed  to  be  123  millions  of  miles  in  length,  by  a  breadth  of  15  millions; 
svhich,  according  to  the  calculations  of  Bessel,  -will  not  repeat  its  visit  till  the  year  5194. 
,EY'S  COMET,  whose  last  appearance  was  in  1835,  has  a  period  of  about  76  years.  This 
b  has  undergone  remarkable  changes  in  appearance.  In  1456  it  passed  near  the  earth,  with 
extending  over  60°'  Its  later  appearances  have  been  much  less  conspicuous.  ENCKE'S 
!T,  is  a  small  comet  which  revolves  round  the  sun.  in  about  1210  days,  within  the  orbit  of 
er.  It  has  no  nucleus,  or  tail,  but  resembles  a  globular  patch  of  vapour,  and  seems  to  be 
asing  in  brightness. 


COMET. 

en  stated,  that  comets  move 
a,  of  which  the  longer  dia- 
1  having  the  sun  noar  one 
aet  moves  in  an  orbit  of  this 
ty.  The  rate  of  motion  of  a 
from  the  sun ;  inconceivably 
in  proportion  to  its  distance 
,  a  comet  is  indicated  it  its 
i  every  part  of  its  course,  to 


THE  ZODIACAL  LIGHT. 

The  Zodiacal  Light  is  a  luminous  phenomenon 
occasionally  seen  in  the  heavens.  Its  figure  resembles  an 
inverted  cone,  having  its  base  towards  the  sun,  and  its 
axis  lying  along  the  zodiac.  It  is  generally  of  a  delicate 
rose  tint,  and  is  most  favourably  seen  early  in  March, 
shortly  before  sunrise  or  after  sunset. 


HSOL.DS.  171.  STKAtfP. 


PICTORIAL 


DESCRIPTIVE   ATLAS 


OP 


GEOLOGY. 


ILLUSTRATING  THE  PRINCIPLES  OF  THIS 
IMPORTANT  SCIENCE. 


REVISED 

BY   JOHN   MORRIS,  F.G.S. 


LONDON:  JAMES  REYNOLDS,    174,   STRAND. 


POPULAR  GEOLOGY, 


Geology  is  a  branch  of  science  which  investigates  both  the  ancient  natural 
history  and  physical  condition  of  the  earth's  crust ;  treats  of  the  successive  modi- 
fications it  has  undergone;  and  the  agencies  which  even  now  are  producing 
changes  on  the  surface  of  the  globe.  Palaeontology,  which  specially  treats  of  the 
history  and  affinities  of  those  animals  and  plants  whose  remains  occur  in  the 
various  strata;  and  Mineralogy,  which  treats  of  the  composition  and  actual 
nature  of  the  materials  composing  the  various  rocks  and  strata,  are  intimately 
connected  with  geology. 

The  crust  of  the  earth,  up  to  the  altitude  of  24,000  feet,  and  down  to  depths  of 
3,000  feet,  has  in  every  direction  of  its  accessible  parts  been  investigated,  and 
sufficient  is  known  of  its  structure  to  warrant  the  assumption,  with  tolerable 
certainty,  of  the  following  important  principle: — The  crust  of  tJie  earth  consists  of 
only  a  proportionably  small  number  of  different  rocks,  and  these  are  similar  to  each 
other  at  the  most  distant  parts  of  the  globe,  as  to  their  principal  mineral  characters. 
Thus  the  various  kinds  of  rock  are  distributed  over  the  entire  globe,  the  granites 
of  South  America  and  of  the  most  northern  climates  are  nearly  alike;  while  on 
the  other  hand,  plants  and  animals  of  the  equator,  of  the  temperate  zones,  and 
of  the  polar  circles,  exhibit  the  most  striking  differences. 

Heat  of  the  Globe.  The  temperature  of  the  globe  is  an  important  element 
in  the  history  of  the  changes  which  the  earth  has  undergone.  At  each  point  of 
the  earth's  surface  there  is  a  certain  mean  temperature ;  but  beneath  the  surface, 
observations  show  that  a  continual  augmentation  of  temperature  proportioned 
to  the  depth  constantly  occurs.  It  is  hence  concluded,  that  the  interior  parts  of 
the  globe  are  incomparably  hotter  than  the  parts  at  the  surface;  must  formerly 
have  been  still  hotter,  and  have  influenced  to  some  extent  the  temperature 
and  all  the  other  phenomena  at  the  surface  of  the  earth.  That  the  internal  heat 
was  once  greater  than  it  now  is,  is  evident  from  many  facts.  The  deepest  rocks 
are  such  as  appear  evidently  to  have  been  cooled  down  from  igneous  fusion;  and 
the  figure  of  the  earth  is  such  as  would  result  from  revolution  on  its  axis,  provi- 
ded the  whole  or  a  large  part  of  its  mass  were  in  a  state  of  fluidity  or  viscidity. 

Modern  causes  Of  Change.  Besides  the  changes  resulting  from  the  gradual 
cooling  of  the  mass  of  the  earth,  there  are  many  other  forces  now  in  action 
tending  to  produce  changes  in  the  external  crust  of  the  globe.  The  varying  heat 
received  from  the  sun;  the  effect  of  heat  and  physical  condition  in  modifying  the 
animal  and  vegetable  world;  the  disintegrating  effect  of  seas,  rivers,  springs,  and 
rain;  the  chemical  and  mechanical  action  of  the  atmosphere;  the  disruptive 
forces  of  volcanoes  and  earthquakes;  the  sediments  transported  by  rivers  j  the 
formations  due  wholly  to  the  labours  of  innumerable  marine  animals ;  the  effects 
of  frost,  glaciers,  and  icebergs — all  tend  to  produce  incessant  change  on  the 
earth's  surface.  These  changes  affect  the  geographical  boundaries  of  land  and 
water,  the  relative  levels  of  land  and  sea,  and  the  forms,  proportions,  and  distri- 
bution of  organic  life. 

The  statement  of  the  effects  of  modern  causes  of  change.oa  the  earth's  surface 
is  also  applicable  to  former  eras  of  the  world,  at  least  in  its  general  features;  but 
they  may  not  always  have  been  equal  in  degree  of  action.  Many  sudden  changes 
have  evidently  occurred,  arising  from  the  unusual  predominance  of  some  of  the 
above  forces. 

Successive  Periods  Of  Formation.  At  a  certain  depth  below  the  surface 
of  the  earth  the  rocks  are  massive,  without  stratification,  and  without  fossils, 
affording  evidence  of  having  been  acted  on  by  heat;  but  above  these  rocks  are 
others  which,  by  being  stratified,  and  by  having  fossils  peculiar  to  themselves, 
may  be  classified  and  arranged.  They  represent  too,  epochs  of  time,  in  respect 
to  their  period  of  formation,  although  we  are  u-nable  to  measure  that  time  by 
years  or  centuries. 

The  rocks  composing  the  earth's  crust  may  be  classified  in  various  ^vays* 
Looking  merely  at  the  formation  of  the  rocks,  we  may  distinguish  Stratified  and 
IJnstratified  rocks.  If  we  consider  whether  remains  of  plants  or  animals  have 
been  found  in  the  deposits,  we  may  distinguish  Fossiliferous  and  Unfossili- 


ferous  rocks.  Lastly,  if  we  consider  the  agencies  which  have  been  at  work  in 
producing  the  different  rocks,  we  may  distinguish  them  into  three  groups,  viz., 
the  Igneous,  Metamorphic,  and  Aqueous  formations.  The  first  have  been  pro- 
duced by  the  fusion  of  mineral  matters  by  the  action  of  heat ;  the  second,  by  the 
action  of  heat  in  modifying  previously  deposited  rocks;  and  the  last  have  for  the 
most  part  been  deposited  in  strata  at  the  bottom  of  seas,  rivers,  and  lakes.  The 
aqueous  rocks  have  been  divided  into  three  great  series,  chiefly  in  reference  to 
their  organic  contents,  viz.,  the  Palaeozoic  series,  or  Primary;  the  Mesozoic,  or 
Secondary;  and  the  Cainozoic,  or  Tertiary.  These  several  series,  with  the  groups 
they  include,  will  be  found  stated  at  length  on  the  Table  of  Geological  Strata, 
forming  one  of  the  plates  of  the  Atlas.  The  Igneous,  Metamorphic,  and  Fossili- 
ferous  rocks  also,  are  described  upon  the  several  Diagrams  illustrating  them. 

Present  Aspect  Of  the  Globe.  The  outlines  of  land  and  sea  throughout 
the  globe  depend  principally  on  the  disposition  and  groups  of  mountain  chains, 
which  in  every  instance  yet  known,  are  certainly  shown  to  have  been  raised  by 
mechanical  agency,  generally  the  result  of  igneous  action.  Frequently,  how- 
ever, this  dependence  of  the  form  of  the  existing  land  upon  the  ranges  of 
mountains  is  disguised  by  the  extent  of  comparatively  plain  country  which 
separates  the  mountains  from  the  sea.  In  such  cases,  it  is  necessary  to  admit 
that  the  general  level  of  the  sea  has  subsided,  or  that  large  tracts  of  land  have 
been  raised  gradually,  or  by  successive  movements  around  the  mountains,  which 
in  earlier  times  may  have  been  uplifted  by  more  violent  causes. 

The  interior  features  of  every  country  in  like  manner  depend  upon  recognized 
geological  agencies.  The  unequal  elevation  of  mountain  ranges  above  the  sea  is 
a  phenomenon  wnich  will  be  found  of  great  importance  in  geological  theory.  It 
appears  to  be  true,  at  least  in  Europe,  that  the  most  elevated  chains  of  mountains 
are  those  whose  elevation  was  not  completed  until  the  tertiary  or  later  epochs. 
Raised  in  this  manner  by  violent  or  gradual  movements  out  of  the  sea,  the  dry 
land  has  since  been  subjected  to  waste  by  atmospheric  action.  The  formation  of 
valleys  is  due  to  the  various  effects  of  atmospheric  agency;  the  action  of  running 
waters;  the  subsidence  of  the  crust  of  the  earth;  dislocations  on  the  line  of 
the  valley;  or  by  the  overwhelming  force  of  a  general  flood.  The  forms 
of  hills,  like  the  depth  and  direction  of  valleys,  are  in  part  dependent  on  the 
presence  of  strata  of  unequal  resisting  power. 

The  land  visible  on  the  surface  of  the  globe  is  not  all  of  the  same  antiquity; 
some  regions  must  have  been  covered  with  trees,  and  traversed  by  animals,  before 
the  substance  of  others  was  laid  on  the  bed  of  the  sea.  Since  life  was  developed 
on  the  globe,  there  appears  never  to  have  been  any  considerable  period  during 
which  the  land  or  sea  was  wholly  deprived  of  organic  beings ;  but  as  the  condition 
of  the  globe  changed,  the  forms  of  life  were  altered,  old  races  perished,  new 
creations  were  awakened,  the  sum  of  animal  and  vegetable  existence  was  con- 
tinually augmented,  and  the  variety  of  their  forms  and  habits  continually 
multiplied,  until  man  was  added  to  the  wonders  of  creation. 

Economic  Geology.  As  geology  advances,  its  application  to  productive 
industry  becomes  more  and  more  valuable.  The  great  aid  aflorded  by  this 
science  to  coal  mining  has  been  shown,  in  indicating  where  coal  may  or  may  not 
be  reasonably  looked  for,  according  to  the  nature  of  the  adjacent  strata.  Of  the 
situation  of  metallic  treasures,  enough  is  known  to  show  that  the  occurrence  of 
mineral  veins  is  a  circumstance  depending  on  conditions  which  are  more  or  less 
ascertainable.  In  planning  the  lines  of  railways,  canals,  &c.,  the  engineer  will 
often  be  benefited  by  the  records  of  geological  surveys.  The  careful  researches 
preparatory  to  the  selection  of  stone  for  the  new  Houses  of  Parliament,  afford  an 
example  of  the  way  in  which  geology  may  be  brought  to  bear  on  the  constructive 
arts,  as  indicating  the  position,  character,  and  extent  of  the  different  marbles, 
limestones,  clays,  &c.  To  the  agriculturalist,  geology  has  rendered  some  services, 
and  probably  may  in  future  be  appealed  to  for  further  aid.  Geology  is  the  basis 
of  all  sound  knowledge  for  ascertaining  the  position  of  springs  and  the  subterra- 
nean distribution  of  water.  The  rain  which  falls  upon  all  soils  and  rocks 
indifferently,  runs  off  the  clays,  but  sinks  into  the  limestones,  sandstones,  and 
other  rocks,  whose  open  joints  act  like  so  many  hidden  reservoirs  Hence,  a 
knowledge  of  the  subsequent  course  of  these  waters  is  of  infinite  importance  to 
the  subject  of  drainage,  the  construction  of  wells,  and  to  the  supply  of  water  to 

towns. 

(In  part  abridged  from  an  able  article  in  the  National  Cyclopaedia.) 


ARRIERS   OF    THE    POLAR    REGIONS 


The  north.  Polar  Regions  consist  chiefly  of  primitive  and.  tra 
tion  rocks ,  with  few  secondary  and,  jiXLuxial  and  slight  tert 
strata  Coal  of  the  oldest  formation  was  roicnd  at  MeLvUlt 
-Land ,  and  the  plants  of  the  coal  formations 
TZaffins  Say  are  similar  to  those  wfa 
now  flourish  between  the  tropics. 


One  of  the  mcst  remarkable  volcat 
Tzanes  of  smoTce,  and/  -red,  'hat  star. 


M 


5    ALLUVIUM 
4-  TERTIARY. 
3    SECONDARY 
2    PRIMARY 
I      ICNEOUSAMETAMORPHI 
VOLCANIC   ROCK: 


t 


Coral  reefs  are  the  work  of  organic   beings    which 
ejcist  in  inappreciable   numbers .    They    consist     of 
agcibuiinated.  skeletons    of  departed,  races  of  polypi, 
composed  of  carbonate  of  Ume ,  cemented  into 
hard   calcareous    rode . 


e^gen 


OCEAN 
Madagascar 


"  Bengal. 

,  action. .  The.  coTie  emits  vast  vo 

fa  weiglrb  three-  ancL   four  tons  . 


jrf.  Gravel 
>i.Crn,,    C/,n 

'k.CoIite    Kai  Sand-rtone 
7 ,  Limestone  ,  Dei'onian 
ft.  Gneiss.  (,><i«rt .- ,  (irmiiti- 
i.  C,r,'i-n.tlom-    /'o/y/M  ri 


Cape    I','  s    Laxid 

A  ran.:, 


IGNEC 


The  Igneous  rocks,  including  under  this  name  the  plutonic  or  older  igneous,  and 
volcanic  or  more  modern  rocks,  are  extensively  distributed  over  the  earth's  surface.  T 
form  the  solid  frame- work  of  the  globe,  and  appear  to  have  once  existed  in  a  state  of  igne 
fusion,  from  which  they  have  cooled  down.  They  contain  no  trace  of  organic  life; 
many  valuable  minerals  and  metallic  ores,  as  tin,  lead,  silver,  copper,  &c.,  are  fount 
them.  The  igneous  rocks  are  either  amorphous  or  at  times  exhibit  a  jointed  struct! 
being  separable  into  cubical  or  prismatic  masses.  They  are  generally  crystalline, 
consist  mostly  of  a  mixture  of  more  or  less  crystalline  minerals. 

Granite  consists  of  quartz,  felspar,  and  sometimes  mica  or  hornblende;  when  ho 
blende  is  substituted  for  mica,  the  rock  is  termed  Syenite.  Granite  is  of  various  coloi 
mostly  dependent  on  the  character  of  the  contained  felspar  or  mica.  It  sometimes  prese 
a  cuboidal  or  rude  columnar  structure.  Granite,  although  generally  considered  a  primi 
rock,  and  the  foundation  upon  which  the  stratified  rocks  are  placed,  appears  to  be  of 
geological  ages,  both  secondary  and  tertiary;  the  latter  strata  in  the  Andes  having  to 
observed  by  Mr.  Darwin  to  be  traversed  by  this  rock.  Protogine  is  a  variety  of  gran 
containing  the  mineral  talc;  and  Pegmatite  is  another  form  of  granite,  in  which  the  fels] 
and  quartz  are  regularly  arranged,  whence  it  is  sometimes  called  graphic  granite. 

Serpentine  or  Ophiolite,  principally  consists  of  silicate  of  magnesia,  combined  with  lii 
water,  and  oxide  of  iron.  Diallage  is  nearly  allied  to  Serpentine. 

Greenstone  (Diorite,  &c.)  consists  of  hornblende  and  compact  felspar.  Hypersthene 
Augite  Greenstone  contains  an  admixture  of  either  hypersthene  or  augite. 

In  Porphyry,  crystals  of  quartz  or  felspar  are  imbedded  in  a  granitic  or  homogenous  ba 

Amygdaloid  (Almond-stone)  contains  almond  shaped  cavities,  either  empty,  encrust 
half,  or  completely  filled.  [Trachy 

Trachyte  is  a  felspathic  rock.    Pitchstone,  pumice,  and  greystone  are  varieties 

In  Basalt»  augite  predominates  over  felspar.  Where  basalt,  and  indeed  also  otl 
igneous  rocks  exhibit  a  resemblance  to  a  series  of  steps,  they  have  received  the  name 
trap  rock.  Under  the  general  name  of  trap  rock  are  included  all  basalts  and  other  rocks 
volcanic  origin.  Fingal's  Cave,  presents  a  beautiful  example  of  columnar  basalt. 

Lava  is  the  result  of  modern  volcanic  action;  it  is  very  variable  in  its  composition  a 
structure,  being  allied  to  the  basalt  and  trachytes. 


GRAPHIC  GRANITE. 


FINGAL'S  CAVE,  Isle  of  Staffa. 


LONDON:  PUBLISHED 


BASALT 


ROCKS. 


ranite  Veins-  In  some  parts  of  Britain,  and  also  in  other  countries,  granite  vein* 
j  been  observed  proceeding  from  the  mass  of  granite  rock  beneath,  and  traversing  in  all 
3tions  the  superior  and  overlying  strata.  In  Glen  Tilt,  and  at  Cape  Wrath,  Scotland, 
spieiss  and  mica-schist  are  intersected  with  numerous  granitic  veins,  the  intrusion  of 
:h  must  have  been  therefore  of  later  date  than  the  rocks  they  traverse, 
ic  Igneous  Bocks  generally  form  the  crests  or  elevated  peaks  of  mountain  suramits; 
if  not  always  entirely  composing  the  upper  limit,  have  by  their  action  and  elevating 
!  on  other  strata,  given  an  elevation  and  direction  to  many  of  the  principal  mountain 
is,  thereby  producing  one  of  the  chief  physical  features  of  the  earth's  surface.  It  is  to 
sffects  arising  from  the  action  of  igneous  rocks,  or  to  their  peculiar  structural  cha- 
ir, that  the  picturesque  features  of  much  mountain  scenery  is  due,  as  well  shown  in 
>old  and  rugged  outline  of  the  naked  and  abrupt  rocks,  and  the  gradually  tapering 
s,  called  Aiguilles,  in  the  Alps.  The  Caucasus  and  Himalayas  present  examples  of  the 
itions  of  ancient  disruption  or  subsequent  weathering  of  the  rocky  mass.  To  this 
r  agency  may  be  attributed  the  singular  forms  of  some  of  the  granite  of  Cornwall. 
ic  principal  elevations  of  Devon  and  Cornwall,  as  the  Brent  Tor,  Dartmoor,  Exmoor, 
are  composed  of  grey  coloured,  coarse,  and  sometimes  very  porphyritic  granite,  in 
h  large  crystals  of  felspar  are  imbedded.  Specimens  of  this  may  be  seen  in  the  pave- 

of  London  Bridge.     Granite  is  also  found  hi  Cumberland  and  Westmoreland,  and  in 
esea.    It  also  occurs  in  Scotland,  and  is  extensively  quarried  near  Aberdeen. 
Syenitic  Granite  forms  the  chief  part  of  the  Malvern  Hills,  and  a  similar  rock  occurs 

Barrow-on-soar,  Leicestershire,  where  it  is  extensively  quarried  as  a  road  stone, 
ite  forms  the  principal  chains  of  Norway,  Sweden,  and  Finland,  portions  of  the  Alps, 
nees,  and  mountain  chains  of  Bohemia,  also  of  the  Ural,  Altai,  and  Himalaya  ranges, 
t  occurs  over  extensive  tracks  in  Africa,  and  South  America. 

anite  and  the  allied  rocks  are  extensively  used  in  the  arts  and  manufactures;  some  of 
olossal  figures  in  the  Egyptian  saloon  of  the  British  Museum,  afford  examples  of  the 
yenitic  granite,  basalt,  and  other  igneous  rocks.  The  granitic  rocks  are  a  source  of 
icr  useful  material  for  the  manufacturer,  the  china  clay  is  derived  from  the  decompo- 

of  the  felspar,  one  of  the  materials  of  granite,  thus  producing  a  substance  from  which 
ner  varieties  of  china  and  porcelain  are  manufactured. 


POKPHYRITIC   GRANITE. 


AIGUILLE  DE  DRU,  Alps. 


fOLDS,  174,  STRAND. 


rl 
§ti 


i 

It 


fc    « 


2  f  * !  S 

Jrilj 

liill 


ITS 

»/'  ,<  ~ 


^^     -                o 

•  |    •! 

•I 

td 

*2 

•Hi 

^       CQ      (Z> 

i 

Gftvnnry, 


I  ,;u 1 1 c  rlmi uti  ,  Stt-f/x. 


Mmsouri ,  jV  .•i/nn-iai  j/?f) 
Grer  Marefc  tail  Srntf/Wfi    550 

Tern i,  Italy.  ,  27 (\ 

Foyers ,  Srs>t/nnd .  2(^7 

r,-iun.i  Fall.  Dalm/itia  15ft 

Tendon,  /'muff,  JZ.'f 

(Wnessp,  NewYork  JtW 

Khiae .  Lmjrfen .  Stri/x. J        65 
TivH!. //,?/,•  50. 

8.  franff.  *5 


WalpH'aJls  Jiftrr  rvrr  bfrn  nyafdfd  a/nt>nq  (hf  tnfsf  ittlfrrstinq  and  foffttt/if'u/  <>/'/Jif  wi 
fttift  //7//v  f>r  xnpw  mf(fs.  T'/t-iS  ts  />arf? cu/<?r/ v  //?/•  />/,?/•  ///  f/if  n&ftJlcm  f>/i/~f.<>  of/hs  ji 
x/fifif  t/r  thr  brrf  rt~  a  rtvtr.  as  r/fuses  thf  water  to  nts7i  d#wn  in  thai  partirj/iar  part  wi< 

Suddenly  hr  a  xtffp  <ifsrs?il.  as  a  Ifdyf  esr  /tui*ss   oft"oc/\crfrrfhis  fdqs  fhf  water 

f>r,-nr  t/i  if  sr/rrr  yrnfif  Srrm  they  aJ'f  rattfd  C<tscadr!>. 


S  eruieio,  FyrtnA 


Lulea.  ,S'n 


.r/V/          Serio  d«-E  Adda 
tfift  Tos«.  /'w 


Powersconrt . 


Montaiorency. 


7^^  TVUberftn-ce.  jV.  Afosri 

J45.  Niaoarai  .  di/ta 

12V  Rnpin.  H.wiala 

J15  Kakahika.  A*  Amf 

Z#(?  Lidford.  AW/^ 


Trolh^tla.  .SV/-* 
I  'a  r  ana  ,  Parfit/i 
Cataracls  of  the  Nil  o.  kt/\/ 


and  r<?c7cy  m0itn2£usi$  upon   wht,- 
ttsifftt  w/tsrc  rupids  and  otfmr  w<i/s/7'/t//s  afound  Rapids  trrr  <>rnt<uf)nsd  fry  such, a 

'  ' 


•Cf  and  xwiffnsfs  Cataracts    orctir  whrn   (hf  IfVfl  on  whirh  (/is  w/rfsr  runs 

ilmos't  fyerpffidtcul&'rl}'.   wilh  sitntiziruy  Lftiprttis>silv  tin/I  qTrafidsHf"  V?7isn  fJ>ss<'  //•'. 

.s,  RncksfcO"    Peacock  lriian.sn.eid. 


METAMOB 


The  Metamorpliic  Hocks  generally  lie  over  or  against  the  igneous  rocks,  and  exhibit  raos 
a  schistose  and  stratified  character,  combined  frequently  with  a  highly  crystalline  structu 
They  are  supposed  to  bear  marks  of  an  aqueous  origin,  subsequently  influenced  by  the  act 
of  heat.  Another  theory  supposes  them  to  be  broken  fragments  of  igneous  rocks,  re-arranj 
into  layers  or  beds  by  the  action  of  water. 

The  Metamorphic  Rocks  are  destitute  of  organic  remains.  Veins  of  copper  and  lead  • 
have  been  found  in  these  rocks,  as  also  those  of  iron,  silver,  gold,  tin,  &c. 

The  Metamorphic  Rocks  are  widely  distributed,  and  form  a  great  part  of  the  earth's  cm 
they  are  found  in  Scandinavia,  Northern  Russia,  Ireland,  the  Highlands  of  Scotland,  the  Al 
in  Brazil,  India,  Africa,  and  North  America.  The  scenery  of  the  districts  composed  oi  th 
rocks  is  frequently  wild  and  picturesque,  and  the  surface  often  sterile  and  unproductive,  par 
arising^from  themature,  but  generally  from  the  elevation  they  attain. 

Gneiss  consists  of  quartz,  felspar,  mica,  and  sometimes  hornblende,  arranged  in  distil 
layers;  with  the  latter  mineral  it  may  be  termed  syenitic  gneiss. 

Mica  Slate  is  a  foliated  aggregate  of  mica  and  quartz,  and  sometimes  contains  crystals 
garnet  and  hornblende. 

In  Hornblende  Slate,  hornblende  forms  the  greater  part  of  the  composition.  It  consi 
of  a  mixture  of  hornblende  and  felspar  or  quartz,  and  is  called  Metamorphic-greenstone  or  gre 
stone  slate.  The  metamorphic  limestone  of  the  primary  period,  is  often  white  and  crystalli 
and  furnishes  some  fine  marbles,  and  contains  occasionally  veins  of  chlorite,  steatite,  and  soi 
disseminated  minerals,  as  augite,  &c. 

Chlorite  Slate  consists  chiefly  of  chlorite,  sometimes  with  quartz,  felspar,  hornblende  or  mi 

Metamorphic  Sandstone,  or  Quartz  Rock  is  granular,  and  occasionally  occurs  as  vei 
in  the  other  rocks. 

Clay  Slate  is  a  slaty  rock  of  extremely  fine  ingredients,  containing  the  elements  of  t 
other  rocks  in  a  very  comminated  state,  subsequently  altered. 

Talcose  Slate  is  a  soft,  unctuous,  and  fissile  rock,  containing 
talc  as  an  ingredient,  generally  associated,  with  quartz. 

Actyiiolite  Slate  or  Schist  is  slaty  rock,  formed  chiefly  of 
actynolite,  with  some  felspar,  quartz  or  mica. 

Serpentine,  although  classed  with  the  igneous  rocks,  may  also 
be  considered  as  belonging  to  this  series. 

The  Metamorphic  Rocks  in  the  above  list  may  be  divided  into  two  SL. 


LONDON:  PUBLISHED  B 


1C  ROCKS. 


iries,  those  which  are  rudely  stratified,  laminated,  foliated  or  slaty,  as  gneiss,  mica  slate,  clay  slate ; 
id  those  which  areunstratified,  as  quartz  rock,  and  the  perfectly  crystalline  limestones  or  marbles 

Metamorphism,  or  the  changes  the  various  strata  have  undergone,  may  have  arisen  from  the 
Tects  of  heat,  heated  vapours,  gaseous  exhalations,  or  the  proximity  of  igneous  rocks ;  and 
lese  changes  may  have  been  different,  according  to  the  localities.  Thus,  in  some  places, 
lere  may  be  simply  a  re-arrangement,  or  alteration  of  the  mineral  substance,  as  the  conver- 
on  of  an  earthy  into  a  crystalline  substance;  others  may  have  undergone  an  entire  change, 
r  even  loss  of  a  portion  of  their  substance;  a  third  change  may  have  effected  the  introduction 
r  elimination  of  minerals  in  some  localities,  which  are  not  generally  found  in  others;  and  a 
•mrth  change  may  entirely  alter,  or  even  obliterate  the  original  character,  and  produce  a  new 
:ructure  in  the  rock,  as  in  slaty  cleavage. 

Although  many  of  the  Metamorphic  Rocks  are  merely  the  altered  palaeozoic  strata,  and  con- 
jquently  referred  to  the  primary  series,  still  there  are  others  of  a  considerable  later  date, 
'or  as  igneous  action  has  been  in  operation  during  every  period  of  the  earth's  history,  so  it  is 
robable  that  different  strata  have  been  successively  changed.  Thus,  some  of  the  limestones 
r  finer  marbles  of  the  south  of  Europe,  as  that  of  Carrara  and  other  localities,  which  were 
>rmerly  considered  to  belong  to  the  primary  series,  are  now  ascertained  to  be  of  the  age  of 
ic  Jurassic  rocks.  The  calcareous  and  argillaceous  strata  belonging  to  the  lias,  in  the  western 

[lands  of  Scotland,  (Portree,  for  example)  have  been  converted  into  highly  compact  limestones 
id  a  species  of  lydian  stone.  The  basaltic  rocks  and  dykes  which  form  so  prominent  a  feature 
n  the  north  coast  of  Ireland,  have  effected  a  change  in  the  earthy  chalk  of  that  vicinity,  (as 
i  the  Island  of  Raghlin),  with  which  they  are  in  contact,  converting  it  into  compact,  and 
Dmetimes  granular  limestone. 

The  ordinary  roofing  slates  belonging  to  the  clay-slate  group,  are  the  result  of  metamorphic 
ption.  These  argillaceous  strata  were  originally  deposited  as  fine  sediment  at  the  bottom 
f  the  sea,  and  have  been  subsequently  elevated  from  their  original  position,  consolidated  and 
contorted;  and  have  been  also  subjected  to  the  operation  of  other 
forces,  which  have  produced  a  peculiar  structure  or  slaty  cleavage, 
which  cleavage  is  very  uniform  over  large  areas,  and  generally 
obliterates  the  original  planes  of  stratification,  and  rarely  coincides 
with  them.  In  the  accompanying  figure,  the  undulating  lines 
are  the  planes  of  bedding,  and  the  oblique  lines  are  those  of  slaty 
AGE.  cleavage. 


IEYNOLDS,  174,  STRAND. 


PAUEOZOIC  OR  PEIMARY. 


^im 

<!"':!:!!'i!;!'!>  <: 


FOSSILIFEROUS  OR 

The  various  strata  composing  the  stratified  or  fossiliferous  rocks,  although  frequeni 
presenting  the  same  mineral  character,  have  a  definite  and  constant  order  and  arrangeme 
which  is  never  inverted.  Thus,  a  group  of  strata  in  England,  characterized  by  a  certain  set 
fossil  remains  and  overlying  another  group  containing  a  different  set  of  fossils,  are  never  fou 
in  other  countries  to  underlie  the  latter;  the  position  of  strata  in  relation  to  each  other  i 
therefore  uniform  and  invariable,  and  upon  this  uniformity  depends  the  practical  and  ecoi 
mical  bearings  of  Geology. 

The  sedimentary  rocks  are  those  which  include  the  remains  of  animals  and  vegetables,  m< 
or  less  abundantly,  and  are  hence  termed  the  fossiliferous  rocks.  They  are  generally  eitl 
arenaceous  argillaceous  or  calcareous  deposits,  which  owe  their  origin  to  the  agency  of  wat 
being  formed  within  the  bed  of  the  sea,  or  at  the  bottom  of  freshwater  streams  or  lakes, 
indicated  by  the  nature  of  the  contained  remains ;  with  which  also  are  sometimes  associal 
land  plants,  showing  that  a  terrestrial  surface  existed  at  different  periods,  and  from  I 
destruction  of  a  portion  of  which,  the  sandy  and  clayey  beds  were  probably  derived. 

The  stratified  rocks  are  for  convenience  divided  into  three  great  series,  according  to  th 
relative  antiquity,  and  the  fossil  remains  found  in  them,  which  materially  differ  and  are  read 
distinguished  from  each  other;  and  they  present  three  great  life  periods,  to  which  the  ten 
primary,  or  palaeozoic;  secondary,  or  mesozoic;  and  tertiary,  or  cainozoic,  have  been  appliec 

PALAEOZOIC,  OR  PRIMARY  SERIES. 

The  primary  series,  overlying  the  metamorphic  rocks,  constitute  with  them  some  of 
most  elevated  and  picturesque  scenery  of  the  British  Isles,  as  in  Cornwall,  North  and  Soi 
Wales,  the  district  of  the  Lakes,  Scotland,  and  a  large  part  of  Ireland.  From  the  frequ 
association  of  igneous  rocks  with  some  of  them,  they  have  undergone  considerable  change  i 
induration,  and  are  in  this  respect  allied  to  the  metamorphic  rocks — in  fact,  the  orclin: 
roofing  slates  so  extensively  quarried  near  Bangor,  and  previously  alluded  to,  form  a  mem 
of  this  series.  Like  the  metamorphic  rocks  also,  they  contain  many  valuable  deposits 
mineral  wealth.  Fine  marbles  are  obtained  from  this  series;  and  the  durable  magnesian  Lii 
stone  used  in  constructing  the  Houses  of  Parliament,  belongs  to  the  permian  group.  Besi 
the  valuable  substance,  coal,  the  carboniferous  group  contains  rich  deposits  of  iron  ore  and  1( 
The  Cambrian  Rocks  include  a  considerable  thickness  of  schists,  sandstones,  and  c 
glomerates,  as  the  Harlech  grits,  and  the  Llanberis  and  Longmynd  strata.  They  are  nef 
unfossiliferous,  only  a  faint  trace  of  organic  remains  having  been  detected  in  them  in  Irel£ 
Some  geologists  include  an  upper  and  more  fossiliferous  series,  as  the  Lingula  and  Trema 
beds  of  North  Wales,  which  are  considered  by  others  to  form  the  lower  zone  of  .the  next  grc 
The  Lower  Silurian  group,  including  the  upper  beds  just  mentioned,  and  the  Cara 
sandstones  and  Llandeilo  flags  of  Wales,  constitute  a  series  containing  many  fossils.  T 
have  been  traced  in  Wales,  'Cumberland,  Scotland,  Ireland,  France,  Spain,  Germany,  Russia, 
The  Upper  Silurian  group  were  first  described  by  Sir  R.  Murchison,  and  include  the 
stones,  Lucllow  group,  and  Wenlock  and  Woolhope  strata,  and  are  marked  by  a  gre 
develo  pmentof  limestone,  containing  a  large  series  of  fossils. 

The  Devonian,  or  Old  Red  Sandstone,  presents  two  aspects,  one  that  of  Scotland  and 
border  counties  of  Wales,  consisting  of  coarse  conglomerates,  sandstones,  and  impure  li 
stones,  locally  called  cornstones,  and  containiug  many  peculiar  fishes;  the  other,  tha 


LONDON:  PUBLISHEE 


CAINOZOIC  OR  TERTIARY. 


OZOIC  OR  SECONDARY. 


3IMENTARY  EOCKS. 

ivonshire,  with  a  greater  development  of  limestones,  (ornamental  marbles,  &c.)  and  con- 
ning many  species  of  corals,  shells,  and  some  trilobites. 

rhe  Carboniferous  group,  so  called  from  being  the  depository  of  the  important  substance, 
il.  A  limestone  shale  usually  interposes  between  the  carboniferous  limestone  and  the  old 
I  san  Istqne.  Next  above  is  a  deposit  of  hard,  coarse  sandstone,  called  millstone  grit;  and 
Dve  this  occurs  an  important  series  of  sands  and  shales,  called  coal  measures,  and  which 
terstratified  with  them,)  contain  the  valuable  mineral,  coal.  They  are  widely  distributed  in 
>  British  Isles,  Belgium,  Germany,  France,  Spain,  America,  Asia,  &c. 

Ilie  Permian  group,  or  upper  member  of  the  primary  series,  includes  sandstones,  marl 
te,  gypseous  beds,  and  magnesian  limestones,  some  of  the  latter  are  durable  building  stones. 
Germany,  this  group  contains  a  thin  band  of  copper  slate,  from  which  copper  is  obtained. 

MESOZOIC,  OR  SECONDARY  SERIES. 

rhe  secondary  series  comprise  a  set  of  alternating  strata  of  sand,  clay,  and  earthy  lime- 
>nes,  generally  less  indurated  than  those  of  the  primary  series.  In  an  economical  point  of 
;w,  they  are  not  less  important;  the  rich  deposits  of  rock-salt  and  beds  of  gypsum,  as  well 
some  good  sandstones,  belong  to  the  triassic  or  lower  portion  of  this  series.  From  some  of 
3  lias  clays  alum  is  made,  and  jet  is  obtained;  the  finer  oolitic  limestones  are  extensively 
>rked  near  Cheltenham,  Bath,  and  in  the  Isle  of  Portland;  the  Purbeck  and  Wealden  strata 
jld  some  marbles  which  were  largely  used  in  many  of  the  earlier  churches  and  other  edifices, 
le  cretaceous  group  is  valuable  for  the  lime,  beds  of  flint,  firestone,  fuller's  earth,  &c.;  while 
ue  portions  of  the  lower  chalk  yield  abundance  of  phosphatic  nodules,  useful  in  agriculture. 
The  Lower  Secondary  or  Triassic  group,  includes  the  variegated  sandstone,  muschel- 
1k,  (wanting  in  England,)  and  the  upper  new  red  sandstone  or  variegated  marl  The  latter 
ntains  gypsum  (plaster  of  Paris)  and  large  deposits  of  rock  salt. 

The  Middle  Secondary  comprises  the  liassic  group;  the  oolitic  or  Jurassic  group,  which 
sub-divided  into  three  parts ;  and  the  purbeck  and  wealden  groups. 

The  Upper  Secondary  or  Cretaceous  group,  includes  the  lower  green-sand,  gault,  upper 
een-sand,  and  the  chalk  strata. 

CAINOZOIC,  OR  TERTIARY  SERIES. 

The  tertiary  series  are  not  so  economically  important.  Cement  stones  are  obtained'  from 
e  London  clay,  which  is  also  used  for  the  manufacture  of  tiles ;  bricks  are  chiefly  made  from 
e  clay  and  loam  beds  of  the  upper  part  of  this  series,  and  which  generally  occur  along  the 
esent  river  courses,  and  frequently  contain  remains  of  extinct  mammalia,  associated  with 
ing  fresh-water  and  land  shells.  Some  portions  of  the  crag  deposits  in  Suffolk  are  exten- 
rely  worked  for  argillaceous  nodules,  highly  impregnated  with  phosphatic  matter,  and  which 
ter  undergoing  a  certain  process,  form  a  highly  valuable  manure. 

The  Lower  Tertiary  or  Eocene,  includes  the  Thanet  sand,  Woolwich  beds,  and  the 
mdon  clay,  the  beds  of  the  Paris  basin,  and  also  of  Belgium,  the  Bracklesham  and  Barton 
rata  of  Sussex  and  Hampshire,  and  the  fluvio-marine  beds  of  the  Isle  of  Wight. 
The  Middle  Tertiary  or  Miocene,  includes  the  upper  molasse  of  Switzerland,  the  brown 
>al  deposits  of  Germany,  &c.,  the  faluns  of  Touraine,  the  beds  near  Bordeaux,  &c.  in  France. 
The  Upper  Tertiary  Or  Pliocene,  comprises  the  coralline  or  red  crag,  sub-appenine  beds, 
•ift,  also  the  alluvial  and  diluvial  deposits,  the  fresh- water  beds,  and  the  gravel  deposits. 


REYNOLDS,  174,  STRAND. 


1 

i 

1 

TABLE  OF  GEO] 

ORDEK  OP  SITPEKPOSITION  AND  MINERAL  01 

WITH  THEIR  MEAN  THICKNESS,  AND  SOME 

GROUPS. 

STRATA. 

MINERAL  ( 

PLEISTOCENE. 
gN.  PLIOCENE. 
o  3  O.  PLIOCENE. 

o  « 
MIOCENE. 
o  5       EOCENE. 

'A   -4 

31     : 

H 

Modern  Deposits 

River  Deltas,  Raised  Beaches,  Peat  Be 
A  ferruginous  shelly  Sand,  with  beds  ( 
Beds  of  ferruginous  Sand  and  Gravel, 
White  calcareous  Sand,  with  Shells  an 
The  leaf  beds  of  the  Isle  of  Mull  proba 
A  series  of  strata  of  Sands,  calcareous 
Yellow  and  white  Sand,  dark  Clay  wit 
Yellow  ferruginous  Sands,  and  Sandst< 
Dark  blue  or  brow^i  Clay,  and  beds  of 
Clays  of  variegated  colours,  as  red,  gr< 

Mammaliferous  or  Norwich  Crag. 
Red  Crag    .»... 

Coralline  Crag  

(Wanting  in  England)  

Fluvio-Marine  Beds  

Barton  Clays   

Bagshot  and  Bracklesham  Sands- 
London  Clay  and  Bognor  Beds  ... 
Plastic  and  Mottled  Clays  

CRETACEOUS. 
»> 
»> 
» 
»> 
»» 
WEALDEN. 

jjf        PURBECK. 
3    UPPER  OOLITE. 

£ 

^   MIDDLE  OOLITE. 

I        " 

o                >» 
02    LOWER  OOLITE. 

M 

O 

O 

1      : 

3                        " 

LIAS. 
n 
>» 
n 

TRIASSIC. 
» 
»» 

Upper  Chalk  
Lower  Chalk                               .  .. 

Soft  Chalk  (an  earthy  carbonate  of  Li 
Chalk  of  a  harder  nature,  and  of  a  less 
Grey  Chalk,  soft  and  very  argillaceous 
A  silicious  or  calcareous  Sand,  with  gr 
Blue  marly  Clay,  sometimes  tenacious 
A  mass  of  green  or  ferruginous  Sands, 
Strong  Clay  of  a  blue  or  brown  colour 
White,  yellowish  and  ferruginous  Sane 
Sandstones,  argillaceous  Shales,  and  b 
Limestone,  oolitic  and  shelly,  coarse,  i 
Dark  blue  or  black  slaty  Clay,  with  bi 
Sands,  with  beds  and  nodules  of  calcai 
Coarse,  shelly,  rubbly,  and  oolitic  Lira 
Sands,  with  beds  and  nodules  of  calcai 
Dark  blue  Clay,  sometimes  slaty  and  1 
A  bed  of  ferruginous,  coarse,  sandy  Li 
Coarse,  shelly,  rubbly  Limestone,  thin 
Coarse,  shelly,  oolitic  Limestone,  Sand 
A  greyish  tenaceous  Clay,  sometimes 
Oolitic  Limestone  and  Freestone,  uppe 
Oolitic,  silicious  Limestone,  very  fissil< 
Marls  and  Clays,  containing  the  argill 
Coarse,  shelly,  calcareous  Ragstone,  w 
Dark  blue  coloured  Clay,  laminated  si 
Calcareous,  sandy,  and  ferruginous  be< 
Dark  inter-laminations  of  Clays  and  S 
A  series  of  laminated  argillaceous  blue 
A  series  of  beds  of  dark  purple  slaty  ft 
Variegated  greenish,  blue,  and  white  I 
(Marls,  enclosing  laminated  Sandstone 
Red  and  white  Sandstone,  mostly  fine 

Chalk  Marl 

Gault  

Lower  Greensand  

Weald  Clay   

Hastings  Sands        .      ..       .     ... 

Purbeck  Beds 

Kimmeridge  Clay  

Upper  Calcareous  Grit    

Coralline  Oolite  

Lower  Calcareous  Grit            .... 

Oxford  Clay  . 

Forest  Marble   

Bradford  Clay   

Great  Oolite             .             

Stonesfield  Slate   

Fullers'  Earth   

Inferior  Oolite  

Upper  Lias  Shale  

Marlstone  

Middle  Lias  Shale     

Lias  Limestone 

Variegated  Marls  or  Keuper  
Muschelkalk,  wanting  in  England 
Red  Sandstone  or  Bunter   

PERMIAN. 

I        :: 

02                  » 
^   CARBONIFEROUS. 

1 
» 

«                »    .  • 
DEVONIAN. 

o                »> 

S 
o  UPPER  SILURIAN. 

|  LOWER  SILURIAN. 

?w                " 
CAMBRIAN. 

Knottingley  Limestone   

Grey  laminated  Limestone,  slightly  m 
Red,  blueish  and  white  Clays  and  Mai 
Fawn-coloured,  granular,  and  compact 
Laminated,  impure  calcareous  beds  of 
Red,  grey,  or  yellow  silicious  grit,  son 
Beds  of  Coal,  alternating  with  layers  c 
Pebbly,  coarse  and  fine  quartzose  Grit 
Compact  or  crystalline  Limestone,  tin 
Argillaceous  Shales,  dark-coloured  an 
Quartzose  grits  and  conglomerates,  pa 
Coloured  Marls,  with  alternating  band 
Finely  laminated,  hard  micaceous  quart 
Grey  micaceous  laminated  Sandstones, 
Grey  nodules,  stratified  Limestone  anc 
Thin  Sandstones  and  Shales,  Limeston 
Beds  of  dark  coloured  flags,  mostly  cal 
A  series  of  grits,  slates,  conglomerates 
Note.  —  The  average  ih 

Gypseous  Marls    

Magnesian  Limestone  

Marl  Slate  

Lower  Red  Sandstone    .    . 

Coal  Measures             . 

Millstone  Grit   

Mountain  Limestone    

Quartzose  Conglomerates    ... 

Cornstone  and  Marl  

Tilestone  Series  

Ludlow  Rocks    

Llandeilo  or  Bala  Rocks  

Snowdon,  Skiddaw,  Bangor,  and 
Longmynd  Rocks   

LONDON:     PUBLISHED  I 


GICAL  STRATA, 

IE 

CTERS  OP  THE  VARIOUS  STRATIFIED  ROCKS; 

3E  LOCALITIES  WHERE  THEY  ARE  FOUND. 


TERS,  THICKNESS,  AND  LOCALITIES  WHERE  FOUND. 


jrged  Forests.  [Cavern  Deposits,  Mammalian  beds,   and  the  Boulder  or  Drift  Clay. 

ed  Clay  and  Loam.     4  to  12  feet.     Thorp  near  Norwich;  Bridlington,  Yorkshire. 

7  Shells,  and  locally  layers  of  Phosphatic  Nodules.     30  feet.     Near  Ipswich,  Sutton,  Ramsholt. 

arals,  sometimes  compact,  forming  thin  beds  of  Limestone.     20  feet.     Orford,  Ramsholt. 

?  to  this  epoch?     (The  shell  beds  of  Touraine  and  Bordeaux  in  France.) 

laceous  Marls,  Limestones,  greenish  Marls,  &c.     400  feet.     Headon  Hill,  Binstead,  Shalcombe. 

;  grains,  septaria  and  iron  Sand.     250  feet.     Barton  Cliffs,  Hampshire. 

layers  of  flint  Pebbles,  and  coloured  Clays  and  Sands.     540  feet.     Bagshot  Heath,  Bracklesham. 

-een,  and  other  coloured  Sands,  nodules  of  Septaria.     520  feet.     London,  Isle  of  Sheppey,  Bognor. 

&c.,  and  layers  of  coloured  Sands  and  Pebbles.    100  ft.  Heading,  Blackheath,  Woolwich,  Alum  Bay. 
beds  and  nodules  of  Flints.     300  feet.     Northfteet,  Purfteet,  Brighton,  Danes  Dyke,  Yorkshire. 
our,  with  few  or  no  Flints.     350  feet.     Near  Cambridge,  Flamborough  Head,  Dover  Cliffs. 
t.     Dover;   Wiltshire;  near  Cambridge;  Surrey  and  Sussex. 

i,  sometimes  compact,  and  with  layers  and  nodules  of  Chert.  120  feet.  Merstham,  Isle  of  Wight,  Sfc. 
times  soft,  with  green  grains  disseminated  in  it.     50  to  100  feet.     Folkstone,  Cambridge. 
rs  of  Chert  and  local  beds  of  Limestone  and  Fullers'  Earth.  250  feet.  Near  Maidstone;  Hythe,8fc. 
[  beds  of  shelly  Limestone  called  Petworth  Marble,  and  Ironstone.    150  feet.   Weald  of  Sussex,  Sfc 
ible  Sandstones.    Tilgate  Stone,  a  compact  grey  grit.     500  feet.     Hastings,  Tunbridge  Wells,  8fc. 
ihwuter  Limestones  and  Marbles.     150  feet.     Swanage  Bay,  Warbarrow  Bay,  Sfc.  Dorsetshire. 
{  or  compact,  with  layers  of  Chert,  and  subordinate  beds  of  Sand.     150  feet.     Isle  of  Portland. 
Shale,  Selenite  and  Septaria.     400  feet.     Kimmeridge  and  Encombe  Bays,  Dorsetshire. 
stone.     20  to  60  feet.     Scarborough,  Yorkshire ;  near  Oxford. 

some  places  entirely  composed  of  Coral.     30  feet.    Farringdon,  Calne,  Malton,  Pickering,  Scarboro. 
stones.     20  to  50  feet.     Scarborough,  Malton,  Yorkshire,  and  Wiltshire. 

i,  containing  Septaria  and  Selenite.     400  feet.     Oxford,  Chippenham,  Scarborough,  Weymouth. 
very  variable  in  quality  and  colour.    30  feet.     Kelloway  Bridge,  near  Chippenham,  Scarborough,  8fc. 
rith  layers  of  Clay  and  calcareous  Sandstone.     10  feet.     Malmsbury,  Chippenham,  Yorkshire,  Sfc. 
•rations  of  fissile  Limestone,  and  layers  of  blue  Clay.    30  feet.    Corsham,  Cirencester,  Sfc. 
y  with  thin  beds  of  brown  Limestone.     10  to  20  feet.     Bradford,  Wilts;  Tetbury,  Cirencester,  Sfc 
•y  shelly,  the  rest  sometimes  sandy,  and  often  thick  bedded.  120  feet.  Bradford  Hill,  near  Bath, 

Stoncsfield,  Oxfordshire;  Sevenhampton  Common,  Gloucestershire. 

bstance  called  Fullers'  Earth.    30  to  100  feet.     Old-down  Hill,  near  Bath;  Box;  near  Stroud. 
f  ferruginous  Sand,  with  concretions  of  sandy  Limestones  and  Shells,     250  feet.     Cotteswold  Hills.  [ 
,  sandy  Limestone  and  Shale.     50  to  200  feet.     Whitby;  Barrow-on- soar, Leicestershire;  Lyme  Regis.] 
s  of  Ironstone.     30  to  150  feet.    Staithes,  Yorkshire;  Dumbleton  Hill,  near  Cheltenham,  fyc. 
i  layers  of  nodules  of  argillaceous  Limestone.  ^  C  Dumbleton;  Batiledown,  nr.  CJieltenham.l 

Limestone,  with  partings  of  Clay  or  Shale.  >  60  to  400  ft.  <  Barrow-on-soar,  Lyme  Regis. 
grey  Limestone,  and  the  bone  bed  of  Bristol. )  C  Lyme  Regis,  Bath,  Bristol. 

.dstone  and  Shales,  with  veins  of  Gypsum  and  Rock  Salt.         Warwickshire,   Cheshire,  Derbyshire. 
raterstone,  form  a  middle  group  in  Cheshire.    400  feet.) 

md  often  impregnated  with  Salt.     Red  Conglomerate.     600  feet.     Cheshire,  Lancashire,  Sfc. 
fine  grained  and  thin  bedded.     40  feet.     Knottingtey  and  Donca&ter,  Yorkshire. 
rypsum.     50  feet.     Mansfield,  Nottinghamshire;  Manchester 
in  Limestone,  thick  bedded.     300  feet.     Derbyshire,  Yorkshire,  Ferry  Hill,  Sfc. 
Alliaceous  or  sandy  nature.     60  feet.     Durham. 

inglomeritic,  loose  Sands,variegated  Marls,  grey  micaceous  Sandstone,  &c.     Shropshire,  8fc. 
nicaceous  Sandstone,  Ironstone,  and  occasionally  Limestone.     3000  feet.    Northern  Counties,  fyc. 
hales,  Ironstones,  thin  Limestones,  and  sometimes  beds  of  Coal.     600  feet.     Northumberlandffyc. 
L    In  some  parts  beds  of  Marble,  veins  of  Lead  and  Calamine.     2400  feet.     Derbyshire ;  Bristol. 
sometimes  bituminous.     1000  feet.     Lanarkshire,  Linlithgowshire,  Sfc. 
nwards  into  a  dark  reddish-brown  coarse  grained  Sandstone.    Symonds  Yat,  Monmouthshire.  ^    5000 
stone,  and  concretionary  impure  Limestone.    Near  Hay  and  Abergavenny.                             >      to 
Istones,  and  beds  of  reddish  Shale.     Between  Ludlow  and  Downton  Castle;  Caithness,  Sfc.          )  8000ft. 
lies,  and  grey  argillaceous  and  somewhat  crystalline  Limestone.     2000  feet.     Ludlow,  8fc. 
nd  dark  argillaceous  Shale,  with  nodules  of  earthy  Limestone.     1800  feet.     Wenlock,  Dudley,  Sfc. 
zose  grits,  conglomerates  and  Freestones.     2400  feet.     May  Hill,  Gloucestershire;  Coniston,  fyc. 
rtdth  conglomerates,  Sandstone  Shale,  and  Schist.     1200  feet.    Builth,  Bala,  #c. 
rstratified  trappean  rock.     20,000  feet.     Snowdon,  Cader  Idris;  Cumberland,  Sfc. 
given  in  round  numbers,  subject  however  to  considerable  variation  in  different  localities. 

1  REYNOLDS.    174,   STRAND. 


LIMESTONE 

COAL       SEAMS 


THE  CAEBONI 


The  Carboniferous  is  the  most  important  group  connected  with  the  industrial  resources 
of  this  and  other  countries.  Independently  of  its  supplying  the  valuable  fuel  coat,  thli 
series  of  strata  contains  other  useful  substances  It  is  in  this  country  the  chief  source  o 
the  iron  ores;  it  also  yields  fire-clay,  millstones,  marbles,  and  limestones,  the  lattei 
enclosing  rich  deposits  of  lead  ore.  The  group  is  commonly  divided  into  Mountain  Lime 
stone,  Millstone  Grit,  and  Coal  Measures,  but  these  are  subject  to  local  variation. 

The  Carboniferous  or  Mountain  Limestone,  may  generally  be  regarded  as  the  base  of  th( 
whole  Carboniferous  group.  In  the  north  of  England  and  Scotland,  however,  this  limestone 
is  not  a  uniform  bed  underlying  the  coal  measures.  In  Ireland  and  other  parts  of  Europe 
the  limestone  is  separated  from  the  Devonian  Rocks  by  shales  and  sandstones.  The  thick- 
ness of  the  limestone  of  this  period  varies  from  a  few  feet  to  2,000  feet;  the  rock  is  usually 
hard,  and  contains  in  its  fissures  numerous  crystalline  minerals,  and  ores  of  lead,  zinc,  anc 
other  metals. 

Above  the  carboniferous  limestone  a  deposit  of  hard  coarse  sandstone  supervenes,  called 
Millstone  Grit;  it  often  contains  bands  or  seams  of  coal,  but  of  small  value. 

The  series  of  strata  which  constitute  the  Coal  Measures,  consists  of  first,  the  under-da^ 
or  floor,  a  rough  argillaceous  substance,  containing  stems  of  stigmaria;  secondly,  the  coat 
which  occurs  in  seams  of  from  a  few  inches  to  six  feet,  and  sometimes,  though  rarely,  thirty 
feet  in  thickness;  thirdly,  the  roof  or  upper  bed,  generally  consisting  of  slaty  clay,  often 
containing  layers  of  ironstone  nodules.  Interstratified  with  the  shales,  finely  laminated 
clay,  micaceous  sand,  grit,  and  pebbles  of  other  rocks,  sometimes  occur.  The  coal  measures 
are  found  in  a  greater  or  lesser  extent  in  most  European  countries,  also  in  Asia,  Australia, 
the  United  States,  and  other  parts  of  America. 

From  its  bituminous' nature  and  structure,  coal  is  presumed  to  be  of  vegetable  origin, 
and  to  have  been  derivecfTrom  numerous  plants  which  grew  on  the  spot  where  the  coal 
seams  are  now  found,  or  they  were  drifted  into  ancient  estuaries  arid  covered  by  sand  and 
mud.  These  changes  must  have  been  successively  repeated  over  large  areas,  as  indicated 
by  the  number  of  beds  of  coal  which  occur  one  above  the  other,  as  well  as  their  great 
extent.  The  plants  found  in  the  coal  measures  are  chiefly  ferns  and  other  cryptogams, 


LONDON:  PUBLISHED  in 


NEW     RED      SANDSTONE 


NODULES      OF       CLAY     IRON      STONE 


:ROUS  GKOUP. 


ome  coniferae  (cono-bearing),  and  other  forms,  as  the  lepidodendron  (scaly  tree),  allied  to 
ut  distinct  from  the  living  Lycopodium  (club  mosses). 

The  general  features  of  the  Coal  Strata  will  be  readily  perceived  by  an  inspection  of  the 
Magram.  The  fissures  or  fractures,  often  nearly  vertical,  and  which  stretch  through  the 
ntire  mass,  have  probably  been  produced  by  the  upheaving  force  which  also  converted  the 
orizontal  strata  into  the  basin  shape  form.  These  rents  are  called  Dykes,  because  they 
ivide  the  continuity  of  the  seams  or  bands  of  coal;  there  are  also  Shifts,  and  still  more 
requently,  Faults  or  Troubles,  (see  F  &  H)  by  which  the  seam  is  either  raised  or  depressed. 
L  Dyke  which  does  not  disturb  the  continuity  of  the  workable  seams  is  called  a  hitch  or 
lip.  Whin  Dykes  (w)  contain  basalt  or  other  rocks  of  igneous  origin.  Thin  strata  of 
rit  or  shale  in  the  heart  of  a  coal  seam  are  called  bands,  (B).  The  Dykes  or  Faults  are  of 
lie  greatest  importance,  as  the  limited  area  contained  between  each  two  faults,  provided 
liey  be  impervious  to  water,  is  thus  drained  with  greater  facility. 

There  are  several  varieties  of  Coal,  all  of  which  appear  to  have  been  formed  by  the  action 
f  certain  chemical  forces  on  wood  or  other  vegetable  matter.  These  varieties  may  for  the 
lost  part  be  arranged  into  two  groups. 

1st.  Anthracite,  also  called  glance  coal  or  stone  coal,  containing  no  bitumen,  is  compact 
nd  hard,  with  a  high  lustre. 

2nd.  Bituminous  Coal,  contains  bitumen,  comprising  caking  or  pitching  coal,  cherry 
oal,  splint,  eannel,  or  candle  coal,  &c. 

The  following  is  the  estimated  yield  per  annum  of  the  European  Coal  Fields. 


Tons. 


heat  Britain  and  Ireland  64,000,000 

'russia  and  Germany 8,000,000 

telgium 5,500,000 

'ranee    4,400,000 

lustria  2,500,000 

talian  States    90,000 

The  United  States  at  the  present  time  yield  about  5,500  000  Tons. 


Spain  and  Portugal 

Russia 

Other  Countries.... 


Tons. 
60,000 
40,000 
50,000 


Total  for  Europe  84,640,000 


REYNOLDS,  174.  STRAND. 


Mil 


Mining  is  the  general  term  applied  to  the  exploring,  working,  extracting,  and  preparing  th< 
distributed,  and  in  greater  or  less  relative  abundance.  Gold  is  frequently  met  with,  but  only 
of  profit.  Iron  is  widely  dispersed,  and  its  ores  occur  abundantly  either  in  regular  beds  or  asi 
occur  in  large  quantities;  arsenic  bismuth,  nickel,  cobalt,  &c.,  although  somewhat  abundant,  i 
do  not  occur  in  the  same  uniform  manner  in  the  various  strata.  Thus,  coal,  salt,  gypsum,  an 
of  copper  and  lead  present  occasionally  a  bedded  appearance;  but  the  greatest  number  of  min 
more  or  less  at  right  angles  to  the  strata.  These  veins  may  be  described  as  fissures  or  crevic 
consolidation  of  the  rock,  and  then  subsequently  filled  with  various  mineral  substances.  The 
with  a  metallic  ore,  but  is  occupied  with  crystalline  (sometimes  not)  minerals  with  which  the 
extracting.  Veins  generally  dip  or  incline  from  a  right  angle,  (see  diagram)  and  sometim 
1,500  feet  from  the  surface. 

The  most  abundant  and  extensive  iron  ores  are  those  of  .the  nodules  of  clay  ironstone  associa 
found  in  the  carboniferous  limestone  of  some  counties.  Galena,  or  lead  ore,  although  found  ir 
Northumberland,  &c.  where 
it  occurs  in  veins  of  differ- 
ent kinds,  and  frequently 
contains  much  silver,  vary- 
ing from  two  to  eight 
ounces  to  the  ton.  Gold 
has  been  found  in  Cornwall, 
North  Wales,  and  in  Wick- 
low  in  Ireland.  Tin  is 
chiefly  associated  with  the 
granitic  and  metamorphic 
rocks  of  Cornwall,  but  is 
also  obtained  by  washing 
the  sands  and  gravel  of  the 
same  county,  a  process 
called  '  streaming',  and  like 
that  employed  for  obtaining 
gold  in  auriferous  districts. 

The  chief  supply  of  cop- 
per  in  England  is  from  the 
ores  which  occur  in  the 
metamorphic  schists,  &c.  of 
Cornwall  and  Devon.  In 
Cornwall,  the  rich  copper 
lodes  run  east  and  west, 
and  when  they  meet  with 
tin  lodes  pass  through  and 
sometimes  heave  or  shift 
them. 

The  chief  objects  in 
mining  are  facility  in  ex- 
tracting the  ore,  drainage, 
and  ventilation.  The  ac- 
companying illustration  is 
a  representation  of  a  copper 
mine;  the  shafts,  of  which 
three  are  shown,  form  the 
principal  entrance  to  and 
exit  from  the  .mine,  and 
through  which  the  ore  is 
brought  to  the  surface  by 
means  of  machinery  moved 
by  horse  or  steam  power, 
and  also  by  which  the  water 
is  raised  to  the  adit  or 
drainage  level.  The  adit 
is  driven  from  the  lowest 
ground  through  the  lodes 
to  the  perpendicular  shaft, 


LONDON:  PUBLISHED 


NG. 


mineral  and  metallic  substances  found  in  the  earth's  crust.  These  substances  are  yariously 
worked  in  a  few  localities;  while  the  ores  of  silver,  though  less  common,  afford  a  larger  source 
ith  earthy  and  other  substances.  Of  the  other  useful  metallic  ores,  lead,  copper,  tin,  and  zinc, 
such  great  demand  or  generally  applicable  as  the  former.  The  metallic  and  other  substances 
,  are  found  in  regular  beds,  interstratified  with  the  rocks  in  which  they  are  imbedded;  veins 
its  occur  in  veins  or  lodes  which  are  not  parallel  to  the  stratification,  but  run  in  a  direction 
ocks,  which  have  been  produced  by  contraction  or  mechanical  force  after  the  deposition  and 
ns  is  very  irregular,  and  of  more  or  less  limited  extent;  the  vein  is  rarely  if  ever  filled  entirely 
mineral  is  associated,  and  which  occurs  sometimes  in  such  small  quantities  as  not  to  be  worth 
to  a  great  depth,  as  in  Cornwall,  where  some  of  the  mines  are  worked  upwards  of  1,000  to 

;he  coal  measures ;  but  iron  is  also  extensively  worked  from  a  species  of  haematite,  which  is 
ts  of  Corn  wall,' is  more  abundant  and  characteristic  of  the  carboniferous  strata  of  Derbyshire, 

and  is  the  level  by  which 
the  mine  is  drained.  The 
cross  cuts  are  passages  driven 
from  the  shafts  to  the  lodes 
for  the  purpose  of  exploring 
it,  and  which,  when  favor- 
able Indications  of  ore  are 
presented,  are  extended  on 
the  course  of  the  lode,  and 
form  .levels.  The  levels  are 
three  feet  wide  and  six  feet 
in  height,  are  about  ten 
fathoms  apart  from  each 
other  in  depth,  and  by 
means  of  which  the  opera- 
tions of  the  mine  are  carried 
en,  and  the  ore  brought  to 
the  principal  shafts.  The 
portions  of  the  veins  be- 
tween the  levels  are  called 
pitches.  Winzes  are  small 
shafts  extending  from  one 
level  to  another.  The  cheeks 
or  walls,  called  roof  and 
floor,  are  definite  partings 
which  enclose  the  lode,  or 
hanging  wall;  and  foot  watt, 
if  the  lode  has  considerable 
inclination.  The  outcrop  is 
where  the  vein  reaches  the 
surface. 


SUMMARY  OF  THE  MINERAL  PRODUCE  OF 

THE  UNITED  KINGDOM  IN  1854. 

From  the  Mining  Records. 


Quantity..  Value. 

Silver 700,000  oz.  £192,500 

Coal 64,661,401  tons.     14,975,000 

Iron  3,069,838     „  9,500,000 

Copper 13,042     „  1,229,807 

Lead 64,005     „  1,472,115 

Tin 5,763     „  690,000 

Zinc 16,500 

Other  Metals  500,000 

Total  Value  £28,575,922 


IEYNOLDS,  174,  STRAND. 


WATER  SUPPLY 


Springs  and  Wells.  It  has  been  roughly 
estimated  that  of  the  quantity  of  rain  fall- 
ing on  the  earth,  about  one-sixth  is  absorbed 
by  the  soil,  a  similar  portion  is  carried 
away  by  rivers,  £c.,  and  the  remainder  is 
re-evaporated.  Springs  are  either  shallow 
or  deep  seated,  and  arise  from  the  natural 
overflowing  of  subterranean  reservoirs  of 
•water.  They  are  of  different  characters, 
either  pure  or  mineral,  cold,  hot,  and  even 
boiling,  being  dependent  on  the  source 
from  whence  they  come. 

Wells  are  of  two  kinds,  ordinary,  or  very 
deep  wells;  the  latter  being  also  termed 
Artesian,  from  their  having  been  first  used 
at  Artois,  in  France.  These  two  sources 
are  well  illustrated  by  a  section  of  the 
London  basin,  from  the  north  to  the  south 
of  the  Thames,  and  they  depend  entirely 
on  the  permeable  and  non-permeable  cha- 
racter of  the  strata  comprised  within  that 
area.  Thus  the  ordinary  or  shallow  wells 

around  London  are  formed  by  sinking  into  the  sand  and  gravel,  (as  shown  at  a  a)  which  from 
their  permeable  nature  become  more  or  less  charged  with  water,  which  is  retained  therein  as 
in  a  reservoir  by  the  retentive  nature  of  the  thick  bed  of  London  clay  immediately  below  it. 
In  the  other  case,  that  of  Artesian  wells,  the  water  supply  is  derived  from  an  entirely 

Rules  for  finding  Springs.  Mr.  Swindell,  in  his  work  on  Wells,  mentions  the  following  j 
grass  assume  a  brighter  colour  in  one  particular  part  of  a  field  than  in  the  remainder,  or  if  whe 
found  beneath  it.  In  summer,  the  gnats  hover  in  a  column  and  remain  always  at  a  certain  he 
dense  vapours  arise  from  those  portions  of  the  surface  from  which,  owing  to  the  existence  of  su 
the  morning  and  evening.  The  Springs  to  which  these  rules  apply  are  only  such  as  are  near  tl 
but  to  execute  such  operations  with  a  chance  of  success,  a  certain  knowledge  of  elementary  G< 


DRAINAGI 


^  // —  j~~^r*-L^iw!&ifi<if //////// ti/m.1! 


Q        1&/s///s///{//////(ff.'f'!£f''''''''f'    <     • 


Soils  may  be  divided  into  three  varieties ;  1,  the  porous  soil,  as  sand,  gravel,  &c.;  2,  the  retentive 
or  impervious,  as  clay,  marl,  dense  locks,  &c.;  3,  the  mixed  or  partly  porous,  as  loam,  soft  chalk, 
and  surface  soils  of  mixed  ingredients ;  according  to  the  relative  positions  of  these  several 
strata,  so  will  the  mode  of  drainage  vary. 

The  general  principles  of  land  drainage  may  be  exemplified  by  the  four  diagrams  here  shown. 
In  the  first  diagram,  we  have  an  illustration  where  the  soil  immediately  beneath  that  forming 
the  surface  is  porous,  the  next  stratum  retentive,  underlaid  by  the  mixed  variety.  In  this  case, 
the  drains  must  either  be  made  with  regard  to  the  porous  soils  only,  without  interference  with 
the  clay;  or  the  main  drains  must  be  made  completely  through  the  clay,  which  should  be  bored 
in  the  lowest  or  wettest  places;  this  will  bring  the  land  into  a  much  drier  condition.  Where 
the  retentive  soil  lies  uppermost,  as  represented  in  the  second  diagram,  with  the  porous  soil 


LONDON:     PUBLISHED  BY  J 


ND  DEAINAGE. 


different  source  than  that  of  the  gravel 
beds  before  mentioned.  It  will  be  seen  by 
the  diagram,  that  the  strata  assume  a 
basin-shaped  arrangement,  and  that  be- 
tween the  London  clay  and  the  chalk,  is 
the  permeable  bed  of  sands,  &c.  of  the 
plastic  clay,  this  receives  the  water  falling 
on  its  surface  at  b  b,  and  is  retained  in  it 
by  the  retentive  nature  of  the  beds  above 
and  below,  and  is  unable  to  escape  except 
at  the  outcrop  b,  where  occasionally  over- 
flowing springs  occur  when  the  bed  is 
fully  saturated  with  water.  If  therefore 
a  well  is  sunk  or  a  boring  made  through 
the  London  clay  into  these  sands,  as  shown 
in  the  section,  water  will  be  reached,  and 
from  the  tendency  to  find  its  level,  assisted 
by  the  surrounding  pressure,  it  will  some- 
times rise  to  the  surface  or  within  a  short 
distance  of  it,  thus  affording  a  supply  of  a 
pure  and  softer  water  than  from  ordinary 
wells.  The  fountains  in  Trafalgar  Square, 

e  of  the  breweries  and  factories  in  London,  are  supplied  by  these  wells.  Similar  Artesian 
Is  may  be  formed  by  sinking  still  deeper  into  the  permeable  beds  of  the  upper  and  lower 
>n-sand,  which  outcrop  at  the  surface  at  c  c.  The  water  of  the  celebrated  Artesian  well  of 
nelle,  at  Paris,  is  derived  from  these  lower  cretaceous  strata. 


;t  simple  rules  for  discovering  Springs  near  the  surface.  In  the  early  part  of  the  year,  if  the 
er  is  ploughed,  if  a  part  be  darker  than  the  rest,  it  may  be  suspected  that  water  will  be 
3  the  ground  over  the  spots  where  springs  are  concealed.  In  all  seasons  of  the  year,  more 
i  springs,  a  greater  degree  of  humidity  gives  rise  to  more  copious  exhalations,  especially  in 
i  when  the  source  is  lower,  they  are  rarely  sufficient,  and  the  only  safe  guide  is  a  boring; 
I  of  the  arrangement  of  strata  in  the  locality  is  absolutely  necessary. 


F  LANDS. 


b,  it  will  be  requisite  to  cut  the  drains  through  the  retentive  soil,  and  if  the  porous  stratum 
hallow,  through  that  also.  In  this  case,  if  a  valley  exposes  as  at  b  the  outcrop  of  the 
)us  bed,  the  land  will  be  more  easily  drained;  otherwise,  if  a  gully  be  cut  into  the  porous 
as  at  a,  the  drainage  can  be  carried  to  lower  levels.  Where  a  tongue  of  porous  soil  lies 
n  a  bed  of  clay,  as  shown  in  the  third  diagram,  producing  a  swamp  or  morass,  a  main  drain 
through  the  clay  at  the  point  D,  will  be  the  proper  remedy. 

ig.  4.  This  figure  may  afford  an  illustration  of  unequal  drainage,  due  to  the  arrangement 
tie  substrata;  the  land  over  a  will  be  more  effectually  drained  in  consequence  of  its  imme- 
ely  overlying  the  mixed  porous  strata,  than  at  b,  where  it  covers  the  retentive  bed;  either 
ace  furrows  to  connect  with  the  part  a,  or  by  boring  down  to  M,  will  render  the  drainage 
form. 


'NOLDS,    174,  STRAND. 


Pterodai-tjlc. 


Ignanodon. 


DINOSAUKIANS. 
Hylaeosaurus. 


Megalosaurus. 


Teier 


GEOLOGICAL  RESTORATIO1 

Tlie  science  of  Palaeontology  treats  of  the  history  of  fossils,  and  its  principal  object  is  to  make  known  the  forms  an 
zoological  relations  of  the  beings  which  have  inhabited  the  globe  at  various  epochs  anterior  to  our  own.  This  scien< 
furnishes  the  only  certain  basis  for  the  determination  of  the  stratified  rocks,  and  for  clearing  up  several  essential  poin 
relative  to  the  ancient  limits  of  seas  and  continents.  The  presence  of  fossils  of  species  which  belong  to  the  kinds  essei 
tially  fluviatile,  serve  to  indicate  the  existence  of  land  and  river  courses;  whilst  fossils  of  marine  species  prove,  on  tl 
contrary,  that  the  strata  where  they  are  deposited  have  been  formed  either  near  to  or  far  from  the  coasts  of  seas  i 
different  epochs  An  inspection  of  the  various  strata  hi  which  fossils  have  been  deposited  shows  that,  in  general, 
constant  order  has  existed  in  their  formation.  The  sea,  by  which  the  earth  appears  to  have  been  covered,  bavin 
rested  in  certain  situations  a  sufficient  length  of  time  to  deposit  particular  strata,  and  to  sustain  the  life  of  certai 
genera  and  species  of  animals,  has  undergone  change;  the  animals  of  each  period  have  become  extinct,  and  bee 
successively  replaced  by  other  forms  of  life  equally  adapted  to  the  changed  conditions,  whose  remains  are  found  in  ea< 
stratum,  and  are  generally  limited  to,  and  characteristic  of,  one  formation,  although  the  mineral  character  may  n< 
always  be  the  same. 

Of  the  two  great  classes  of  life,  the  vertebrate  and  invertebrate,  the  latter  are  more  abundant  than  the  former;  ar 
the  forms  belonging  to  the  sea  far  more  numerous  than  those  of  freshwater.  If  we  divide  the  three  great  series 
stratified  rocks  by  the  forms  of  vertebrate  life  occurring  in  them,  we  shall  find  that  Fishes  characterize  the  primar; 
Reptiles  the  secondary;  and  Mammalia  the  tertiary  series.  Of  some  of  these  we  shall  offer  a  few  illustrations. 

In  the  primary  series,  the  prominent  vertebrate  forms  were  fishes  belonging  to  tribes  but  feebly  represented  In  01 
present  seas.  Two  genera  of  reptiles  only  have  yet  been  met  with  in  them,  these  are  the  Telerpeton  from  tl 
Devonian  beds  of  Scotland,  and  the  Archegosaurus  from  the  coal  measures. 

The  diagram  is  intended  to  illustrate  the  restoration!  of  the  more  remarkable  forms  of  reptile  life,  whose  remains  a 
found  in  those  formations  which  constitute  the  secondary  epoch.  The  illustration  is  partly  copied  from  a  sketch  1 
Mr.  Waterhouse  Hawkins,  F.G.S.,  to  whose  genius  and  industry  the  restorations  of  these  animals  at  the  Crystal  Palai 
are  due.  With  the  lower  secondary  p3riod  or  Trias,  appeared  new  forms  of  reptilian  life, -the  Capitosaurus,  Noth 
saurus,  and  Labyrinthodon.  For  soms  time  impressions  of  foot  prints  only  had  been  observed  on  some  sandstoni 
belonging  to  the  trias  of  Cheshire,  and  to  which,  from  their  form,  the  term  Chirothcrium  was  applied,  iintil  Professi 
Owen  investigated  and  showed  that  the  remains  of  the  teeth  and  bones  found  in  this  deposit  in  Warwickshire,  belongt 
to  a  reptile  allied  to  the  Batrachian  order,  and  from  the  peculiar  structure  of  its  teeth  it  has  been  named  tl 
LABYRINTHODON,  and  to  which  the  footmarks  were  probably  due. 

*  Next  in  ascending  order  we  have  the  group  of  Enaliosaurians  or  sea  lizards,  reptiles  with  back  bones  somewh 
resembling  those  of  fishes,  and  from  the  structure  of  the  air  passage  leading  to  the  nostrils,  they  must  have  breaths 


LONDON:  PUBLISHED 


ENAMOSAI'RIANS. 


terodacfyle. 


Plesiosaiirus. 


Ichthvosanrus. 


Labyrinthodon. 


T  THE  CRYSTAL  PALACE. 

!  air  like  land  quadrupeds,  but  were  cold-blooded  like  the  crocodiles  and  other  reptiles.  Of  these  are  represented  the 
HTHYOSAURUSandthe  PLES1OSAURUS  from  the  Lias.  The  former,  or  fish-lizard,  presents  combinations  of 
i  mammalian,  reptile,  and  fish  structure.  The  short  neck  and  long  tail  distinguish  it  from  the  Plesiosaurus;  its 
go  and  peculiar  eye  endowed  it  with  great  powers  of  vision,  and  the  wide  mouth  and  long  jaws  armed  with  many 
nted  teeth,  indicate  its  carnivorous  and  predatoiy  nature.  The  PLESIOSAURUS,  another  singular  form  from  the  Lias, 
:haracterized  by  its  neck  of  enormous  length  supporting  a  head  resembling  that  of  the  lizard,  furnished  with  the 
th  of  a  crocodile,  with  a  trunk  and  tail  of  an  ordinary  quadruped,  the  ribs  of  the  chameleon,  and  paddles  similar  to 
ise  of  the  whale.  The  TELEOSAURUS,  found  also  in  the  Lias  and  Oolite,  was  a  large  extinct  reptile,  somewhat 
embling  the  long  and  slender  jawed  crocodile  of  the  Ganges. 

rhe  PTERODACTYLES,  or  flying  lizards,  were  covered  by  scales,  and  provided  with  wings,  consisting  of  folds  of 
n,  supported  on  the  long  outer  finger. 

'n  the  secondary  strata,  are  also  found  another  group  of  colossal  reptiles  of  great  magnitude  and  extraordinary 
ucture,  called  the  Dinosaurians;  the  genera  of  this  group  combined  both  crocodilian  and  lacertian  characters,  they 
s  principally  marked  by  the  peculiar  construction  of  their  sacral  and  dorsal  vertebrae,  by  the  articulation  of  the  ribs, 
I  the  modification  of  the  teeth.  Of  this  tribe,  Professor  Owen  remarks,  that  the  principal  genera  are  the  Megalo- 
irus,  Hylseosanrus,  and  Iguanodon,  the  gigantic  crocodile-lizards  of  the  dry  land;  whose  peculiarities  of  osteological 
ucture  distinguish  them  as  clearly  from  the  living  terrestrial  and  amphibious  saurians,  as  the  opposite  modifications 
an  aquatic  life,  characterize  the  extinct  Enaliosaurians  or  marine  lizards.  The  MEGALOSAURUS  occurs  in  the 
rer  oolitic  strata  near  Oxford.  The  HYUtOSAURUS  and  IGUANODON  belong  to  the  wealden  deposits;  the 
mcr,  or  weald-lizard,  is  marked  by  its  extraordinary  dermal  covering.  Of  the  Iguanodon,  Dr.  Mantell  states  that  it 
jailed  in  bulk  the  large  herbivorous  mammalia,  and  was  as  massive  in  its  proportions,  for  living  exclusively  on 
;etables,  it  must  have  had  the  abdominal  region  greatly  developed.  Its  limbs  must  have  been  of  proportionate  size 
1  strength  to  sustain  and  move  so  enormous  a  carcase;  its  hinder  extremities  prob  bly  resembled  those  of  the 
ipopotamus,  while  the  fore  feet  appear  to  have  been  less  bulky,  and  adapted  for  seizing  and  pulling  down  the  foliage 
J  branches  of  trees;  the  remains  of  coniferous  trees,  arborescent  ferns,  and  cyc-ideous  plants,  which  are  found 
bedded  with  its  remains,  attest  the  nature  of  the  flora  adapted  for  its  sustenance. 

I'he  mammalia  are  represented  by  the  MEGATHERIUM,  a  colossal  sloth,  whose  remains  occur  abundantly  in  South 
nerica.  This  genus  belonged  to  an  extinct  family  of  Edentata,  (so  named  from  the  absence  of  incisor  teeth)  and  is 
resented  at  the  present  day  by  the  diminutive  sloths,  anteaters,  and  armadilloes.  The  gigantic  fossil  IRISH  ELK, 
lich  far  exceeded  in  magnitude  iny  living  deer,  has  been  found  in  the  shell  marl  underlying  the  peat  beds  of 
(land,  and  the  Isle  of  Man;  its  remains  have  also  been  obtained  from  some  parts  of  England, 


KYSOLDS,  171,  STKAXD. 


I  ON 

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FROM  THE  DISCOVERIES  OF    THE 


THIS  MAP  /.v  intended  to  cmihle  th<-  r\r  fc  i>*ra'i\-e  tit  a  (jlanfe  the  iffent  Physical 
EU-vated  and  TaMo  lauds  by  the  darhw  the  Mountains  by  the  darkest,  the  Descrls 
yreata-  velocity-,  cind  the  arrows  shoin/u?  tin.-  lUwtion  <>f  the  current  'lit*-  \\ari 
-pei-atnre  of  the  Air  is  shwn  by  the  Isotherms,  or  *<ninv  l.rntv  t-rn.tsnui  ihf  Ma 
mfftn  uriniial  tenipernturr  .  A.n  observation  <>/  the  Arctof  Current,  (uul  the  fjiilt  . 


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MINENT  MODERN  GEOGRAPHERS. 


ft<;  Surface  of'  the  globe-.    In  the  Continents,  thf  Lowlauds  or<?  marked  by  M<-  <&?A/  /J>z/,  <&e 
w//.    In  the  (><•(•<  in  ,the  Currents  arc  .ftu-n-n  b\   fine  tines  .the  deeper  shading  iruiu-atiiuj  the 
aters  /.-•  .vhwn  b\    figures  indicating  the  degree,  of  Fahrenheit  at   those  spots  .   The  tern 
m,ji  ,-uil  the  ilearet-  of'  Fahrenheit,  all  pUnes  situated  on,  these  lines  having   the,  sajne. 
the  (fti-dt  nit  Inencf  />/   those  currents  upon  ihe  cltmate  of  the  nayhbourinfl  (Countries. 


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P   H    E 


SHOWING   THE    INFLUENCE    EXERTED  BY  THE    HEA' 


V  _/'*H 


^g^lil 

V?3siNfo 


7    jBourbon .  Indian  Ocean  .        \  12   lianbora  .  Jia   I 


8     Peshan,  Taatcay .  B  Mahave, 

Sinqallanq ,  Sumatra  .  14 

JO   <Vf«-cO7i '.  ...r D? Z5  JfluUchcwskaja ,  1 


3  Jtrcanboli .  Lipni-i  I' 

4  Vesuvius .  Naples  . 

5  tibia,  Su-ily . 


RIOR    OF  THE   EARTH   UPON   ITS    EXTERNAL  SURFACE 


on    by  the    Great    Eartk<juake   Nov1  1st  1755 


4F=-  = 

TbrT 
|     The  Earthqiiake  re  gi  on 


C        MOUNTAINS 


M*E<rmont  .  Ne-#  Zealand    |  21  JanilLo  .Mejcico .  t  26  Artquipa,  Peru 

Edgetumbe, J)°. 22  Cojfegiamji.Guateniala  |  27  Antuco.  QnLe 


Hauna.  Loa  .  Sandwich  7°:" 
Tobreoncu.  Sodetvs  Is 
Popocatepetl .  MeJncc  . 


23  Cotopajci .  Quito 

24  Tanmtrcujua, .  D° 

25  Oualatieri ,  Peru . 


I  28  YantaLes...Dc 

29  Blue  Mountains.  Jamaica 
I  30  Ml  Erebw*.  .4ntarcac  Sea. . 


PHYS 


TIDAL  ACTION    IN   THE     BRITISH    SEAS. 

17if  progress  of  the  wave  of  high  water  is  shown  by  the  co 

lines ,  the  figures  indicating  the  time  of  hufTi  water, at  New  and 

FuR  Moan,  along  the  course  c>f  eadi .  The  small  figures  near 

the  coast  denote  the  rise  <jf  the  tide  in   feet . 


Dra-rvn  &•  Engraved,   ly   Jchn  Ernsl> 


l   SufiL:  en   the 


\P    OF 


DEPTH    OF  THE   OCEAN 
The  tightest    shading    aver 
the    Ocean,    indicates 
depth   under  5O  fathoms, 
qreater  depths  are   shown 
try  contour    lines    and 


Rain.  The  comparative  quantity  of  rain  ^ 

77t  different  districts  is  indicated  by  the  increas 

-ing  depth  of  shading;  the  small  futures  shonr 

the  annual  amount  in  indies.  The  rtaures  nith 

R.D.  denote  the  number  of  rainy  days  in  a.  i'ear.  Tempera!  ure  The  mean  t 

of  January  is  showily  the  Isothermal  tines  thus 36°  and  of  Jtt2}  thuj 64*? 


'line  A  B  en.  the  Ma 


RANUNCULACEXE. 


^   Fig.     1. 
CROWFOOT. 

NYMPHACE/E. 


Fig.  4. 
WATER-LILY. 

RESEDACE/E. 


MAGNOLIACE/E. 

x/'S 


ANONACEXE. 


Fig.  2. 
MAGNOLIP. 

NELUMBIACE/E. 


Fig.  3. 
CUSTARD  APPLE. 

PAPAVERACE/E. 


FLACOURTIACE/E. 


Fig.  6. 
POPPY. 

DROSERACEXE. 


Fig.  7. 
WELD. 


Fig.  8. 

A  UNOTTO. 


Fig.  9. 
VENUS'S  FLY  TRAP. 


POPULAK     SKETCH 

OP 

THE    VEGETABLE    KINGDOM. 

SHOWING   THE 

CLASSIFICATION   OF   PLANTS   ACCORDING   TO   THE   NATURAL 

SYSTEM, 

WITH   THEIR  LOCALITIES,   PROPERTIES,   AND   USES. 

COMPILED  FROM  THE  WORKS  OF  LINDLEY,  BALFOUR,  &c. 

PHANEROGAMOUS,    OR    VASCULAR   FLOWERING    PLANTS. 

EXOGENS. 

The  largest  class  in  the  Vegetable  Kingdom.  It  is  distinguished  by  the  following 
characteristics: — 1.  The  Wood  is  exogenous,  that  is,  increases  in  bulk  by  the  addition 
of  new  wood  on  the  outside  of  the  old  wood,  between  it  and  the  bark.  2.  The  Veins  of 
the  Leaves  are  netted,  and  the  leaves  are  joined  to  the  stem,  so  that  when  dead  they 
separate  readily  at  the  joint.  3.  The  Flowers  have  their  parts  arranged  in  fours  or 
fives,  or  some  multiple  of  those  numbers.  4.  The  Seeds  have  usually  two  lobes,  as  in 
the  Bean,  Almond,  &c.,  rarely  more,  as  in  the  Firs,  but  never  one. 

THALAMIFLOR2G, 

Having  Calyx  and  Corolla  ;  Petals  distinct,  and  inserted  into  the  thalamus; 
Stamens  hypogynous. 

1.  Rammeulacese,  CROWFOOTS.     Herbs,  or  rarely  shrubs,  found  in  cold,  damp 
climates.    These  plants  are  all,  more  or  less,  acrid  and  poisonous.    Lindley  enumerates 
41  genera,  and  1,000  species.     (See  Fig.  1.) 

2.  Dilleniaceae,  DILLENIADS.     Trees,  shrubs,  or  undershrubs,  found  chiefly  in  Aus- 
tralia, India,  and  the  warm  parts  of  America.     They  have  astringent  properties,  and 
some  species  are  used  for  tanning  purposes;  others  afford  valuable  timber.    There  are 
26  genera,  and  200  species. 

3.  Magnoliaceae,  MAGNOLIADS.    Fine  trees  or  shrubs,  abounding  in  North  America, 
and  found  also  in  South  America,  Australia,  China,  and  Japan.     Lindley  notices  11 
genera,  and  65  species.     These  plants  have,  in  general,  a  bitter  tonic  taste,  and  fragrant 
flowers.     Some  species  yield  by  distillation  an  aromatic  oil,  similar  to  the  oil  of  anisej 
and  others  are  valuable  for  their  timber.     (Fig.  2  ) 

4.  Anonaceae,  ANONADS,  or  CUSTARD  APPLE  Family.    Trees  or  shrubs  of  tropical 
countries.     Their  properties  are  usually  aromatic  and  fragrant;  some  species  yield 
edible  fruits,  and  others  a  kind  of  pepper.    The  lancewood  of  coachaaakers  is  furnished" 
by  a  plant  of  this  order.    Lindley  mentions  20  genera,  including  300  species.    (Fig.  3.) 

5.  MenispermaC83B,  MENISPERMADS,  or  MOONSEEDS.     Twining  shrubs,  common  in 
tropical  countries.     There  are,  according  to  LinSley,  44  known  genera,  and  302  species. 
The  properties  of  these  plants  are,  in  general,  bitter  and  narcotic;  some  are  tonic  and 
others  poisonous.   Among  the  former  is  the  root  of  Cocculus  palmalus,  or  Columba-root, 
a  valuable  bitter  tonic;  among  the  poisonous  species  is  Anamirta  cocculus,  the  fruit  of 
which  is  known  as  Cocculus  indicus 

6.  Berberidaceae,  BERBERIDS.   Shrubs  or  herbaceous  perennial  plants,  found  chiefly 
in  the  mountainous  parts  of  the  north  temperate  regions.     Their  properties  are  bitter 
and  acid.     The  bark  and  stem  of  the  common  Berberry  supplies  a  yellow  dye,  and  the 
fruit  is  used  as  a  preserve.     Lindley  gives  12  genera,  and  100  species. 

7.  Caboinbacese,  WATERSHIELDS.    American  aquatic  plants,  with  floating  peltate 
leaves.    Their  properties  are  slightly  astringent.    Lindley  notices  2  genera,  and  3  species. 

8.  Nympliacese,  WATERLILLIES.     Aquatic  plants,  growing  in  quiet  waters.     These 
plants  are  mostly  confined  to  the  northern  hemisphere.     The  properties  of  some  are 
astringent  and  bitter,  others  are  sedative,  and  some  contain  starch.     Their  flowers  are 
universally  admired.     Victoria  regia,  the  beautiful  lily  of  South  America,  is  one  of  the 
largest  of  known  aquatics.     Its  odoriferous  flowers  are  more  than  a  foot  in  diameter, 
and  its  leaves  from  four  to  six  feet  in  diameter.    Lindley  notices  5  genera,  and  50 
species.     (Fig.  4.) 

9.  Nelumbiaceae,  WATERBEANS.     Aquatic  herbs,  with  large  and  beautiful  flowers. 
Found  in  quiet  waters,  in  both  temperate  and  tropical  regions,  but  most  abundant  in 

B 


2  POPULAR   SKETCH  OF 

India.    Their  nuts  are  wholesome,  and  the  root  or  creeping  stem  is  used  as  food  in 
China.     1  genus,  and  3  species.    (Fig.  5.) 

10.  Sarraceniaceae,  SARRACENIADS,  or  SIDE-SADDLE  Family.    Herbaceous  plants, 
found  in  boggy  places  in  North  America  and  Guayana.     Their  uses  are  unknown. 
2  genera,  and  7  species. 

11.  Papaveraceae,  POPPYWORTS.    Herbaceous  plants  or  shrubs,  often  with  a  milky 
juice.     These  plants  are  chiefly  European,  but  are  found  also  in  tropical  America,  Asia, 
Australia,  and  at  the  Cape  of  Good  Hope.     Their  properties  are  narcotic.     Opium  is 
procured  from  the  capsules  of  Papaver  somniferum,  and  its  varieties.     The  seeds  of  the 
Opium  Poppy  yield  a  bland,  wholesome  oil,  which  is  largely  used  on  the  Continent. 
Lindley  enumerates  18  known  genera,  and  130  species.    (Fig.  6.) 

12.  Fumariaceae,  FCMEWORTS.     Herbaceous  plants,   with  brittle  stems   and  a 
'watery  juice.    Found  chiefly  in  the  north  temperate  climates.    Their  properties  are 
bitter  and  diaphoretic.     Lindley  gives  15  genera,  and  110  species. 

13.  Cmciferae,  CRUCIFERS.    Herbaceous  plants,  found  in  all  parts  of  the  world. 
These  plants  possess  in  general  antiscorbutic  and  stimulant  qualities.     To  this  order 
belong  many  of  the  common  culinary  vegetables,  as  Cabbages,  Cauliflower,  Turnip, 
Radish,  Cress,  &c.    Lindley  enumerates  173  genera,  including  1,600  species. 

14.  Capparidaceae,  CAPPARIDS.   Herbs,  shrubs,  and  sometimes  trees.   Found  chiefly 
in  warm  countries,  and  abundant  in  Africa.    There  are  28  genera,  and  340  species. 
These  plants  have  stimulant  and  pungent  qualities.    Capparis  spinosa  furnishes  capers. 

15.  Resedaceae,  RESIDADS  or  WELDWORTS.     Herbaceous  plants,  chiefly  inhabiting 
Europe,  and  the  adjoining  parts  of  Asia.    There  are  6  genera,  and  41  species.    Mesida 
luteola,  called  Weld  (Fig.  7),  yields  a  yellow  dye,  and  Resida  odorata  is  the  fragrant 
Mignionette. 

16.  FlaCOUrtiaceae,  BIXADS.     Shrubs  or  small  trees,  chiefly  natives  of  the  warmest 
parts  of  the  East  and  West  Indies,  and  Africa.     Many  of  these  plants  furnish  edible 
fruit,  some  are  astringent,  and  others  purgative.    The  red  dye,  Arnotto,  is  obtained 
from  the  pulp  surrounding  the  seeds  of  Bixa  orellano  (Fig.  8).    Lindley  enumerates 
31  genera,  and  85  species. 

17.  Cistaceae,  ROCK-ROSES.    Shrubs  or  herbaceous  plants  of  the  southern  parts  of 
Europe  and  the  north  of  Africa.     Some  of  the  plants  yield  a  resinous  balsamic  juice. 
There  are  7  known  genera,  and  185  species. 

18.  Violacese,  VIOLET  WORTS.     Herbaceous  plants   or  shrubs,   natives  of  Europe, 
Asia,  and  America.    There  are  14  genera,  and  315  specks.     The  roots  of  these  plants 
possess  emetic  properties. 

19.  Droseraceae,  SUNDEWS.     Herbaceous  plants  of  morasses  and  marshy  places. 
There  are  8  known  genera,  and  upwards  of  90  species.     The  Droseras  have  an  acid 
taste,  and  some  are  said  to  be  poisonous  to  cattle;  others  have  dyeing  properties. 
Droncea  muscipula,  or  Venus's  Fly  Trap,  is  a  North  American  plant,  having  the  laminae 
of  the  leaves  in  two  halves,  each  furnished  with  irritable  hairs,  which,  on  being 
touched,  cause  the  folding  together  of  the  divisions  (Fig.  9). 

20.  Polygalaceae,  MILKWORTS.  Shrubs  or  herbs,  sometimes  twiners,  found  in  most 
parts  of  t|Tt  world.     They  are  generally  bitter,  and  their  roots  yield  a  milky  juice. 
Snake-root  and  Rhatany-root,  used  in  medicine,  are  obtained  from  plants. belonging  to 
this  order.     Lindley  mentions  19  genera,  and  495  species. 

21.  Tremandraceae,  POREWORTS.  Slender  heath-like  shrubs,  natives  of  Australia. 
There  are  3  genera,  with  16  species.     Nothing  is  known  of  their  properties. 

22.  Tamaricaceae,   TAMARISKS.    Shrubs  or  herbs,  found   in  the   vicinity  of   the 
Mediterranean.     Their  bark  is  bitter  and  astringent,  and  some,  when  burned,  yield 
sulphate  of  soda.     Lindley  mentions  3  genera,  including  43  species. 

23.  FranckeniaceaBj    FRANKENIADS.    Herbs   or  under   shrubs,  found    chiefly    in 
Southern  Europe  and  Northern  Africa.    They  have  mucilaginous  and  slightly  aroma- 
tic properties.    4  genera,  24  species. 

24.  ElatinaceaB,  WATER-PEPPERS.    Annual  marsh  plants,   with  hollow  creeping 
stems,  found  in  all  parts  of  the  world.    Some  of  them  have  acrid  properties.    There 
are  6  genera,  and  22  species. 

25.  Caryophyllaceae,  SILENADS  or  CLOVEWORTS.  Herbs,  and  sometimes  suffruticose 
plants,  chiefly  of  temperate  and  cold  regions.    Most  of  these  plants  are  weeds,  but  some 
are  admired  garden  flowers,  as  the  pink,  carnation,  &c.    Lindley  mentions  53  genera, 
aud  1,055  species. 

26  Vivianaceaa,  VIVIANADS.  Herbaceous  or  suffruticose  plants  of  South  America, 
having  no  properties  of  importance.  4  genera,  15  species. 

27.  Malvaceae,  MALLOW-WORTS.  Herbaceous  plants,  trees,  or  shrubs.  Found 
chiefly  in  tropical  countries,  and  in  the  warm  parts  of  the  temperate  zone.  All  these 
plants  are  wholesome,  and  generally  yield  much  mucilage.  Some  furnish  materials  for 


MALVACEAE. 


MALVACE/E. 


MALVACE/E. 


Fig.  10. 
HERBACEOUS  COTTON. 

STERCULIACE/E. 


Fig.  18. 
THE  BAOBAB. 

TILIACE/E. 


Fig.  11. 
SEA  ISLAND  COTTON. 

STERCULIACE/E. 


Fig.  14. 
MONKEY'S  BREAD. 

TILIACE>£. 


Fig.  12. 
GREEN  SEED  COTTON. 

BYTTNERIACE/E. 


Fig.  15. 
CHOCOLATE  NCT. 

TERNSTRCEMIACE/E. 


Fig.  17. 
JUTE. 


Fig.  18. 
TEA  PLANT. 


AURANTIACE/E. 


AURANTIACE/E. 


AURANTIACE/E. 


Fig.  19. 
CITRON. 

GUTTIFERXE. 


Fig.  22. 
GAMBOGE  PLANT. 

SAPINDACE/E. 


Fig.  25. 
HORSE  CHESTNUT. 


Fig.  20. 
LIME. 

GUTTIFERXE. 


Fig.  21.. 
SHADDOCK. 

ACERACE/E. 


Fig.  23. 
MANGOSTEEN. 

RHIZOBOLACE/E. 


Fig.  24. 
SUGAR  MAPLE. 

CEDRELACE/E. 


Fig.  26. 
S I:\VARROW  Nrr. 


Fig.  27. 
MAHOGANY  TREE. 


THE    VEGETABLE    KINGDOM.  3 

cordage,  and  others  supply  cotton,  &c.  Cotton  is  composed  of  the  hairs  surrounding 
the  seeds  of  various  species  of  yossypium.  (See  Figs.  10,  11,  and  12).  Lindley  enumerates 
37  genera,  including  1,000  species. 

28.  SterCllliacese,  STERCULIADS.    Trees  or  shrubs  of  warm  climates.     These  plants 
are  mucilaginous  and  demulcent;  many  are  used  for  food,  and  others  supply  a  material 
like  cotton.     Adansonia  digitata,  the  Baobab  tree  of  Senegal  (Fig.  13),  is  one  of  the 
most  ancient  of  trees     Its  trunk  has  been  found  with  a  diameter  of  thirty  feet,  and  the 
age  of  some  specimens  is  calculated  at  5,000  years.     The   pulp  of  its  fruit,  called 
Monkey's  bread  (Fig.  14),  is  used  as  an  article  of  food.    Lindley  mentions  34  genera, 
and  125  species. 

29.  Byttneriacese,  BYTTNERIADS.    Trees,  shrubs,  or  undershrubs,  abounding   in 
tropical  countries.     These  plants  are  highly  mucilaginous,  and  many  supply  materials 
for  cordage.     The  seeds  of  Theobroma  Cacao,  or  Cacao-beans  (Fig.  15),  furnish  the 
chief  ingredient  in  chocolate.     Lindley  mentions  45  genera,  and  400  species. 

30.  Tiliaceae,  LINDEN -BLOOMS.     Trees  or  shrubs  found  chiefly  in  tropical  countries 
(Fig.  16).     Lindley  enumerates  35  genera,  including  350  species.    These  plants  possess 
mucilaginous  properties,  and  many  supply  excellent  cordage  material,  as  Jute.  (Fig.  17.) 

31.  Dipterocarpaceae,  DIPTERADS.     Gigantic  trees,  abounding  in  resinous  juice, 
found  in  India  and  the  East  Indian  Islands.     There  are  about  8  known  genera,  and  48 
species.     A  kind  of  camphor  is  yielded  by  Dryobalanops  Camphora.     Indian  copal,  the 
Gum  animi  of  commerce,  is  procured  from  Valeria  Indica ;  this  tree  also  yields  the 
Butter  of  Canara,  or  Pinei  Tallow. 

32.  Chlsenacese,  CHL^NADS.    Trees  or  shrubs  found  in  Madagascar.    Their  pro- 
perties are  unknown.     There  are  4  genera,  and  10  species. 

33.  Ternstrcemiacese,  THEADS,  or  TEAS.     Trees  or  shrubs  abounding  in  South 
America,  India,  China,  and  North  America.     There  are' 33  genera,  and  130  species. 
The  most  important  plants  of  this  order  are  those  which  yield  Tea.     The  black  and 
green   teas  of  the  northern  districts  of  China  are  obtained  from  the  same  species, 
namely,  that  known  in  Britain  as  the  Thea  viridis,  while  the  black  and  green  teas  from 
the  Canton  district  are  made  from  the  variety  known  as  Thea  Bohea  (Fig.  18). 

34.  Olacaceae,  OLACADS.  Trees  or  shrubs,  chiefly  tropical  or  sub-tropical.    Little  is 
known  of  their  properties.     Balfour  gives  24  genera,  and  53  species. 

35.  Alirantiacese,  CITRONWORTS.     Trees  or  shrubs,  remarkable  for  their  beauty. 
They  abound  in  the  East  Indies,  and  are  found  in  other  warm  regions.     There  are  20 
genera,  and  95  species.     The  plants  of  this  order  secrete  a  fragrant  bitter  and  volatile 
oil,  and  the  fruit  has  a  more  or  less  acid  pulp.     The  orange,  lemon,  citron,  shaddock, 
and  lime  belong  to  this  order.     (Figs.  19,  20,  21.) 

36.  HypericaceaB,  TUTSANS.   Herbaceous  plants,  shrubs,  or  trees.    They  are  dis- 
tributed generally  over  the  globe,  being  found  in  elevated  and  low,  dry  and  damp 
situations.    They  yield  a  resinous  juice  having  purgative  properties.    There  are, 
according  to  Lindley,  13  known  genera,  and  276  species. 

37.  Guttiferse,  GUTTIFERS.    Trees  or  shrubs,  sometimes  parasitical,  and  natives  of 
tropical  regions,  especially  of  South  America.    Lindley  enumerates  30  genera,  com- 
prising 150  species.     These  plants  yield  a  yellow  resinous  juice,  which  is  acrid  and 
purgative.      Gamboge,  employed   medicinally  and    as  a   pigment,  and  the  Mangos- 
teen,  a  fruit  of  the  Spice  Islands,  are  produced  by  plants  of  this  order.    (Figs.  22 
and  23.) 

38.  Marcgraviacese,  MARGRAVIADS.  Trees  or  shrubs,  sometimes  climbing1,  occurring 
chiefly  in  the  warm  parts  of  America.    Their  properties  are  unimportant.    There  are 
4  genera,  and  26  species. 

39.  Hippocrateacese,  HIPPOCRATEADS.     Arborescent  or  climbing  shrubs.    Found 
principally  in  South  America,  while  a  few  are  natives  of  Africa  and  the  East  Indies. 
The  fruit  of  some  is  edible.     Lindley  gives  6  genera,  including  86  species. 

40.  Erythroxylacese,  ERYTHROXYLS.    Shrubs  or  trees,  found  chiefly  in  the  West 
Indies  and  South  America.     Their  qualities  are  tonic,  purgative,  and  narcotic;  some 
yield  a  reddish-brown  dye.     There  are  3  genera,  and  80  species. 

41.  Malpighiacese,  MALPIGHIADS.     Trees  or  shrubs,  of  tropical  countries  chiefly, 
a  great  number  of  them  being  found  in  South  America.    Lindley  mentions  42  genera, 
comprising  555  species.     Many  of  these  plants  are  astringent,  and  some  have  stinging 
hairs. 

42.  Aceraceae,  MAPLES.    Trees,  which  are  confined  chiefly  to  the  temperate  parts 
of  the  globe.     They  yield  a  saccharine  sap,  from  which  sugar  is  sometimes  manu- 
factured (Fig.  24).    There  are  three  genera,  and  60  species. 

43.  Sapindacese,  SOAPWORTS.     Trees  or  shrubs,  and  sometimes  climbing  herbaceous 
plants.     They  are  natives  principally  of  South  America  and  India.     Lindley  notices 
50  genera,  and  380  species.    In  this  order  are  included  the  Horse-chesnuts  (Fig.  25). 

B  2 


4  POPULAR  SKETCH  OF 

Many  of  the  plants  yield  edible  fruits,  while  others  are  poisonous.    The  fruit  of 
Sapindus  saponaria  is  used  as  a  substitute  for  soap  iu  the  West  Indies. 

44.  Rhizobqlaceae,  RHIZOBOLS.    Large  trees,  of  the  warm  forests  of  South  America. 
Some  yield  edible  nuts,  known  as  Suwarrow  nuts  (Fig.  26),  from  which  an  oil  is  ex- 
tracted equal  in  quality  to  that  of  the  Olive.    Lindley  mentions  2  genera,  and  8  species. 

45.  MeliaceSB,  MELIADS.     Trees  or  shrubs,  found  chiefly  in  the  tropical  parts  of 
America  and  Asia.    There  are  40  known  genera,  and  upwards  of  160  species.    The 
plants  of  this  order  possess  bitter,  tonie,  and  astringent  qualities.     Oils  are  procured 
from  some  species,  and  others  yield  a  fragrant  balsam. 

46.  Cedrelaceae,  CEDRELADS.    Trees,  of  the  tropical  parts  of  America  and  Asia. 
There  are  9  genera,  including  25  species.     The  plants  of  this  order  are  bitter  and 
fragrant.     Swietenia  Mahogani  (Fig.  27)  supplies  the  well-known  mahogany  wood;  and 
Chloroxylon  Swietenia,  satin-wood. 

47.  Vitaceae,  VINEWORTS.    Climbing  shrubs,  inhabiting  the  milder  and  hotter  parts 
of  the  globe,  and  abounding  in  the  West  Indies.     There  are  7  genera,  and  260  species. 
The  fruit  of  these  plants,  when  ripe,  is  saccharine.    The  Grape  Vine  belongs  to  this 
order.     (Fig.  28.) 

48.  Geraniacese,  CRANESBILLS.    Herbs  or  shrubs,  distributed  over  various  parts  of 
the  world.     The  plants  of  this  order  are  astringent  and  aromatic;  some  of  the  species, 
as  Geranium  and  Pelargonium,  are  remarkable  for  the  beauty  of  their  flowers.  (Fig.  29.) 
There  are  4  genera,  and  500  species. 

49.  Linacese,  FLAXWORTS.    Annual  and  perennial  plants,  scattered  over  the  globe, 
but  -most  abundant  in  Europe,  and  in  the  north  of  Africa.      There  are  3  genera, 
including  90  species.     These  plants  yield  mucilage  and  fibre.    Flax  is  procured  from 
the  inner  bark  of  the  stalk  of  Linum  usitatissium  (Fig.  30).  The  seeds  yield  Linseed  oil. 

50.  Balsaminaceae,  BALSAMS.     Succulent  herbaceous  plants,  with  watery  juice  and 
showy  flowers.     They  are  found  chiefly  in  the  East  Indies.    Their  properties  are 
unimportant.    Lindley  mentions  3  genera,  comprising  110  species. 

51.  Oxalidacese,  OXALIDS,  or  WOOD  SORRELS.    Herbs,  undershrubs,  or  trees,  found 
in  the  hot  and  temperate  parts  of  the  globe,  and  abundant  in  North  America  and  at 
the  Cape  of  Good  Hope.    There  are  6  known  genera,  and  320  species.    Some  are  acid 
in  their  properties;  others  yield  esculent  roots. 

52.  Tropaeolacese.  INDIAN  CRESSES.    Herbaceous  trailing  or  twining  plants,  with 
gay  flowers.     Natives  of  the  temperate  parts  of  America.    Their  fruit  is  used  as  a 
cress,  or  pickled  and  used  as  capers.    Lindley  enumerates  6  genera,  including  44  species. 

53.  PittosporaceSB,  PITTOSPORADS.    Trees  or  shrubs,  found  chiefly  in  Australia. 
Many  of  them  are  resinous,  and  of  some  species  the  berries  are  edible.    Lindley  men- 
tions 12  genera,  and  78  species. 

54.  Brexiaceffi,    BREXIADS.      Trees,   existing   chiefly    in    Madagascar.     Lindley 
enumerates  4  genera,  including  6  species. 

55  Zygophyllacese,  BEAN  CAPERS.  Herbs,  shrubs,  or  trees,  occurring  in  various 
parts  of  the  globe,  chiefly  in  warm  regions.  Lindley  mentions  7  genera,  including  100 
species.  Some  of  the  plants  abound  in  a  stimulant  resin;  others  are  bitter  and  acrid. 
Guaiacum  qfficinale  is  a  ber.utiful  West  Indian  tree,  yielding  the  hard  and  heavy  wood 
called  Lignum-vitffi.  (Fig.  31.) 

56.  Rutacese    RUEWORTS.    Trees  or  shrubs,  found  chiefly  in  the  south  temperate 
zone.    There  are  48  genera,  and  400  species.    These  plants  have  a  peculiar  odour; 
many  possess  anti-spasmodic  properties;  and  others  are  bitter,  and  act  as  febrifuges 
and  tonics. 

57.  Xanthoxylacese,  XANTHOXYLS.    Trees  or   shrubs  of  the  tropical    parts    of 
America.    Lindley  mentions  20  genera,  comprising  110  species.     The  plants  yield  an 
aromatic,  pungent,  and  volatile  oil;  some  are  diaphoretic  in  their  properties,  others 
are  febrifugal  and  tonic. 

58.  Simarubacese    QUASSIADS.    Trees  or  shrubs,  found  in  the  tropical  regions  of 
America,  Asia,  and  Africa.     10  genera,  and  35  species.     These  plants  are  all  intensely 
bitter.    Quassia  is  used  medicinally  as  a  tonic,  and  frequently  by  brewers  as  a  sub- 
stitute for  hops. 

59.  Odmacese    OCHNADS.    Undershrubs  or  trees,  growing  in  tropieal  countries. 
They  are  mostly  bitter,  and  some  of  them  are  used  as  tonics.    Lindley  enumerates  6 
genera,  comprising  82  species. 

60.  Coriariacese    CORIARIADS.     Shrubs  found  in  small  numbers  in  the  south  of 
Europe,  South   America,  India,  and  New  Zealand.    Some  of  them  are  poisonous. 
1  genus,  8  species. 

CALYCIFLOR^E. 

Calyx  and  Corolla  present;  Petals  distinct;  Stamens  attached  to  the  Calyx. 

61.  Stackhousiacese,  STACKHOUSIADS.    Shrubs  found  in  Australia,  without  any 
marked  properties.    2  genera,  10  species. 


VITACEXE 


LINACE/E. 


Fig.  28. 
THE  VINE. 


Fig.  29. 
GERANIUM 


Fig.  30. 
FLAX  PLANT. 


ZYGOPHYLLACE/E. 


ANACARDIACE/E. 


ANACARDIACEXE. 


Fig.  31. 
LIGNUM  VITJB. 


Fig.  32. 
CASHEW  NUT. 


Fig.  33. 
MANGO. 


ANACARDIACE/E. 


LEGUMINOSXE. 


LEGUMINOS/E. 


Fig.  34. 
HOG  PLUM. 


Fig.  35. 
SENNA  PLANT. 


Fig.  36. 
LIQUORICE  PLANT. 


LEGUMINOS/E. 

A 


LEGUMINOS/C. 


ROSACE/E. 


Fig.  37. 
LOGWOOD  TREE. 

RHIZOPHORACE/E. 


Fig.  40. 
MANGROVE  TREE. 

MYRTACE>C. 


Fig.  43. 

GUAVA. 


Fig.  38. 
INDIGO  PLANT. 

MYRTACE/E. 


Fig.  41. 
ALLSPICE. 

MYRTACE/E. 


Fig.  44. 
MALAY  API-LL. 


Fig.  39. 
ALMOND. 

MYRTACE/E. 


Fig.  42. 

POMEGRANITE. 

CUCURBITACE>E. 


Fig.  45. 
GOURDS. 


THK   VEGETABLE   KINGDOM.  5 

62.  Celastraceae,  SPINDLE-TREES.    Small  trees  or  shrubs  found  in  the  warm  parts 
of  Europe,  North  America,  and  Asia;  and  also  at  the  Cape  of  Good  Hope.     There  are 
24  genera,  and  260  species.    These  plants  have  sub-acrid  properties,  and  the  seeds  of 
some  yield  a  useful  oil;  others  are  considered  poisonous.     The  bark  of  Enonymus 
tingens  furnishes  a  yellow  dye. 

63.  Staphyleaceae,  BLADDER-NUTS.    Shrubs  scattered  over  various  parts  of  the 
globe.     Some  of  them  are  sub-acrid,  and  others  bitter  and  astringent.    They  are  culti- 
vated as  handsome  shrubs.     3  genera,  and  14  species. 

64.  Rhamnaceae,  BUCKTHORNS.  Trees  or  shrubs,  distributed  generally  over  the  globe, 
and  found  both  in  temperate  and  tropical  regions.      There  are  42  genera,  and  250 
species.     Many  of  these  plants  have  active  cathartic  properties;  some  yield  edible 
fruit,  and  others  are  tonic  and  febrifugal. 

65.  AnacardiaceSJ,  ANACARDS.    Trees  or  shrubs  with  a  resinous  and  often  caustic 
juice.     They  are  found  chiefly  in  the  tropical  parts  of  the  world.    There  are  41  genera, 
and  95  species.     Many  of  these  plants  supply  varnishes.     Anacardium  occidental  fur- 
nishes the  edible  Cashew-nut.     Although  a  resinous  principle  pervades  the  plants  of 
this  order,  yet,  in  some  cases,  it  is  not  developed  in  the  fruit,  which  becomes  eatable,  as 
exhibited  in  the  Mango  and  the  Hog-plums  of  the  West  Indies.    (F;gs.  32,  33,  34.) 

66.  Amyridaceae,  AMTRIDS.  Trees  or  shrubs  abounding  in  resin,  and  natives  of 
tropical  regions.    Lindley  mentions  22  genera,  and  45  species.    The  plants  yield  a 
fragrant  balsamic  and  resinous  juice,  which,  when  dry,  is  often  used  as  frankincense, 
and  is  employed  medicinally  as  a  stimulant  and  expectorant, 

67.  Connaraceae,  CONNARADS.  Trees  or  shrubs  of  the  tropics,  and  possessing  febri- 
fuge properties.    Lindley  notices  5  genera,  and  41  species. 

68.  Leguminosse,  PEA  and  BEAN  Tribe.    Herbaceous  plants,  shrubs,  or  trees.    The 
plants  of  this  order  are  very  generally  distributed  over  the  globe.     The  number  of 
known  genera,  according  to  Lindley,  is  467,  comprehending  6,500  species.    This  exten- 
sive and  important  natural  order  embraces  many  valuable  medicinal  plants,  as  those 
yielding  senna,   gum-arabic,  catechu,  &c.;  important  dyes,  as  indigo  and  logwood; 
many  valuable  timber  trees,  as  locust-tree  and  rosewood ;  and  food  plants,  as  the  bean 
and  pea.    The  properties  of  the  order  are  in  general  wholesome,  although  it  contains 
some  poisonous  plants.    (Figs.  35,  36,  37,  38.) 

69.  Moringaceae,  MORINGADS.  Trees  of  the  East  Indies  and  Arabia.    Some  of  them 
have  pungent  and  aromatic  qualities.     The  seeds  of  Moringa  pieryyosperma,  the  horse- 
radish tree,  are  winged,  and  are  called  Ben-nuts;  from  these  is  procured  a  fluid  oil, 
used  by  watchmakers,  and  called  Oil  of  Ben,    Lindley  notices  1  genus,  and  4  species. 

70.  Rosaceae,  ROSEWORTS.      Herbaceous  plants,  shrubs,  or  trees,  found  chiefly  in 
the  cold  and  temperate  climates  of  the  northern  hemisphere.    There  are  82  known 
genera,  and  about  1,000  species.   Many  of  the  plants  yield  edible  fruits,  as  Strawberries, 
Plums,  Apples,  Cherries,  Almonds,  &c.  (Fig.  39).    Some  are  astringent,  others  yield 
hydrocyanic  acid. 

71.  Calycanthaceae.  CALYCANTHS.     Shrubs   with  square  stems,   and  natives  of 
North  America  and  Japan.     Their  flowers  are  aromatic,  and  the  bark  of  some  is  used 
as  a  carminative.     The  order  includes  2  genera,  and  6  species. 

72.  Lythraceae,  LOOSESTRIFES.     Herbs  and  shrubs,  natives  of  Europe,  North   and 
South  America,  and  India.    Lindley  mentions  35  genera,  and  300  species.     Many  of 
the  plants  have  astringent  qualities,  and  some  are  used  for  dyeing. 

73.  Rhizophoraceae,  MANGROVES.    Trees  or  shrubs  found  on  the  muddy  shores  of 
the  tropics.     There  are  5  genera,  and  20  species  known.      Some  of   these  plants 
have  an  astringent  bark,  which  is  used  for  dyeing  black.     Rhizophora  Mangle,  the 
Mangrove-tree,  forms  thickets  at  the  muddy  mouths  of  rivers,  and  sends  out  adven- 
titious roots  which  raise  the  trunk  above  its  original  level,  giving  the  tree  the  appear- 
ance of  being  supported  upon  stalks.    The  fruit  is  sweet  and  edible  (Fig.  40). 

74.  Vochysiaceae,  VOCHYADS.     Trees  or  shrubs,  inhabiting  the  warmer  parts  of 
America.    Their  properties  are  imperfectly  known.    There  are  8  genera,  and  51  species. 

75.  Combretaceae,  MYROBALANS.    Trees  or  shrubs,  natives  of  the  tropics.    Their 
properties  are  astringent,  many  are  used  for  tanning,  and  some  for  dyeing.    Lindley 
enumerates  22  genera,  including  200  species. 

76.  MelastoinaceaB,  MELASTOMADS.    Trees,  shrubs,  or  herbs,  found  chiefly  in  warm 
climates.     The  plants   are   wholesome,  and  the  succulent  fruit  of  several  is  edible. 
They  possess  slight  astringent  qualities.    Lindley  mentions   118  genera,  including 
1,200  species. 

77.  Alangiaceae,  ALANGIADS.    Trees  or  shrubs,  found  chiefly  in  India;  some,  how- 
ever,  are  natives  of  America.    Lindley  enumerates  3  genera,  including   8   species. 
Some  of  the  plants  yield  edible  fruits,  others  are  purgative. 

78.  PMladelphaceae,  SYRINGAS.    Shrubs,  natives  of  the  south  of  Europe,  of  North 


POPULAR   SKETCH   OP 

America,  Japan,  and  India.    They  have  no  important  properties.    There  are  3  genera 
and  25  species. 

79.  Myrtaceae,  MYRTLES.    Trees  or  shrubs,  natives  of  warm  climates,  but  many 
are  found  in  temperate  regions,  while  some  of  the  genera  are  peculiar  to  Australia. 
There  are  77  known  genera,  and  upwards  of  1,400  species.     Many  of  these  plants 
yield  an  aromatic  volatile  oil;  many  supply  edible  fruits;  and  others  furnish  astringent 
and  saccharine  substances.    The  leaves  of  some  species  are  used  as  tea  in  Australia. 
The  species  of  Eucalyptus  constitute  the  gigantic  gum  trees  of  Australia,  some  of 
which  attain  a  height  of  200  feet.     (Figs.  41,  42,  43,  44.) 

80.  Onagraceae,   EVENING  PRIMROSES.      Herbs   or   shrubs,   of  temperate  regions 
chiefly.     Some  yield  edible  fruits,  and  others  edible  roots.    Many  of  them  possess 
mucilaginous  properties,  while  a  few  are  astringent.     There  are  about  30  known 
genera,  and  upwards  of  450  species. 

81.  HalprageaceaB,    MARES-TAILS.      Herbs   or  undershrubs,  often    aquatic,    and 
found  in  ditches  and  lakes  in  various  parts  of  the  world.    They  have  no  properties  of 
importance.    8  genera,  70  species. 

,,  82.  Loasaceae,  CHILI  NETTLES.    Herbaceous  plants,  natives  of  America,  and  dis- 
tinguished for  their  stinging  qualities.     15  genera,  and  70  species. 

83.  Cucurbit aceae,  CUCURBITS.     Herbaceous  plants,  with  succulent  stems.     They 
are  natives^  of  warm  climates  chiefly,  and  abound  in  India.     60  genera,  and  about  300 
species.    These  plants  are  acrid,  and  many  of  them  are  drastic  purgatives.    In  some 
cases,  however,  the  fruits  are  eatable,  as  the  Melon,  Cucumber,  Gourd,  and  Vegetable 
Marrow.     (Fig.  45.) 

84.  Papayaceae,  PAPAYADS.    Trees  or  shrubs,  found  in  South  America,  and  other 
warm  countries.     The  Papa w- tree  (Fig.  46)  yields  an  acrid  milky  juice,  which  has  the 
property  of  rendering  tough  meat  tender;   and  an  edible  fruit.    There  are  11  genera, 
and  29  species. 

85.  Belvisiaceae,  BELVISIAS,  or  NAPOLEON-WORTS.    Shrubs,  of  the  tropical  regions 
of  Africa  chiefly.     There  are  2  genera,  and  4  species.     Some  are  used  as  astringents. ' 

86.  Passifloraceae,  PASSION-FLOWERS.    Herbs  or  shrubs,  natives  chiefly  of  warm 
climates.     There  are   14  known  genera,  and  215  species.     Many  of  the  plants  yield 
edible  fruits;  others  are  hitter  and  astringent;  and  some  narcotic  (Fig.  47). 

87.  Turneraceae,  TURKERADS.     Herbaceous  or  shrubby  plants,  natives  of  the  West 
Indies,  and  South  America.    Their  properties  are  unimportant.    Lindley  notices  2 
genera,  including  60  species. 

88.  Portulacaceae,  PURSLANES.    Succulent  shrubs  or  herbs  found  in  various  parts  of 
the  world.  They  have  few  properties  of  importance.  There  are  12  genera,  and  184  species. 

89.  ParonycMaceae,  KNOTWORTS.    Herbaceous  or  shrubby  plants,  found  in  barren 
places  in  various  parts  of  Europe,  Asia,  and  North  America.    Their  properties  are 
unimportant.    28  genera,  120  species. 

90.  CrassulaceaB,  HOUSELEEKS.     Herbaceous   plants  or  shrubs,    often   succulent, 
found  in  the  driest  situations,  as  on  rocks,  walls,  &c.,  in  various  parts  of  the  world. 
25  genera,  460  species. 

91.  Ficoideae,  FICOIDS.    Herbaceous  or  shrubby  succulent  plants,  found  generally 
in  warm  regions.    There  are  16  known  genera,  and  440  species.     Some  are  used  as 
food;  others  yield  soda. 

92.  Cactaceae,  CACTUSES.    Succulent  shrubs,  with  peculiar  angular  or  flattened 
stems,  and  usually  without  leaves.    They  grow  in  hot,  dry,  and  exposed  places,  and 
are  natives  chiefly  of  the  tropical  parts  of  America.     There  are  16  genera,  and  about 
800  species.   These  plants  are  remarkable  for  their  succulence,  for  their  great  develop- 
ment of  cellular  tissue,  and  the  anomalous  forms  of  their  stems.     Many  yield  a  re- 
freshing edible  fruit  (Fig.  48). 

93.  GrossalariaceaB,  GOOSEBERRY  and  CURRANT  TRIBE.      Shrubs  of  temperate 
regions,  many  of  which  yield  edible  fruits.    3  genera,  100  species. 

94.  SaxifragaceaB,  SAXIFRAGES.    Trees,  shrubs,  or  herbs,  of  temperate  climates. 
There  are  57  genera,  and  upwards  of  900  s'pecies.  Few  of  the  plants  are  put  to  any  use. 

95.  Bruniaceae,  BRUNIADS.    Branched  heath-like  shrubs,   natives  chiefly  of  the 
Cape  of  Good  Hope,  with  no  important  properties.     15  genera,  65  species. 

96.  Hamainelidacese,   WITCH-HAZELS.     Shrubs  or  small  trees,  found  in  various 
parts  of  Asia,  Africa,  and  America.     The  seeds  of  Hamamelis  virginica  are  used  as 
food.     10  genera,  15  species. 

97.  UmbelliferaBj  UMBELLIFERS.    Herbaceous  plants,  often  with  hollow  and  fur- 
rowed stems.     Found  chiefly  in  the  northern  hemisphere.      There  are  267  genera, 
including  1,500  species.     The  properties  of  these  plants  are  various.     Some  yield  food, 
others  gum,  resinous,  and  oily  substances,  while  others  are  highly  poisonous.    The 
species  have  been  grouped  into  four  divisions :  1.  The  esculent  species,  as  the  Carrot, 
Parsnip,  Celery,  Parsley,  &c.    2.  Those  producing  milky  juices,  which  concrete  into  a 


PAPAYACEXE. 


PASSIFLORACE/E. 


CACTACEXE. 


Fig.  46. 
PAPAW. 


Fig.  47. 
PASSION  FLOWER. 


Fig.  48. 
CACTTT»-TUNA. 


UM  BELLI  FERXE. 


RUBIACEXE. 


RUBIACEXE. 


Fig.  49. 
HEMLOCK. 


Fig.  50. 
PERUVIAN  BARK. 


Fig.  51. 
COFFEE  PLANT. 


RUBIACEXE. 


DIPSACACEXE. 


COMFOSITXE. 


Fig.  52. 
MADDER. 


Fig.  53. 
TEAZEL 


•*  V- 


ERICACEAE. 


SAPOTACEXE. 


OLEACE/E. 


Fig.  55. 
RHODODENDRON. 


OLEACE/E. 


CONVOLVULACE/E. 


Fig.  56. 
GUTTA  PERCHA  PLANT. 

GENTIANACE/E. 


Fig.  59. 
GENTIAN. 

SOLANACE/E. 


Fig.  61. 
JALAP  PLANT. 


Fig.  62. 
TOBACCO  PLANT. 


Fig.  57. 

OHVE. 

BIGNON1ACE/E 


Fig.  60. 
TRUMPET  FLOWER. 

SOLANACE/E. 


Fig.  63.      , 
LOVE  APPLE. 


SCROPHULARIACEC. 


POLYGONACE/E. 


LAURACE/E. 


Fig.  64. 
FOX-GLOVE. 

LAURACE/E. 


Fig.  67. 
CINNAMON  PLANT. 

EUPHORBIACE/E. 


Fig.  70. 
EUPHORBIA. 


Fig.  65. 
BUCK  WHEAT. 

LAURACE/E. 


Fig.  68. 
CLOVE. 

EUPHORBIACE/E 


Fig.  66. 
CAMPHOR. 

MYRISTICACE/E. 


EUPHORBIACE/E. 


Fig.  71. 
CASTOR  OIL  PLANT. 


Fig.  72. 
INDIA-RUBBER  PLANT. 


GRAM  IN  EXE. 


RHIZANTH/E. 


Fig.  133. 
SUGAR  CANE. 

FILICES. 


Fig.  136. 
TREE  FERNS. 


FUNGI. 


Fig.  134. 
RAFFLESIA. 


LYCOPODIACE/E. 


Fig.  137. 
CLUB  Moss, 


Fig.  135. 
EQUISETUM. 

LICHENES. 


Fig.  138. 
ORCHIL. 


ALG/E. 


Fig.  139. 
MUSHROOMS. 


Fig.  140. 
IRISH  Moss  SEA-WEED 


THE    VEGETABLE   KINGDOM.  7 

fetid  gum  resin,  aa  Assafoetida,  Ammoniac,  Galbanura,  &c.  3.  Those  species  which 
supply  a  carminative  and  aromatic  oil,  as  Carra way- seeds,  Anise,  Coriander,  &c. 
4.  The  poisonous  species  include  Hemlock,  Water  Dropwort,  &c.  (Fig.  49.) 

98.  Araliaceae,  IVYWORTS.     Trees,  shrubs,  or  herbaceous  plants,  found  both  in 
tropical  and  in  cold  regions.    Lindley  enumerates  21  genera,  comprising  160  species. 
These  plants  are  allied  to  Umbelliferae,  and  have  generally  aromatic  and  stimulant 
properties.    Some  species  of  Aralia  yield  an  aromatic  gum-resin. 

99.  CornaceaB,   CORNELS.     Trees,  shrubs,  or  herbs,  of  temperate  climates.    The 
bark  of  some  species  is  used  as  a  tonic  and  febrifuge;  the  seed  of  Cornus  mascula  has 
been  used  as  food;  and  the  seeds  of  Cornus  sanguinea  furnish  oil.   9  genera,  and  40  species. 

COROLLIFLOE^B. 

Calyx  and  Corolla  present;  Petals  united,  bearing  the  Stamens. 

100.  LoranthaceaB,  LORANTHS,  or  MISTLETOES.    Shrubs,  usually  parasitical.    Many 
in  the  tropical  regions  have  showy  flowers,  which  hang  from  the  branches  of  trees, 
presenting  a  beautiful  appearance.    Lindley  mentions  23  genera,  and  412  species.    The 
bark  is  astringent. 

101.  Caprifoliaceae  CAPRIFOILS,  or  HONEYSUCKLE  TRIBE.    Shrubs  or  herbs,  chiefly 
found  in  the  temperate  climates.    There  are  14  genera,  and  220  species.     Many  of  the 
plants  have  odoriferous  flowers,  and  some  possess  emetic  and  purgative   properties. 
The  fruit  of  the  common  Elder  is  used  in  the  manufacture  of  Elder  Wine. 

102.  Kubiaceae,    CINCHONADS.      Trees,  shrubs,  or  herbs.     The  order  has  been 
divided  into  two   sub -orders:    1.  Cinchoneae,  natives  of  the  warm  regions;    and  2. 
Galieas,  or  Stellatea,  natives  of  colder  regions.    There  are  nearly  280  genera,  and 
upwards  of  2,800  known  species.    The  properties  of  these  plant?  are,  in  general,  tonic, 
febrifuge,  and  astringent;  some,  however,  have  emetic  and  purgative  qualities,  as 
Ipecacuanha.     Among  the  food  plants  of  this  order  the  most  important  is  Coffea 
arabica,  the  Coffee   plant,  a  native  of  Arabia.    The  Madder  of  commerce,  used  in 
dyeing,  is  produced  by  the  root  of  Rubia  tinctoria.     (Figs.  50,  51,  52.) 

103.  Valerianaceae,  VALERIAN-WORTS.      Herbs    of  temperate  climates.      These 
plants  are  strong-scented  or  aromatic,  and  some  of  them  are  employed  as  bitter  tonics 
and  anti-spasmodics.    There  are  12  genera,  and  185  species. 

104.  Dipsacaceae,  TEAZELS.    Herbs  or  undershrubs,  found  in  the  south  of  Europe, 
the  Levant,  and  at  the  Cape  of  Good  Hope.    Their  properties  are  unimportant.    The 
heads  of  Dipsacus  fullonum,  Fuller's  Teazel  (Fig.  53),  on  account  of  their  spiny  bracts, 
are  used  in  dressing  cloth.    Lindley  notices  6  genera,  including  150  species. 

105.  Calyceraceae,  CALYCERS.    Herbaceous  plants  of  South  America.     Their  pro- 
perties are  unknown.     5  genera,  10  species. 

106.  Compositae,   COMPOSITES.      Herbs  or  shrubs.    This   is   one  of  the  largest 
families  in  the  vegetable  kingdom.    De  Candolle's  division  of  the  order,  now  generally 
adopted,  is  as  follows:  1.  Tubulifloree;  2.  Labratiflorse;  3.  Liguliflorse.     The  plants  of 
this  order  are  variously  distributed  over  the  globe.    In  northern  regions  they  are 
mostly  herbaceous,  while  in  warm  climates  they  become  shrubby  or  even  arborescent. 
Their  properties  are  more  or  less  bitter,  and  sometimes  astringent,  acrid,  and  narcotic. 

.In  this  order  is  comprised  the  following  well-known  plants  and  vegetable  products- 
Artichoke,  Thistle,  Camomile,  Wormwood,  Southernwood,  Sunflower,  Lettuce,  and 
Safflower.  (Fig.  54.)  There  are  1,000  genera,  and  9,500  species. 

107.  BrunqniaceSBj  BRUNONIADS.    Stemless  herbaceous  plants,  natives  of  Australia. 
Their  properties  are  unknown.     1  genus,  9  species. 

108.  Gcodeniaseae-  GOODENIADS.     Herbs,  found  in  Australia  and  the  South  Sea 
Islands.     Some  are  eaten  as  pot-herbs.     14  genera,  and  150  species. 

109.  StylidiaceaB,  STYLEWORTS.    Non-lactescent  herbs  or  undershrubs,  natives  of 
marshy  places  in  Australia.     Some  are  also  found  at  the  southern  extremity  of  South 
America.     5  genera,  and  121  species. 

110.  Campanulaceae,   BELL-WORTS.      Lactescent   herbs   or    undershrubs,  natives 
chiefly  of  northern  and  temperate  regions.     The  milky  juice  found  in  the  plants  of  this 
order  has  acrid  properties.   There  are,  according  to  Lindley,  28  genera,  and  500  species. 

111.  Lobeliaceffi,  LOBELIADS.    Lactescent  herbs  or  shrubs,  found  both  in  temperate 
and  warm   climates.     Acridity  is   their  prevailing  characteristic.      Lobelia  inflata, 
Indian  Tobacco  of  North  America,  is  used  medicinally  as  a  sedative  and  expectorant, 
the  milky  juice  of  some  species  of  this  order  contains  Caoutchouc.    There  are  27 
known  genera,  including  375  species. 

112.  Gesneraceae,  GESNERWORTS.    Herbs  or  shrubs,  found  chiefly  in  the  warmer 
regions  of  America.    Their  properties  are  unimportant.    There  are  22  known  genera, 
and  upwards  of  120  species. 

113.  Ericaceae,  HEATHS.    Shrubs,  undershrubs,  or  herbaceous  plants,  with  ever- 
green  leaves.     Th>  order  has  been   divided   into— 1.  Ericeje,  the  true  Heaths  and 


8  POPULAR   SKETCH   OF 

Rhododendrons,  with  scaly  conical  huds;  2.  Monotropese,  including  the  true  Mono- 
tropas,  or  Fir-rapes;  and  Pyroleae,  or  the  Wintergreen  tribe.  There  are  52  genera, 
and  nearly  880  species.  The  order  contains  many  beautiful  plants,  which  abound  at 
the  Cape  of  Good  Hope,  and  are  also  found  in  other  parts  of  the  world.  The  fruits  of 
some  of  these  plants  are  eatable,  as  Gaultheria  procumbeus,  and  Shallon,  American 
shrubs;  others  have  poisonous  narcotic  properties,  as  many  species  of  Rhododendron, 
Azalea,  &c.  /See  Fig.  55.) 

114.  VacciniaceSB,  CRANBERRIES.  Shrubby  plants,  closely  allied  to  Ericaceae.    They 
are  natives  of  temperate  regions,  and  same  of  them  are  marsh  plants.     Some  are 
astringent,  others  yield  sub-acid  edible  fruits.     There  are  15  genera,  and  200  species. 

115.  Epacridaceae,  EPACRIDS.    Shrubs  or  small  trees,  allied  to  Ericaceae,  and  occu- 
pying the  place  of  heaths  in  Australia.    Their  flowers  are  beautiful,  and  some  yield 
edible  fruits.    30  known  genera,  320  species. 

116.  Columelliacese,  COLUMELLIADS.  Evergreen  shrubs  or  trees,  natives  of  Mexico 
and  Peru.    Properties  unknown.     1  genus,  3  species. 

117.  Styracaceae,  STORAX- WORTS.  Trees  or  shrubs,  natives  chiefly  of  warm  climates. 
Lindley  mentions  6  genera,  and  115  species.    These  plants  are  in  general  stimulant, 
aromatic,  and  fragrant.     Some  of  them  yield  balsamic  resinous  substances,  as  storax, 
benzoin,  Sec.,  and  others  dyeing  material. 

118.  Ebenacese,  EBENADS.     Trees  or  shrubs,  found  chiefly  in  the  tropical  regions 
and  India.    These  plants  are  remarkable  for  the  hardness  and  durability  of  their  wood. 
Some  yield  edible  fruit.    Lindley  notices  9  genera,  and  160  species. 

119.  Aquifoliaceae,  HOLLTS.     Evergreen  trees,  or  shrubs,  found  in  various  parts  of 
the  world.     Their  properties  generally  are  astringent  and  tonic.    The  leaves  and  bark 
of  the  holly  are  tonic  and  febrifuge,  while  its  berries  are  emetic  and  purgative.    Its 
wood  is  white  and  hard,  and  is  esteemed  in  turnery  and  cabinet  work.    Lindley 
enumerates  11  genera,  including  110  species. 

120.  Sapotaceae,  SAPOTADS.    Lactescent  trees  or  shrubs,  natives  of  the  tropical 
parts  of  India,  Africa,  and  America.     Many  of  the  plants  yield  edible  fruits,  while 
others  supply  oily  matter.    The  milky  juice  of  some  of  the  plants  contains  elastic 
matter,  as  Gutta  Percha,  which  is  obtained  from  Isonandra  Gutta  (Fig.  56).     There 
are  21  known  genera,  and  212  species. 

121.  MyrsinaceSB,  ARDISIADS.    Trees,  shrubs,  or  undershrubs,  found  chiefly  in  the 
isFands  of  Africa,  Asia,  and  America.    Little  is  known  of  their  properties.    31  known 
genera,  and  325  species. 

122.  Jasminacese,  JASMINES.     Shrubs,  often  with  twining  stems,  abounding  chiefly 
in  the  tropical  parts  of  India.    Their  flowers  yield  fragrant  oil,  and  their  leaves  and 
roots  are  sometimes  bitter.     5  genera,  100  species. 

123.  Oleacese,  OLIVES.    Trees  or  shrubs,  found  chiefly  in  temperate  regions.    There 
are  two  sections  of  this  order:  1,  Olese,  with  a  drupaceous,  or  berried  fruit ;  2,  Fraxineae, 
with  a  samaroid,  or  winged  fruit.     Lindley  notices  24  genera,  including  130  species. 
These  plants  are  bitter,  tonic,  and  astringent,  and  some  yield  oil.     Olea  Europcea  is 
the  Olive-tree  of  the  coast  of  the  Mediterranean  and  south  of  Europe.    The  oil  of  com- 
merce is  obtained  by  expression  from  the  fleshy  pericarp  of  the  fruit  .(Fig.  57).   Several 
species  yield  a  sweet  exudation,  called  Manna,     The  flowering  Ash  is  a  native  of  the  - 
south  of  Europe,  where  it  attains  a  height  of  twenty  or  thirty  feet.    The  common  Ash 
(Fig.  58),  attains  a  much  greater  height;  its  wood  is  tough  and  elastic,  and  is  used 
for  oars,  &c.     To  this  order  also  belongs  Syringa  vulgaris,  the  common  Lilac,  and 
Ligustrum  vulgare,  common  Privet. 

124.  Asclepiadacese,  ASCLEPIADS.    Shrubs  or  herbs,  with  a  milky  juice,  often 
twining.     Inhabitants  chiefly  of  tropical  regions,  but  many  species  extend  to  northern 
climates.    There  are  141  genera,  and  910  species.     These  plants  have  acrid,  purgative, 
emetic,  and  diaphoretic  properties.      The  milky  juice  is  generally  bitter  and  acrid, 
but  sometimes  it  is  bland,  and  is  used  as  milk.    The  milky  juice  of  many  of  the  plants 
contains  Caoutchouc. 

125.  Apocynacese,  DOGBANES.    Trees  or  shrubs,  usually  lactescent,  found  chiefly 
in  tropical  regions.    Lindley  enumerates  100  genera,  including  566  species.     Many  of 
the  .plants  are  poisonous;  some  are  used  medicinally  as  cathartics;  and  a  few  yield 
edible  fruits.     The  juice  of  l^aberncemontana  utilis,  the  Cow-tree  of  Demerara,  is  used 
as  milk.  Many  of  the  plants  supply  Caoutchouc;  and  some  species  yield  a  dye  like  Indigo^ 

126.  Loganiacese,  LOGANIADS.     Shrubs,  herbs,  or  trees  of   tropical    and   warm 
climates  chiefly.    The  order  is  divided  into  three  sub-orders:—!,  Loganitaa;  2,  Strych- 
nese;  3,  Spigeliese.     There  are  about  24  known  genera,  and  nearly  170  species.    The 
plants  of  this  order  are  highly  poisonous,  and  possess  also  narcotic  properties.     It 
includes  Strychnos  Nux-  Vomica,  the  Poison-nut,  from  which  Strychnia  is  obtained. 

127.  Gentianacese,  GENTIAN-WORTS.     Herbs,  and  occasionally  shrubs,  distributed 


URTICACE/E, 


URTICACE/E. 


URTICACE/E. 


Fig.  73. 
HEMP. 

URTICACE/E 


Fig.  76. 
BLACK  MULBERRY 


URTICACE/E. 


Fig.  77. 
BREAD  FRUIT. 


Fig.  75. 
MULBERRY. 


URTICACE/E. 


URTICACE/E. 


Fig.  79. 
BANIAX  TREE 


THE   VEGETABLE  KINGDOM.  9 

generally  over  the  globe.  There  are  two  sub-orders:  1.  Gentianese;  2.  Menyanthese. 
The  general  property  of  these  plants  is  bitterness,  and  they  are  used  as  tonics. 
Lindley  mentions  60  genera,  including  450  species.  (Fig.  59.) 

128.  Bignoniaceae,    BIGNONIADS,  or  Trumpet-flower  Family.     Trees,  shrubs,  or 
herbs,  of  tropical  regions  chiefly.     The  order  has  been  divided' into  four  sub-orders: 

1.  Bignoniae;    2.   Cyrtandrcrc;  3.  Crescentieae;    4.  Pedalieaa.     There  are  upwards  of 
100  known  genera,  and  about  650  species.     This  order  comprises  many  showy  plants; 
sonae  are  timber  trees,  others  furnish  dyes  and  articles  of  diet,  and  a  few  have  bitter 
and  astringent  qualities.    (Fig.  60  ) 

129.  Polemoniacese,  PHLOX-WORTS.     Herbaceous  or  climbing  plants,  of  temperate 
climates  generally,  abounding  in  the  north-west  of  America.     There  are  17  genera, 
and  104  species.    Many  of  these  plants  have  showy  flowers,  and  some  are  remarkable 
for  their  development  of  spiral  cells. 

130.  Hydrophyllaceaa,  HYDROPHYLLS.    Trees,  shrubs,  or  herbs,  of  America  chiefly. 
Their  properties  are  unimportant.     Many  have  showy  flowers,  and  some  have  stinging 
hairs.     The  order  has  been  divided  into  two  sub-orders:  1.  Hydrophylleae;  2.  Diapen- 
sienese.     There  are  18  known  genera,  and  77  species. 

131.  Convolvulaceae,  BINDWEEDS.     Herbs  or  shrubs,  usually  twining,  sometimes 
parasitical,  and  with  a  milky  juice.     They  occur  chiefly  in  tropical  and  temperate 
regions.    The  order  has  been  divided  into  two  sub-orders:  1.  Convolvuleae,  true  Bind- 
weeds, leafy  plants;  2.  Cuscutea},  leafless  parasites.    There  are 45  genera,  and  upwards 
of  700  species.    The  roots  of  many  of  these   plants  possess  an  acrid  juice,  which, 
having  purgative  properties,  is  used  medicinally.    To  this  order  belong  the  Jalap 
plant,  Convolvulus  Jalapa  (Fig.  61).  and  the  Scammony  plant,  Convolvulus  Scammonia. 
The  roots  of  some  species  are  used  as  food,  as  Batatas  edulis,  the  sweet  Potato. 

132.  CordiaceaB,  SEBESTENS.     Trees,  natives  chiefly  of  warm  countries.     Some  yield 
edible  fruit;  their  bark  is  occasionally  bitter,  tonic,  and  astringent.    There  are  11 
genera,  and  1 80  species. 

133.  Boraginacese,  BORAGE-WORTS.    Herbs,  shrubs,  or  trees.     The  order  has  been 
divided  into  three  sub-orders:  1.  Boragineae,  natives  chiefly  of  temperate  climates; 

2.  Ehretieae,  of  tropical  climates;    3.    Heliotropiea?,  of  both   warm  and  temperate 
countries.    There  are  67  known  genera,  and  nearly  900  species.    These  plants  are 
generally  mucilaginous  and  emollient.     Some  are  astringent,  others  yield  nitrate  of 
potash, 

134.  SolanaceSB,  NIGHTSHADES.    Herbs  or  shrubs,  natives   of  most  parts  of  the 
world,  but  most  abundant  in  the  tropics.     The  order  has  been  divided  into  two  sub- 
orders: 1.  Rectembryse;  2.  Curvembryae.    There  are  66  known  genera,  and  935  species. 
These  plants  have,  in  general,  narcotic  properties,  and  some  are  very  poisonous.    In 
some  species,  certain  parts  of  the  plant  have  poisonous  properties,  while  other  parts 
are  harmless,  and  are  used  as  food.     Thus  Solarium  tuberosum,  the  Potato,  has  slight 
narcotic  properties  in  its  leaves  and  fruit,  but  in  the  tubers  there  is  an  abundance  of 
starch,  and  when  cooked  they  are  wholesome  and  nutritious.     To  this  family  belong 
Belladonna,  Henbane,  &c.,   also  the  Tobacco  plant,  Nicotiana  Tabacum  (Fig.  62),  a 
native  of  the  hotter  parts  of  North  and  South  America.     The  species  of  Capsicum, 
supplying  Cayenne  pepper  and  Chillies,  and  Lycopersicum  esculentum,  the  Tomato,  or 
Love  Apple  (Fig.  63),  likewise  belong  to  this  order  of  plants. 

135.  Orobanchaceae,  BROOM-RAPES.    Herbaceous  parasitical  plants,  having  scales 
in  place  of  leaves.    Natives  of  the  southern  parts  of  Europe,  of  Asia,  North  America, 
and  the  Cape  of  Good  Hope.    Lindley  mentions  12  genera,  and  116  species.    The 
properties  of  these  plants  are,  in  general,  astringency  and  bitterness. 

136.  ScrophulariaceSB,  FIGWORTS.    Herbs,  undershrubs,  or  shrubs,  generally  dis- 
tributed over  the  globe.    There  are  176  known  genera,  and  1,814  species.   These  plants 
are  acrid  and  slightly  bitter,  and  some  are  sedative  and  poisonous.    The  most  im- 
portant medicinal  plant  of  the  order  is  Digitalis  purpurea,  Foxglove  (Fig.  64).     Some 
of  the  species  of  Linaria  and  Calceolaria  are  used  for  dyeing. 

137.  Labiatae,   LABIATES.     Herbs  or  undershrubs,  natives   chiefly  of  temperate 
regions.     These  plants  are  in  general  fragrant  or  aromatic,  and  none  of  them  are  in- 
jurious.    Many  of  them  form  agreeable  condiments,  although  none  are  used  for  ordi- 
nary food.    Peppermint,  Rosemary,  Lavender,  Marjoram,  Mint,  Sage,  and  Thyme, 
belong  to  this  family.     Lindley  mentions  125  genera,  including  2,350  species. 

138.  Verbenacejfi,  VERBENES.    Trees,  or  shrubs,  rarely  herbs.    The  order  has  been 
divided  into  three  sub-orders. — 1,  Myoporineae,  natives  of  South  America,  Africa,  and 
Australia;  2,  Verbenae,  natives  of  America,  tropical  and  temperate,  and  found  also  in 
Asia  and  Europe;  3,  Selaginese,  natives  chiefly  of  the  Cape  of  Good  Hope,  and  found 
also  in  Europe.     There  are  75  known  genera,  and  upwards  of  770  species.     Many  of 
the  plants  are  fragrant  and  aromatic;  some  are  bitter,  tonic,  and  astringent;  and 
others  are  acrid.    The  bark  of  Avicennia  tomentosa  is  used  in  Brazil  for  tanning.    To 


10  POPULAR    SKETCH   OF 

this  order  belongs   Tectcna  grandis,  the  gigantic  Teak-tree  of  India,  which  attains  a 
height  of  200  feet. 

139.  Acanthaceae,  ACANTHADS.    Herbaceous  plants  or  shrubs,  abounding  in  tropi- 
cal regions,     'i  here  are,  according  to  Lindley,  105  genera,  and  about  750  species. 
These  plants  have   mucilaginous  and  bitter  qualities.     The  leaves  of  the  Acanthus 
gave  origin  to  the  capital  of  the  Corinthian  column. 

140.  Lentibulariaceae,    BUTTERWORTS.      Aquatic  or   marsh  herbaceous   plants, 
found  in  all  parts  of  the  world.    Lindley  enumerates  4  gemra,  and  173  species.    These 
plants  have  no  properties  of  importance. 

141.  Primulaceae,  PRIMWORTS.     Herbaceous  plants  of  temperate  and  cold  regions. 
There  are  29  genera,  and  215  species.     Acridity  prevails  more  or  less  in  these  plants. 
They  are  chiefly  cultivated  as  showy  garden  flowers. 

142.  Plumbaginaceae,  LEADWORTS  or    SEA-PINKS.      Herbs   or  undershrubs,   in- 
habiting the  sea  shores  and  salt  marshes  of  temperate  regions  chiefly.    Lindley  enume- 
rates 8  genera,  and  160  species.    Some  of  the  plants  are  acrid,  others  have  tonic 
properties. 

143.  PlantaginaceaB,  RIBWORTS.    Herbs  which  are  often  stemless;  they  are  found 
chiefly  in  temperate  and  cool  regions.     Lindley  notices  3  genera,  and  120  species. 
These  plants  are  frequently  bitter  and  astringent,  and  their  mucilaginous  seeds  are 
sometimes  used  as  demulcents. 

MONOCHLAMYDEJE. 

Calyx  or  simple  Perianth  present;  Corolla  wanting;  Flowers  sometimes  achlamydeous. 

144.  Nyctaginaceae,  NYCTAGOS.     Herbs,  shrubs,  or  trees,  natives  principally  of 
•warm  regions.     Lindley  mentions   14  genera,   and   100  species.     Their  qualities  are 
mostly  purgative.     Some  species  are  cultivated  as  garden  flowers. 

145.  AmaranthaCfcSB,  AMARANTHS.     Herbs  and  shrubs  of  tropical  and  temperate 
regions.      There  are  38   known  genera,  and  282  species.     These  plants  are  mostly 
mucilaginous  and  demulcent.      Many  of  them  are  cultivated  in  gardens,  including 
those  known  under  the  popular  names  of  Love-lies-bleeding,  Cockscomb,  &c. 

146.  Chenopodiacese,  CHENOPODS.     Herbs,  under-shrubs,  or  weeds,  found  in  most 
parts  of  the  world.  There  are  67  genera,  and  372  species.  Many  of  these  plants  are  used 
as  esculent  pot-herbs,  as  spinage,  beet,  &c.     Beetroot  yields  a  quantity  of  sugar,  and 
Ambrina  anthelmintica  yields  a  volatile  oil,  which  is  used  as  a  vermifuge. 

147.  Phytolaccaceae,    PHYTOLACCADS.      Undershrubs   or  herbs,  natives  both   of 
tropical  and  warm  countries.     They  are  found  in  Asia,  Africa,  and  America.     The 
order  has  been  divided  into  two  sub-orders:  1.  Phytolacceae;  2.  Petiveriea?.     There  are 
12  genera,  and  about  70  species.     These  plants  have  frequently  acrid  qualities,  and  act 
as  irritant  emetics  and  purgatives.     Some  yield  potash. 

148.  Polygonaceae,  BUCKWHEATS.    Herbaceous,  rarely  shrubby  plants,  found  in 
most  parts  of  the  world,  but  especially  in  north  temperate  regions.     The  order  has 
been  divided  into—  1.  Poly goneas;  2.  Eriogoneae.     These  plants  have  astringent  and 
acrid  properties;  some  are  purgative,  and  a  few  acrid.     The  fruit  of  Fagopyrum  escu- 
lentum  (Fig.  65),  and  other  species  of  Buckwheat,  is  used  as  food.     One  of  the  most 
important  plants  of  the  order  is  the  Rhubarb  plant.    Lindley  notices  29  genera,  and 
490  species. 

149.  Begoniaceae,  BEGONIADS.    Semi -succulent  herbaceous  plants  and  undershrubs, 
natives  of  warm  countries.     Their  leaves  and  young  stems  are  acrid,  the  roots  are 
astringent  and  slightly  bitter.     Begonia  obliqua  is  sometimes  called  Wild  Rhubarb. 
There  are  3  genera,  and  159  species. 

150.  Lauraceae,  LAURELS.    Trees,  and  sometimes  twining  parasitic,  and  leafless 
herbs,  or  undershrubs.     Natives  chiefly  of  the  tropical  regions  of  Asia  and  America. 
The  order  has  been  divided  into  two  sub-orders:  1.  Lauieae,  true  laurels,  trees  with 
leaves;  2.  Gassy  these,  Dodder-laurels,  climbing  parasitic  plants  without  leaves.   There 
are  46  genera,  and  450  species.     These  plants  are,  in  general,  aromatic  and  fragrant; 
many  of  them  furnish  oils,  others  camphor,  some  have  bitter  and  tonic  barks,  and 
others  supply  useful  timber.     Camphora  officinarutn  is  the  camphor  tree  of  China  and 
Japan.     Sassafras  officinarum  is  an  American  tree,  the  root  of  which  is  used  in  medi- 
cine.    Cinnamamvm  zeylanicum  is  the  true  Cinnamon  tree  of  Ceylon.     The  bark  of  the 
tree  is  the  cinnamon  of  commerce;  the  root  yields  camphor.     Another  species,  Cinna- 
momum  Cassia,  supplies  the  Cassia  bark  of  commerce.     The  clove  nutmegs  of  Mada- 
gasca  are  produced  by  Agathophyllum  aromaticum ;  and  Brazilian  nutmegs  by  Crypto- 
can/a  moschata.     (Figs,  66,  67,  68.) 

151.  Myristicaceae,  NUTMEGS.     Trees  of  the  tropical  regions  of  Asia  and  America. 
There  are  5  genera,  and  upwards  of  30  species.     Acridity  and  aromatic  fragrance  are 
the  properties  of  these  plants.     The  most  important  species  is  Myrisiica  officinalis, 
a  tree  of  the  Moluccas.     The  fruit  is  drupaceous,  and  when  ripe  opens  by  two  valves, 


URTICACEXE. 


PIPERACEXE. 


AMENTACEXE. 


Fig.  80. 
HOP. 

AMENTACEXE. 


Fig.  83. 
BIRCH. 


AMENTACEXE. 


Fig.  81. 
BLACK  PEPPER  PLANT. 


AMENTACEXE. 


Fig.  84. 
PLANE. 

AMENTACEXE. 


Fig.  82. 
WILLOW.  /  / 

AMENTACE/E. 


Fig.  85. 
ALDER. 

AMENTACEXE. 


Fig.  88. 
SPANISH  CHESTNUT. 


AMENTACE/E. 


AMENTACE/E. 


JUGLANDACE/E. 


Fig.  89. 
POPLAR. 

CONIFERXE. 


Fig.  92. 
NORWAY  FIR. 

CONIFERS. 


Fig.  90. 
CORK  TREE. 


CONIFER/E. 


Fig.  93. 
SCOTCH  FIR. 

CONIFER/E. 


Fig.  91. 
WALNUT. 

CON1FERXE. 


Fig.  94. 
SILVER  FIR. 

CONIFER/E. 


Fig.  95. 
LARCH. 


Fig.  96. 
TAR  TREE. 


Fig.  98. 
WKYMOUTH  PINE. 


THE   VEGETABLE   KINGDOM.  11 

displaying  the  beautiful  scarlet  arillus,  which   constitutes  mace.     Within  this  is  a 
dark-brown  shell,  covering  the  kernel,  which  is  the  nutmeg  of  commerce.     (Fig.  69.) 

152.  ProteaceaB,  PROTEADS.     Shrubs  or  small  trees,  natives  chiefly  of  Australia 
and  the  Cape  of  Good  Hope.     Lindley  mentions  44  genera,  and  650  species.    The 
order  has  been  divided  into  two  sub-orders:  1.  Nucumentaceae;  2.  Follicalares.     These 
plants  have  no  medicinal  qualities  of  importance.     They  present  great  diversity  of 
appearance,  and  are  cultivated  for  their  beauty  and  the  peculiarity  of  their  flowers. 

153.  ElseagnaceaB,  OLEASTERS.     Trees  or  shrubs,  found  in  all  parts  of  the  northern 
hemisphere.     Properties  unimportant.     The  fruit  of  some  is  eaten,  and  Hippophaee 
rhamnoides  also  yields  a  yellow  dye.     There  ara  4  known  genera,  and  30  species. 

154.  PenseaceJfi,  SARCOCOLLADS.    Shrubs,  found  at  the  Cape  of  Good  Hope,  with 
no  properties  of  importance.     The  gum-resin,  Sarcocal,  is  furnished  by  some  species. 

3  known  genera,  21  species. 

155.  Thymelseaceae,  DAPHNADS.    Shrubby,  rarely  herbaceous  plants.    Natives  of 
various  parts   of  the  world,  both  in  warm  and  temperate  regions.     There  are  two 
sections  of  the  order:  1.  Daphneae;  2.  Hemandieae.     Lindley  mentions  38  genera,  and 
SOO  species.     The  bark  of  many  species  is  acrid  and  irritant,  the  fruit  narcotic.     The 
bark  of  many  of  the  plants  is  made  into  ropes  and  paper. 

156.  AquilariaceSB,  AQUILARIADS.    Trees,  of  the  tropical  regions  of  Asia.    Some 
species  furnish  a  fragrant  wood  called  Eagle,  or  Aloes- wood.     There  are  6  genera,  and 
10  species. 

157.  Chailletiaceae,  CHAILLETIADS.    Trees  or  shrubs,  of  the  warm  parts  of  Africa 
and  South  America.     The  fruit  of  some  species  is  said  to  be  poisonous.     There  are 

4  known  genera,  and  10  species. 

158.  SamydaceJB,  SAMYDS.    Trees,  natives  chiefly  of  tropical  America.     Some  spe- 
cies of  Casearia  are  bitter  and  astringent.     There  are  5  known  genera,  and  80  species. 

159.  Homaliacese,  HOMALIADS.     Trees. or  shrubs  of  the  tropics.     They  do  not  pos- 
sess   any  important  properties.    Lindley  mentions  8  genera,  including  30  species. 

160.  Santalacese,  SANDALWOODS.     Trees,  shrubs,  or  herbs  found  in  Europe,  Asia, 
America,  and  Australia.     There  are  18  genera  and  110  species.     Some  are  astringent, 
others  yield  fragrant  wood.     The  seeds  of  some  species  are  eaten,  and  the  large  seeds 
of  Pyrularia  oleifera,  Buffalo-tree,  or  Oil-nut,  yield  oil. 

161.  Aristolbclliacese,  BIRTHWORTS.    Herbs  or  shrubs,  often  climbing,  found   in 
abundance  in  the  warm  regions  of  South  America,  and  found  also  in  temperate  ami 
cold  regions  of  other  parts  of  the  world.     These  plants  are  generally  bitter,  tonic,  and 
stimulant,  while  some  are  acrid.    The  snake-roots  of  Canada  and  Virginia  belong  to 
plants  of  this  order.     There  are  8  known  genera  and  130  species. 

162.  Nepenthacese,  PITCHER- PLANTS.     Herbs  or  half-shrubby  plants,  natives  of 
swampy  parts  in  the  East  Indies    and  China.      They    have  no  known   properties. 
Lindley  mentions  1  genus  and  6  species. 

163.  Datiscacese,  DATISCADS.     Herbaceous  branched  plants  or  trees,  scattered  over 
North  America,  parts  of  Asia,  and  the  south-east  of  Europe.     Some  of  the  plants  are 
bitter,  and  others  purgative.     Lindley  mentions  3  genera,  and  4  species. 

164.  Empetracese,  CROWBERRIES.    Heath-like  shrubs  of  Europe  and  North  Ame- 
rica, chiefly.      They  have  slightly  acid  properties.   4  genera,  and  4  species. 

165.  EuphOfbiaceae,  SPURGE- WORTS.     Trees,  shrubs,  or  herbs,  often  having  acrid 
milk.     These  plants  abound  in  warm  regions,  especially  in  tropical   America,  where 
they  are  found  as  trees  or  bushes,  or  lactescent  herbs,  often  presepting  the  appearance 
of  Cactuses.     They  are  also  found  in.  North  America  and  Europe.     In  Britain  there 
are  18  species.    There  are  in  all  192  known  genera,  and  upwards  of  2.500  species. 
These  plants  are  acrid  and  poisonous.    In  many  cases,  the  elaborated  sap  contains 
caoutchouc  and  resin.     The  seeds  of  many  species  yield  oils,  some  of  a  bland,  and 
others  of  an  irritating,  nature.     Castor-oil  is  expressed  from  the  seeds  of  Recinus  corn- 
munis.     Croton-oil   is  obtained  from  the  seeds  of  Croton  Tiglium,  an  Indian   shrub. 
Cascarilla  is  the  bark  of  Croton  Eleuteria,  and  other  species.     The  Box-tree,  Buxus 
sempervirens,  whose  wood  is  used  for  wood- engraving,  belongs  to  this  family — as  does 
the  Cassava,  or  Manioc  plant,   the   starch  of  which  is   used   in  the  form  of  bread. 
From   the   starch  of  the  Bitter  Cassava,  Tapioca  is  prepared.     The  milky  sap  of 
Siphonia  elastica  furnishes  the  bottle  India-rubber.      Aleurites  laccifera  supplies  gum- 
lac;  and  Crozophora  tinctoria,  a  purple  dye  called  Turnsole.     (Figs.  70,  71,  72.) 

166.  UrticaceSB,   NETTLE  WORTS.     Herbs,  shrubs,  or  trees.     The  order  has  been  di- 
vided into   five   sub-orders:—!.   Urticeae,  True  Nettles;  2.  Cannabinae,  Hemp  tribe; 
3.  Ulmaceae,  Elm  tribe;  4.  Moreae,  Mulberry  tribe;  5.  Artocarpeae,  Bread-fruit  tribe. 
These  plants  are  widely  scattered,  most  of  them  are  found  in  temperate  climates;  the 
Mulberry  tribe  in  temperate  and  warm  regions,  and  the  Bread-fruit  tribe  within  the 
tropics.     Tiie  properties  of  the  order  are  various.     Many  yield  valuable  fibres,  others 


12  POPULAR  SKETCH   OF 

edible  fruits,  others  supply  caoutchouc,  and  some  form  important  forest  trees. 
Cannubis  sativa  furnishes  the  valuable  fibre,  Hemp.  Humulus  Lupulus  supplies  the 
Hop.  Several  species  of  Elm  are  cultivated  for  timber.  The  common  Fig  is  the  fruit 
of  Ficus  Carica;  and  many  other  species  of  Ficus  yield  edible  fruits.  The  plants  of 
the  Fig  tribe  are  remarkable  for  the  adventitious  roots  which  they  send  out  from  the 
stems.  Ficus  indica,  the  Banyan  tree,  is  celebrated  in  this  respect.  Ficus  elastica  is 
an,. Indian  tree  which  yields  a  large  quantity  of  caoutchouc,  as  do  also  some  other 
species  of  Ficus.  Morus  alba  is  the  White  Mulberry,  the  leaves  of  which  are  the 
favourite  fruit  of  silk-worms.  Broussonetia  papyrifera  is  the  Paper  Mulbeny, 
which  is  used  in  China  and  Japan  for  making  a  kind  of  paper.  The  dye-wood  called 
Fustic  is  produced  by  Madura  (Broussonetia)  tinctoria.  Artocarpus  incisa,  the  Bread- 
fruit tree,  supplies  an  amylaceous  fruit  which  affords  an  abundant  supply  of  food  in 
tropical  countries.  This  important  order  comprises  between  60  and  70  known  genera, 
and  about  600  species.  (Fies.  73  to  80.) 

167.  Ceratophyllaceae,  HORN  WORTS.    Aquatic  herbs,  found  in  ditches.     1  genus, 
and  6  species.     Properties  unimportant. 

168.  Podostemaceae,  PODOSTEMADS.     Herbaceous  floating  plants,  of  South  America 
and  some  African  islands.   Little  is  known  of  their  properties.   Lindley  gives  9  genera, 
and  25  species. 

169.  Stilaginacese,  ANTIDESMADS.     Trees  or  shrubs,  of  the  East  Indies.     Some 
furnish  edible  fruits.     There  are  3  genera,  and  20  species. 

170.  MonimiaceSB,  MONIMIADS.    Trees  or  shrubs,  of  South  America  and  Australia. 
They  are  fragrant  and  aromatic,  and  some  yield  edible  fruit.    8  genera,  and  40  species. 

171.  Atherospermaceae,   PLUME  NUTMEGS.     Trees,  of   Australia  and  parts  of 
South  America.     Mostly  fragrant.    There  are  3  genera,  and  4  species. 

172.  LacistemaC633,  LACISTEMADS.      Shrubs  or  small  trees,  found  in  the  warm 
parts  of  America.     Properties  unknown.     There  are  2  genera,  and  6  species. 

173.  ChloranthaceSB,  CHLORANTHS.    Herbs  or  undershrubs,  of  the  warm  parts  of 
India  and  America.     Some  are  fragrant  and  aromatic.     3  genera,  and  15  species. 

174.  Sauniiaceae,  SAURURADS.     Marsh  herbs,  of  North  America,  India,  and  China. 
They  have  acrid  properties.     There  are  4  genera,  and  7  species. 

175.  Piperacese,  PEPPER-WORTS.    Shrubs  or  herbs,  natives  of  the  hottest  regions 
of  the  globe.     These  plants  are  pungent,  acrid,  and  aromatic;  some  are  narcotic. 
Most  of  them  contain  an  acrid  resin  and  a  crystalline  matter,  called  Piperin.     The 
Black- pepper  plant  (Fig  81)  is  a  climbing  species  common  in  the  East  Indies.     There 
are  21  known  genera,  and  upwards  of  600  species. 

176.  Amentaceae,  CATKIN-BEARING  TRIBE.     Trees  or  shrubs,  chiefly  natives  of 
temperate  regions.    The  order  has  been  divided  into  seven  sub-orders,  as  follows: 
1.  Salicinese,  the  Willow  Tribe,  found  in  temperate  and  cold  regions;  2.  Myricege,  the 
Gule  Tribe,  found  in  North  and  South  America,  India,  and  at  the  Cape  of  Good  Hope. 
3.  Casuarinese,  the  Beef-wood  Tribe,  Australian  trees  and  shrubs ;  4.  Betulineae,  the 
Birch  tribe,  natives  of  temperate  and  cold  regions;  5.  Balsamaceae,  the  Liquidambar 
tribe,  balsamic  trees  of  warm  regions;  -6.  Platanese,  the  Plane  tribe,  trees  of  temperate 
climates;    7.  Cupiliferse,  the  Nut  tribe,  natives  of  temperate  regions  chiefly.    This 
extensive  Amental  alliance  embraces  18  genera,  and  600  species.    Some  of  its  plants 
yield  resinous  and  balsamic  fluids,  and  the  seeds  of  others  are  used  for  food.    Among 
the  timber  trees  of  this  order  may  be  mentioned  the  Birch,  Alder,  Plane,  Hazel,  Oak, 
Beech,  Spanish  Chesnut,  Poplar,  and  the  Willow.     The  specie  sof  Myrica  are  aromatic, 
and  yield  resinous  and  oily  matter.     Myricia  cerifera,  or  Wax  Myrtle,  yields  a  greenish 
wax,  used  for  candles.     A  resinous  matter,  known  as  Liquid  Storax,  is  obtained  from 
various  species  of  Liquidumbar ;  and  from  the  bark  of  the  common  Birch  is  obtained 
an  oil  which  gives  the  peculiar  odour  to  Russian  leather.    (Figs.  82  to  90  ) 

177.  Juglandaceae,  WALNUTS.    Trees,  natives  chiefly  of  North  America.     There 
are  4  genera,  and  27  species.     These  plants  yield  oily  nuts,  and  the  seeds  of  the 
common  Walnut  supply  a  bland  oil.     The  trees  furnish  a  valuable  timber,  which  is 
hard,  and  susceptible  of  a  high  polish.     (Fig.  91.) 

178.  Garryacese,    GARRYADS.      Shrubs  of  North  America,  remarkable  for  their 
peculiar  silky  catkins.     2  genera,  and  6  species. 

179.  Coniferse,   CONE  BEARING  TRIBE.     Trees  or  shrubs,   of  both  hot  and  cold 
regions.    Some  of  the  genera  are  peculiar  to  the  Southern  hemisphere.    This  extensive 
order  has  been  divided  into  four  sub-orders,  as  follow:—!.  Abietinese,  the  Fir  and 
Spruce  tribe;    2.    Cupressinese,  the  Cypress   tribe;   3.  Taxineae,  the  Yew  tribe;  4. 
Gnetacese,  the  Joint-Fir  tribe.     The  order  comprises  31  genera,  and  about  165  species. 
These  plants  furnish  valuable  timber,  and  yield  various  important  products,  as  tur- 
pentine, pitch,  and  resin.     The  various  kinds  of  Pine,  Fir,  Spruce,  and  Cedar,  belong 
to  this  family.     Turpentine  is  obtained  from  the  Scotch  Fir,  and  different  species  of 
Pine.    Pitch  is  yielded  by  the  Norway  Spruce  Fir.    Balsam  is  procured  from  different 


CONIFER/E. 


CONIFER/C. 


CONIFER/E. 


Fig.  101. 
CEDAB. 

CYCADACE/E. 


Fig.  97. 

WELLINGTONIA  GIGANTEA. 

The  Mammoth  Tree  of  California. 

Height  363/f.,  diameter  31ft. 

Supposed  age  3000  years. 


DIOSCOREACE/E. 


Fig.  102. 
CYPRESS. 

ORCHIDACE/E. 


Fig.  103. 
CYCAS. 


Fig.  104. 
YAM  PLANT. 


Fig.  105. 
ORCHID. 


ZINGIBERACE7E. 


ZINGIBERACE/E. 


MARANTACE/E. 


Fig.  106. 
GINGER  PLANT. 


MUSACE/E. 


Fig.  109. 
BANANA. 

BROMELIACE/E. 


Fig.  107. 

TURMERIC. 


AMARYLIDACE/E. 


Fig.  110. 
AGAVE. 

LILIACE/E. 


Fig.  108. 
ARROW-ROOT. 

BROMELIACE/E. 


Fig.  111. 
PINE- APPLE. 

LILIACE/E. 


Fig.  112. 
MANY-HEADED  PINE. 


Fig.  113. 
ALOES  PLANT. 


Fig.  114. 
DRAGON'S-BLOOD  TREE. 


THE    VEGETABLE    KINGDOM.  13 

species  of  Fir  and  Pine.  To  this  order  belongs  Wellingtonia  gigantea,  the  Mammoth 
tree  of  California,  363  feet  in  height  (about  that  of  St.  Paul's  Cathedral,  London),  and 
having  a  diameter  of  31  feet.  A  portion  of  the  bark  of  one  of  these  trees  is  placed 
round  a  framework  at  the  Crystal  Palace,  Sydenham,  showing  the  enormous  size  of 
this  giant  of  the  vegetable  kingdom.  (Figs.  92  to  102.) 

180.  Cycadaceae,  CTCADS.      Trees    or  shrubs,  in  some  respects  resembling   the 
Palms,  and  in  others  the  Ferns.     These  plants  are  found  in  the  warm  and  temperate 
parts  of  America  and  Asia,  and  at  the  Cape  of  Good  Hope.     There  are  6  genera  and 
45  species.     These  plants  yield  starch  and  mucilaginous  matter,  the  latter  hardening 
into  a  transparent  gum.   Some  species  furnish  sago  and  a  kind  of  arrow-root.  (Fig.  103.) 

ENDOGENS. 

This  great  class  of  plants  is  distinguished  by  the  following  physiological  peculi- 
arities:— 1.  The  wood  is  endogenous — that  is,  increases  by  the  addition  of  new  woody 
matter  in  the  centre  of  the  trunk.  2.  The  leaves  are  straight-veined  (except  in  the 
sub  class,  Dictyogenze),  and  are  not  jointed  to  the  stem;  consequently,  do  not  readily 
fail  off  when  dead.  3.  The  organs  of  fructification  are  ternary.  4.  The  seeds  have 
only  one  cotyledon  or  seed-lobe. 

DICTTOGEN^J. 

Leaves  reticulated.    Ilhizomes  mostly  circular. 

181.  Dioscoreaceae,  YAMS.     Twining  shrubs,  with  large  tubers,  natives  of  tropical 
regions.     There   are  6  genera,  and   lip  species.     Acridity  prevails  in  these  plants, 
although  a  farinaceous  matter  is  found  in  the  tubers  of  some  species.   The  latter,  called 
Yams,  are  used  in  warm  countries  as  a  substitute  for  the  potato.     (Fig.  104.) 

182.  SmilaceSJ,    "ARSAPARILLAS.     Herbs  or  under-shrubs,  often  climbing.     Found 
in  the  temperate  and  tropical  parts  of  Asia  and  America.     There  are  4  or  5  genera, 
and  about  120  species.     These  plants  possess  mucilaginous  and  demulcent  properties. 
The  various  species  of  Smilax  furnish  the  sarsaparilla,  which  is  used  as  a  tonic  and 
alterative. 

183.  Trilliaceae,  PARIDS.     Herbaceous  plants,  with  tubers  or  rhizomes.    Natives  of 
the  temperate  parts  of  Europe,  Asia,  and  America.     Some  are  narcotic,  others  more 
or  less  acrid,  and  some  emetic.    Lindley  mentions  4  genera,  and  30  species. 

PETALOIDE^C. 

Flowers  having  usually  a  Perianth  of  verticillate  leaves,  or  of  a  few  whorled  scales. 
Occasionally  the  Perianth  is  abortive. 

184.  Hydrocharidaceae,  HYDROCHARADS.   Floating  or  aquatic  plants,  found  chiefly 
in  Europe,  Asia,  and  North  America.     Their  properties  are  not  important;  some  are 
mucilaginous  and  astringent.     There  are  12  genera,  and  20  species. 

185.  OrcMdaceae,  ORCHID&    Perennial  herbs  or  shrubs,  with  showy  flowers,  found 
in  most  parts  of  the  world,  and  abounding  in  moist  tropical  regions.    Lindley  enu- 
merates 396  genera,  and  about  3,000  species.     Some  of  these  plants  are  fragrant  and 
aromatic,  others  are  mucilaginous.     (Fig.  105  ) 

186  Zingiberaceae,  GINGER  WORTS.  Tropical  herbs,  with  a  creeping  rhizome  and 
frequently  showy  flowers.  Their  rhizomes  and  seeds  have  aromatic  stimulant  proper- 
ties, and  some  species  yield  starch.  The  rhizome  of  Zingiber  qfficinale  constitutes  the 
Ginger  of  commerce.  Curcuma  longa  furnishes  Turmeric.  Amomum,  Elettaria,  and  some 
other  species,  furnish  Cardamoms  and  Grains  of  Paradise.  Curcuma  auguslifolia  sup- 
plies East  Indian  Arrow-root.  There  are  29  genera  and  247  species.  (Figs.  106,  107.) 

187.  MarantaceaB,  MARANTS.    Herbaceous  plants,  with  tuberous  rhizomes,  similar 
to  the  Ginger  Family,  and  natives  likewise  of  the  tropics.    Lindley  mentions  6  genera, 
and  160  species.   These  plants  contain  starch  in  the  rhizomes  and  roots.  Arrow-root  is 
supplied  by  the  tuberous  rhizome  of  Maranta  arundlnacece  and  M.  indica,  as  well  as 
some  other  species.    (See  Fig.  108.) 

188.  MusaceSB,  MUSADS,  or  BANANAS.     Stemless  or  nearly  stemless  plants,  with 
leaves  sheathing  at  the  base,  and  forming  a  kind  of  spurious  stem.     Natives  of  warm 
and  tropical  regions.    These  plants  furnish  a  large  supply  of  nutritious  fruit,  and  their 
leaves  yield  valuable  fibres.    It  is  said  that  the  same  extent  of  ground  which  in  wheat 
would  only  maintain  two  persons  will  yield  sustenance,  under  the  Banana,  to  fifty. 
Manilla  Hemp  is  the  produce  of  Musa  textihs.     5  genera  and  21  species.     (Fig  109.) 

189.  IridaceSB,  IRIDS.     Herbaceous  plants,  with  rhizomes,  or  under  ground  corms. 
Natives  chit  fly  of  warm  and  temperate  regions,  and  abounding  at  the  Cape  of  Good 
Hope.   There  are  53  genera,  and  550  species.   Some  species  are  fragrant  and  stimulant, 
others  acrid,  and  some  yield  dyes.    The  rhizome  of  Iris  Florentina  furnishes  Orris-root. 
Crocus  sa tivus  supplies  the  dye  Saffron,  which  is  also  obtained  from  some  other  species. 

190.  Burmanniaceae,  BURMANNIADS.    Tropical  herbs,  found  in  moist,  grassy  places. 
Their  properties  are  unimportant.     There  are  10  genera,  and  35  species. 

191.  HaBUlodoraceSB,  BLOOD-ROOTS.    Herbaceous  plants,  with  fibrous  roots.   Found 


14  POPULAR   SKETCH   OF 

in  various  warm  parts  of  the  world.    Lindley  mentions  13  genera,  and  50  species.    The 
roots  of  these  plants  supply  a  red  dye. 

192.  Amaryllidacese,  AMARYLLIDS.     Generally   bulbous   plants,   sometimes    with 
fibrous  roots.     Natives  chiefly  of  the  Cape  of  Good  Hope.     Lindley  notices  68  genera, 
and  400  species,  and  he  divides  them  into  four  sub-orders: — 1.    Amarylleae,  bulbs 
without  a  coronet  in  the  flower.     2.  Narcisseae,  bulbs,  with  a  coronet.     3.  Alstrome- 
riete,  fibrous  rooted,  sepals  different  in  form   from  the  petals.     4.  Agaveae,  fibrous 
rooted,  sepals  and  petals  alike.     The  bulbs  ef  many  of  these  plants  are  poisonous; 
some  are  emetic,  and  others  yield  a  spirit,     The  tough  fibres  of  some  species,  as  the 
American  Aloe  (Fig.  110),  are  used  for  flax.    The  juice  of  this  plant  yields  also  an 
intoxicating  drink. 

193.  Ilypoxidacese,  HYPOXIDS.    Herbaceous  and  frequently  stemless  plants,  with 
tuberous  and  fibrous  roots.     Natives  of  warm   countries.     Some  have  bitter  roots, 
others  have  edible  tubers.     Lindley  mentions  4  genera,  and  60  species. 

194.  BromeliaceaB,  BROMEL-WORTS  or  PINE- APPLES.    Stemless  or  short- stemmed 
plants  of  the  warm  parts  of  America  chiefly.     These  plants  are  more  or  less  epiphytic, 
that  is,  are  able  to  grow  without  any  direct  attachment  to  the  soil.     The  fruit  of 
Ananassa  is  the  Pine-apple  or  Ananus,  well  known  for  its  sweetness  and  fine  flavour. 
In  its  wild  state,  however,  it  is  excessively  acid  (Figs  111  and  112).     There  are  23 
genera,  and  170  species. 

195.  Liliacese,  LILY-WORTS.    Herbaceous  plants,  shrubs,  or  trees,  with  bulbs,  tubers, 
rhizomes  or  fibrous  roots.     They  are  found  both  in  temperate  and  tropical  countries. 
There  are,  according  to  Lindley,  133  genera,  and  1.200  species.     He  divides  the  order 
into  twelve  sub-orders,  as  follows :— 1.  Tulipeae,  Tulip  tribe;  2.  Herrnerocallidea?,  or  Day- 
lily  tribe;  3.  Aloinea3,  or  Aloes;  4.  Scillese,  or  Squills;  5.  Conantherea?;  6.  Anthericeas; 
7.  Aphyllan these;  8.  Wachendorflfeae;  9.  Asparageas;  10.  Aspidistreas;  11.  Ophiopogcneae; 
12.  Convallarieas.     Many  of  these  plants  are  showy  garden  flowers,  as  Tulips,  Lilies, 
&c.;  others  are  used  medicinally,  as  Squill,  Aloes,  &c.     Some  yield  valuable  fibres,  as 
Phormium  tenax,  New  Zealand  Flax.     Drucccna  Daruco,  and  other  species,  supply  n 
resinous  matter  called  Dragon's-blood.  Xanthorrcea  hastilis,  the  Grass-tree  of  Australia, 
which  gives  a  peculiar  feature  to  the  vegetation  of  that  region,  yields  a  yellow  gum. 
The  base  of  the  inner  leaves  of  some  Grass-trees  is  also  used  as  food.    (Figs.  113, 
114,  and  115). 

196.  MelanthaC68B,  MELANTHS,  or  COLCHICUMS.    Bulbous,  tuberous,  or  fibrous- 
rooted  plants,  extremely  variable  in  appearance.    Found  in  various  parts  of  the  world, 
but  most  abundant  in  northern  countries.  There  are  30  known  genera,  and  130  species. 
These  plants  are  mostly  poisonous;  some,  however,  have  valuable  medicinal  qualities, 
and  are  employed  in  the  cure  of  gout  and  rheumatism. 

197.  Gilliesiaceae,  GILLIESIADS.    Herbaceous  plants,  with  bulbs.    Natives  of  Chili. 
Their  properties  are  unknown.     There  are  2  genera,  and  5  species. 

198.  Pontederiaceae.  PONTEDERADS.     Aquatic  or  marsh  plants,  without  important 
properties.    They  are  Ibund  in  America,  the  East  Indies,  and  Africa.     6  genera,  and 
30  species. 

199.  Xyridacese,  XYRIDS.    Herbaceous,  sedgy  plants,  with  fibrous  roots.    Natives 
chiefly  of  tropical  countries,  and  without  important  properties.   6  genera,  and  70  species. 

200.  Juncacese,  BUSHES.    Herbaceous  plants,  of  the  colder  regions  of  the  globe. 
Many  species  are  used  in  the  manufacture  of  mats,  bottoms  of  chairs,  &c.    There  are 
14  genera,  and  200  species. 

201.  Palmse,   PALMS.     Arborescent  plants,  with  simple,  rarely -branched  trunks, 
marked  with  the  scars  of  the  leaves.    Natives  of  the  tropics  chiefly,  and  imparting 
to  them  much  of  their  botanical  physiognomy.     "  The  race  of  plants  to  which  the 
name  of  Palms  has  been  assigned  is,  no  doubt,"  says  Dr.  Lindley,  "  the  most  interest- 
ing in  the  vegetable  kingdom,  if  we  consider  the  majestic  aspect  of  their  towering 
stems,  crowned  by  a  still  more  gigantic  foliage;  the  character  of  grandeur  which 
they  impress  upon  the  landscape  of  the  countries  they  inhabit,  their  immense  value 
to  mankind,  as  affording  food  and  raiment,  and  numerous  objects  of  economical  im- 
portance; or,  finally,  the  prodigious  development  of  those  organs  by  which  their  race 
is  to  be  propagated."    There  are  73  known  genera,  and  400  species,  but  the  numbers 
are  probably  much  greater.     They  have  been  divided  into  the  following  tribes: — 
1.  Arecinea3,  the  Betel-nut  tribe;  2.  Lepidocaryinae,  the  Sago  tribe;  3   Borassina?,  the 
Palmyra  tribe;  4.  Coryphinaa,  the  Talipot  and  Date  tribe;  5.  Coccinae,  the  Cocoa-nut 
tribe.     The  properties  of  these  plants  are  very  various.     In  the  countries  where  they 
grow  they  supply  food,  and  are  used  for  forming  habitations.     Many  supply  oil,  wax, 
starchy  matter,  and  sugar,  which,  fermented,  forms  an  intoxicating  beverage.     Their 
fibres  also  furnish  materials  for  ropes,  cordage,   and   weaving.      Some   species  of 
Calamus  furnish  canes  more  than  500  feet  in  length,  which  are  used  as  cables.     Tliytde- 
phas  macrccarpa,tlie  Ivory  Palm,  supplies  a  hard  white  substance  called  Vegetable 


LILIACE/E. 


PALM/E. 


PALM/E. 


Fig.  115. 
AUSTRALIAN  GRASS  TREE. 

PALM/E. 


Fig.  118. 
WAX  PALM. 

PALM/E. 


Fig.  116. 
COCOA-NUT  PALM. 

PALM/E. 


Fig.  119. 
OIL  PALM. 


PALM/E. 


Fig.  117. 
DATE  PALM. 

PALM/E. 


Fig.  120. 
SAGO  PALM. 

PALM/E. 


Fig.  121. 
MAURITIA  PALM. 


Fig.  122. 
PALMYRA  PALM. 


Fig.  123. 
DWARF  FAN  PALM, 


PALMXE. 


PALMXE. 


PANDANACEXE. 


Fig.  124. 
IVORY  PALM. 


Fig.  125. 
DOOM  PALM. 


Fig.  126. 
SCREW  PINE. 


ARACEXE. 


GRAM  IN  EXE. 


GRAM  IN  EXE. 


Fig.  127. 
ARUM. 


Fig.  128. 
WHEAT  AND  BARLEY. 


Fig.  129. 
OATS. 


GRAM  IN  EXE. 


GRAM  IN  EXE. 


GRAM  IN  EXE. 


Fig.  130. 
RYE  AND  MILLET. 


Fig.  131. 
RICE. 


Fig.  132. 
MAIZE,  OR  INDIAN  CORN. 


THE    VEGETABLE   KINGDOM.  15 

Ivory.  The  Date  Palm  furnishes  food  to  the  tribes  of  the  Desert,  and  the  Doom  Palm 
of  Egypt  is  called  the  Gingerbread  Tree,  from  the  resemblance  of  its  mealy  rind  to 
that  article.  Palm  oil  is  obtained  chiefly  from  Elais  guineensis,  and  melanococca,  and 
these  trees  are  also  said  to  yield  the  best  Palm  wine.  The  Ceroxylon  andicola,  or  Wax 
Palm  of  Humboldt,  has  its  trunk  covered  with  a  coating  of  wax,  which  exudes  from 
the  spaces  between  the  insertion  of  the  leaves.  (See  Figs.  116  to  125.) 

202.  Cominelynaceae,  SPIDER- WORTS.    Herbaceous  plants  of  warm  climates.   Some 
have  fleshy  rhizomes,  containing  a  starchy  matter,  which  is  used  for  food.    There  are 
17  genera,  and  264  species. 

203.  Alismaceas,  ALISMADS.    Aquatic  plants,  natives  both  of  tropical  and  tempe- 
rate climates.  Their  properties  are  unimportant.  There  are  5  genera  and  about  70  species. 

204.  ButomaceJB,  BUTOMADS,  or  FLOWERING- RUSHES.     Aquatic  plants,  often  lac- 
tescent.   Found  chiefly  in  marshes  of  northern  countries.    Some  of  them  have  bitter 
and  acrid  properties.    Lindley  mentions  4  genera,  and  7  species. 

205.  Pandanaceae,  SCREW-PINES.    Trees  or  bushes,  sometimes  sending  down  aerial 
roots.    Natives  of  tropical  regions,  and  common  in  the  islands  of  the  Indian  Archi- 
pelago.   There  are  7  genera  and  75  species.    Their  flowers  are  generally  fragrant,  and 
their  seeds  are  used  as  food.    The  roots  of  these  remarkable  trees  are  sent  down  from 
all  parts  of  their  stems,  and  appear  like  artificial  props.     (Fig.  126.) 

206.  Araceae,  ARUMS.     Herbaceous  or  shrubby  plants,  sometimes  with  tubers  or 
creeping  rhizomes.     They  occur  in  various  parts  of  the  world,  abounding  in  the  tropics. 
These  plants  have  been  arranged  in  four  orders,  as  follows:— 1.  Arineae,  Cuckoo-pint 
tribe.     2.  Typhinese,  Bulrush  tribe.    3.  Acoreae,  Sweet- flag  tribe.    4.  Pistieae,  Duck- 
weed tribe.     The  order  includes  47  genera  and  273  species.     Their  general  property 
is  acridity,  and  some  of  the  plants  are  dangerous  poisons.    The  rhizomes  of  some 
species  yield  starchy  matter,  and  when  boiled  or  roasted  are  used  as  food.    Some  of 
these  plants  send  out  aerial  roots,  by  means  of  which  they  climb  upon  trees.  (Fig.  127.) 

207.  Naiadacese,  NAIADS,  or  PONDWEEDS.  Water  plants  of  both  the  ocean  and  fresh 
water.    They  are  found  in  various  parts  of  the  world,  but  have  no  properties  of  import- 
ance.    There  are  19  known  genera,  and  upwards  of  70  species. 

208.  RestiaceSB,  RESTIADS,  or  CORD-RUSHES.    Herbaceous  plants  or  under-shrubs. 
They  are    found  chiefly  in  America  and  Australia,  and  are  without  important  pro- 
perties.   The  tough,  wiry  stems  of  some  species  are  used  for  making  baskets  and 
brooms.    There  are  36  genera,  and  286  species. 

209  Cyperaceae,  SEDGES.  Grass-like  herbs  growing  in  tufts,  with  solid  stems, 
sometimes  creeping,  often  angular,  and  without  joints.  They  are  found  in  all  quarters 
of  the  globe,  and  at  all  elevations;  many  species  occur  in  marshy  ground.  Lindley 
mentions  112  ge'nera,  and  2,000  species.  This  order  includes  the  Papyrus  of  the  Nile, 
the  plant  anciently  used  in  the  manufacture  of  paper.  Some  species  of  Cyperus  have 
tubers  which  are  used  as  food,  and  the  roots  of  others  have  been  employed  as  bitter 
tonics.  The  stems  of  some  are  used  for  chair  bottoms. 

210.  Gramine33,  GRASSES.     Herbaceous  plants,  with  cylindrical,  hollow,  and  jointed 
stems,  called  culms.     The  grasses  are  found  in  all  parts  of  the  world,  and  are  said  to 
form  about  one  twenty-second  part  of  all  known  plants.    In  tropical  regions  they 
frequently  occur  as  trees.     Lindley  enumerates  291  genera,  including  about  3,800 
species.    To  the  section  of  grasses  supplying  food  for  man  belong  the  nutritious  cereal 
grains,  as  Wheat,  Oats,  Barley,  Eye,  Rice,  Maize,  Millet,  &c.     Sugar  is  also  obtained 
from  many  grasses,  known  as  sugar  canes.     To  the  herbage  grasses,  affording  food  for 
animals,  belong  the  various  pasture  grasses,  as  Rye  grass,  Meadow  grass,  &c.     In  the 
warmer  parts  of  the  world,  the  fodder  grasses  attain  the  height  of  five  or  six  feet,  but 
are  yet  sufficiently  tender  to  be  used  as  animal  food.  *(Figs.  128  to  133.) 

211.  Rhizantlieae,  RIIIZANTHS,  or   RHIZOGENS.     Leafless,  scaly,  parasitic  plants, 
having  a  fungus-like  appearance,  and  of  a  brown  yellow  or  purple  colour.  These  plants 
are  frequently  stemleas,  but  have  sometimes  a  creeping  rhizome.     They  are  found 
chiefly  in  tropical  climates,  and  are  employed  as  styptics.     There  are  21  genera,  and 
53  species.  To  this  order  belong  the  species  of  Rafflesia,  gigantic  parasites,  the  perianth 
of  which  is  frequently  three  feet  in  diameter.    (Fig.  134). 

CRYPTOGAMOUS,  OR  CELLULAR  FLOWERLESS  PLANTS. 
ACROGENS. 

The  most  simple  form  of  plants;  their  structure  mostly  entirely  cellular;  their 
propagation  effected  by  means  of  spores. 

ACROGEN2E. 

Having  usually  distinct  stems,  leaves,  stomata,  some  vascular  tissue,  and  thecse  or 

spore  cases. 

212.  Equisetacese,  HORSE-TAILS.    Leafless  branched  plants,  with  a  striated  fistular 


16  POPULAR   SKETCH   OF   THE   VEGETABLE   KINGDOM. 

stem,  in  the  cuticle  of  which  silex  is  secreted.  Found  in  rivers,  ditches,  &c.,  in  various 
parts  of  the  world.  They  are  sometimes  used  for  polishing  furniture,  &c.  Lindley 
mentions  1  genus,  and  10  species.  (Fig.  135.) 

213.  .Filices,    FERNS.     Elegant  leafy  plants,   occurring  chiefly  in   moist,  insular 
climates,  and  abounding  in  the  tropical  islands.     In  warm  countries  they  occur  as 
Tree-ferns,  fifty  or  sixty  feet  in  height.     The  properties  of  the  Ferns  are  in  general 
demulcent  and  astringent.     The  rhizomes  of  some  are  used  as  food,  and  others  supply 
tanning  material.    The  syrup  called  Capillaire  is  prepared  from  some  species.   Liudley 
notices  192  genera,  and  upwards  of  2,000  species.     (Fig.  136). 

214.  MarsileaceSB,  PEPPER-WORTS.     Stemless  plants,  creeping  or  floating,  found  in 
ditches  and  pools.    They  are  not  put  to  any  important  use.    There  are  4  genera,  and 
upwards  of  20  species. 

215.  LyCOpodiaceSB,   CLUB-MOSSES.     Moss-like  plants,  with  creeping  stems,  and 
imbricated  leaves,  intermediate  between  Ferns  and  Mosses.     They  abound  in  moist, 
warm,  insular  climates.     These  plants  have,  in  their  spore  cases,  an   inflammable 
powder,  called  vegetable  brimstone,  which  is  employed  on  the  Continent  in  the  manu- 
facture of  fire-works,  and  in  pharmacy  to  roll  up  pills  to  render  them  impervious  to 
damp.     There  are  6  genera,  and  200  species.     (Fig.  137). 

216.  MllSCi,  MOSSES.     Erect,  creeping,  terrestrial,  or  aquatic  plants,  found  in  all 
moist  regions,  and  abounding  in  temperate  climates.    There  are,  according  to  Lindley, 
46  known  genera,  and  1,100  species. 

217.  HepaticSB,    LIVERWORTS      Plants  growing  on  the  earth   or  trees  in  damp 
places.    They  are  generally  distributed  over  the  globe,  both  in  cold  and  warm  climates. 
There  are  65  genera,  and  about  700  species. 

THALOGEN.ZE,  Of   CELLULARES. 

Structure  entirely  cellular,  without  distinct  stems,  leaves,  or  stomata. 

218.  LiclieneS,  LICHENS.    Plants  often  spreading  over  the  surface  of  the  earth,  or 
rocks,  or  trees,  in  dry  places,  as  a  foliaceous,  hard,  or  leprous  substance,  called  a 
thallu?.     They  are  found  in  all  parts  of  the  world,  and  seem  to  derive  their  nourish- 
ment principally  from  the  atmosphere.    Lichens  furnish  articles  of  food  and  important 
dyes;  among  the  former  class  is  the  substance  known  as  Iceland  Moss.      Cladonia 
rangiferina  is  a  Lichen  upon  which  the  Reindeer  feeds.     The  valuable  dyes,  Orchil, 
Cudbear,  and  Parietin,  are  obtained  from   different  species  of  Lichens  (Fig.  138). 
Lindley  gives  58  genera,  and  2,400  species. 

219.  Fungi,  MUSHROOMS.    Cellular  plants,  variable  in  their  consistence,  soft  or 
hard,  fibrous  or  gelatinous,   fleshy  or  leathery.     Found  in  all  parts  of  the  world. 
There  are,  according  to  Berkeley,  598  genern,  and  4,000  species.    Some  species  are 
edible,  as  the  common  Mushroom,  Morel,  and  Truffle;  others  are  poisonous;  and  some 
very  destructive,  from  their  parasitical  growth.     Some  Fungi  are  limited  to  certain 
kinds  of  decaying  matter;   thus  peculiar  species  are   developed  in  vinegar,  yeast, 
flour,  &c.     The  rapidity  of  their  growth  is  also  remarkable.    Blight,  mildew,  rust, 
and  smut,  are  diseases  in  grain  due  to  the  attacks  of  Fungi,  as  is  also  dry-rot  in 
timber.    (Fig.  139.) 

220.  AlgSJ,  SEA- WEEDS.  Cellular  plants  found  in  salt  and  fresh  water,  and  in  moist 
places,  as  on  damp  rocks,  the  glass  and  pots  of  hothouses,  and  in  hot  springs.  These 
plants  have  been  arranged  into  five  divisions,  as  follows: — 1.  Characeae,  water  plants 
formed  of  parallel  tubes,  sometimes  encrusted  with  carbonate  of  lime.  2.  Fucaceae,  the 
Sea- wrack  tribe,  usually  growing  in  salt  water.  3.  Floridese,  rose  or  purple- coloured 
sea-weeds,  with  fronds.  4.  Confervacese,  aquatic  plants,  consisting  of  one  or  more 
cells  united  so  as  to  form  an  articulated  or  flat  frond.  5.  Diatomaceae,  crystalline, 
angular,  fragmentary,  and  brittle  fronds,  united  by  a  gelatinous  substance.  Found  in 
still  waters  and  moist  places.  Lindley  enumerates  283  genera,  and  2,000  species. 
Some  of  the  species  are  very  gigantic,  others  exceedingly  minute,  requiring  a  micro- 
scope for  their  detection.  The  lowest  members  of  the  order  approach  so  nearly  the 
lowest  tribes  of  animals,  that  it  is  difficult  to  draw  a  line  of  demarcation.  Some 
species  are  said  to  occur  in  red  and  green  snow,  and  the  red  and  green  colours  of  certain 
lakes  and  seas  are  attributed  to  these  plants.  A  quantity  of  gelatinous  matter  is  ob- 
tained from  these  plants,  and  some  of  them  are  used  for  food,  as  Carrajeen  or  Irish 
Moss  (Fig.  140),  Dulse,  Tangle,  Laver,  &c.  Kelp  is  obtained  by  the  burning  of  Sea- 
weeds, and  Iodine  is  also  procured  from  them. 


For  details  of  the  structure  and  physiology  of  plants,  see  "  STEWART'S  SYNOPSIS  OF  STRUCTURAL 
AND  PHYSIOLOGICAL  BOTANY,"  with  84  Engravings.  Price  Is.  plain ;  2s.  coloured.  Pub- 
lished by  JAMES  REYNOLDS,  174,  Strand. 


. 


LAWS  OF  MATTER    &  MOTION 

*  c>        8 


LAWS  OF  MATTER  AND  MOTION. 

As  no  branch  of  science  can  be  understood  without  some  previous  knowledge 
of  the  general  properties  of  matter,  it  will  be  desirable  to  commence  by  shortly 
describing  them  : — 

Extension  is  tne  bulk  of  a  body,  its  length,  breadth,  and  thickness. 

Impenetrability  is  that  property  by  which  two  bodies  cannot  at  the  same 
time  occupy  one  and  the  same  place.  If  a  nail  be  driven  into  a  blocK  of  wood 
it  displaces  the  particles,  but  does  not  become  incorporated  with  them  (fig.  1). 
If  in  a  full  glass  of  water  a  stone  be  placed,  the  water  will  be  forced  over  to 
make  way  for  the  stone  (fig.  2).  If  we  endeavour  to  fill  a  phial  by  plungiug 
it  into  water,  the  air  will  rush  out  of  the-%phial  to  make  way  for  the  water 
(fig.  3). 

Divisibility  denotes  the  property  by  which  a  body  is  susceptible  of  being 
subdivided  into  an  indefinite  number  of  parts.  Animalculse  have  been  found  so 
small  that  a  grain  of  sand  will  cover  300,000  of  them,  each  one  having  a  perfect 
organization  ;  fig.  4  represents  the  forms  of  some  highly  magnified. 

Porosity  arises  from  the  influence  which  heat  exercises  in  separating  the 
particles  of  matter.  The  piece  of  iron  B,  fig.  6,  when  cold,  will  exactly  fit 
into  the  hole  and  notch  of  A  ;  but  if  heated  it  will  do  neither.  Fig.  7  repre- 
sents the  action  of  heat  in  expanding  and  setting  in  motion  the  particles  of 
water. 

Inertia  or  Persistence  is  the  tendency  of  matter  to  preserve  its  present 
state,  whether  of  rest  or  motion,  unchanged.  Fig.  8  illustrates  the  first :  if  the 
card  be  struck  away  the  coin  will  remain  balanced  on  the  finger:  fig.  9  illustrates 
the  second :  a  body  in  motion  has  a  tendency  to  proceed  in  a  straight  line  ;  but 
the  hare  being  pursued  by  a  dog,  turns  quickly,  and  the  latter  is  irresistibly 
thrown  out  of  its  track  and  compelled  to  take  a  wider  turn,  thus  affording  the 
hare  the  only  chance  of  escape. 

Cohesion  is  the  force  by  which  the  atoms  of  a  body  are  held  together  in  one 
solid  mass.  It  is  greater  in  some  bodies  than  in  others,  the  solidity  or  weight  of 
the  body  corresponding  to  the  cohesive  attraction.  It  is  this  po.wer  which  holds 
the  drop  of  water  suspended  at  the  end  of  the  finger,  and  keeps  its  minute 
watery  particles  united  (fig.  10).  Capillary  attraction  1S  another  effect  of 
this  power  which  enables  liquids  to  rise  above  their  level  in  minu-te  tubes  (fig  .11) 
Sap  ascends  in  plants  by  the  same  force  (fig.  12). 

Gravitation  is  that  force  which  causes  all  bodies  on  or  near  the  earth  to  tend 
towards  its  centre  with  a  force  proportioned  to  their  respective  quantities  of 
matter  (fig.  13).  All  bodies  attract  each  other  inversely  as  the  squares  of  the 
distances.  All  influences  emanating  from  a  central  point  follow  the  same  law. 
Fig.  14  illustrates  the  law  in  reference  to  light.  At  a  certain  distance  the  rays 
illuminate  the  space  A  B  ;  at  twice  that  distance  they  are  spread  over  c  D.  four 
times  the  former  space,  but  with  four  times  less  intensity ;  at  three  times  the 
distance  they  illuminate  the  space  E  F  with  nine  times  less  intensity,  and  so  on. 
All  bodies  possess  gravity  or  weight ;  there  is  no  such  thing  as  perfect  lightness. 
Smoke  ascends  only  because  it  is  lighter  than  the  atmosphere  (fig.  15).  The 
force  of  gravity  at  the  surface  of  the  earth  is  such  that  in  the  first  second  of  time, 
it  gives  to  a  body  allowed  to  fall,  a  velocity  of  16  feet ;  in  the  next  second  48 
feet ;  in  the  third  second  80  feet.  Fig.  16  shows  the  rate  at  which  bodies  fall ; 
each  of  the  triangular  portions  representing  16  feet,  the  figures  on  the  right,  the 
seconds. 

THE  CENTRE  OF  GEAVITY. 

The  centre  of  gravity  in  a  body  is  that  about  which  all  its  other  parts  equally 
balance  each  other.  Figs.  17  to  21  show  the  position  of  the  centre  of  gravity  in 
bodies  of  different  forms.  The  stability  of  a  body  resting  on  the  ground  depends 
greatly  upon  the  centre  of  gravity.  The  body  will  stand  provided  a  vertical  line 
drawn  from  the  centre  of  gravity  falls  within  the  base  (figs.  22,  24).  The  mass  of 
rock  (fig.  23)  will  fall  because  the  vertical  line  falls  beyond  the  base.  Bodies 
having  a  narrow  base  are  easily  upset,  for  if  they  are  the  least  inclined  their 
centre  is  no  longer  supported,  as  seen  in  fig.  25.  Rope  dancers  are  provided 
with  a  pole,  loaded  at  the  ends,  for  the  purpose  of  bringing  their  centre  of  gravity 
vertically  over  the  rope  (fig.  26). 


LAWS  OF  MATTER  AND  MOTION. 
THE  PENDULUM. 

This  body,  represented  at  fig.  27,  depends  for  its  motion  upon  the  forces  of 
gravitation  and  persistence.  The  longer  the  pendulum  the  slower  are  its  vibra- 
tions, and.  as  the  length  is  affected  by  temperature,  various  contrivances  have 
been,  resorted  to  to  correct  this  expansion  and  contraction ;  these  are  termed 
compensation  pendulums  (figs.  28,  29).  Fig.  30  represents  the  balance  wheel  of 
a  watch,  with  a  spring,  which  is  expanded  or  contracted  by  the  lever  c,  producing 
a  corresponding  effect  on  the  movement  of  the  watch. 

CENTRAL  FORCES. 

These  are  of  two  kinds,  centripetal,  or  the  force  of  gravity,  tending  towards 
the  centre  ;  and  centrifugal,  flying  from  it.  The  first  may  be  illustrated  by  a 
whirlpool  at  sea,  or  a  whirlwind  on  land  (figs.  31  and  32).  Centrifugal  force 
may  be  illustrated  in  a  variety  of  ways.  If  we  whirl  rapidly  a  sling  with  a  stone 
in  it,  and  suddenly  set  free  the  stone,  it  will  proceed  in  a  straight  line  (fig.  33). 
In  turning  rapidly  a  circular  grindstone  in  contact  with  water,  the  latter  will  fly 
off  at  right  angles  (fig.  34).  A  practical  application  of  this  power  is  seen  in  the 
governor-balls  of  a  steam  engine  (fig.  35).  By  any  increase  in  the  velocity  in 
the  engine,  the  balls  are  thrown  apart,  and  the  levers  draw  down  the  collar,  D, 
and  with  it  the  end  of  the  lever,  F,  which  thus  partially  closes  the  throttle-valve 
of  the  steam  pipe. 

The  centripetal  and  centrifugal  forces  are  sublimely  exemplified  in  the  motions 
of  the  planetary  bodies  ;  the  former  in  their  attraction  towards  the  central  lumi- 
nary by  gravitation  ;  and  the  latter  in  their  tendency  to  proceed  in  e  straight 
line  by  the  force  of  persistence. 

The  velocity  of  revolving  bodies  increases  in  proportion  to  the  distance  from 
-*•*/  the  centre  of  motion.  The  extremities  of  the  vanes  of  the  windmill  move  over 
a  much  greater  space  than  the  parts  near  the  axis,  yet  describe  the  circle  in  the 
same  space  of  time  (fig.  36).  In  like  manner,  as  our  globe  turns  on  its  axis, 
those  parts  nearer  the  poles  describe  smaller  circles  than  those  more  remote  -, 
the  equatorial  regions  describing  the  largest  circles  of  all,  hence,  it  follows,  that 
the  equatorial  regions  move  at  a  far  greater  velocity  than  the  regions  near  the 
poles  (fig.  37). 

LAWS  OF  MOTION, 

A  body  projected  by  a  single  force  naturally  proceeds  in  the  direction  of  that 
force  ;  but  if  in  its  progress  a  new  force  acts  upon  it,  it  will  then  be  sent  in  a 
new  direction.  Thus,  a  ball  projected  in  the  line  ABC  (fig.  38),  strikes  obliquely 
the  ledge  at  c,  there  meeting  an  obstacle  to  its  progress,  which  acts  as  a  new 
force,  it  is  caused  to  rebound  in  the  direction  ODE,  making  the  same  angle 
with  the  ledge  as  did  the  original  path  of  the  ball  A  B  c.  This  effect  is  com 
monly  expressed  by  saying  that  the  angle  of  incidence  is.  equal  to  the  angle  of 
reflection,  the  former  meaning  the  angle  ABC,  and  the  latter  e  D  E  ;  and  this 
is  a  law  that  applies  equally  to  the  motions  of  sound,  heat,  and  light ;  and 
therefore,  is  of  the  utmost  importance  throughout  physics.  If  two  or  more 
forces  act  upon  a  body  at  certain  angles,  a  single  force  may  be  found  which  would 
produce  the  same  effect.  This  single  force  is  called  the  resultant  or  equivalent. 
In  fig.  39  we  have  an  example  of  this  :  a  ball  receiving  a  blow  in  the  direction 
A  B,  and  at  the  same  time  a  blow  of  equal  force  in  the  direction  A  D,  does  not 
pursue  either  of  those  directions,  but  takes  a  diagonal  course  between  them  to  c. 
The  effect  being  the  same  as  if  the  ball  had  been  sent  in  the  direction  A  c,  by  a 
single  force. 

The  process  of  finding  a  single  fo*ee^quivalent  to  two  or  more  forces  is  called 
whe  composition  of  forces,  and  the^orcss  of  finding  forces  which  will  produce  a 
motion  equal  to  that  of  a  single  force,  is  called  the  resolution  of  forces.     In  fig. 
40,  this  is  illustrated  in  reference  to  the  action  of  the  wind  upon  the  sail  of  a 
ship,  and  of  the  tide  upon  the  helm.     Let  A  B  represent  the  direction  of  the 
wind  acting  upon  the  sail  E  F,  placed  obliquely  to  it,  then,  by  drawing  A  c  per- 
pendicular to  F  E,  and  by  completing  the  parallellogram  D  c;  the  diagonal  A  B  is 
resolvable  into  the  adjacent  sides  A  c  and  A  D  ;  now,  A  c  being  at  right  angles  to 
E  F,  will  have  the  effect  of  propelling  the  yessel,  although  not  in  a  straight  line;  but 
it  may  be  guided  in  the  desired  direction  by  means  of  the  helm,  upon  which  the 
water  re-acts  by  the  progressive  motioa  of  the  vessel 


MECHANICAL  POWERS 


MECI1MICAL  POWERS. 

THE  mechanical  powers  are  essentially  but  two  in 'number,  but  are  usually 
considered  as  six  ;  namely,  the  Lever,  the  Wheel  and  Axle,  the  Pulley,  the  In- 
clined Plane,  the  Wedge,  and  the  Screw.  The  three  first  are  assemblages  of 
levers,  and  the  three  last  inclined  planes.  One  or  more  of  these  powers  enters 
into  the  composition  of  every  machine. 

Ths  LsVSI  consists  of  an  inflexible  rod  or  bar,  resting  on  a  support  called 
a  fulcrum,  for  the  purpose  of  raising,  by  a  power  applied  at  one  end,  a  weight  at 
the  other.  The  advantage  gained  is  in  proportion  to  the  greater  distance  of  the 
power  from  the  fulcrum,  than  is  the  distance  from  the  fulcrum  to  the  weight  to 
be  raised  ;  thus,  if  the  distance  from  the  power  to  the  fulcrum  be  five  times 
greater  than  the  distance  from  the  weight  to  the  fulcrum,  a  force  of  one  pound 
in  the  power  will  balance  five  in  the  weight. 

There  are  three  kinds  of  levers  ;  the  first  kind  is  that  where  the  fulcrum 
(F)  is  placed  between  the  ws  ight  (w)  and  the  power,  (p,  fig.  1).  The  com- 
mon balance,  (fig.  2)  is  a  lever  of  the  first  kind,  as  is  also  the  Roman  steel- 
yard, (fig.  3). 

The  boy'-s  amusement  of  see-saw  (fig.  4)  is  another  illustration  of  a  lever  of 
the.  first  kind,  the  bigger  boy  taking  the  shorter  end  of  the  plank,  that  his  lighter 
companion  at  the  longer  end  may  balance  him. 

Fig.  5,  shows  the  application  of  a  lever  of  the  first  kind  in  moving  a  heavy 
body  ;  the  nearer  the  fulcrum  to  the  body  to  be  moved  the  more  powerful 
being  the  leverage. 

In  levers  of  the  second  kind,  the  weight  is  situated  between  the  power  and 
the  fulcrum,  (fig.  6).  This  kind  of  lever  is  seen  in  the  common  wheelbarrow, 
where  the  wheel  is  the  fulcrum,  the  load  in  the  barrow  the  weight,  and  the 
power  the  man  who  holds  up  the  shafts.  The  oars  of  a  boat  present  another 
instance  ;  here  the  water  is  the  fulcrum  against  which  the  blades  of  the  oars 
press. 

Levers  of  the  third  kind  are  those  where  the  fulcrum  is  at  one  end,  the  weight 
at  the  other,  and  the  power  between  them,  (fig.  7).  Here  the  power  acts  with  a 
considerable  disadvantage,  and  this  kind  of  lever  is  only  used  where  the  object  is 
to  produce  great  velocity,  and  which  can  only  be  effected  by  an  expenditure  of 
power.  The  footboard  of  a  common  turning  lathe  affords  an  example  of  this 
kind  of  lever.  But  one  of  the  most  striking  instances  of  it  is  seen,  in  the  human 
irm  in  the  act  of  raising  a  weight  in  the  halul,  when  the  lower  part  of  the  arm 
becomes  a  lever  of  the  third  kind,  the  elbow  joint  being  the  fulcrum,  and  the 
muscles  which  move  the  arm,  the  power  (fig.  8).  The  muscle,  by  contracting 
its  fibres  less  than  an  inch,  raises  the  hand  twenty  inches  ;  and  if  it  raises  also  a 
weight  of  twenty-five  pounds  in  the  hand,  it  must  act  with  a  force  at  least  twenty 
times  as  intense,  or  of  five  hundred  pounds  ;  thus  showing  the  extraordinary 
strength  of  the  living  muscle. 

Levers  may  be  combined  in  a  great  variety  of  ways,  and  the  aggregate  effect  of 
such  combination  is  as  the  product  of  the  effect  of  thcj  separate  levers.  Fig.  9, 
represents  a  combination  of  levers  of  the  first  kind,  in  which  the  power  of  i^ie 
small  weight  P  brings  down  A,  which  raises  B,  bringing  down  c,  and  conse- 
quently raising  D  ;  and  thus,  if  properly  supported,  will  balance  the  large  weight 
w.  By  this  means  a  weight  of  one  pound  will  balance  one  of  a  hundred  and 
twenty  pounds. 

The  Wheel  and  Axle  maJ  be  considered  as  a  kind  of  perpetual  lever,  of 
which  the  fulcrum  is  the  centre  of  the  axis,  and  the  long  and  short  arms  the 
radius  of  the  wheel  and  the  radius  of  the  axle,  as  shown  at  fig.  10  ;  the  power  P 
acting  upon  the  weigh*  w,  through  the  intervention  of  the  lever  A  B,  whose 
fulcrum  is  the  centre  of  the  axle.  Supposing  the  semi-diameter  of  the  wheel 
to  be  six  times  greater  than  the  semi-diameter  of  the  axle,  a  power  of  one 
will  balance  a  weight  of  six,  exactly  upon  the  principle  of  a  lever  of  the  first 
kind. 

There  are  many  modifications  of  this  mechanical  power  ;  one  of  the  most  com- 
mon is  the  windlass  for  raising  water  from  a  well  by  means  of  buckets,  (fig.  11). 
The  capstan  used  on  board  ships  is  an  upright  axle,  the  moveable  bars  or 
levers  acting  as  the  wheel  (fig.  12).  Like  the  lever,  the  wheel  and  axle  may 
be  used  in  combination,  the  circumference  of  one  wheel  acting  by  means  of 
teeth  upon  the  axle  of  another,  as  shown  at  fig.  13 ;  the  effect  of  such 
combination  being  similar  to  that  produced  by  the  combination  of  levers  already 
described. 


MECHANICAL  POWERS. 

The  compound  axle,  (fig.  14),  is  s  contrivance  by  which  the  power  is  increased 
without  increasing  the  diameter  of  the  wheel.  This  axle  has  one  half  of  it  twice 
the  diameter  of  the  other  half.  A  moveable  pulley  being  attached  to  the  weight 
to  be  raised,  the  rope  is  passed  round  the  wheel,  and  coiled  in  the  same  direction 
upon  both  parts  of  the  axle:  upon  every  revolution  of  the  axle,  a  portion  of  the 
rope  equal  to  the  circumference  of  the  thicker  part  will  be  drawn  up,  but  at  the 
same  time,  a  portion  equal  to  the  circumference  of  the  thinner  part  will  be  let 
down  :  hence,  every  revolution  of  the  cylinder  raises  the  weight  through  a  space 
equal  to  half  the  difference  between  the  circumferences  of  the  thicker  and  thinner 
parts  of  the  axle. 

The  Pulley  is  a  sma11  wheel  turning  on  an  axis,  and  having  a  groove  upon 
its  circumference  for  the  reception  of  a  rope.  It  is  either  fixed  or  moveable.  The 
fixed  pulley  (fig.  15)  possesses  no  mechanical  advantage,  but  is  used  to  change 
the  direction  of  the  power,  or  to  give  convenience  in  pulling. 

The  moveable  pulley,  however,  affords  mechanical  assistance  by  dividing  the 
weight.  This  is  illustrated  at  fig.  16,  where  the  weight  of  the  barrel  is  equally 
divided  between  the  part  of  the  rope  affixed  to  the  beam,  and  that  held  in  the 
hand.  Fig.  17  shows  this  more  clearly;  if  the  large  weight  be  twenty  pounds, 
ten  pounds  is  borne  by  A,  and  ten  pounds  by  p.  The  fixed  pulley,  B,  is  of  no 
other  use  than  to  change  the  direction  of  the  power. 

The  power  of  pulleys  is  increased  by  their  combination.  Fig.  18  illustrates 
this  :  here  the  weight  is  equally  distributed  between  four  ropes,  consequently  it 
may  be  supported  by  a  power  only  a  fourth  of  its  own  weight.  Fig.  19  is  a  sys- 
tem of  pulleys,  or  a  tackle,  as  it  is  usually  called,  by  which  a  power  of  one 
hundred  will  balance  a  weight  of  six  hundred.  Fig.  20  exhibits  a  system  of  pulleys 
in  combination,  in  which  a  power  of  one  will  balance  a  weight  of  sixteen.  The 
power  of  this  system  may  be  greatly  augmented  by  substituting  fixed  pulleys  for 
the  hooks  to  which  the  ends  of  the  ropes  are  attached,  in  the  manner  shown  at 
fig.  21.  In  order  to  obviate  the  loss  of  power  occasioned  by  the  friction  of  the 
separate  axles,  where  several  pulleys  are  employed,  an  ingenious  arrangement  has 
been  resorted  to  in  White's  patent  pulley  (fig.  22),  by  which  all  the  pulleys  in 
each  block  turn  on  the  same  axis. 

The  Inclined  Plane*  It  is  not  difficult  to  understand  that  a  body  may 
with  much  greater  ease  be  drawn  up  a  slope,  than  it  can  be  raised  the  same  height 
perpendicularly.  Hence  the  advantage  of  the  inclined  plane,  which  acts  as  a 
mechanical  power,  in  partly  supporting  the  weight  (fig.  23).  The -.longer  the 
inclined  space  is  in  proportion  to  the  perpendicular  height,  the  greater  is  the 
advantage  afforded.  Suppose  the  inclined  plane  A  B  (fig.  24),  to  bear  the  pro- 
portion to  the  perpendicular  height  B  c,  as  three  to  one,  then  a  power  of  one  will 
balance  a  weight  of  three. 

Persons  have  often  been  struck  with  astonishment  when  viewing  Stonehenge, 
how  those  enormous  cross-pieces  of  stone  were  raised  to  the  elevation  at  which 
we  see  them,  but  the  mechanical  feat  is  by  no  means  very  wonderful,  for  it 
would  only  be  necessary  to  raise  an  inclined  plane  of  earth  in  the  direction 
of  the  line  A  B  (fig.  25),  and  by  means  of  rollers  placed  under  the  stone,  pass 
it  to  its  situation  on  the  top  ;  the  earth  being  removed,  the  stone  would  remain 
secure.  • 

The  Wedge  is  a  combination  of  two  inclined  planes  united  at  their  base 
(fig.  26).  The  wedge  derives  its  great  power  chiefly  from  the  way  in  which  the 
force  is  applied — by  being  struck. 

The  Screw  is  a  machine  of  great  mechanical  power,  and  is  a  modification  of 
the  inclined  plane,  as  will  be  seen  by  reference  to  fig.  27.  The  screw  has  no 
power  by  itself,  it  can  operate  only  by  working  in  spiral  grooves  corresponding 
to  its  threads  :  these  grooves  are  formed  on  the  inside  of  a  box  or  nut, 
through  which  the  screw  winds  itself.  Fig.  28  shows  the  screw,  and  its  nut, 
fig.  29,  exhibits  the  screw  with  a  section  of  the  nut,  showing  the  spiral  groores, 
The  power  is  applied  by  a  lever,  the  screw,  therefore,  acts  with  the  combined 
power  of  the  lever  and  the  inclined  plane,  thus  becoming  in  reality  a  compound 
machine. 

Screws  are  much  used  in  presses  of  all  kinds.  The  bookbinders'  standing 
press  (fig.  30),  affords  one  of  the  best  examples  of  this  application  of  its 
powei. 


HOROST1TIC3. 

THIS  department  of  science  treats  of  the  pressure  and  equilibrium  of  liquids, 
the  most  remark-able  property  of  which  is,  that  of  equality  of  pressure.  This 
property  arises  from  the  extreme  minuteness  and  independent  gravitation  of  each 
of  the  particles,  and  from  the  manner  in  which  they  act  upon  each  other ; 
being  arranged,  not  perpendicularly  one  above  the  other,  but  obliquely,  as  shown 
at  fig.  1.  One  particle  above  pressing  between  two  particles  beneath,  the 
latter  consequently  sustain  a  lateral  pressure,  just  as  a  wedge  driven  irko  a 
piece  of  wood  separates  the  parts  laterally.  This  lateral  pressure  is  the 
result,  therefore,  of  the  pressure  downwards,  or  the  weight  of  the  liquid  above. 

Fig.  2  illustrates  the  different  degrees  of  force  with  which  water  flows  from 
apertures  in  a  vessel  at  different  heights.  Fig.  3  represents  part  of  a  teapot, 
which  we  suppose  to  be  filled  with  columns  of  particles  of  water  ;  the  particle  1, 
at  the  bottom,  will  be  pressed  laterally  by  the  particle  2,  and  thus  be  forced  into 
the  spout,  where,  meeting  with  the  particle  3,  it  presses  it  upwards,  and  this 
pressure  will  be  continued  till  the  water  in  the  spout  has  risen  to  a  level  with 
that  in  the  pot. 

Fig.  4  is  another  illustration  of  the  upward  pressure  of  water.  A  is  a  glass 
tube,  widened  at  the  lower  end,  against  which,  by  a  string  passing  up  the  tube,  a 
thick  piece  of  metal  is  held  close  by  the  hand.  Upon  immersing  the  glass  and 
plate  thus  held  together  in  the  water  to  a  certain  depth,  the  hand  may  be  with- 
drawn from  the  string,  the  upward  pressure  of  the  water  being  sufficient  to  sup- 
port the  piece  of  metal. 

Several  interesting  illustrations  can  be  offered  to  prove  the  remarkable  fact, 
that  the  pressure  of  water  on  the  bottom  of  the  containing  vessel  does  not  at  all 
depend  on  the  quantity  of  water,  but  upon  the  size  of  the  base  and  the  perpen- 
dicular height  at  which  the  water  stands. 

Figs.  5  and  6  represent  two  vessels  of  precisely  similar  capacities,  and  each 
containing  the  same  quantity  and  weight  of  water,  but  which  have  very  different 
pressures  upon  their  bottoms  ;  that  upon  c  D  being  less  than  the  absolute 
weight  of  the  water,  viz.,  the  weight  only  of  the  cylindrical  column,  A  B  c  D  ; 
while  that  upon  o  H  is  more  than  the  absolute  weight  of  the  water,  viz.,  the 
weight  of  a  cylindrical  column,  E  F  G  H,  for  the  water  in  the  central  column 
G  H  I  K,  presses  laterally  with  the  same  force,  as  it  does  on  the  part  ou  which 
it  stands ;  and  thus  an  uniformity  of  pressure  is  exerted  over  every  part  of  the 
bottom. 

Fig.  7  illustrates  the  latter  case  still  more  strikingly :  F  is  a  tube  communi- 
cating with  the  chamber,  E  E,  and  on  these  being  filled  with  water,  the  pressure 
upon  the  bottom,  c  D,  will  be  precisely  the  same  as  if  the  whole  space,  A  B  c  D, 
were  filled  with  water. 

Fig.  8  represents  the  hydrostatic  bellows,  which  has  been  contrived  to  exem- 
plify the  great  effect  of  a  column  of  water.  The  tube  A  communicates  with  the 
interior  of  the  bellows,  and  upon  these  being  Glled  with  water,  the  upper  board,  B 
will  be  raised,  and  enabled  to  sustain  a  very  considerable  weight;  for  if  the  tube 
A  hold  but  an  ounce  of  water,  and  have  an  area  equal  to  the  thousandth  part  of 
the  area  of  the  top  of  the  bellows,  the  ounce  of  water  in  the  tube  will  sustain  a 
thousand  ounces  placed  on  the  bellows. 

Another  important  principle  in  reference  to  liquids  is  their  tendency  to  seek  an 
uniform  level.  If  we  pour  water  into  a  bent  tube,  as  fig.  10,  it  will  stand  at  as 
equal  height  in  both  limbs. 

If  there  be  two  tubes  or  limbs  of  a  tube  connected  together,  however  different 
their  width  or  form  may  be,  a  liquid  poured  into  them  will  stand  at  the  same 
level  in  both,  and  thus  a  portion,  however  small,  will  balance  a  portion,  however 
large,  as  shown  at  fig.  11. 

Fig.  12  represents  a  number  of  vessels  of  different  forms  fixed  in  the  vessel 
A  B,  so  as  to  communicate  with  it,  and  by  means  of  it  with  each  other.  Water 
being  poured  into  any  one  of  them  will  stand  at  the  same  level  in  all,  as  shown 
by  the  line,  c  c. 

From  these' considerations,  a  most  important  conclusion  follows,  namely,  that 
water  will,  by  being  confined  in  pipes  or  close  channels,  rise  to  the  height  from 
whence  it  came  ;  and  upon  this  principle  depend  all  the  useful  contrivances  for 
conveying  water  into  to.vns  and  houses  by  pipes  from  distant  reservoirs. 
References  to  figs.  1'3  and  14  will  illustrate  this  more  clearly. 
Fig.  13  represents  the  water  level,  and  tig.  16  the  spirit  level. 


HYDROSTATICS. 

Intermitting  Springs- — Those  springs  which  flow  and  stop  by  regular 
aternations  may  be  accounted  for  upon  the  principle  of  the  syphon,  represented 
at  fig.  17.  If  this  tube  be  filled  with  water,  and  the  shorter  leg  be  plunged  into 
a  vessel  of  water,  the  water  will  flow  up  the  tube,  over  the  bend,  and  out  at  the 
longer  leg,  till  the  vessel  is  emptied. 

Fig.  18  represents  a  section  of  a  hill,  having  within  a  cavity,  A,  from  which 
runs  a  channel  in  the  form  of  a  syphon  ;  the  rain  falling  upon  the  hill,  preco- 
lates  through  the  crevices  and  pores,  d  d  d,  and  in  course  of  time  will  fill  the 
cavity  with  water  up  to  the  level,  E  E  ;  it  will  then  flow  over  the  bend,  B,  and 
continue  to  flow  and  supply  the  spring  till  the  level  of  the  water  falls  below  the 
mouth  of  the  channel,  when  the  action  of  the  syphon  will  cease,  until,  by  fresh 
supplies,  the  level  of  the  water  is  again  raised,  so  as  to  flow  over  the  bend,  when 
the  syphon  will  act  as  before. 

The  Hydrostatic  Press- — Fig.  19.  This  is  perhaps  the  most  powerful 
machine  ever  invented,  the  only  assignable  limits  to  its  power  being  the  strength 
of  the  materials  of  which  it  is  formed.  A  is  the  force  pump,  by  the  action  of 
which  water  is  forced  through  the  small  tube,  B  B,  and  its  pressure  communicated 
to  the  mass  of  water  in  the  cylinder,  c,  there  the  water  in  its  endeavour  to  resist 
compression  forces  up  the  moveable  piston,  D  D,  with  its  burden,  and  the  action 
of  the  pump  being  continued,  the  pressure  is  gradually  increased  until  the 
required  degree  is  produced. 

Fluid  Support — Specific  Gravity- — A  solid  body  immersed  in  a  fluid 
displaces  exactly  its  own  bulk  of  fluid,  and  the  force  with  which  the  body  is 
buoyed  up,  is  equal  to  the  weight  of  the  fluid  which  is  displaced  ;  therefore,  the 
body  will  sink  or  swim,  according  as  its  own  weight  is  greater  or  less  than  the 
bulk  of  the  displaced  fluid.  This  refers  to  bodies  of  less  density  than  water. 
Any  body  of  greater  density  than  water,  when  wholly  immersed  in  that  fluid, 
loses  exactly  as  much  of  its  weight  as  the  weight  of  an  equal  bulk  of  the  water 
which  it  displaces. 

These  laws  are  of  much  importance,  as  an  acquaintance  with  them  enables  us 
to  explain  innumerable  phenomena  in  nature,  in  reference  to  the  floating  of  bodies 
in  water,  or  in  the  atmosphere. 

Fig.  20  is  a  vessel  of  water,  and  A  a  solid  body  of  the  same  density  im- 
mersed in  it,  and  which,  being  equally  pressed  upon  from  above  and  below, 
retains  its  position,  just  as  the  mass  of  water  it  has  displaced  would  have  done. 
But  if  a  solid  body  as  B,  fig.  21,  heavier  than  water,  bulk  for  bulk,  be  placed  in 
it,  it  will  sink  to  the  bottom ;  while  a  body  lighter  than  water  will  float  on  the 
surface  partially  immersed,  as  A,  fig.  21,  the  weight  of  the  water  displaced 
being  equal  to  the  weight  of  the  whole  solid.  Thus,  the  weight  of  any  floating 
body  may  be  ascertained  by  measuring  the  quantity  of  water  which  it  displaces. 

F'ig.  22  represents  the  hydrostatic  balance  used  for  ascertaining  the  specific 
gravity  of  solid  bodies,  which  are  suspended  in  water  by  a  horse-hair  attached 
to  the  bottom  of  the  scales. 

Hydrometers- — These  are  instruments  which,  beittg  immersed  in  liquids, 
determine  the  proportion  of  their  densities,  or  specific  gravities,  and  thence  their 
qualities.  The  use  of  the  hydrometer  depends  on  the  following  propositions  : — 
1.  The  hydrometer  will  sink  in  different  fluids  in  an  inverse  proportion  to  the 
density  of  the  fluids.  2.  The  weight  required  to  sink  a  hydrometer  equally 
far  in  different  fluids  will  be  directly  as  the  fluids.  Each  of  these  two  proposi- 
tions gives  rise  to  a  particular  kind  of  hydrometer;  the  first  with  the  graduated 
scale,  as  fig.  23,  the  second  with  weights,  usually  hollow  glass  beads  of  various 
weights,  which  are  dropped  into  the  liquid  till  one  is  found  to  remain  stationary, 
indicating  t8e  density  of  the  liquid. 

Fig.  24,  represents  Nicholson's  hydrometer,  consisting  of  a  hollow  copper  ball 
A,  with  a  steel  stem  B,  supporting  a  small  dish  c.  By  the  successive  addition  of 
weights  to  the  dish  c,  the  instrument  may  be  sunk  so  as  to  obtain  the  complete 
range  of  specific  gravity. 

Fig.  25,  represents  the  areometer,  an  instrument  for  determining  the  relative 
specific  gravities  of  any  two  fluids  which  may  be  poured  together  without  mixing, 
as  mercury  and  water,  oil  and  water,  &c. 


HYDRAULICS 


HYDRAULICS. 


THIS?  science,  which  may  be  considered  a  branch  of  hydrostatics,  treats  of 
liquids  in  motion. 

The  particles  of  liquids  flow  over  and  amongst  each  other  with  less  friction 
than  over  solid  substances,  and  all  the  substances  gravitate  independently.  If  a 
hole  be  made  in  the  bottom  of  a  vessel  the  liquid  will  flow  out ;  those  particles 
directly  over  the  orifice  being  discharged  first,  their  motion  causes  a  temporary 
vacuum,  into  which  the  particles  tend  to  flow  from  all  directions  ;  and  thus  the 
whole  mass  of  the  water  is  set  in  motion  (fig.  1).  As  water  flows  through 
bended  pipes  to  the  same  level  from  whence  it  proceeds,  it  enables  us  to  form 
jets  or  fountains  (fig.  2).  If,  for  example,  a  body  of  water  be  collected  in  a 
reservoir  on  the  upper  part  of  a  house,  and  a  tube  descending  from  it  to  the 
garden  be  made  to  turn  upwards,  having  a  very  small  bore,  the  water  will  spurt 
up  in  a  jet  to  nearly  the  same  height  as  the  surface  of  the  water  in  the  reservoir. 
It  will  not  rise  quite  so  high  on  account  of  the  resistance  of  the  air,  and  the 
effect  of  gravitation.  Most  of  the  ornamental  fountains  in  public  gardens  are 
formed  upon  this  principle. 

Pumps  and  Machines  for  Raising  Water-— These  may  be  divided 

into  four  classes.  First,  those  machines  in  which  water  is  lifted  in  vessels  by  the 
application  of  some  mechanical  force  to  them.  The  earlier  hydraulic  machines 
were  constructed  on  this  principle  ;  such  as  the  Persian  wheel  (fig.  3),  consisting 
of  upright  buckets  attached  to  the  rim  of  a  wheel  moving  in  a  reservoir  of  water ; 
the  buckets  are  filled  at  bottom  as  they  pass  through  the  water,  and  emptied  at 
top  ;  the  water  is  thus  raised  to  a  height  equal  to  the  diameter  of  the  wheel: 
The  Archimedean  screw  (fig.  4),  and  the  chain  pump  (fig.  5),  are  modifications  of 
the  same  principle. 

The  second  class  of  machines  are  those  in  which  the  water  is  raised  by  the 
pressure  of  the  atmosphere,  and  comprises  all  those  machines  to  which  the  name 
of  pump  is  more  particularly  applied.  These  act  entirely  by  removing  the  pres- 
sure of  the  atmosphere  from  the  surface  of  the  water,  which  may  thus  be  raised 
to  any  height  not  exceeding  thirty-two  feet. 

Fig.  6  represents  the  common  pump,  which  consists  of  a  cylinder,  with  an 
air-tight  piston,  h'aving  a  valve,  A,  opening  upwards.  When  the  piston  is  raised 
a  vacuum  is  raised  in  the  tube  beneath,  which  is  immediately  occupied  by  the 
water  ;  on  depressing  the  piston,  the  water  passes  through  the  valve,  -A,  in  its 
centre,  and  on  being  raised,  the  water  is  lifted  to  the  top  of  the  barrel,  and  flows 
through  the  spout.  To  prevent  the  water  returning  to  the  well  when  the 
piston  is  depressed,  a  valve  (B)  opening  upwards  is  placed  near  the  bottom  of  the 
pump. 

When  it  becomes  necessary  to  raise  water  to  a  greater  height  than  thirty-two 
feet,  the  third  class  of  machines,  or  those  which  act  by  compression  on  the  water, 
usually  by  the  intervention  of  compressed  air,  are  employed.  All  pumps  of  this 
description  are  called  forcing  pumps,  and  by  these  water  may  be  raised  to  any 
height  by  applying  sufficient  force. 

Fig.  7  represents  the  forcing  pump,  consisting  of  two  parts,  or  barrels,  one 
similar  to  the  common  pump,  and  the  other  rising  by  its  side.  The  water  is  first 
raised  in  the  former  part  in  the  same  manner  as  in  the  common  pump,  excepting 
that  the  piston  has  no  opening  valve,  but  is  solid,  and  the  air  is  forced  out 
through  the  valve,  A,  into  the  adjoining  barrel.  Through  this  valve  the  water  is 
also  forced,  and  the  pressure  of  the  descending  piston  causes  it  to  flow  up  the 
ascending  pipe  and  issue  out  of  the  top.  The  vessel  in  which  the  lower  end  of 
the  ascending  pipe  is  placed,  encloses  a  volume  of  air  ;  when  the  water  rises  this 
air  is  compressed,  and  being  elastic  it  re-acts  upon  the  water,  thus  causing  it  to 
flow  upwards  with  greater  force. 

The  fire-engine  is  an  interesting  example  of  the  utility  of  this  machine  ;  its 
principle  will  be  readily  understood  by  reference  to  fig.  8.  A  is  the  suction-pipe 
by  which  water  is  supplied  from  the  street  main ;  B  B  are  two  valves  opening 
upwards  into  the  barrels  of  two  forcing  pumps,  containing  solid  pistons  ;  from 
the  lower  sides  of  the  pump-barrels  proceed  force-pipes,  which  communicate 
with  an  air-chamber,  c  c,  by  valves,  D  D,  opening  upwards  into  it.  Through  the 
top  of  the  air-chamber  descends  nearly  to  its  bottom  a  pipe.  E  E.  vo  tjie  uppeij 
part  of  which  is  attached  the  hose  for  directing  a  stream  of  watt-;i  on  thjp^re..  By0 
the  alternate  action  of  the  pistons,  water  is  drawn  through  the'  valfes  *B*B,  *aad 


HYDRAULICS. 

propelled  through  the  forcing  valves,  D  D;  and  the  enclosed  air  being4compressed, 
re-acts  upon  the  water,  which  is  projected  up  the  centre  pipe  and  along  the  hose 
with  a  force  proportioned  to  the  power  applied  to  the  pistons  by  the  persons 
who  work  the  engine. 

The  fourth  class  of  hydraulic  machines  for  raising  water  consists  of  such 
engines  as  act  either  by  the  weight  of  a  portion  of  the  water  which  they  have  to 
raise,  or  of  the  water,  or  by  its  centrifugal  force,  momentum,  or  other  natural 
powers.  The  centrifugal  pump  (fig.  9)  belongs  to  this  class.  This  machine 
raises  water  by  means  of  the  centrifugal  force,  combined  with  the  pressure  of 
the  atmosphere.  A  B  is  an  upright  spindle,  so  fixed  that  rapid  rotary  motion 
may  he  communicated  to  it  by  a  wheel  and  pinion,  or  winch,  c  D,  c  D,  repre- 
sent any  number  of  curved  pipes  BO  disposed  and  fixed  to  the  spindle  that  their 
lower  ends  may  be  near  to  't,  and  be  covered  by  the  water  to  be  raised,  and  their 
upper  ends  to  be  extended  to  a  considerable  distance  from  the  centre  of  motion, 
and  bent  downwards  to  prevent  the  scattering  of  the  water.  Before  putting  the 
machine  in  action  the  several  pipes  must  be  rilled  with  water,  which  will  be  re- 
tained in  them  by  a  valve  near  the  bottom  opening  upwards.  The  machine  is 
then  put  in  motion  by  turning  the  spindle  rapidly.  The  upper  ends  of  the  pipes 
will  describe  a  much  larger  circle  than  the  ends  below,  and,  consequently,  such  a 
centrifugal  force  will  be  generated  at  the  upper  ends  as  will  produce  a  vacuum, 
and  the  water  below  will  then  rise  and  flow  from  the  upper  ends  of  the  pipes 
into  the  circular  trough,  whence  it  may  be  delivered  by  a  pipe  as  required. 

Power  to  be  derived  from  Water- — Motion  is  generally  obtained  from 
water  either  by  exposing  obstacles  to  the  action  of  its  current,  as  in  water-wheels, 
or  by  arresting  its  progress  in  raoveable  buckets  or  receptacles,  which  retain  it 
during  its  descent  A  water-wheel  consists  of  a  hollow  cylinder  or  drum,  re- 
volving on  a  central  axle,  from  which  the  power  is  communicated  ;  while  the 
exterior  surface  is  occupied  by  float-boards,  or  cavities  upon  which  the  water  is 
to  act.  Water-wheels  are  divided  into  three  classes — first,  the  Undershot  wheel 
(fig  10),  having  floats  dipping  into  the  water,  the  current  of  which,  acting 
against  them,  causes  the  wheel  to  revolve.  The  second  'class  are  those  termed 
Overshot  wheels  (fig  11),  in  which  the  circumference  is  occupied  by  a  series  of 
cavities,  into  which  the  water  falls  from  above ;  as  the  wheel  revolves  these 
cavities  become  inverted  and  discharge  their  contents  at  the  bottom  of  the 
wheel.  This  description  of  wheel  is  much  more  powerful,  as  well  as  much  more 
economical  in  its  consumption  of  water,  than  the  preceding.  The  third  kind  of 
watei'- wheel  is  that  termed  the  Breast  wheel.  In  this  the  water  is  delivered 
about  half-way  up  it,  or  rather  below  the  level  of  the  axis,  and  the  brickwork 
upon  which  the  water  descends  is  built  in  a  circular  form,  so  as  to  make  it 
parallel  to  the  edges  of  the  float-boards  of  the  wheel ;  its  arrangement  and  mode 
of  action  will  be  readily  understood  by  reference  to  fig.  12. 

Fi£.  13  represents  Barker's  mill,  a  machine  which  owes  its  efficacy  to  the 
centrifugal  force.  It  consists  of  a  long  cylindrical  pipe,  having  a  funnel  at  A, 
and  terminating  in  a  pivot,  turning  in  a  socket,  at  B.  About  A  is  an  axis  c, 
passing  through  a  frame,  and  carrying  with  it  the  upper  millstone.  At  the 
bottom  of  the  pipe  at  B,  is  a  cross  pipe,  D  E,  at  the  opposit-1  sides  of  which  arc  t\vo 
aperture;',  from  which  the  water  poured  into  the  funnel  at  A,  spouts  with 
considerable  velocity,  and,  from  the  resistance  of  the  air,  gives  motion  to  the 
machine. 


PNEUMATICS 


"or  BAROMETER  IN  INCHES 


L  . 

1  Himalaya  2fiLOOOfeet.  2  .Ar.de  s  2.^250  feet.  3  Alp*  16650  feet.  4  Bru 
5Siiow(ion3i571£eet.  6^r(TreeTisBal]ooTiml837,  27,(.H"Hi  feet. 


SEA    LEVEL 

436')  feel. 


PNEUMATICS. 


THIS  branch  of  science  treats  of  the  nature  and  properties  of  the  atmosphere, 
and  of  their  effects  upon  solid  and  fluid  bodies.  The  atmosphere  is  a  thin 
gaseous  substance,  which  envelopes  the  earth  on  every  side  to  the  height  of  about 
forty-five  miles,  its  density  decreasing  with  its  height.  Fig.  1,  represents  the 
atmosphere,  which  is  divided  by  lines  into  thirty  spaces,  each  of  which  contains 
the  same  quantity  of  air,  the  lower  layers  being  so  much  compressed  by  the 
weight  of  those  above  them,  that  the  lower  half  of  the  atmosphere  lies  within 
about  three  and  a  half  miles  of  the  earth's  surface,  while  the  upper  half  is  so 
expanded  as  to  occupy  upwards  of  forty  miles.  The  upper  thirtieth  part  alone 
occupies  more  space  than  all  the  remaining  thirty-nine  parts. 

Mechanical  Properties  of  Air. — The  most  essential  point  in  which  air 
differs  from  other  fluids  is  by  its  elasticity  ;  that  is,  its  power  of  increasing  or 
diminishing  its  bulk,  according  as  it  is  less  or  more  compressed.  Air  possesses 
the  universal  properties  of  matter.  Its  impenetrability  may  thus  be  shown  : 
Fig.  2,  is  a  vessel  partly  filled  with  water,  upon  the  surface  of  which  floats  a 
small  cork ;  fig.  3  is  a  smaller  cylindrical  glass  vessel,  with  a  stop  cock,  which  is 
closed.  If  this  vessel  be  inverted  over  the  cork,  as  at  fig.  4,  and  its  mouth 
pressed  into  the  water,  it  will  be  fonud  that  the  water  will  not  enter  the  inverted 
glass,  except  to  a  very  limited  height,  owing  to  the  air  in  the  glass  excluding  the 
water  ;  but  if  the  stop  cock  be  opened,  the  air  will  escape,  and  the  water  rise  to 
the  same  level  within  as  it  is  without  the  glass. 

That  air  is  inert  and  moveable,  we  have  many  and  familiar  proofs,  as  the 
resistance  it  offers  to  a  body  passing  through  it,  and  the  force  exerted  by  the 
wind.  It  also  possesses  weight,  one  hundred  cubic  inches  weighing  about  thirty- 
one  grains. 

Laws  of  Air- — First,  the  pressure  of  the  air  is  equal  in  all  directions  ;  second, 
its  degree  of  pressure  depends  on  the  vertical  height,  and  is  in  proportion  to  its 
density,  and  to  the  weight  of  the  fluid  displaced. 

That  air  presses  in  all  directions  may  be  proved  by  filling  a  bladder  with  that 
fluid,  and  then  pressing  upon  it;  the  pressure  will  be  freely  communicated 
through  the  mass,  and  the  confined  air  will  rush  out  with  equal  force  at  whatever 
part  a  hole  is  made  in  the  surface. 

The  pressure  depending  on  vertical  height  or  depth  of  air,  is  an  important 
property  of  the  atmosphere,  and  on  it  depends  the  explanation  of  numerous 
phenomena. 

Air  being  a  substance  possessing  gravity,  necessarily  presses  downwards  in  the 
direction  of  the  centre  of  the  earth  ;  and,  therefore,  the  degree  of  pressure  on, 
any  given  point  will  be  equal  to  the  weight  of  the  column  of  air  above  that 
point,  and  proportional  to  its  density.  The  atmosphere  is  of  the  greatest 
vertical  height  at  the  level  of  the  sea,  and  here  its  pressure  is  about  fifteen 
pounds  on  every  square  inch  of  surface.  The  pressure  being  exerted  upwards 
sideways,  obliquely,  and  in  every  other  direction,  as  well  as  downwards. 

Some  illustrations  may  be  given  of  the  pressure  of  the  air.  Figs.  5  and  6 
represent  two  hollow  hemispheres  of  brass ;  these  being  placed  in  contact  and  the 
air  withdrawn  from  the  interior,  the  external  air  will  exert  a  pressure  of  15  Ibs. 
upon  every  square  inch  of  their  surface,  so  that  if  two  persons  pull  the  handles 
in  opposite  directions  they  will  be  unable  to  separate  the  hemispheres.  The 
common  leather  sucker  (fig.  7)  with  which  boys  raise  stones,  acts  from  the 
pressure  of  the  atmosphere.  It  is  the  pressure  of  the  atmosphere  which  causes 
liquids  to  rise  in  pumps  and  syphons. 

The  Barometer-  This  instrument  consists  of  a  column  of  mercury,  sup- 
ported in  a  tube  by  the  pressure  of  the  atmosphere,  and  therefore  indicating  that 
degree  of  pressure  (fig.  8).  It  is  formed  by  a  glass  tube  about  34  inches  long, 
closed  at  one  end  and  open  at  the  other.  The  tube  being  filled  with  mercury,  the 
open  end  is  stopped  with  the  finger  to  prevent  any  running  out,  and  the  tube 
being  inverted,  the  open  end  is  placed  in  a  small  cup  of  mercury,  and  the  finger 
being  withdrawn,  the  mercury  in  the  tube  now  subsides  three  or  four  inches, 
above  the  top  of  which  in  the  tube  is  a  perfect  vacuum.  The  tube  being  then 
fixed  to  a  graduated  frame,  we  have  a  barometer.  The  mercury  will  stand  in  the 
tube  at  the  height  of  from  28  to  30  inches,  according  to  the  state  of  the  air  ;  and 
the  reason  of  this  is,  that  the  pressure  of  the  whole  atmosphere  will  not  raise 


PNEUMATICS. 

a  column  of  mercury  higher  than  about  30  inches  j  that  is,  a  column  of  air  equa* 
to  the  height  of  the  atmosphere,  from  the  level  of  the  sea,  is  of  the  same  weight 
as  a  column  of  mercury  30  inches  high,  the  one  thus  balancing  the  other.  The 
figures  at  the  sides  of  fig.  1,  show  the  height  of  a  column  of  mercury  at  different 
elevations  :  the  barometer  thus  becomes  an  important  means  of  determining  the 
altitude  of  mountains. 

The  wheel  barometer  is  represented  at  fig.  9.  The  tube  is  closed  at  the  top, 
and  bent  upwards  at  its  lower  extremity,  which  is  open,  and  the  mercury  buoys 
•ip  a  small  float,  F,  to  which  a  thread  is  attached,  passing  over  a  pulley  and  ter- 
minating in  the  little  ball,  w.  The  friction  of  the  thread  on  the  pulley  turns  an 
index  which  points  to  the  words  on  the  dial  plate. 

When  the  mercury  falls  in  the  barometer,  an  indication  is  given  of  diminished 
pressure ;  and  as  this  causes  the  air  to  expand  and  become  sensibly  cooled, 
moisture  is  likely  to  be  precipitated  in  the  form  of  rain. 

The  Ail  Pump-— Air  may  be  artificially  withdrawn  from  a  containing  ves- 
sel by  means  of  an  apparatus  called  the  air  pump,  represented  at  figs.  10  and  11 
(the  latter  showing  the  pistons  and  valves).  A  is  the  receiver,  resting  in  close 
contact  with  the  pump  plate  B,  near  the  centre  of  which  is  the  open  end  of  the 
tube  c  c,  communicating  with  the  exhausting  barrels  D  D  ;  these  are  fitted  with 
pistons  having  valves  opening  upwards,  so  as  to  allow  the  air  beneath  to  pass  out 
but  preventing  its  return.  At  the  bottom  of  the  barrels  are  two  other-  valves 
also  opening  upwards,  admitting  the  air  from  the  tube  into  the  barrels  when  the 
pistons  are  raised,  and  on  their  descent  preventing  its  return ;  the  air  thus  con- 
fined in  the  barrel,  by  the  descent  of  the  piston,  becomes  compressed,  and  forc- 
ing open  the  valve  in  the  piston,  escapes  into  the  open  air.  The  pistons  are  con- 
nected by  a  rack  and  pinion  movement  with  a  handle,  and  are  raised  alternately, 
thus  producing  a  vacuum  beneath  the  receiver.  By  means  of  the  air  pump  many 
interesting  experiments  in  pneumatics  may  be  performed.  When  the  air  is 
thoroughly  exhausted,  light  and  heavy  bodies  fall  with  equal  swiftness:  most 
animals  die  immediately  ;  vegetation  stops ;  combustion  ceases  ;  gunpowder  will 
not  explode ;  heat  is  slightly  transmitted  ;  a  bell  sounds  faintly ;  magnets  are 
powerless  ;  glowworms  give  no  light ;  and  watery  and  other  fluids  turn  to 
vapour.  We  thus  see  the  important  uses  of  the  air  in  supporting  life,  vegetation, 
and  combustion  ;  in  forming  a  medium  for  conveying  to  us  the  sound  of  each 
others  voices ;  besides  contributing  in  numberless  ways  to  our  comfort  and 
enjoyment. 

Air  Condenser* — Fig'  12  represents  a  section  of  the  condensing  syringe, 
having  an  opening  at  A  to  admit  the  air,  and  a  valve  at  B  opening  downwards. 
The  air  being  forced  by  the  piston  through  the  valve  B,  is  prevented  from  return- 
ing by  the  form  of  the  latter.  Fig.  13  represents  a  vessel  partly  filled  with 
water.  By  means  of  the  condensing  syringe,  a  large  quantity  of  air  may  be 
forced  through  the  tube  into  the  space  A  A  ;  the  stop  cock  being  then  closed  and 
the  syringe  detached,  and  the  stop  cock  being  again  opened,  the  pressure  of  the 
air  upon  the  surface  of  the  water  will  force  it  up  in  the  form  of  a  jet  d'eau.  The 
elastic  force  of  compressed  air  is  very  great,  and  is  sometimes  employed  for  the 
projection  of  balls  from  the  air  gun  (fig.  14). 

Air  Balloon-— The  air  balloon  (fig.  15)  is  a  light  silken  bag  of  large  dimen. 
ions,  filled  with  a  gas,  which  bulk  for  bulk,  is  lighter  than  air,  so  that,  when  in- 
flated, the  machine  becomes  lighter  than  the  air  which  it  displaces,  and  this  differ- 
ence is  so  considerable  that  it  is  enabled  to  carry  up  with  it  several  persons  in  a 
car  attached.  As  it  ascends,  the  air  becoming  less  dense,  the  difference  between 
its  weight  and  that  of  the  air  displaced  is  gradually  diminished,  until  it  attains 
such  a  height  that  the  air  it  displaces  is  so  rare,  as  to  be  only  equal  in  weight  to 
the  balloon;  this,  therefore,  becomes  the  limit  of  its  ascent.  In  order  to  descend 
the  bulk  of  the  balloon  is  diminished,  by  the  gas  being  allowed  to  escape  by  open- 
ing a  valve ;  thus,  the  weight  of  the  balloon  is  made  to  exceed  that  of  an  equal 
bulk  of  air  and  it  accordingly  falls. 

The  Diving  Bell-— Fig.  16.  This  machine  is  formed  of  iron,  and  is  usually 
capacious  enough  to  hold  three  or  four  persons.  It  is  constructed  on  the  impene- 
trability of  air,  before  described.  Air  is  pumped  in  from  above  by  means  of  a 
forcing  air  pump,or  condenser  ;  the  water  is  thereby  prevented  from  rising  in 
the  machine,  and  the  persons  within  are  enabled  to  breathe  freely.  A  represents 
the  pipe  conveying  the  fresh  air  from  force  pumps,  and  B  the  pipe  conveying  the 
ritiated  air  from  the  bell. 


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OPTICS. 

OPTICS  is  the  science  of  light  and  vision. 

All  visible  bodies  may  be  divided  into  two  classes— self-luminous  and  non-lu- 
minous. The  first  comprise  those  bodies  which  shine  by  their  own  light,  as  the 
stars,  sun,  flames,  &c.  Non-luminous  bodies  are  those  which  have  no  power  of 
discharging  light  of  themselves,  but  which  throw  back  the  light  that  falls  upon 
them  from  self-luminous  bodies.  Light  emitted  from  a  self-luminous  body  is 
projected  in  straight  lines  in  every  possible  direction,  so  that  the  luminous  body 
not  only  seems  the  general  centre  whence  all  the  rays  proceed,  but  every  point 
of  it  may  be  considered  as  a  centre  which  radiates  light  in  every  direction  (fig.  1). 
A  ray  of  light  is  a  straight  line  of  light  projected  from  a  luminous  body,  and  a 
pencil  of  rays  is  a  collection  of  rays  proceeding  from  any  one  point  of  a  luminous 
body  (fig.  2). 

When  rays  of  light  meet  with  an  opaque  body  through  which  they  cannot  pass, 
they  are  stopped  short  in  their  course,  and  cause  the  opaque  body  to  form  a 
shadow  on  the  other  side  of  it.  If  the  luminous  body  (as  A,  fig.  3)  be  larger 
than  the  opaque  body  (B),  the  shadow  will  gradually  diminish  in  size  till  it  ter- 
minates in  a  point ;  if  smaller,  the  shadow  will  increase  in  size,  as  it  is  more 
distant  from  the  object  that  projects  it  (fig.  4).  A  number  of  lights  in  different 
directions,  .while  they  decrease  the  intensity  of  the  shadows,  increase  their  num- 
oor7  which  corresponds  witnthat  of  the  lights  (fig.  5). 

Reflection  Of  Light- — When  a  ray  of  light  falls  perpendicularly  on  an 
opaque  body,  it  is  reflected  back  in  the  same  line  towards  the  point  whence  it 
proceeded  ;  if  it  falls  obliquely,  it  is  reflected  obliquely,  but  in  the  opposite  direc- 
tion, the  angle  of  reflection  being  equal  to  the  angle  of  incidence  (fig.  6). 

The  principle  of  reflection  may  be  illustrated  by  the  case  of  a  plane  mirror  or 
looking  glass  (A  B.  fig.  7).  The  ray  from  the  eye  of  the  spectator  at  c  will  be 
reflected  in  the  same  line  C  A  ;  but  the  ray  D  B,  coming  from  the  foot,  in  order 
to  be  seen  at  the  eye,  must  be  reflected  in  the  line  B  c,  and  therefore  the  foot 
will  appear  behind  the  glass  at  E,  along  the  line  c  B  E. 

There  are  three  kinds  of  mirrors  used  in  optics  ;  the  plane  or  flat,  the  convex, 
and  the  concave.  A  convex  mirror  has  the  peculiar  property  of  making  the 
reflected  rays  diverge  ;  and  a  concave  mirror  makes  the  rays  converge. 

M  N,  fig.  1,  represents  a  convex  mirror  formed  of  a  portion  of  the  exterior  of  a 
sphere,  whose  centre  is  o.  ABC  are  three  parallel  rays,  the  middle  one  of  which 
only  is  perpendicular  to  the  centre  of  the  mirror,  and  is  reflected  in  the  same 
line  ;  the  two  others  falling  obliquely,  will  be  reflected  obliquely  to  G  and  H,  the 
dotted  lines,  P  P,  being  perpendiculars  which  divide  their  angles  of  incidence  and 
reflection.  By  continuing  the  reflected  rays  G  B  and  H  E,  backwards,  they  will 
meet  at  F,  their  virtual  focus  behind  the  mirror. 

If  A  B,  fig.  9,  be  an  object  placed  before  the  convex  mirror  (M  K),  and  lines 
be  drawn  from  its  extreme  points  A  B,  to  o,  the  centre  of  the  sphere,  a  diminished 
representation  of  the  objects  will  be  formed  at  the  focus. 

Fig.  10  illustrates  the  property  of  a  concave  mirror.  ABC  are  three 
parallel  rays,  which,  striking  the  mirror,  are  reflected,  the  middle  ray  in  the  same 
line,  and  the  two  others  converged  so  ^s  to  meet  at  the  focus  F,  midway  between 
the  surface  of  the  mirror,  and  the  centre  of  its  concavity  c.  The  dotted  lines  P  P, 
are  perpendiculars. 

Images  reflected  from  concave  mirrors  appear  larger  than  the  real  objects,  pro- 
vided these  objects  are  within  the  focus,  as  A  B,  fig.  11. 

A  B,  fig.  12,  is  an  object  placed  at  some  distance  in  front  of  a  concave  mirror. 
In  this  case,  a  small  and  inverted  image  of  the  object  will  be  formed  at  D  E. 
When  the  object  is  placed  at  D  E,  a  magnified  representation  of  it  will  be 
formed  at  A  B. 

Concave  mirrors  are  used  as  burning  glasses  (fig.  13). 

Refraction  Of  Light* — Refraction  is  the  effect  which  transparent  mediums 
produce  on  light  on  its  passage  through  them.  Opaque  bodies  reflect  the  rays  j 
transparent  bodies  transmit  them  ;  but  it  is  found  that  if  a  ray,  in  passing  from 
one  medium  into  another  of  different  density,  fall  obliquely,  it  is  turned  out  of 
its  course,  or  refracted ;  but  if  it  fall  perpendicularly  it  is  not  refracted,  but  pro- 
ceeds through  the  new  medium  in  its  original  direction. 

Let  fig.  14,  be  a  vessel  half  filled  with  water.  If  a /ay  strike  it  in  the 
perpendicular  direction,  A  B,  it  will  be  continued  in  the  same  line  to  c  ;  but  if  a 
ray  be  admitted  at  D,  it  will  strike  the  water  obliquely  at  B,  when  it  will  become 
subject  to  two  opposite  forces,  the  attraction  of  the  water  endeavouring  to  draw 

perpendicularly  to  c,  and  the  projectile  force  of  the  3fay  inducing  it  to  proceed 


in  its  original  direction  to  F  ;  the  consequence  will  be,  that  it  will  pursue  an 
intermediate  course  to  E. 

If  a  coin  be  placed  in  a  basin,  so  that  on  standing  at  a  certain  distance  it  be 
just  hid  from  the  eye  of  an  observer  by  the  edge  of  the  basin,  and  then  water  be 
poured  in  by  a  second  person,  the  first  keeping  his  position,  as  the  water  rises 
the  coin  will  become  visible,  and  will  appear  to  have  moved  from  the  side  to  the 
middle  of  the  vessel  (fig.  15). 

These  facts  lead  to  an  important  axiom  in  optics ;  namely,  that  we  see  every- 
thing in  the  direction  of  that  Line  in  which  the  rays  approach  us  last.  Hence, 
the  sun  is  seen  several  minutes  before  it  comes  to  the  horizon,  and  as  long  after 
it  has  sunk  beneath  it,  because  its  rays  strike  first  upon  the  atmosphere,  and  are 
by  it  refracted,  or  bent  towards  the  earth  (fig.  16). 

In  passing  through  a  pane  of  glass  the  rays  suffer  two  refractions,  but  which, 
being  in  contrary  directions,  produce  nearly  the  same  effect  as  if  no  refraction 
kad  taken  place.  A  A,  fig.  17,  represents  a  thick  pane  of  glass  seen  edgeways. 
When  the  ray  B  approaches  the  glass  at  c,  it  is  refracted  to  D  ;  at  that  point, 
returning  into  the  air,  it  is  again  refracted,  but  in  a  contrary  direction,  and  in 
consequence  proceeds  to  E.  But  this  is  the  case  only  when  the  two  surfaces 
are  parallel  to  each  other  j  if  they  are  not,  the  two  refractions  may  be  made(  in 
the  same  direction.  Thus,  when  the  parallel  rays  (fig.  18)  fall  on  a  piece  ' of 
glass  having  a  double  convex  surface,  that  ray  only  which  falls  in  the  direction 
of  the  axis  of  the  lens  is  perpendicular  to  the  surface  :  thp-  nt.hr.r  rays  falling 
obliquely  are  refracted  towards  the  axis,  and  meet  at  a  point  beyond  the  ic,nn° 
called  its  focus. 

Figs.  19  to  23  represent  sections  of  lenses  of  various  forms,  having  different 
refractive  properties.  The  property  of  those  which  have  a  convex  surface  is  to 
collect  the  rays  of  light  to  a  focus ;  and  of  those  having  a  concave  surface  to 
disperse  them.  The  rays  falling  on  the  concave  lens,  fig.  25,  will  each  be  at- 
tracted towards  its  thicker  extremities,  both  on  entering  and  quitting  it ;  and 
will,  therefore,  by  the  first  refraction  be  made  to  diverge  to  A  c,  and  by  the 
second  to  d  e  The  ray  B,  falling  perpendicularly  on  the  axis  of  the  lens,  suffers 
no  refraction. 

Lenses  which  have  one  side  flat,  and  the  other  convex  or  concave,  as  figs.  19 
and  20,  are  called  plano-convex  and  plano-concave.  The  focus  of  the  former  is 
at  the  distance  of  the  diameter  of  the  sphere,  of  which  the  convex  surface  of  the 
lens  forms  a  portion,  as  shown  at  fig.  26. 

Fig.  24  represents  a  section  of  a  prism,  the  principal  use  of  which  is  to  enable 
us  to  decompose  the  rays  of  light. 

Decomposition  Of  Light- — White  light,  as  emitted  from  the  sun,  or  other 
luminous  body,  is  found  to  be  composed  of  seven  different  kinds  of  light ;  namely, 
red,  orange,  yellow,  green,  blue,  indigo,  and  'violet ;  and  this  compound  substance 
may  be  decomposed  or  separated  into  its  elementary  parts. 

Fig.  27,  represents  a  prism,  so  placed,  that  a  beam  of  light,  admitted  by  a 
small  aperture,  A,  falls  upon  it,  and  being  refracted  is  thrown  upon  the  screen 
B  c,  forming  an  oblong  image  called  the  prismatic  spectrum,  containing  the  seven 
colours  already  named. 

The  Raint)OW  is  formed  by  the  sur^s  rays  falling  upon  the  upper  parts 
of  the  drops  of  rain,  and  being  then,  by  refraction,  thrown  on  another  part  of  the 
same  drop,  where  they  are  again  refracted  and  reflected  to  the  eye,  so  as  to  pro- 
duce the  successive  colours  from  the  upper  part  of  red,  orange,  yellow,  green, 
blue,  indigo,  and  violet  (fig.  28). 

The  Eye— Vision- — Figs.  29  and  30  represent  a  front  view  and  a  section 
of  the  eye.  The  eye  is  composed  of  three  coats  or  skins,  one  covering  the  other. 
Within  the  coverings  of  the  eye-ball  are  contained  three  transparent  sub- 
stances, called  humours.  These  different  humours  form  a  compound  lens,  which 
refracts  the  rays  of  light  rebounding  from  objects,  forming  an  image  of  them 
upon  the  retina,  the  sensation  being  transmitted  by  the  optic  nerve  to  the  brain. 

Telescopes- — Fig.  31  illustrates  the  construction  and  action  of  a  refracting 
telescope,  and  fig.  32,  that  of  a  reflecting  telescope.  The  lines  show  the  direc- 
tion in  which  the  rays  are  transmitted  through  the  various  lenses. 

Fig.  33  represents  the  camera  olscura.  This  interesting  optical  instrument 
consists  of  a  convex  lens  A,  through  which  the  rays  of  any  objects  are  admitted 
into  a  darkened  chamber,  where  they  fall  on  a  plane  mirror  B,  placed  at  an  angle 
of  forty-five  degrees  ;  by  this  they  are  reflected  upwards  against  a  plate  of  ground 
glass  c,  upon  the  upper  surface  of  which  the  objects  appear  in  their  natural  colours 

Fig.  34  represents  that  well  known  instrument,  the  magic  lantern. 


<  CO 


iTBS . 


fc.LE.CTR  I  CITY 


ELECTRICITY. 

ELECTRICITY  is  the  operation  of  a  subtile  fluid,  generally  invisible,  which  ap- 
pears to  be  diffused  through  most  bodies. 

If  a  stick  of  sealing-wax  or  a  watch-glass  be  rubbed  upon  a  dry  piece  of 
woollen  cloth,  it  will  be  found,  while  warm  by  the  friction,  that  they  have 
acquired  the  property  of  attracting  small  light  bodies,  as  feathers,  &c.  Some  of 
these  will  adhere  to  the  surface  of  the  wax  or  glass,  and  others  will  be  thrown  off 
from  the  body,  as  if  they  were  repelled  from  it.  This  phenomenon  may  be 
strikingly  exemplified  by  the  small  apparatus  represented  at  fig.  1.  A,  is  a  stand 
with  a  bent  wire,  to  which,  at  the  hook,  B,  a  fine  silk  thread  is  attached,  having  at 
its  extremity  a  small  pith  ball,  c.  If  the  glass  rod,  0,  be  rubbed  and  presented  to 
the  ball,  this  will  be  immediately  attracted  to  the  glass,  and  will  remain  in  con- 
tact with  it  for  a  few  seconds  ;  if  the  glass  be  now  withdrawn,  and  again  pre- 
sented to  the  ball,  the  latter  will  be  repelled  (fig.  2).  If,  instead  of  the  glass,  a 
piece  of  sealing-wax,  rubbed  in  the  same  way,  be  employed,  the  same  effect  is 
produced.  Both  these  electrics  have,  therefore,  in  the  first  place,  the  power  of 
attracting  another  body  before  they  have  communicated  to  it  any  of  their  own 
electricity;  and,  secondly,  having  communicated  a  portion  of  their  electricity, 
they  repel  it.  But  a  very  remarkable  circumstance  takes  place,  if  we,  after 
having  conveyed  electricity  to  the  ball,  c,  by  means  of  excited  glass,  should  pre- 
sent to  it,  after  the  former  was  withdrawn,  excited  sealing-wax  :  the  ball,  instead 
of  being  repelled,  as  it  would  be  were  the  ball  again  applied,  is  attracted  by  the 
wax.  If  the  experiment  be  reversed,  and  the  excited  wax  first  presented  to  the 
ball,  and  then  the  excited  glass,  the  latter  will  be  found  to  repel  the  ball.  Hence, 
we  conclude,  that  there  are  two  opposite  electricities  ;  namely,  that  produced  by 
excited  glass,  to  which  the  name  of  vitreous,  or  positive  electricity,  has  been  given, 
and  that  produced  by  excited  wax,  to  which  the  name  of  re&inous,  or  negative 
electricity,  has  been  given. 

Fig.  3  represents  the  Cylindrical  Electrical  Machine,  consisting  of  a  hollow 
cylinder  of  polished  glass,  c  c,  revolving  upon  an  axis.  Two  hollow  metallic 
conductors,  D  E,  are  placed  parallel  to  the  cylinder  on  each  side,  upon  two 
insulated  pillars  of  glass.  To  one  of  these  conductors,  E,  a  cushion  is  attached, 
and  held  close  to  the  cylinder  ;  from  the  upper  edge  of  the  cushion  there  proceeds 
a  flap  of  oiled  silk,  which  extends  over  the  upper  surface  of  the  cylinder  to 
within  an  inch  of  a  row  of  metallic  points,  proceeding  from  a  hollow  rod  fixed  to 
the  side  of  the  opposite  conductor.  When  the  cylinder  is  driven  round  by  the 
handle,  the  friction  of  the  cushion  upon  it  produces  a  transfer  of  the  electric 
fluid  from  the  latter  to  the  former ;  that  is,  the  cushion  becomes  negatively,  and 
the  glass  positively,  electrified.  By  the  revolution  of  the  cylinder,  the  fluid 
adhering  to  the  glass  is  carried  round,  and  its  escape  prevented  by  the  silk  flap, 
until  it  arrives  near  to  the  metallic  points,  which  absorb  most  of  the  electricity, 
and  convey  it  to  the  prime  conductpr,  i>,  which  thus  becomes  positively  electri- 
fied, while  the  other  conductor,  having  parted  with  this  electricity,  is  negatively 
electrified. 

Fig.  4  represents  the  Plate  Electrical  Machine.  The  plate  is  turned  by  the 
handle  through  the  rubber,  which  is  coated  with  a  metallic  amalgam,  and 
diffuses  the  excitement  over  the  glass,  the  points  carrying  off  a  constant  stream 
of  positive  electricity  to  the  prime  conductor,  upon  the  principle  already 
described. 

Fig.  5  represents  the  Hydro-Electric  Machine,  an  apparatus  of  recent  date 
and  construction,  and  of  immense  power.  It  consists  of  a  steam  boiler,  A,  in- 
sulated on  stout  glass  pillars.  The  steam  is  made  to  issue  through  a  great  num. 
ber  of  bent  iron  tubes,  B  B,  terminating  in  jets  of  wood.  An  insulated  projecting 
eonductor,  c,  is  placed  in  connexion  with  the  boiler,  for  the  purpose  of  col'lecling 
the  excited  electricity ;  and  another  conductor,  D,  formed  of  a  metallic  case 
having  several  rows  of  points,  is  placed  immediately  in  front  of  the  jeta,  to  re- 
ceive and  carry  off  the  opposite  electricity  of  the  steam,  and  prevent  ita  return  to 
the  boiler,  by  which  the  excited  forces  would  be  neutralized.  The  electricity 
thus  produced  is  the  result  of  the  friction  of  condensed  particles  of  water,  whilst 
teing  driven  by  the  still  issuing  steam  through  the  jets,  these  watery  particles, 
performing  the  office  of  the  glass  plate,  or.  cylinder  of  the  common  machine,  and 
giving  out  vitreous  electricity.  The  wood  jets  and  pipes  act  as  the  rubfcei,  and 
give  out  resinous  electricity.  .  'r ; 


ELECTRICITY. 

Electricity  can  be  transferred  or  communicated  from  one  body  to  another. 
An  electrified  ball  can  be  deprived  of  its  electricity  by  being  touched  with  a 
metallic  rod,  but  if  we  touch  it  with  glass  or  wax  the  electricity  will  remain 
unaffected.  Hence,  metals  are  said  to  be  conductors,  and  glass  and  wax  non- 
conductors. Bodies  differ  greatly  in  their  power  of  conduction.  A  list  of  the 
principal  substances  that  possess  these  properties  will  be  found  on  the 
diagram.  The  most  convenient  mode  of  obtaining  an  accumulation  of  elec- 
tricity, is  by  employing  a  cylindrical  glass  jar,  coated  within  and  without  nearly 
to  the  top  with  tin-foil,  and  having  a  cover  of  baked  wood  incased  with  sealing- 
wax  to  exclude  moisture  and  dirt.  A  metallic  rod  rising  above  the  jar,  and  ter- 
minating in  a  brass  nob,  is  made  to  descend  through  the  cover  and  communicate 
with  the  interior  coating.  An  apparatus  of  this  kindjs  called  a  Leyden  jar,  and  is 
represented  at  fig.  6. 

Fig.  7  represents  a  discharging  rod,  for  establishing  a  communication  between 
the  inner  and  outer  coating  of  the  jar.  The  handle  is  of  glass,  to  prevent  the 
operator  from  receiving  the  charge  of  the  jar. 

By  uniting  a  sufficient  number  of  jars,  we  are  able  to  accumulate  a  large 
amount  of  electricity.  Such  a  combination  of  jars  is  called  an  Electrical  Battery. 
(fig.  8). 

Fig.  9  represents  an  instrument  called  a  Universal  Discharger,  which  is  used 
for  passing  charges  through  any  substance  that  may  be  laid  on  plate  A. 

Fig.  10  represents  an  Electro-meter,  an  instrument  used  to  detect  the  presence 
of  electricity.  If  charged,  either  by  placing  the  instrument  on  one  of  the  con- 
ductors of  a  machine,  or  on  the  rod  of  an  electrical  jar,  the  reed  rises  and  marks 
as  an  index  on  the  graduated  semicircle  the  angle  of  divergence,  by  which  the 
comparative  amount  of  electrification  may  be  estimated.  The  hairs  upon  the 
well-known  electrical  toy,  represented  at  fig.  11,  are  spread  out,  and  stand  on  end 
upon  the  same  principle. 

Fig.  12  represents  two  bells  suspended  from  a  brass  wire,  D  i>,  supported  by 
a  glass  pillar,  A.  The  electricity  being  conducted  to  the  knob  E,  passes  down 
the  wires,  D  D,  to  the  bells,  which  are  then  positively  electrified,  and  attract  the 
clappers,  c  c,  that  are  negatively  so,  in  consequence  of  being  insulated  by  silken 
strings.  The  clappers  having  become  charged,  strike  against  the  centre  bell  to 
discharge  themselves,  and  thus  a  peal  is  rung  on  the  bells  till  the  electricity  is 
taken  off. 

Electric  sparks  are  of  a  bluish  colour  in  the  atmosphere  in  its  ordinary  state, 
und  their  character  depends  almost  entirely  on  the  form,  area,  and  electrical 
intensity  of  the  discharging  surfaces.  If  the  small  ball,  p  (fig.  13),  be  attached  to 
the  prime  conductor  of  a  machine,  and  a  larger  ball,  N,  be  presented  to  it,  a 
series  of  brilliant  sparks,  of  a  crooked  or  zigzag  form,  will  pass  from  the  smaller  to 
the  larger  ball.  When,  however,  electricity  is  given  off  from  short  points,  it 
is  unaccompanied  by  noise,  and  presents  the  brush -like  appearance  represented 
at  fig.  14. 

The  influence  of  pointed  conductors  on  electrically  charged  bodies,  was  first 
observed  by  Franklin,  who  showed  that  when  presented  to  them,  their  charges 
became  silently  and  rapidly  dissipated.  Hence,  the  utility  of  pointed  conductors 
to  secure  buildings  from  the  effects  of  lightning  (fig.  15). 

Galvanism- — The  production  of  electricity  in  this  case  arises  from  the  cor- 
roding action  of  an  acid  upon  metallic  surfaces.  The  acid  being  interposed  be- 
tween two  plates  of  dissimilar  metals,  usually  copper  and  zinc,  and  the  zinc 
being  the  more  oxidable,  gives  out  positive  electricity.  The  two  plates  are  con- 
nected together  at  the  top  by  a  wire,  and  this  communciation  establishes  what  is 
called  a  voltaic  or  galvanic  circuit ;  the  electricity  circulating  round  the  zinc, 
wire,  copper,  and  liquid  (fig.  16). 

There  are  many  fortes  of  galvanic  batteries.  Fig.  17,  represents  Daniell's 
battery,  consisting  of  a  cylinder  of  copper  containing  a  porous  tube,  having  a 
solid  rod  of  amalgamated  zinc  in  its  centre.  Fig.  18,  represents  Griffin's  im- 
proved Smee's  battery,  consisting  of  six  cells ;  the  plates  are  arranged  upon  a 
frame  suspanded,  by  means  of  a  rod  and  rocket  wheel,  over  the  trough  con- 
twining  the  exciting  liquid.  By  this  arrangement  any  desired  degree  of  powei 
may  be  obtained  by  merely  raising  or  depressing  the  frame. 


I  (• 


CONDUCTORS 

.•1rnilH)rii  in  n/'f fi •/•  ni' iln'ir  C<>ndut~tihiiitv 


iliuii  ijj-on.&  Mel  aJ  s  in  <7«'n«irHl,ChnrroalFhiinbiio  .fon 
i<ls.J>i]iitf-d-A<-Kis.SrtJineS.»lutJi 
l  Flu i<l.s,Watcr,Jjvj)io.\!ni)i;<J:<  ,v 


NON   CONDUCTORS 

Arranged  in  orrier  of  Ihw  n»n  <;>/t,/<,,if'/,;/,/ 


Slidllac.Ajuher,  Resins,  Sniphm-,  Wax.  {jr-ass.Viu-i 
Minei^Js,Silk>T(Hi].Haii;Featliers.J.f-atJn'r,  Air.          ' 
Gases.  »akH  Wood.Drv  Vpgetalilc  B<»li«-.s. 
.  Caontchouc.Drv  Chi\Jk.  LJ>II«-.  lMi 
Ashes  of  Animal*  and  V»-srei;it>J«-  Modif-s  Oil 


MAGNETISM. 

THE  theory  of  magnetism  bears  a  very  strong  resemblance  to  that  of  electri- 
city. Like  it,  magnetism  has  its  attractions  and  repulsions,  and  it  can  be  ex- 
cited in  one  body  and  transferred  to  another,  with,  however,  this  striking  pecu- 
liarity, that  carbonized  iron  or  steel,  is  nearly  the  only  substance  capable  of 
exhibiting  any  strong  indication  of  its  presence.  The  loadstone,  or  natural 
magnet  (fig.  1),  is  a  hard,  dark  coloured  mineral,  found  chiefly  in  iron  mines  ; 
it  is,  however,  seldom  used,  as  its  properties  can  be  imparted  to  bars  of  steel, 
which  may  be  made  more  powerful  than  itself. 

Fig.  2  illustrates  the  polarity  of  the  magnet.  If  a  bar  or  needle,  which  has 
been  rendered  magnetic,  be  accurately  poised  on  a  point,  one  of  its  ends  will 
point  towards  the  north,  and  the  other  towards  the  south ;  hence,  those  parts  of 
the  magnet  are  termed  the  north  and  south  poles. 

The  reciprocal  attractions,  repulsions,  and  neutralizations  of  the  opposite 
magnetic  forces  may  be  illustrated  by  straining  a  piece  of  paper  upon  an  open 
frame,  and  placing  it  over  a  bar  magnet  (N  s,  fig.  3).  If  some  iron  filings  be 
now  sifted  upon  the  paper  screen,  the  particles  will  arrange  themselves  in  a  series 
of  curved  lines,  proceeding  from  similar  points  on  each  side  of  the- middle  of  the 
bar;  others  will  stand  out  at  the  extremities,  as  if  repelled  from  the  poles  HT  s. 
If  the  opposite  poles  of  two  magnets  be  presented  to  each  other,  ati  about  two 
inches  distance,  and  iron  dust  be  projected  over  them  as  before,  similar  results 
will  ensue.  Magnetic  lines  proceeding  from  similar  points  of  each  bar  will 
appear  uniting  the  two  poles,  as  represented  at  fig.  4.  If  two  similar  poles  be 
presented  to  each  other,  the  lines  of  force  mutually  repelling  each  other,  will 
present  the  appearance  shown  at  fig.  5. 

Fig.  6  represents  the  horse-shoe  form  of  magnet,  in  which  the  two  poles 
are  brought  near  together,  so  as  to  attract  a  piece  of  iron  by  their  combined 
force. 

The  earth  itself  is  found  to  be  a  vast  magnet,  having  its  two  magnetic  poles 
situated  in  the  neighbourhood  of,  but  at  some  distance  from,  its  poles  of  revolu- 
tion. ^  This  is  the  reason  why  magnetized  needles  point  in  a  north  and  south 
direction,  not  to  the  earth's  axis  (except  at  certain  places),  but  to  the  magnetic 
poles.  This  will  be  seen  by  reference  to  fig.  7,  which  represents  compass  needles 
distributed  over  the  globe,  all  lying  in  the  direction  of  lines  drawn  from  one 
magnetic  pole  to  the  other. 

Fig.  8  represents  the  manner's  compass,  the  most  essential  part  of  which  is  a 
magnetized  bar  of  steel,  called  the  needle,  accurately  poised  on  a  fine  central 
point  within  a  bowl  or  case,  which  is  so  supported  as  always  to  preserve  a  hori- 
zontal position.  Upon  the  needle  is  placed  the  circular  card  represented  at 
fig.  <J,  the  ornamental  point  N  being  placed  over  the  north  pole  of  the  needle, 
consequently  the  points  round  the  circle  indicate  the  cardinal  and  all  interme- 
diate points. 

The  inclination,  or  dip  of  the  needle— that  is,  its  deviation  from  the  horizontal 
plane — affords  a  manifestation  of  the  influence  exercised  upon  it  by  the  magnetism 
of  the  earth.  Hence  a  dipping  needle  poised  on  a  horizontal  axis  (as  fig.  10"). 
will,  when  carried  to  either  of  the  earth's  magnetic  poles,  stand  upright,  the  end 
which  is  upward  at  one  pole,  being  downward  at  the  other.  The  further  we 
recede  from  either  pole,  the  less  does  the  needle  dip,  as  shown  at  fig.  11,  where 
the  dotted  lines  indicate  the  lines  of  equal  dip,  or  parallels  of  magnetic  latitude, 
and  A  and  B,  the  north  and  south  magnetic  poles. 

Electro  Magnetism. — This  department  of  science  is  founded  on  the  con- 
nection ascertained  to  exist  between  electricity  and  magnetism.  A  (fig.  12) 
represents  a  bar  of  soft  iron,  bent  into  the  horse-shoe  form,  around  it  is  coiled  a, 
quantity  of  copper-wire  covered  with  silk.  The  ends  of  the  wire  are  connected 
with  the  poles  of  an  active  voltaic  battery,  the  electricity  from  which  passing 
along  the  coiled  wire,  converts  the  soft  iron  bar  into  a  powerful  electro -magnet, 
capable  of  sustaining,  by  its  attractive  force,  a  weight  of  many  hundred  pounds, 
and  which  it  will  continue  to  support  so  long  as  the  connection  with  the  battery 
is  maintained,  but  the  moment  that  connection  is  broken,  the  magnetic  power  of 
the  iron  ceases,  and  the  weights  fall. 

The  magnetic  action  circulates  round  the  wire  in  two  currents,  moving  in  op- 
posite directions,  as  represented  at  fig,  13.  The  wire  being  electric  along  it« 
length  and  magnetic  across. 


MAGNETISM. 


Fig.  14,  illustrates  the  action  of  electric  currents  upon  a  magnetic  needle.  A  A, 
is  a  coil  of  copper  wire,  B,  a  magnetic  needle  freely  poised,  and  pointing  north  and 
south.  If  the  wire,  c,  be  connected  with  the  copper  pole,  and  the  wire,  D,  with 
the  zinc  pole,  of  an  active  voltaic  battery,  the  needle  will  turn  eastward,  and  upon 
reversing  the  wires,  the  needle  will  turn  westward.  Upon  this  simple  principle 
depends  the  action  of  that  astonishing  apparatus  the  Electric  Telegraph,  of  which 
our  limits  will  only  allow  a  brief  description. 

Fig.  15,  represents  a  front  view  of  the  Telegraph  instrument  in  which  two 
needles  are  employed.  Upon  the  dial  plate  are  arranged  certain  letters,  figures, 
and  conventional  signs.  At  the  top  of  the  instrument,  within  an  ornamental 
case,  is  placed  a  bell  or  alarum  to  call  attention  to  the  instrument  when  a  com- 
munication is  about  to  be  made.  The  alarum  is  put  in  action  by  a  current  of 
electricity  being  passed  through  a  coil  of  wire  encircling  a  piece  of  soft  iron,  which 
is  thus  converted  into  an  electro-magnet,  and  attracts  a  lever,  by  which  clock-work 
is  set  in  motion,  and  the  hammer  caused  to  strike  the  alarum. 

Fig.  16,  represents  the  internal  mechanism  for  moving  each  needle.  The  handle 
shown  on  the  front  of  the  instrument  is  attached  to  and  works  the  cylinder  A.  This 
cylinder  has  its  two  ends  capped  with  brass  and  insulated  from  each  other  by  a 
belt  of  wood  B  ;  from  the  under  part  of  one  end  projects  a  steel  pin,  c,  and  from 
the  upper  part  of  the  other  end,  a  similar  pin,  z,  these  pins  representing  the  copper 
and  zinc  poles  of  the  battery  with  which  they  are  in  connection.  In  giving  a  sig- 
nal, the  handle  is  turned  either  to  the  right  or  left  according  to  the  direction  the 
needle  is  required  to  take.  Thus,  by  turning  the  cylinder  so  as  to  press  the  pin,  z, 
against  the  spring  D,  separating  the  latter  from  the  point  on  the  brass  rod,  E,  the 
pin,  c,  is  brought  into  contact  with  the  boss,  F.  The  electric  current  now  passes 
from  the  pin,  c,  by  the  boss  and  metallic  conductor  through  the  wire  coils,  deflects 
the  needle,\  and  passing  from  the  terminal,  H,  to  the  line  wire  it  similarly  deflects 
the  needles  of  all  the  instruments  in  connection,  and,  being  conducted  at  the  extre- 
mity of  the  line  to  a  plate  of  metal  buried  in  the  ground,  it  is  transmitted  by  the 
earth  to  the  terminal,  G,  and  by  the  conductor  and  spring,  D,  to  the  pin  z.  By 
reversing  the  movement  of  the  cylinder  the  direction  of  the  current  is  also  reversed, 
and  the  needles  are  deflected  in  the  opposite  direction. 

Magneto-Electricity. — As  magnetism  is  derived  from  electricity,  so  elcctri 
city  may  be  obtained  from  magnetism.  If  a  piece  of  soft  iron,  A  A,  fig.  17,  encir- 
cled by  coils  of  copper  wire  be  brought  into,  or  removed  from  contact  with  the 
poles  of  a  magnet,  B  B,  electrical  currents  of  a  considerable  magnitude  are  produced 
in  the  Avire,  and  sparks  will  pass  between  the  ends  of  the  wire,  p  and  N.  To  pro- 
duce the  effect,  it  is  essential  that  the  magnet  be  in  motion,  or  that  the  conductor 
be  in  motion  across  the  magnet. 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

LOAN  DEPT. 

This  book  is  due  on  the  last  date  stamped  below,  or 

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.9^-fr 

6KC'D  t 

AUG  1  1  1963 

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General  Library 
LD  2  1  A-5  Om-  1  1  ,'  62                             University  of  California 
(D3279slO)476B                                           Berkeley 

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