June  i,  1893.] 
THE  TROPICAL  AGRICULTURIST. 
761 
THE  TECHNICAL  INSTITUTE. 
In  an  interview  with  the  representative  ot  a 
contemporary  Mr.  Hrarnn,  the  Instructor  of  the 
Teohnioal  Institute  whioh  will  be  temporarily  oarried 
on  in  the  Old  St.  Sebastian  Mills  is  reported  to  have 
said  with  regard  to  the  ourriculum 
“In  the  wood-work  shop  we  shall  teaoh  the  prin- 
ciples of  working  in  wood,  with  no  regard  to  any 
particular  branch  of  trade.  The  training  we  shall 
give  will  be  such  as  will  fit  a pupil  for  beginning 
any  kind  of  woodwork,  and  it  will  also  fit  him  for 
handicraft  in  other  directions.  We  shall  teach  him 
how  to  handle  and  use  tools,  how  to  make  joints, 
bow  to  use  the  plane,  and  the  use  of  tools  generally, 
and  in  illustrating  these,  more  or  less  useful 
ends  are  looked  to.  We  shall  have  lathes  for  wood- 
working also.  In  the  metals  workshop  there 
will  be  training  in  the  uses  of  the  lathe  and 
planing  and  drilling  machines,  and  the  students 
will  have  to  do  a certain  amount  of  smith's 
work  The  training  is  of  a very  through  nature,  and 
before  a student  makes  a thing  he  has  to  draw  it, 
after  which  he  makes  it  according  to  the  drawing,  and 
this  he  will  be  taught  to  do  in  the  drawing  school  ; 
while  the  lectures  will  further  increase  his  knowledge 
of  fundamental  prinoip'es  and  their  applications,  and 
when  the  pupil  has  required  this  knowledge,  higher 
work  can  be  undertaken  under  the  auspices  of  the 
school,  anti  he  will  be  able  to  draw  more  complicated 
objects — which  he  need  not  make,  although  there 
will  be  a chance  for  him  to  make  them. 
Suppose  a complete  machine  is  undertaken,  I mean, 
he  will  work  on  parts  of  this  machine  ; also  he  will 
undergo  a training  in  the  laboratory  for  mechanics 
and  physics,  and  get  a grounding  in  the  general  laws 
whioh  govern  the  motions  of  bodies,  the  stability 
and  equilibrium  of  structures,  and  the  strength  of 
material*,  and  similarly  in  Physics,  by  means  of 
handling  the  apparatus  which  exhibits  them.  In  the 
physical  laboratory  the  first  thiDg  a student  will 
be  required  to  do  will  be  to  make  a thermometer. 
With  regard  to  the  cost  of  the  school  he  said 
“ I cannot  say  even  approximately  yet  what  the 
cost  of  the  echool  is  likely  to  be.  In  the  larger 
sohools  in  England  the  deficiency  that  has  to  be 
made  up  is  about  £2  a head  every  year.  These  are 
very  large  sohools,  however  ; in  smaller  schools  the 
deficiency  is  greater.  Here,  with  the  low  fees  that 
prevail,  the  deficiency  woold  of  course  be  larger. 
Suppose,  say,  the  cost  of  the  school  were  about  £600 
and  we  had  50  students,  I do  not  suppose  we  would  get 
much  more  than  £1  a year  from  each  out  of  the 
students,  which  would  leave  a deficieooy  of  £550,  or 
£11  a head.  I hope,  however,  we  will  be  able  to  cet 
more  than  a pound  a head  in  the  way  of  fees.  We 
shall  not  make  articles  for  sale.  The  objection  to 
that  is  that,  instead  of  pupils  learning,  it  makes  the 
school  more  of  a factory,  and  the  school  must  not  take 
the  place  of  a factory  in  any  sense. 
* 
IMITATIONS  OF  PRECIOUS  STONES. 
A recent  writer  in  a Washington  technical  journal 
describes  the  methods  employed  for  producing  imita- 
tions of  precious  stones.  He  says  that  in  maju- 
facturing  glass  for  this  purpose  the  processes  emplo\el 
have  to  be  conducted  with  the  utmost  nicety.  For 
making  even  the  best  mirrors  the  necessary  silica  is 
obtained  from  ordinary  white  quartz,  while  common 
window  panes  are  produced  from  sea  sand  to  a large 
extent;  but  in  this  case  rock  crystal  is  substituted, 
composing  about  50  per  cent  of  the  ingredients  of 
the  paste.  To  it  must  be  added  22  per  cect  of 
carbonate  of  soda,  and  due  proportions  of  calcined 
borax,  saltpetre,  and  red  lead.  All  of  these  things 
are  reduced  to  the  finest  powder,  mixed,  fused  to- 
gether by  heat  in  a crucible  add  cooled  slowly.  The 
density,  transparency,  and  beauty  of  the  plate  depend 
upon  the  care  taken  in  these  processes.  Thus,  made 
H is  ready  to  be  cut  into  diamonds  and  prepared 
for  market.  It  may  be,  however,  that  the  manu- 
fftoture*  desires  to  produce  counterfeit  genus  of  all 
sorts.  If  he  wants  rubies  be  fuses  with  the  paste  a 
small  quantity  of  peroxide  of  maogenese  and  a trace 
of  Cassius  purple,  which  will  give  the  proper  colour. 
For  emeralds  he  employs  in  like  manner  oxide  of 
iron,  and  for  sapphires  oxide  of  oobalt.  Topaz  is 
easily  formed  in  the  crncible  by  mixing  with  1,000 
parts  of  paste,  40  parts  of  glass  of  antimony,  and 
1 part  of  Cassius  purple.  For  manufacturing  other 
kinds  of  gems  there  are  methods  equally  simple.  Of 
course  these  imitation  preoious  stones  have  not  the 
chemical  construction,  hardness,  specific  gravity,  or 
optical  properties  of  real  ones.  Accordingly  their 
spurious  character  is  readily  perceived  by  an  expert. 
Inasmuch  as  the  elements  of  whioh  various  gems  are 
composed  are  well-known,  synthetio  ohemistry  has 
attempted  to  reproduce  them  by  putting  the  ingredi- 
ents together  and  effecting  crystallisation  in  the 
laboratory.  In  this  way  large  masses  of  what  might 
be  termed  true  rubbies  and  sapphires  are  turned  out 
artificially,  such  gem-like  material  having  some  use- 
fulness for  industrial  purposes,  although  lacking  the 
brillianoy  of  nature’s  products. 
THE  COMING  JAVA  CINCHONA  CROP. 
From  a return  just  to  hand  which  has  been  com- 
piled by  the  Java  Planters’  Association,  a Commis- 
sion of  which  has  collected  statistics  from  all  the 
plantations  on  the  island,  (with  a very  few  unimportant 
exceptions),  it  appears  that  the  exports  for  the  year 
1893  are  likely  to  amount  to  3,783,839  kilos,  of  bark 
(against  3,232,922  kilos,  in  1892),  representing  169,761 
kilos,  sulphate  of  quinine,  as  compared  with  138,315 
kilos,  last  year.  The  average  percentage  of  the  bark 
this  season  (quin,  sulph.)  is  estimated  at  4'48  ; last  year 
it  was  4'27.  If  these  figures  prove  approximately  correct 
(as  the  statistics  for  the  last  four  seasons  have  done), 
the  present  year’s  exports  will  exceed  by  about  10 
per  cent,  those  of  1891,  when  they  were  the  highest 
on  record,  and  will  surpass  those  of  1892  by  17  per  cent, 
in  weight  and  by  23  per  cent,  in  quinine  value.  “This 
increased  production  (the  Commission  report)  is  in 
some  degree  due  to  the  total  or  partial  uprooting  of 
a few  plantations,  and  in  some  degree  to  the  fact 
that  younger  plantations  of  a higher  standard  are 
gradually  being  brought  into  exploitation.”  “ Java, 
they  add,  “ till  remains  on  the  wrong  edge  of  over- 
production, and  caution  should  be  exercised  in 
harvesting  and  in  laying  down  new  plantations.” 
Out  of  ninety-seven  plantations  now  in  existence  on 
the  island,  five  are  not  yet  harvesting  anything,  six 
will  produce  a crop  for  the  first  time  this  season,  three 
have  been  wholly  or  partially  uprooted,  and  six  are 
temporarily  suspending  their  bark  shipments.— 
Chemist  and  Druggist , April  8, 
4, 
PROSPECTS  OF  THE  TEA  SEASON 
AT  FOOCHOW. 
The  departure  of  many  of  the  teamen  this  week 
for  what  are  known  as  the  high  districts,  with 
treasure,  opium  and  lead  for  the  purchase  of  the 
new  season’s  leaf,  leads  to  the  consideration  of  what 
the  prospects  are  for  season  1893-94.  The  informa- 
tion given  us  at  this  time  last  year  by  certain 
teamen  of  our  acquaintance  regarding  the  prospects 
last  season  proved  to  be  so  correct  that  we  are  quite 
willing  to  give  credence  to  what  we  have  learned 
from  the  same  source  within  the  last  few  days.  The 
general  impression  is  that  foreign  buyers  have 
done  well  in  the  past  season.  Much  importance  is 
attached  to  the  traditional  belief  that  a tea  crop 
following  a heavy  fall  of  snow  must  be  a 
good  one ; and  on  the  strength  of  these 
premises  more  men  and  more  money  are  going 
up  country  than  last  year.  This  means  more 
competition  and  consequently  higher  prices  ; for, 
contrary  to  the  general  experience  that  a good  orop 
will  be  a large  one,  this  year,  is,  according  to  accounts 
from  the  country,  to  prove  a singular  exception. 
The  reason  given  for  tnis  is  that  the  ends  of  the 
branohes  of  the  plants  were  so  frost-bitten  that  they 
bad  to  be  out  back  to  such  an  extent  that  tbe  pointy 
