Magazine  of  the  School  of  Agriculture. 
53 
regime  of  publicity.  There  may  probably  have 
been  as  many  as  a hundred  patents  in  the  matur- 
ing of  photography,  and  a great  numberof  different 
contributors.  They  followed  each  other  at  first 
slowly  but  in  recent  years  the  development  of  the 
invention  has  been  indicated  by  rapid  progress. 
The  last  achievement  of  the  art  that  has  come  un- 
der my  notice  w’as  a set  of  illustrations  in  the  It  ci- 
vile des  Sciences  of  photograped  cannon  shot  in 
flight.  They  are  the  greatest  triumphs  of  instan- 
taneous photography  yet  accomplished.  The  elec- 
tric light  is  another  instance  of  progressive  de- 
velopment. and  it  seems  to  be  yet  far  from  the 
maturity  which  may  be  hoped  for  it.  The  aniline 
dyes  afford  another  and  important  illustration. 
Commencing  when  benzole,  an  essent  ial  ingredient 
was  obtained  from  tar,  its  use  as  a dying  material 
was  taken  up  successively  by  chemists,  and  then 
by  practical  dyers,  until  the  aniline  dyes  came  into 
uni\  ersal  use.  The  last  illustration  of  this  kind 
to  which  1 will  invite  your  attention,  is  the  very 
familiar  seuing  machine.  Many  attempts  were 
made  before  success  wras  attained.  Embroidery 
was  done  mechanically  long  before  proper  sewing 
was  done  by  machine.  The  problem  was  solved 
by  Elias  Howe  in  1846.  His  machine  was  me- 
chanically imperfect,  but  it  contained  the  one  es- 
sential feature,  without  which  no  true  sewing 
machine  is  practicable,  that  is  : a needle  with  the 
eye  in  the  point.  Fortunately,  the  inventor  in- 
cluded this  item  in  the  claim  under  his  patent,  and 
though  the  mechanical  arrangements  of  his 
machine  were  little  esteemed  and  were  -speedily 
superseded,  the  sum  he  received  and  heartily 
merited  was,  over  2 million  dollars.  The  problem 
once  solved,  a great  many  improvements  were 
made,  and  accessories  were  added,  until  the  inven- 
tion reached  its  present  perfection,  and  its  appli- 
cation extended  to  all  kinds  of  sewing,  including 
every  kind  of  fancy  stitch. 
This  last  example  would  serve  equally  to  illus- 
trate those  inventions  which  have  for  their  object 
to  substitute  mechanical  contrivances  for  the  use 
of  the  human  hand.  These  constitute  the  great 
majority  of  all  mechanical  inventions.  There  are 
scarcely  any  manual  operations  of  importance, 
for  which  machinery  has  not  been  adopted. 
Time  wTould  fail  us  to  adduce  adequate  examples 
of  this  class.  We  may  mention  two  however, 
which  afford  lessons  to  the  technical  student, 
not  suggested  by  those  already  given.  One  is  that 
of  an  invention  to  supersede  corks  for  closing 
bottles  by  substituting  a screwed  stopper  to  be 
used  with  a washer  of  indiarubber  or  cork.  The 
inventor,  a wealthy  old  retired  merchant,  expati- 
ated on  the  eonvenience  his  invention  would  af- 
ford, especially  for  champagne  and  effervescing 
drinks  from  which  a glass  could  be  taken  and  the 
bottle  resealed.  After  having  secured  his  patent, 
he  took  his  invention  to  a bottle  manufacture,  who 
ghowed  him  that  his  plan  was  impracticable  by 
the  usual  method  of  making  bottles,  and  would 
require  a special  apparatus.  Fortbis  the  patentee 
had  to  seek  the  help  of  a mechanical  engineer, 
who  supplied  what  was  accessary.  Otherwise, 
the  invention  would  have  died  at  its  birth.  The 
other  example  is  one  in  which  two  inventors 
simultaneously  invented  the  means  whereby  the 
driver  of  a Hansom  Cab  could  open  or  shut  the 
doors  of  his  Cab  without  moving  from  his  seat. 
The  two  inventors  worked  independently,  and 
neither  knew  of  the  other’s  proceeding.  Eventu- 
ally, the  one  who  was  senior,  by  a few  days  only 
filed  his  specification,  and  the  other  followed  im- 
mediately after.  Their  inventions  were  substan- 
tially different,  but  had  one  feature  in  common., 
This  feature  the  former,  who  was  an  amateur, 
claimed  as  part  of  his  invention,  not  knowing  that 
it  was  in  common  use.  The  other,  who  was  an 
expert,  avoided  that  mistake,  in  consequence  of 
which  the  later  patent  w-as  good  and  the  former 
was  invalid,  by  its  having  claimed  as  a novelty  a 
well-known  expedient,  the  universal  joint.  These 
two  examples  show  the  importance  to  inventors  of 
a thorough  acquaintance  with  the  processes  and 
designs  they  propose  to  improve  upon,  and  also  to 
be  conversant  with  all  the  mechanical  expedients 
in  ordinary  use,  lest  they  should  claim  as  a novelty 
one  that  is  well  known. 
The  foregoing  exumples  and  illustrations  are 
adduced  to  give  a general  idea  of  the  commonest 
causes  of  failure,  and  the  general  conditions  neces- 
sary to  success,  and  they  are  to  be  considered  only 
in  their  bearing  on  these  points.  It  was  deemed 
necessary  for  this  purpose  to  select  such  inven- 
tions as  are  either  well  known,  or  were  easily 
understood,  and  would  therefore  convey  clearer 
ideas  than  others  less  'popular,  that  might  have 
afforded  more  striking  evidence.  They  show,  in 
general  terms,  that  there  are  three  principal  quali- 
fications for  successful  invention,  namely: — 
First,  a know  ledge  of  constructive  powers,  tools 
and  api  l ances  for  giving  effect  to  the  inventor’s 
ideas.  Puckle  and  the  inventor  of  the  bottle 
stopper  failed  for  want  of  this  qualification,  and 
Whitworth  succeeded  mainly  by  virtue  of  his  in- 
timate knowledge  of  what  could  be  accomplished 
by  the  means  he  could  command. 
Secondly.  A knowledge  of  metals  and  materials, 
their  capabilities,  and  special  qualities,  and  adap- 
tability to  the  purposes  required.  The  sub- 
marine cable  is  a notable  instance  of  success,  and 
the  lead-coated  projectile  of  failure  attributable 
to  this  cause. 
Thirdly.  An  inventor  must  be  thoroughly  ac- 
quainted with  all  the  available  devices  and  ex- 
pedients by  which  required  mechanical  movements 
may  be  produced.  This  knowledge  is  indispens- 
able, and  is  called  into  requisition  in  almost  every 
mechanical  contrivance  for  superseding  hand 
labour.  Almost  all  the  complex  movements  of  the 
human  hand  may  be  simulated  by  suitable  mecha- 
nical expedients,  as  may  be  seen  well  illustrated 
in  the  common  sewing  machine,  and  still  more 
perfectly  in  some  other  machines  well-known  in 
the  mother  country  which  have  not  yet  been  in- 
troduced here. 
In  order  that  technical  students  in  Ceylon 
should  acquire  these  three  essential  qualifications 
for  successful  invention,  it  will  be  absolutely 
necessary  that  they  should  have  access  to  a 
museum  or  gallery  of  illustration,  furnished  with 
working  models  of  machines,  tools,  materials,  and 
appliances,  that  will  exhibit  this  essential  infor- 
mation practically,  not  merely  by  seeing  them, 
but  by  close  investigation  and  dissection.  It  is 
as  essential  to  the  technical  student  that  he  should 
dissect  machines,  tools,  and  contrivances,  as  that 
the  botanist  should  investigate  the  various  parts 
of  a plant,  or  that  the  medical  student  should 
study  the  anatom y of  the  human  frame  by  operat- 
ing on  the  human  corpse.  It  is  not  enough  that 
