industrial biography-µÚ51ÕÂ
°´¼üÅÌÉÏ·½Ïò¼ü ¡û »ò ¡ú ¿É¿ìËÙÉÏÏ·ҳ£¬°´¼üÅÌÉ쵀 Enter ¼ü¿É»Øµ½±¾ÊéĿ¼ҳ£¬°´¼üÅÌÉÏ·½Ïò¼ü ¡ü ¿É»Øµ½±¾Ò³¶¥²¿£¡
¡ª¡ª¡ª¡ªÎ´ÔĶÁÍꣿ¼ÓÈëÊéÇ©ÒѱãÏ´μÌÐøÔĶÁ£¡
Thus¡¡the¡¡expedients¡¡of¡¡wheels£»¡¡riggers£»¡¡and¡¡drums£»¡¡of¡¡different
diameters£»¡¡by¡¡which¡¡it¡¡had¡¡been¡¡endeavoured¡¡to¡¡alter¡¡the¡¡speed¡¡of¡¡the
lathe¡mandrill£»¡¡according¡¡to¡¡the¡¡hardness¡¡of¡¡the¡¡metal¡¡and¡¡the
diameter¡¡of¡¡the¡¡thing¡¡to¡¡be¡¡turned£»¡¡were¡¡effectually¡¡disposed¡¡of¡£
These£»¡¡though¡¡answering¡¡very¡¡well¡¡where¡¡cylinders¡¡of¡¡equal¡¡diameter
had¡¡to¡¡be¡¡bored£»¡¡and¡¡a¡¡uniform¡¡motion¡¡was¡¡all¡¡that¡¡was¡¡required£»¡¡were
found¡¡very¡¡inefficient¡¡where¡¡a¡¡Plane¡¡surface¡¡had¡¡to¡¡be¡¡turned£»¡¡and¡¡it
was¡¡in¡¡such¡¡cases¡¡that¡¡Mr¡£¡¡Clement's¡¡lathe¡¡was¡¡found¡¡so¡¡valuable¡£¡¡¡¡By
its¡¡means¡¡surfaces¡¡of¡¡unrivalled¡¡correctness¡¡were¡¡produced£»¡¡and¡¡the
slide¡lathe£»¡¡so¡¡improved£»¡¡became¡¡recognised¡¡and¡¡adopted¡¡as¡¡the¡¡most
accurate¡¡and¡¡extensively¡¡applicable¡¡of¡¡all¡¡machine¡tools¡£
The¡¡year¡¡after¡¡Mr¡£¡¡Clement¡¡brought¡¡out¡¡his¡¡improved¡¡turning¡lathe£»¡¡he
added¡¡to¡¡it¡¡his¡¡self¡adjusting¡¡double¡¡driving¡¡centre¡chuck£»¡¡for¡¡which
the¡¡Society¡¡of¡¡Arts¡¡awarded¡¡him¡¡their¡¡silver¡¡medal¡¡in¡¡1828¡£¡¡¡¡In
introducing¡¡this¡¡invention¡¡to¡¡the¡¡notice¡¡of¡¡the¡¡Society£»¡¡Mr¡£¡¡Clement
said£»¡¡¡¨Although¡¡I¡¡have¡¡been¡¡in¡¡the¡¡habit¡¡of¡¡turning¡¡and¡¡making
turning¡lathes¡¡and¡¡other¡¡machinery¡¡for¡¡upwards¡¡of¡¡thirty¡five¡¡years£»
and¡¡have¡¡examined¡¡the¡¡best¡¡turning¡lathes¡¡in¡¡the¡¡principal
manufactories¡¡throughout¡¡Great¡¡Britain£»¡¡I¡¡find¡¡it¡¡universally
regretted¡¡by¡¡all¡¡practical¡¡men¡¡that¡¡they¡¡cannot¡¡turn¡¡anything
perfectly¡¡true¡¡between¡¡the¡¡centres¡¡of¡¡the¡¡lathe¡£¡¨¡¡¡¡It¡¡was¡¡found¡¡by
experience£»¡¡that¡¡there¡¡was¡¡a¡¡degree¡¡of¡¡eccentricity£»¡¡and¡¡consequently
of¡¡imperfection£»¡¡in¡¡the¡¡figure¡¡of¡¡any¡¡long¡¡cylinder¡¡turned¡¡while
suspended¡¡between¡¡the¡¡centres¡¡of¡¡the¡¡lathe£»¡¡and¡¡made¡¡to¡¡revolve¡¡by
the¡¡action¡¡of¡¡a¡¡single¡¡driver¡£¡¡¡¡Under¡¡such¡¡circumstances¡¡the¡¡pressure
of¡¡the¡¡tool¡¡tended¡¡to¡¡force¡¡the¡¡work¡¡out¡¡of¡¡the¡¡right¡¡line¡¡and¡¡to
distribute¡¡the¡¡strain¡¡between¡¡the¡¡driver¡¡and¡¡the¡¡adjacent¡¡centre£»¡¡so
that¡¡one¡¡end¡¡of¡¡the¡¡cylinder¡¡became¡¡eccentric¡¡with¡¡respect¡¡to¡¡the
other¡£¡¡¡¡By¡¡Mr¡£¡¡Clement's¡¡invention¡¡of¡¡the¡¡two¡armed¡¡driver£»¡¡which¡¡was
self¡adjusting£»¡¡the¡¡strain¡¡was¡¡taken¡¡from¡¡the¡¡centre¡¡and¡¡divided
between¡¡the¡¡two¡¡arms£»¡¡which¡¡being¡¡equidistant¡¡from¡¡the¡¡centre£»
effectually¡¡corrected¡¡all¡¡eccentricity¡¡in¡¡the¡¡work¡£¡¡¡¡This¡¡invention
was¡¡found¡¡of¡¡great¡¡importance¡¡in¡¡ensuring¡¡the¡¡true¡¡turning¡¡of¡¡large
machinery£»¡¡which¡¡before¡¡had¡¡been¡¡found¡¡a¡¡matter¡¡of¡¡considerable
difficulty¡£
In¡¡the¡¡same¡¡year¡¡£¨1828£©¡¡Mr¡£¡¡Clement¡¡began¡¡the¡¡making¡¡of¡¡fluted¡¡taps
and¡¡dies£»¡¡and¡¡he¡¡established¡¡a¡¡mechanical¡¡practice¡¡with¡¡reference¡¡to
the¡¡pitch¡¡of¡¡the¡¡screw£»¡¡which¡¡proved¡¡of¡¡the¡¡greatest¡¡importance¡¡in
the¡¡economics¡¡of¡¡manufacture¡£¡¡¡¡Before¡¡his¡¡time£»¡¡each¡¡mechanical
engineer¡¡adopted¡¡a¡¡thread¡¡of¡¡his¡¡own£»¡¡so¡¡that¡¡when¡¡a¡¡piece¡¡of¡¡work
came¡¡under¡¡repair£»¡¡the¡¡screw¡hob¡¡had¡¡usually¡¡to¡¡be¡¡drilled¡¡out£»¡¡and¡¡a
new¡¡thread¡¡was¡¡introduced¡¡according¡¡to¡¡the¡¡usage¡¡which¡¡prevailed¡¡in
the¡¡shop¡¡in¡¡which¡¡the¡¡work¡¡was¡¡executed¡£¡¡¡¡Mr¡£¡¡Clement¡¡saw¡¡a¡¡great
waste¡¡of¡¡labour¡¡in¡¡this¡¡practice£»¡¡and¡¡he¡¡promulgated¡¡the¡¡idea¡¡that
every¡¡screw¡¡of¡¡a¡¡particular¡¡length¡¡ought¡¡to¡¡be¡¡furnished¡¡with¡¡its
appointed¡¡number¡¡of¡¡threads¡¡of¡¡a¡¡settled¡¡pitch¡£¡¡¡¡Taking¡¡the¡¡inch¡¡as
the¡¡basis¡¡of¡¡his¡¡calculations£»¡¡he¡¡determined¡¡the¡¡number¡¡of¡¡threads¡¡in
each¡¡case£»¡¡and¡¡the¡¡practice¡¡thus¡¡initiated¡¡by¡¡him£»¡¡recommended¡¡as¡¡it
was¡¡by¡¡convenience¡¡and¡¡economy£»¡¡was¡¡very¡¡shortly¡¡adopted¡¡throughout
the¡¡trade¡£¡¡¡¡It¡¡may¡¡be¡¡mentioned¡¡that¡¡one¡¡of¡¡Clement's¡¡ablest
journeymen£»¡¡Mr¡£¡¡Whitworth£»¡¡has£»¡¡since¡¡his¡¡time£»¡¡been¡¡mainly
instrumental¡¡in¡¡establishing¡¡the¡¡settled¡¡practice£»¡¡and¡¡Whitworth's
thread¡¡£¨initiated¡¡by¡¡Clement£©¡¡has¡¡become¡¡recognised¡¡throughout¡¡the
mechanical¡¡world¡£¡¡¡¡To¡¡carry¡¡out¡¡his¡¡idea£»¡¡Clement¡¡invented¡¡his
screw¡engine¡¡lathe£»¡¡with¡¡gearing£»¡¡mandrill£»¡¡and¡¡sliding¡table
wheel¡work£»¡¡by¡¡means¡¡of¡¡which¡¡he¡¡first¡¡cut¡¡the¡¡inside¡¡screw¡tools
from¡¡the¡¡left¡handed¡¡hobsthe¡¡reverse¡¡mode¡¡having¡¡before¡¡been
adopted£»while¡¡in¡¡shaping¡¡machines¡¡he¡¡was¡¡the¡¡first¡¡to¡¡use¡¡the
revolving¡¡cutter¡¡attached¡¡to¡¡the¡¡slide¡¡rest¡£¡¡¡¡Then£»¡¡in¡¡1828£»¡¡he¡¡fluted
the¡¡taps¡¡for¡¡the¡¡first¡¡time¡¡with¡¡a¡¡revolving¡¡cutter£»other¡¡makers
having¡¡up¡¡to¡¡that¡¡time¡¡only¡¡notched¡¡them¡£¡¡¡¡Among¡¡his¡¡other¡¡inventions
in¡¡screws¡¡may¡¡be¡¡mentioned¡¡his¡¡headless¡¡tap£»¡¡which£»¡¡according¡¡to¡¡Mr¡£
Nasmyth£»¡¡is¡¡so¡¡valuable¡¡an¡¡invention£»¡¡that£»¡¡¡¨if¡¡he¡¡had¡¡done¡¡nothing
else£»¡¡it¡¡ought¡¡to¡¡immortalize¡¡him¡¡among¡¡mechanics¡£¡¡¡¡It¡¡passed¡¡right
through¡¡the¡¡hole¡¡to¡¡be¡¡tapped£»¡¡and¡¡was¡¡thus¡¡enabled¡¡to¡¡do¡¡the¡¡duty¡¡of
three¡¡ordinary¡¡screws¡£¡¨¡¡¡¡By¡¡these¡¡improvements¡¡much¡¡greater¡¡precision
was¡¡secured¡¡in¡¡the¡¡manufacture¡¡of¡¡tools¡¡and¡¡machinery£»¡¡accompanied¡¡by
a¡¡greatly¡¡reduced¡¡cost¡¡of¡¡production£»¡¡the¡¡results¡¡of¡¡which¡¡are¡¡felt
to¡¡this¡¡day¡£
Another¡¡of¡¡Mr¡£¡¡Clement's¡¡ingenious¡¡inventions¡¡was¡¡his¡¡Planing
Machine£»¡¡by¡¡means¡¡of¡¡which¡¡metal¡¡plates¡¡of¡¡large¡¡dimensions¡¡were
planed¡¡with¡¡perfect¡¡truth¡¡and¡¡finished¡¡with¡¡beautiful¡¡accuracy¡£¡¡¡¡There
is¡¡perhaps¡¡scarcely¡¡a¡¡machine¡¡about¡¡which¡¡there¡¡has¡¡been¡¡more
controversy¡¡than¡¡this£»¡¡and¡¡we¡¡do¡¡not¡¡pretend¡¡to¡¡be¡¡able¡¡to¡¡determine
the¡¡respective¡¡merits¡¡of¡¡the¡¡many¡¡able¡¡mechanics¡¡who¡¡have¡¡had¡¡a¡¡hand
in¡¡its¡¡invention¡£¡¡¡¡It¡¡is¡¡exceedingly¡¡probable¡¡that¡¡others¡¡besides
Clement¡¡worked¡¡out¡¡the¡¡problem¡¡in¡¡their¡¡own¡¡way£»¡¡by¡¡independent
methods£»¡¡and¡¡this¡¡is¡¡confirmed¡¡by¡¡the¡¡circumstance¡¡that¡¡though¡¡the
results¡¡achieved¡¡by¡¡the¡¡respective¡¡inventors¡¡were¡¡the¡¡same£»¡¡the
methods¡¡employed¡¡by¡¡them¡¡were¡¡in¡¡many¡¡respects¡¡different¡£¡¡¡¡As¡¡regards
Clement£»¡¡we¡¡find¡¡that¡¡previous¡¡to¡¡the¡¡year¡¡1820¡¡he¡¡had¡¡a¡¡machine¡¡in
regular¡¡use¡¡for¡¡planing¡¡the¡¡triangular¡¡bars¡¡of¡¡lathes¡¡and¡¡the¡¡sides
of¡¡weaving¡looms¡£¡¡¡¡This¡¡instrument¡¡was¡¡found¡¡so¡¡useful¡¡and¡¡so
economical¡¡in¡¡its¡¡working£»¡¡that¡¡Clement¡¡proceeded¡¡to¡¡elaborate¡¡a
planing¡¡machine¡¡of¡¡a¡¡more¡¡complete¡¡kind£»¡¡which¡¡he¡¡finished¡¡and¡¡set¡¡to
work¡¡in¡¡the¡¡year¡¡1825¡£¡¡¡¡He¡¡prepared¡¡no¡¡model¡¡of¡¡it£»¡¡but¡¡made¡¡it¡¡direct
from¡¡the¡¡working¡¡drawings£»¡¡and¡¡it¡¡was¡¡so¡¡nicely¡¡constructed£»¡¡that
when¡¡put¡¡together¡¡it¡¡went¡¡without¡¡a¡¡hitch£»¡¡and¡¡has¡¡continued¡¡steadily
working¡¡for¡¡more¡¡than¡¡thirty¡¡years¡¡down¡¡to¡¡the¡¡present¡¡day¡£
Clement¡¡took¡¡out¡¡no¡¡patent¡¡for¡¡his¡¡invention£»¡¡relying¡¡for¡¡protection
mainly¡¡on¡¡his¡¡own¡¡and¡¡his¡¡workmen's¡¡skill¡¡in¡¡using¡¡it¡£¡¡¡¡We¡¡therefore
find¡¡no¡¡specification¡¡of¡¡his¡¡machine¡¡at¡¡the¡¡Patent¡¡Office£»¡¡as¡¡in¡¡the
case¡¡of¡¡most¡¡other¡¡capital¡¡inventions£»¡¡but¡¡a¡¡very¡¡complete¡¡account¡¡of
it¡¡is¡¡to¡¡be¡¡found¡¡in¡¡the¡¡Transactions¡¡of¡¡the¡¡Society¡¡of¡¡Arts¡¡for
1832£»¡¡as¡¡described¡¡by¡¡Mr¡£¡¡Varley¡£¡¡¡¡The¡¡practical¡¡value¡¡of¡¡the¡¡Planing
Machine¡¡induced¡¡the¡¡Society¡¡to¡¡apply¡¡to¡¡Mr¡£¡¡Clement¡¡for¡¡liberty¡¡to
publish¡¡a¡¡full¡¡description¡¡of¡¡it£»¡¡and¡¡Mr¡£¡¡Varley's¡¡paper¡¡was¡¡the
result¡£*
¡¡£§footnote¡£¡£¡£
Transactions¡¡of¡¡the¡¡Society¡¡for¡¡the¡¡Encouragement¡¡of¡¡Arts£»¡¡vol¡£¡¡xlix¡£
p¡£157¡£
¡¡¡£¡£¡££§
It¡¡may¡¡be¡¡briefly¡¡stated¡¡that¡¡this¡¡engineer's¡¡plane¡¡differs¡¡greatly
from¡¡the¡¡carpenter's¡¡plane£»¡¡the¡¡cutter¡¡of¡¡which¡¡is¡¡only¡¡allowed¡¡to
project¡¡so¡¡far¡¡as¡¡to¡¡admit¡¡of¡¡a¡¡thin¡¡shaving¡¡to¡¡be¡¡sliced¡¡off£»the
plane¡¡working¡¡flat¡¡in¡¡proportion¡¡to¡¡the¡¡width¡¡of¡¡the¡¡tool£»¡¡and¡¡its
length¡¡and¡¡straightness¡¡preventing¡¡the¡¡cutter¡¡from¡¡descending¡¡into
any¡¡hollows¡¡in¡¡the¡¡wood¡£¡¡¡¡The¡¡engineer's¡¡plane¡¡more¡¡resembles¡¡the
turning¡lathe£»¡¡of¡¡which¡¡indeed¡¡it¡¡is¡¡but¡¡a¡¡modification£»¡¡working¡¡up
on¡¡the¡¡same¡¡principle£»¡¡on¡¡flat¡¡surfaces¡£¡¡¡¡The¡¡tools¡¡or¡¡cutters¡¡in
Clement's¡¡machine¡¡were¡¡similar¡¡to¡¡those¡¡used¡¡in¡¡the¡¡lathe£»¡¡varying¡¡in
like¡¡manner£»¡¡but¡¡performing¡¡their¡¡work¡¡in¡¡right¡¡lines£»the¡¡tool
being¡¡stationary¡¡and¡¡the¡¡work¡¡moving¡¡under¡¡it£»¡¡the¡¡tool¡¡only
travelling¡¡when¡¡making¡¡lateral¡¡cuts¡£¡¡¡¡To¡¡save¡¡time¡¡two¡¡cutters¡¡were
mounted£»¡¡one¡¡to¡¡cut¡¡the¡¡work¡¡while¡¡going£»¡¡the¡¡other¡¡while¡¡returning£»
both¡¡being¡¡so¡¡arranged¡¡and¡¡held¡¡as¡¡to¡¡be¡¡presented¡¡to¡¡the¡¡work¡¡in¡¡the
firmest¡¡manner£»¡¡and¡¡with¡¡the¡¡least¡¡possible¡¡friction¡£¡¡¡¡The¡¡bed¡¡of¡¡the
machine£»¡¡on¡¡which¡¡the¡¡work¡¡was¡¡laid£»¡¡passed¡¡under¡¡the¡¡cutters¡¡on
perfectly¡¡true¡¡rollers¡¡or¡¡wheels£»¡¡lodged¡¡and¡¡held¡¡in¡¡their¡¡bearings
as¡¡accurately¡¡as¡¡the¡¡best¡¡mandrill¡¡could¡¡be£»¡¡and¡¡having¡¡set¡screws
acting¡¡against¡¡their¡¡ends¡¡totally¡¡preventing¡¡all¡¡end¡motion¡£¡¡¡¡The
machine¡¡was¡¡bedded¡¡on¡¡a¡¡massive¡¡and¡¡solid¡¡foundation¡¡of¡¡masonry¡¡in
heavy¡¡blocks£»¡¡the¡¡support¡¡at¡¡all¡¡points¡¡being¡¡so¡¡complete¡¡as
effectually¡¡to¡¡destroy¡¡all¡¡tendency¡¡to¡¡vibration£»¡¡with¡¡the¡¡object¡¡of
securing¡¡full£»¡¡round£»¡¡and¡¡quiet¡¡cuts¡£¡¡¡¡The¡¡rollers¡¡on¡¡which¡¡the
planing¡machine¡¡travelled¡¡were¡¡so¡¡true£»¡¡that¡¡Clement¡¡himself¡¡used¡¡to
say¡¡of¡¡them£»¡¡¡¨If¡¡you¡¡were¡¡to¡¡put¡¡but¡¡a¡¡paper¡¡shaving¡¡under¡¡one¡¡of¡¡the
rollers£»¡¡it¡¡would¡¡at¡¡once¡¡stop¡¡all¡¡the¡¡rest¡£¡¨¡¡¡¡Nor¡¡was¡¡this¡¡any
exaggerationthe¡¡entire¡¡mechanism£»¡¡notwithstanding¡¡its¡¡great¡¡size£»
being¡¡as¡¡true¡¡and¡¡accurate¡¡as¡¡that¡¡of¡¡a¡¡watch¡£
By¡¡an¡¡ingenious¡¡adaptation¡¡of¡¡the¡¡apparatus£»¡¡which¡¡will¡¡also¡¡be¡¡found
described¡¡in¡¡the¡¡Society¡¡of¡¡Arts¡¡paper£»¡¡the¡¡planing¡¡machine¡¡might¡¡be
fitted¡¡with¡¡a¡¡lathe¡bed£»¡¡either¡¡to¡¡hold¡¡two¡¡centres£»¡¡or¡¡a¡¡head¡¡with¡¡a
suitable¡¡mandrill¡£¡¡¡¡When¡¡so¡¡fitted£»¡¡the¡¡machine¡¡was¡¡enabled¡¡to¡¡do¡¡the
work¡¡of¡¡a¡¡turning¡lathe£»¡¡though¡¡in¡¡a¡¡different¡¡way£»¡¡cutting¡¡cylinders
or¡¡cones¡¡in¡¡their¡¡longitudinal¡¡direction¡¡perfectly¡¡straight£»¡¡as¡¡well
as¡¡solids¡¡or¡¡prisms¡¡of¡¡any¡¡angle£»¡¡either¡¡by¡¡the¡¡longitudinal¡¡or
lateral¡¡motion¡¡of¡¡the¡¡cutter£»¡¡whilst¡¡by¡¡making¡¡the¡¡work¡¡revolve£»¡¡it
might¡¡be¡¡turned¡¡as¡¡in¡¡any¡¡other¡¡lathe¡£¡¡¡¡This¡¡ingenious¡¡machine£»¡¡as
contrived¡¡by¡¡Mr¡£¡¡Clement£»¡¡therefore¡¡represented¡¡a¡¡complete¡¡union¡¡of
the¡¡turning¡lathe¡¡with¡¡the¡¡planing¡¡machine¡¡and¡¡dividing¡¡engine£»¡¡by
which¡¡turning¡¡of¡¡the¡¡most¡¡complicated¡¡kind¡¡might¡¡readily¡¡be¡¡executed¡£
For¡¡ten¡¡years¡¡after¡¡it¡¡was¡¡set¡¡in¡¡motion£»¡¡Clement's¡¡was¡¡the¡¡only
machine¡¡of¡¡the¡¡sort¡¡available¡¡for¡¡planing¡¡large¡¡work£»¡¡and¡¡being
consequently¡¡very¡¡much¡¡in¡¡request£»¡¡it¡¡was¡¡often¡¡kept¡¡going¡¡night¡¡and
day£»the¡¡earnings¡¡by¡¡the¡¡planing¡¡machine¡¡alone¡¡during¡¡that¡¡time
forming¡¡the¡¡principal¡¡income¡¡of¡¡its¡¡inventor¡£¡¡¡¡As¡¡it¡¡took¡¡in¡¡a¡¡piece
of¡¡work¡¡six¡¡feet¡¡square£»¡¡and¡¡as¡¡his¡¡charge¡¡for¡¡planing¡¡was
three¡halfpence¡¡the¡¡square¡¡inch£»¡¡or¡¡eighteen¡¡shillings¡¡the¡¡square
foot£»¡¡he¡¡could¡¡thus¡¡earn¡¡by¡¡his¡¡machine¡¡alone¡¡some¡¡ten¡¡pounds¡¡for
every¡¡day's¡¡work¡¡of¡¡twelve¡¡hours¡£¡¡¡¡We¡¡may¡¡add¡¡that¡¡since¡¡planing
machines¡¡in¡¡various¡¡forms¡¡have¡¡become¡¡common¡¡in¡¡mechanical¡¡workshops£»
the¡¡cost¡¡of¡¡planing¡¡does¡¡not¡¡amount¡¡to¡¡more¡¡than¡¡three¡halfpence¡¡the
square¡¡foot¡£
The¡¡excellence¡¡of¡¡Mr¡£¡¡Clement's¡¡tools£»¡¡and¡¡his¡¡well¡known¡¡skill¡¡in
designing¡¡and¡¡executing¡¡work¡¡requiring¡¡unusual¡¡accuracy¡¡and¡¡finish£»
led¡¡to¡¡his¡¡being¡¡employed¡¡by¡¡Mr¡£¡¡Babbage¡¡to¡¡make¡¡his¡¡celebrated
Calculating¡¡or¡¡Difference¡¡Engine¡£¡¡¡¡The¡¡contrivance¡¡of¡¡a¡¡machine¡¡that
should¡¡work¡¡out¡¡complicated¡¡sums¡¡in¡¡arithmetic¡¡with¡¡perfect
precision£»¡¡was£»¡¡as¡¡may¡¡readily¡¡be¡¡imagined£»¡¡one¡¡of¡¡the¡¡most¡¡difficult
feats¡¡of¡¡the¡¡mechanical¡¡intellect¡£¡¡¡¡To¡¡do¡¡this¡¡was¡¡in¡¡an¡¡especial
sense¡¡to¡¡stamp¡¡matter¡¡with¡¡the¡¡impress¡¡of¡¡mind£»¡¡and¡¡render¡¡it
subservient¡¡to¡¡the¡¡highest¡¡thinking¡¡faculty¡£¡¡¡¡Attempts¡¡had¡¡been¡¡made
at¡¡an¡¡early¡¡period¡¡to¡¡perform¡¡arithmetical¡¡calculations¡¡by¡¡mechanical
aids¡¡more¡¡rapidly¡¡and¡¡precisely¡¡than¡¡it¡¡was¡¡possible¡¡to¡¡do¡¡by¡¡the
operations¡¡of¡¡the¡¡individual¡¡mind¡£¡¡¡¡The¡¡preparation¡¡of¡¡arithmetical
tables¡¡of¡¡high¡¡numbers¡¡involved¡¡a¡¡vast¡¡deal¡¡of¡¡labour£»¡¡and¡¡even¡¡with
the¡¡greatest¡¡care¡¡errors¡¡were¡¡unavoidable¡¡and¡¡numerous¡£¡¡¡¡Thus¡¡in¡¡a
multipltcation¡table