,,transcrib]',s ,,note ,italic text is d5ot$ by und]scores4 ,bold text is d5ot$ by equal signs4 ,obvi\s typographical errors & punctuation errors h be5 correct$ aft] c>eful comp>ison ) o!r occurr5ces )9 ! text & consultation ( ext]nal s\rces4 ,m detail c be f\nd at ! end ( ! book4 ,,sci5ce ,,= ,,! ,,s*ool ,,& ,,family4 ,,"p ,i4 ,,natural ,,philosophy4 ,,by ,,wor?+ton ,,hook]1 ,m4,d41 ,,pr(essor ,,( ,,! ,,!ory ,,& ,,practice ,,( ,,m$ic9e ,,9 ,,yale ,,college1 ,,au?or ,,( ,,human ,,physiology1 ,,*ild',s ,,book ,,( ,,nature1 ,,natural ,,hi/ory1 ,c4 ,illu/rat$ by ne>ly #cjj ,engrav+s4 ,,new ,,york3 ,,h>p] ,,bro!rs1 ,,publi%]s1 ,,frankl9 ,,squ>e4 #ahgc4 ,by ,dr4 ,wor?+ton ,hook]4 ,! ,*ild's ,book ( ,nature4 ,= ! ,use ( ,families & ,s*ools2 int5d$ to aid ,mo!rs & ,tea*]s 9 tra9+ ,*ildr5 9 ! ,obs]vation ( ,nature4 ,9 ?ree ,p>ts4 ,illu/rat$ by ,engrav+s4 ,! ,?ree ,p>ts complete 9 "o vol4 ,small #dto1 ,clo?1 #b #jj2 ,sep>ately1 ,clo?1 #ij c5ts ea*4 ,,"p ,i4 ,,plants4 ,,"p ,,ii4 ,,animals4 ,,"p ,,iii4 ,,air1 ,,wat]1 ,,heat1 ,,light1 c4 ,fir/ ,book 9 ,*emi/ry4 ,= ! ,use ( ,s*ools & ,families4 ,illu/rat$ by ,engrav+s4 ,squ>e #dto1 ,clo?1 #ij c5ts4 ,natural ,hi/ory4 ,= ! ,use ( ,s*ools & ,families4 ,illu/rat$ by ne>ly #cjj ,engrav+s4 #abmo1 ,clo?1 #a #ej4 ,sci5ce = ! ,s*ool & ,family4 ,,"p ,i4 ,,natural ,,philosophy4 ,illu/rat$ by ne>ly #cjj ,engrav+s4 #abmo1 ,clo?1 #a #ej4 ,,"p ,,ii4 ,,*emi/ry4 ,illu/rat$ by num]\s ,engrav+s1 #abmo1 ,clo?1 #a #ej4 ,,"p ,,iii4 ,,m9]alogy ,,& ,,geology4 ,illu/rat$ by num]\s ,engrav+s4 #abmo4 ,clo?1 #a #ej4 ,publi%$ by ,,h>p] ,,bro!rs1 ,frankl9 ,squ>e1 ,n4 ,y4 ,any ( ! above ,works s5t to any "p ( ! ,unit$ ,/ates1 po/age pre-paid1 ^u receipt ( ! ,price4 ,ent]$1 accord+ to ,act ( ,congress1 9 ! ye> "o ?\s& eight hundr$ & sixty-?ree1 by ,,h>p] ,,bro!rs1 9 ! ,cl]k's ,(fice ( ! ,di/rict ,c\rt ( ! ,s\!rn ,di/rict ,c\rt ( ,new ,york4 ,,preface4 ,daniel ,web/]1 9 8 ,autobiography1 speaks ?us ( 8 ent]+ ^u ! /udy ( law3 ,i 0 put to /udy 9 ! old way--t is1 ! h>de/ books fir/1 & lo/ mu* "t4 ,i read ,coke on ,littleton ?r\gh )\t und]/&+ a qu>t] "p ( x4 ,happ5+ to take up ,esp9asse's ,law ( ,nisi ,prius1 ,i f\nd ,i c\ld und]/& x2 & argu+ t ! object ( read+ 0 to und]/& :at 0 writt51 ,i laid d[n ! v5]able ,coke et alios similes rev]5dos1 & kept company = a "t ) ,mr4 ,esp9asse & o!rs1 ! mo/ pla91 easy1 & intelligible writ]s4 ,a boy ( tw5ty1 ) no previ\s k on su* subjects1 c n und]/& ,coke4 ,x is folly to set him on su* an au?or4 ,!re are propositions 9 ,coke s ab/ract1 & di/9ctions s nice1 & doctr9es embrac+ s _m conditions & qualifications1 t x requires an ef=t1 n only ( a mature m9d1 b ( a m9d bo? /rong & mature1 to und]/& him4 ,:y disgu/ & disc\rage a boy by tell+ him t he mu/ break into 8 pr(ession ?r\gh su* a wall z ?is8 ,i really (t5 despair$4 ,i ?\ght t ,i nev] c\ld make myself a lawy]1 & 0 almo/ go+ back to ! bus9ess ( s*oolkeep+4 ,mr4 ,esp9asse1 h[ev]1 help$ me out ( ?is 9 ! way t ,i h m5tion$1 & ,i h always felt greatly oblig$ to him4 ,"h is mo/ graphically depict$ a defect :i* is n[1 z x 0 !n1 v prom95t 9 all dep>tm5ts ( education4 ,x is ev5 m s 9 e>ly education ?an 9 t ( ! college & ! pr(essional s*ool4 ,ev5 9 t5d] *ildhood pupils are put to /udy+ books ( :i*1 z 0 true ( ,web/] ) 8 ,coke on ,littleton1 !y d n und]/& a qu>t] "p4 ,if ! rule is n ! h>de/ books fir/1 !re are _m ?+s 9 ! books t x is n only h>d b impossible = !m to und]/&4 ,& ! h>de/ ?+s are (t5 put fir/4 ,= example1 9 a v popul> prim>y geography :i* lies be=e me ! pupil is introduc$ to ! _w & its gr& divisions at ! outset1 :ile he is taught ab\t 8 own /ate & c\ntry only at ! conclusion ( ! book4 ,& ?is unnatural mode is ! "o v commonly pursu$4 ,simil> criticism c be pass$ ^u mo/ ( ! books us$ 9 tea*+ "y *ildr54 ,"s ( !m are :olly useless4 ,?is is true ( ! gramm>s = prim>y s*ools4 ,! =mal /atem5ts1 call$ ! rules ( gramm>1 are beyond ! und]/&+ ( v "y s*ol>s1 & !re=e are useless burd5s ^u _! memories4 ,!y are z useless to !m z ! ?ree-f\r?s ( ,coke :i* ,web/] c\ld n und]/& 0 to him4 ,if we foll[ education1 upw>d f ! prim>y s*ool we f9d ! same defect ?r\gh\t ! :ole c\rse4 ,9 ! books :i* are us$ 9 tea*+ natural sci5ce x is especially prom95t4 ,ev5 9 ! elem5t>y books1 or comp5diums1 s call$1 =mal propositions & te*nical t]ms r5d] ! /udy un9vit+1 & to a great ext5t un9telligible4 ,! pupil is apt to be disgu/$ & disc\rag$1 z ,web/] 0 ) ,coke on ,littleton1 & = ! same reason4 ,ano!r defect intimately connect$ ) t ( :i* ,i h spok5 is ! v sp>+ & late introduction ( ! physical sci5ces4 ,!y are g5]ally po/pon$ to ! latt] "p ( ! c\rse ( education1 & !n b little "t is devot$ to !m4 ,g5]ally1 :5 a pupil designs to g ?r\gh college1 ! /udy ( ^! sci5ces is :olly neglect$ 9 8 prep>ation1 because a k ( !m is n requir$ = admission4 ,!n 9 ! college !y are n att5d$ to till ! latt] "p ( ! c\rse1 & 9 ! %ort "t allott$ to !m !re is s mu* to be le>n$ t ! tea*+ ( !m is a failure4 ,especially is ?is true ( ,*emi/ry & ,geology4 ,?is defect is a radical "o4 ,a ?or\gh *ange %\ld be effect$ 9 ?is respect 9 ! :ole c\rse ( education4 ,! natural sci5ces %\ld be made prom95t f ! beg9n+ to ! end1 n only because !y are ( practical value1 b also because !y are z useful 9 _! way = m5tal discipl9e z ! /udy ( ma!matics & ( language4 ,!y c be taught to "s little ext5t to ! y\nge/ pupils4 ,!re are facts ab\t air1 wat]1 & ! v>i\s objects t !y see ar\nd !m1 :i* !y c und]/& if !y be pres5t$ 9 ! "r mann]4 ,& ! busy inquiries :i* !y make aft] ! reasons ( ! facts1 & _! appreciation ( !m if /at$ simply & )\t te*nical t]ms1 %[ ! appropriat5ess ( su* tea*+4 ,*ildr5 are really v good philosoph]s 9 _! way4 ,!y h great activity n only ( _! p]ceptive b ( _! reason+ faculties also1 to :i* due range %\ld be giv5 9 _! education4 ,beg9n+ ?us1 n a ye> %\ld pass dur+ ! :ole c\rse :5 ! pupil %all n be engag$ 9 /udy+ "s "o ( ! physical sci5ces to "s ext5t4 ,?is cont9u$ att5tion to su* /udies 9 a reasonable am\nt1 s f> f int]f]+ ) ! due prosecution ( ! o!r /udies deem$ s ess5tial1 w s promote ! pupil's advance 9 !m z to m ?an make up = ! "t t is tak5 f !m4 ,x w d ?is n only by ! g5ial influ5ce :i* su* /udies ex]t ^u ! m9d1 b by ! contributions :i* !y make to ! k ( language & ma!matics2 = language is l>gely built up f natural objects & f ! acquisitions ( sci5ce1 & !re is an abundance ( int]e/+ applications ( portions ( ! ma!matics 9 ! facts :i* ! physical sci5ces develop to u4 ,i h said t ! tea*+ ( ! natural sci5ces 9 our colleges is g5]ally a failure1 & x always w be s z long z ! pres5t plan is cont9u$4 ,9 ord] to h x successful !re mu/ be ! same gradation 9 tea*+ !m t we h 9 tea*+ language & ! ma!matics4 ,! college /ud5t ne$s to be prep>$ = ! lectures :i* he he>s on natural philosophy1 *emi/ry1 etc41 & = 8 /udy ( ^? bran*es1 by previ\s famili>ity ) ! simpl] portions ( !m acquir$ 9 ! s*ool-room4 ,!re is ano!r v important reason = ! e>ly introduction ( ! physical sci5ces into education4 ,by f> ! l>g] portion ( pupils 9 our s*ools /op %ort ( ! college1 or ev5 ! academy & high s*ool4 ,t !y %\ld g =? into ! _w ) no k ( ! pr9ciples t lie at ! basis ( ! arts 9 :i* s _m ( !m are to engage is a %ame & a wrong1 if ! communication ( su* k be inde$ practicable1 z x und\bt$ly is4 ,ev5 ^? :o are n to engage 9 ^! arts w be greatly b5efit$ by ?is k1 because 9 addition to its con/ant practical applications 9 ! managem5t ( life1 x w contribute to _! m5tal p[]1 &1 :at is no small consid]ation1 to _! enjoym5t2 & x is 9 fact requisite to con/itute !m well-in=m$ p]sons4 ,if ! views :i* ,i h pres5t$ be correct1 !re %\ld be a s]ies ( books on ! natural sci5ces c>efully adapt$ to ! diff]5t p]iods ( ! c\rse ( /udy4 ,^? int5d$ = ! "y beg9n] %\ld be exce$+ly simple1 & %\ld n attempt to pres5t any ?+ l a full view ( ! subjects treat$4 ,!y %\ld deal l>gely ) famili> facts or ph5om5a4 ,! t]m9ology ( sci5ce & =mal /atem5ts ( pr9ciples1 su* z we (t5 see 9 s-call$ comp5diums1 %\ld h no place 9 !m1 b %\ld be gradually introduc$ z ! s]ies advances1 & %\ld be made complete only 9 ! conclud+ books4 ,x has be5 ! object ( ! au?or to supply a "p ( su* a s]ies4 ,! fir/ book 9 ! s]ies is ! ,*ild's ,book ( ,common ,?+s1 int5d$ to tea* ! obs]vation ( famili> facts1 or1 9 o!r words1 ! beg9n+s ( philosophy1 to *ildr5 z soon z !y h got well />t$ 9 read+4 ,next comes ! ,*ild's ,book ( ,nature1 :i* 9 its ?ree p>ts 7,"p ,i41 ,plants2 ,"p ,,ii41 ,animals2 ,"p ,,iii41 ,air1 ,wat]1 ,light1 ,heat1 etc47 ext5ds consid]ably ! k ( ! philosophy ( ?+s :i* ! *ild has obta9$ f ! fir/ book 9 ! s]ies4 ,!n foll[s ! ,fir/ ,book 9 ,*emi/ry4 ,on a level ) ?is is my ,fir/ ,book 9 ,physiology4 ,! next /ep 9 ! gradation br+s u to ?ree books "u "o title1 ,sci5ce = ! ,s*ool & ! ,family2 ,"p ,i41 ,natural ,philosophy2 ,"p ,,ii41 ,*emi/ry2 ,"p ,,iii41 ,m9]alogy & ,geology4 ,on a level ) ^! is ano!r book1 ,natural ,hi/ory1 & ano!r /ill is to be writt51 an ,introduction to ,botany4 ,! ?ree books1 ( :i* ! pres5t is "o1 are int5d$ = ! old] s*ol>s 9 :at are commonly call$ gramm>-s*ools4 ,at ! same "t !y are suit$ to s*ol>s :o are advanc$ to a high] grade :o h n gone ?r\gh ! previ\s books ( ! s]ies4 ,! prep>ation ( books especially adapt$ to high s*ools & colleges ,i h left to o!rs1 except 9 "o bran* ( sci5ce1 ,physiology1 on :i* ,i "s ye>s ago publi%$ a "w entitl$ ,human ,physiology4 ,all ( ^! books are f ! press ( ,h>p] & ,bro!rs except ! two works on ,physiology1 publi%$ by ,%eldon & ,co41 ,new ,york1 & ! ,*ild's ,book ( ,common ,?+s1 publi%$ by ,peck1 ,:ite1 & ,peck1 ,new ,hav54 ,! g5]al plan & /yle ( ^! books are v diff]5t f :at we see 9 mo/ ( ! books = s*ools on ! same subjects4 ,! ord] ( ! subjects & ! mode ( develop+ !m diff] f ! /]eotype plan :i* has s g5]ally be5 adopt$4 ,"o prom95t feature is ! free use ( illu/rations f famili> ph5om5a4 ,?is leads ! pupil to reason or philosophize ab\t common ?+s1 ?us giv+ an em95tly practical "* to 8 k4 ,at ! same "t x makes ! books suitable = use 9 ! family z well z ! s*ool1 betwe5 :i* !re %\ld be m common gr\nd ?an ! pres5t mode ( education all[s4 ,! /yle :i* ,i h *os5 = all ! books ,i h writt5 = use 9 tea*+ is :at may be call$ ! lecture /yle4 ,!re are ?ree o!r k9ds ( /yle :i* are m commonly us$ 9 s*ool-books4 ,! mo/ common is :at ,i t]m ! =mal /atem5t /yle4 ,9 ?is pr9ciples & rules are /at$1 & !n illu/rations are giv54 ,?is makes a =mal & un9vit+ book4 ,! b>e skeleton ( ! sci5ce is g5]ally = ! mo/ "p pres5t$1 & ! "y pupil is apt to le>n ! /atem5ts by rote )\t und]/&+ !m4 ,x is a /yle fitt$ only = books int5d$ = advanc$ s*ol>s4 ,ano!r /yle is ! cate*etical4 ,?is is an unnatural mode ( communicat+ k2 & besides1 x enc\rages le>n+ by rote z ! =mal /atem5t /yle does4 ,9 ! ?ird /yle1 ! dramatic1 conv]sations are held betwe5 ! tea*] & "s le>n]s4 ,! *ief objection to ?is is t x und]takes to put 9 p]man5t %ape :at %\ld be extemporiz$ 9 ! recitation4 ,:at is ne$$ 9 ! book is simply cle> & concise /atem5t 9 an int]e/+ /yle1 & ! liv+ tea*] & 8 s*ol>s c be/ furni% ! conv]sational elem5t z ! recitation goes on4 ,9 ! lecture /yle !re may be & %\ld be z mu* precision ( /atem5t z 9 ! =mal /atem5t /yle1 :ile x is m int]e/+1 because x is ! natural mode ( communicat+ k4 ,9 ?is /yle ! facts are ord9>ily s /at$ z to develop pr9ciples2 :ile 9 ! o!r ! ord] is rev]s$1 ! pr9ciples be+ fir/ /at$ & ! facts giv5 aft]w>d4 ,"o ( ! mo/ successful books ev] us$ 9 our colleges--,paley's ,natural ,!ology--is 9 ! lecture /yle1 & x is a matt] ( surprise t ?is fact has _h s little influ5ce ) ^? :o h prep>$ books = in/ruction4 ,:atev] may be true ( advanc$ s*ol>s1 9 tea*+ ! "y /ud5t 9 sci5ce b>e1 dry /atem5t %\ld be avoid$1 & ! subjects %\ld be pres5t$ 9 all _! attractive features4 ,i w\ld n be und]/ood z advocat+ ! dress+ up ( sci5ce 9 adv5titi\s *>ms4 ,?is is n necess>y4 ,sci5ce possesses 9 itself an abundance ( *>ms1 :i* ne$ only to be prop]ly develop$ to attract ! "y m9d2 & ! lecture /yle furni%es ! be/ vehicle = su* a developm5t4 ,"o gr& ess5tial = giv+ int]e/ to any /udy is ! pres5tation ( ! v>i\s po9ts 9 ! natural ord] 9 :i* !y %\ld ent] ! m9d4 ,!y %\ld be s pres5t$ t ea* portion ( a book %all make ! foll[+ portions m int]e/+ & m easily und]/ood4 ,?is pr9ciple1 :i* is s commonly transgress$1 ,i h endeavor$ to obs]ve /rictly 9 ! prep>ation ( ^! volumes4 ,que/ions are put at ! end ( ?is book = ^? tea*]s :o desire to use !m4 ,!re is also an ,index4 ,w4 ,,hook]4 ,janu>y1 #ahfc4 ,,cont5ts4 ,,*apt] ,,page ,i4 ,,matt] #ac ,,ii4 ,,prop]ties ,,( ,,matt] #ai ,,iii4 ,,! ,,ess5tial ,,prop]ties ,,( ,,matt] #cc ,,iv4 ,,attraction #ch ,v4 ,,gravitation #ea ,,vi4 ,,c5tre ,,( ,,gravity #fg ,,vii4 ,,hydro/atics #hj ,,viii4 ,,specific ,,gravity #ajj ,,ix4 ,,pneumatics #aaj ,x4 ,,motion #acc ,,xi4 ,,! ,,me*anical ,,p[]s #agd ,,xii4 ,,s\nd #aic ,,xiii4 ,,heat #bjg ,,xiv4 ,,light #beh ,,xv4 ,,electricity #bhg ,,xvi4 ,,magnetism #cjh ,,natural ,,philosophy4 ,,*apt] ,i4 ,,matt]4 #a4 ,matt] & ,_s4--,! di/9ction betwe5 matt] & _s is almo/ univ]sally recogniz$ ev5 by ^? :o h giv5 little ?\ght to su* subjects4 ,x is a di/9ction ( :i* we are consci\s 9 our own p]sons4 ,we "k in/9ctively t !re is a some?+ )9 u t causes ! movem5ts ( our mat]ial bodies1 & t some?+ we call _s4 #b4 ,bi%op ,b]keley's ,ideas4--,"s philosoph]s1 9 _! speculations1 h d5i$ t !re is any su* ?+ 9 exi/5ce z matt]4 ,bi%op ,b]keley1 = example1 taught t ! impressions :i* we suppose t we receive f mat]ial objects d n come f real sub/ances1 b are ! effects ( ! imm$iate ag5cy ( an ev]-pres5t ,deity4 ,x is no wond] t ! wisdom & le>n+ ( a man :o c\ld s]i\sly adopt su* a belief c\ld n save him f be+ ! dupe ( quack]y4 ,he believ$ t t>-wat] 0 a sov]eign cure = all diseases2 & ,dr4 ,holmes playfully rem>ks ( him1 t he held two v odd op9ions3 t t>-wat] 0 e ?+1 & t ! :ole mat]ial univ]se 0 no?+4 #c4 ,hume's ,ideas4--,! infidel ,hume w5t beyond ,bi%op ,b]keley1 d5y+ ev5 ! exi/5ce ( ! s\l z an individual & responsible ag5t4 ,he made e ?+ to consi/ ( ideas & impressions1 & said t ^! h no necess>y connection1 b are a bundle ( p]ceptions t succe$ ea* o!r ) inconceivable rapidity1 & t !re=e ,i myself ( to-day am no m ! ,i myself ( ye/]day or to-morr[ ?an ,i am ,nebu*adnezz> or ,cleopatra4 ,a wag propos$ ! foll[+ epitaph = 8 tomb-/one z a suitable illu/ration ( 8 !ory3 ,"u ?is circul> idea1 vulg>ly call$ tomb1 ,impressions & ideas re/ :i* con/itut$ ,hume4 #d4 ,orig9 ( ! ^w ,_s4--,! "n _s came orig9ally f an att5uat$ =m ( matt]1 ! air or brea?1 because ! air1 l spiritual exi/5ce1 is invisible4 ,! =mation ( language is to a l>ge ext5t ?us bas$ on analogies4 #e4 ,_s n an ,object ( ,s5se4--,none ( ! s5ses c p]ceive _s itself1 ?\gh !y p]ceive ! effects :i* _s produces on mat]ial sub/ances4 ,if1 = example1 y move y\r arm1 x is ! _s )9 y1 act+ ^u ! muscles ?r\gh ! n]ves1 t causes x to move2 & y see "h ! effects produc$ by _s ^u matt]1 b y d n see ! _s itself4 #f4 ,effects ( ,matt] on ! ,s5ses4--,"s =ms ( matt] c be p]ceiv$ by all ! s5ses2 o!rs c be p]ceiv$ by only a "p ( !m2 "s by only "o4 ,air y c n see1 nor smell1 nor ta/e2 b y c feel x1 & he> ! s\nd ( its motion4 ,sometimes matt] affects only ! s5se ( smell1 or t ) ! s5se ( ta/e4 ,sea-air smells salt2 b ! salt 9 ! air is s f9ely divid$ t we c n see x4 ,& yet x is ! salt1 ent]+ ! no/rils & com+ 9 contact ) ! extreme fibres ( ! n]ve ( smell1 t produces ! effect4 ,s :5 we smell a fl[]1 matt] comes f x 9 p>ticles s f9e t no microscope c detect !m1 b !y produce s5sation :5 !y /rike ^u ! n]ve4 #g4 ,=ms ( ,matt]4--,matt] appe>s 9 ?ree =ms3 solid1 liquid1 & gase\s or a]i=m--t is1 l air4 ,sometimes matt] is spok5 ( z hav+ only two =ms--solid & fluid4 ,9 ?is case fluids are divid$ into two classes1 ! ela/ic & non-ela/ic4 ,! air & ! v>i\s gases & vapors are ! ela/ic fluids2 :ile ^? :i* are call$ liquids are ! non-ela/ic fluids4 ,a foot-ball b\nds because ! air 9 x is an ela/ic fluid4 ,if x 7 fill$ ) a non-ela/ic fluid2 z wat]1 x w\ld n b\nd4 ,:5 wat] takes ! =m ( /eam x is an ela/ic fluid4 ,?\gh x is v common to use ! expression ela/ic fluids1 ! division ( matt] into ?ree =ms is ! "o usually recogniz$4 #h4 ,solids4--,9 solid matt] ! p>ticles c n be mov$ ab\t among ea* o!r2 b ea* p>ticle g5]ally reta9s ! same position 9 relation to ^? p>ticles :i* are ar\nd x--9 o!r words1 x does n *ange its neighborhood4 ,?is is m true ( "s solids ?an ( o!rs4 ,x is absolutely true ( su* h>d solids z granite & ! diamond4 ,9 ^! ! p>ticles are always 9 ! same relative position4 ,b x is n s ) gold or lead4 ,by hamm]+ ^! y c *ange greatly ! relative position ( _! p>ticles4 ,india-rubb] is a solid1 b ! relative position ( its p>ticles c be mu* alt]$ 9 v>i\s ways4 #i4 ,liquids4--,x is ! gr& *>act]i/ic ( a liquid t its p>ticles *ange _! relative position f ! slighte/ causes4 ,x is 9 /rong contra/ ) solids 9 ?is respect4 ,:5 y move any portion ( a solid body y move all ! o!r portions ( x1 & g5]ally 9 ! same direction4 ,b a body ( liquid c n be mov$ all toge!r z "o body except by conf9+ x2 z1 = example1 9 ! case ( a wat]-pipe or a syr+e4 ,& !n1 ! mom5t t ! wat] c escape1 ! p>ticles use _! lib]ty ( alt]+ _! relative position4 ,z w9d & o!r ag5ts act cont9ually ^u wat]1 no p>ticle /ays = any l5g? ( "t 9 ! neighborhood ( ! same p>ticles4 ,un/able z wat] is1 !n1 an exce$+ly significant expression4 ,wat] is nev] at re/4 ,a p>ticle ( x may at "o "t be float+ on ! surface ( ! ocean1 & at ano!r be 9 dep?s beyond ! s\nd+ ( man4 ,x flies on ! w+s ( ! w9d1 falls 9 ! ra91 runs 9 ! /ream1 is exhal$ f a leaf1 trembles 9 ! dew-drop1 fl[s 9 ! blood ( an animal or 9 ! sap ( a plant1 & is always ready to be jo/l$ along 9 its ev]-*ang+ c\rse4 #aj4 ,gases4--,! p>ticles ( gase\s or a]i=m sub/ances move among ea* o!r ev5 m freely ?an ^? ( a liquid4 ,air1 !re=e1 is m un/able & re/less ?an wat]4 ,ev5 :5 ! air seems to be p]fectly /ill its p>ticles are mov+ ab\t among ea* o!r4 ,y c see ?is to be true if y d>k5 a room1 leav+ a s+le %utt] a little op54 ,:]e ! light ent]s y w see motes fly+ ab\t 9 e direction1 :i* w\ld n be ! case if ! air 7 really at re/4 ,! p>ticles ( air h a great] range ( travel ?an ^? ( wat]2 = ! sea ( atmosph]e :i* envelops ! e>? rises to ! height ( ab\t fifty miles4 ,h[ f> wat] rises 9 its evaporation we "k n2 b x is n at all probable t x rises to ! upp]mo/ regions ( ! atmosph]e4 #aa4 ,fill+ ( ,spaces by ,liquids & ,gases4--,x is ! fre5ess ) :i* ! p>ticles ( liquids & gases move among ea* o!r t enables !m to ins9uate !mselves into spaces e :]e4 ,!y are ev] ready to ent] into any sub/ances :i* h int]/ices or pores ( su* size z w admit !m4 ,!re are m+l$ ) ! gra9s ( ! soil n only wat]1 b air & gases4 ,^! are pres5t also 9 all liv+ sub/ances1 bo? vegetable & animal4 ,wat] is ! *ief "p ( sap & ( blood1 & air & gases always g ) wat]4 ,"p ( ! air t we brea! 9 ent]s ! blood 9 ! lungs1 & c\rses ) x ?r\gh ! sy/em4 ,! fi%es c\ld n live 9 wat] if !re 7 n air m+l$ ) x4 ,?is c be prov$ by exp]im5t4 ,if y put a fi% into a close vessel x w soon die1 because x uses up all ! air t is 9 ! wat]4 ,9 an op5 vessel ! fi% is kept alive by ! con/ant accessions ( fre% air to ! wat]4 #ab4 ,solution4--,9 solutions ( solid sub/ances 9 wat] x is ! fre$om ) :i* ! p>ticles ( wat] move ab\t among ea* o!r t enables !m to take 9 among !m ! m9ute p>ticles ( ! solid4 ,& :5 wat] asc5ds into air by evaporation x may be said to be a real solution ( wat] 9 ! air2 = ! p>ticles ( wat] m+le ) ^? ( ! air1 j z ! p>ticles ( a solid m+le ) ^? ( wat] 9 a solution4 #ac4 ,relation ( ,heat to ! ,=ms ( ,matt]4--,"s k9ds ( matt] are se5 9 all ! ?ree =ms4 ,:e!r ^! %all assume "o =m or ano!r dep5ds on ! am\nt ( heat pres5t4 ,?us :5 wat] is solid1 ice1 x is because a "p ( its heat is gone4 ,apply heat1 & x becomes a liquid1 wat]4 ,increase ! heat to ! boil+ po9t1 & x becomes /eam1 or an a]i=m sub/ance4 ,alcohol has only two =ms--liquid & a]i=m4 ,x has nev] be5 kn[n to be froz54 ,iron is usually solid2 b 9 ! f\ndry1 by ! application ( great heat1 x is made liquid4 ,m]cury is liquid 9 all ord9>y temp]atures2 b x (t5 becomes solid 9 ! extreme cold ( arctic w9t]s4 ,a m]curial !rmomet] is ( c\rse useless "u su* circum/ances1 & ! alcoholic !rmomet] is reli$ ^u to d5ote ! degree ( cold4 ,! diff]5ce betwe5 m]cury1 wat]1 & iron 9 reg>d to ! liquid /ate is ?is3 ,x takes b little heat1 comp>atively1 to make m]cury liquid1 :ile m is requir$ = ?is condition 9 wat]1 & mu* m = x 9 ! case ( iron4 #ad4 ,! ,nature ( ,matt] ,unkn[n4--,:at n[1 let u inquire1 d we "k ( ! nature ( matt]8 ,c we say t we "k any ?+ ( x8 ,we may obs]ve its ph5om5a1 & le>n its prop]ties2 b ) our mo/ se>*+ analyses ( x we c no m det]m9e :at matt] is ?an we c :at _s is4 ,newton suppos$ t ,god 9 ! beg9n+ =m$ matt] 9 solid1 massy1 h>d1 imp5etrable p>ticles4 ,?is he believ$ to be true ( liquids1 & ev5 ( gases1 z well z solids4 ,9 ! gas ^! h>d p>ticles are mu* f>!r ap>t ?an 9 ! solid4 ,! supposition is a v probable "o2 b if x be true x does n let u "k :at matt] is1 = x leaves u 9 ! d>k z to ! nature ( ! p>ticles4 ,newton f>!r suppos$ t ^! p>ticles h always rema9$ unalt]$ amid/ all ! *anges t are tak+ place2 ^! *anges be+ occasion$ by ! v>i\s sep>ations & new associations & motions ( ^! p]man5t p>ticles4 ,:51 = example1 any ?+ is burn$ up1 z x is express$1 n "o ( ^! p>ticles is ei!r de/roy$ or alt]$1 b !y m]ely take on new arrangem5ts4 ,?\gh mo/ ( ! sub/ance has fl[n (f 9 ! =m ( gas1 ! ultimate p>ticles compos+ ! gas are ! same n[ t !y 7 :5 mak+ a "p ( ! solid sub/ance2 & !y may soon aga9 become a "p ( "s new solids4 ,su* *anges 9 ! =ms ( matt] are e :]e go+ on2 & :5 y become acqua9t$ ) ,*emi/ry1 9 ! ,second ,"p1 y w be famili> ) !m4 #ae4 ,atomic ,!ory4--,^! ultimate p>ticles ( matt] are s m9ute t !y h nev] be5 se5 by man4 ,! smalle/ p>ticle t c be se5 ) ! mo/ p[]ful microscope is probably made up ( v _m ( !m unit$ toge!r4 ,^! ultimate p>ticles we t]m atoms2 & ! !ory 9 reg>d to ! composition by !m ( diff]5t sub/ances is call$ ! atomic !ory4 ,! atoms ( diff]5t sub/ances are n suppos$ to be alike1 b to diff] 9 bo? size & weight4 ,?is !ory w be m p>ticul>ly notic$ 9 ! ,second ,"p4 #af4 ,impond]able ,ag5ts4--,!re are c]ta9 ag5ts--light1 heat1 electricity1 etc4--:i* are suppos$ by "s to be =ms ( matt]4 ,if !y are1 !y are exce$+ly att5uat$2 = _! pres5ce1 z has be5 prov$ by _m exp]im5ts1 nev] adds 9 ! lea/ to ! weight ( any sub/ance4 ,!y h !re=e be5 /yl$ impond]able ag5ts4 ,_! ag5cy is ( great importance & v active1 produc+ e :]e con/ant *anges4 ,two ( !m--heat & light--are obvi\sly & imm$iately ess5tial to life4 ,:at _! real nature is rema9s z yet an entire my/]y4 ,,*apt] ,,ii4 ,,prop]ties ,,( ,,matt]4 #ag4 ,v>iety 9 ! ,prop]ties ( ,matt]4--,all matt] has prop]ties or qualities4 ,"s ( ^! are diff]5t 9 ! diff]5t k9ds ( matt]4 ,?us its ?ree =ms h diff]5t prop]ties1 z y saw 9 ,*apt] ,i4 ,!re is v>iety also 9 ! prop]ties ( sub/ances ( ! same class4 ,?us liquids are unlike ea* o!r 9 "s respects4 ,"s1 = example1 are light] ?an o!rs4 ,oil is light] ?an wat]4 ,gase\s sub/ances also diff] 9 ?is & 9 o!r respects4 ,b ! v>iety 9 ! prop]ties ( solids is great] ?an 9 ^? ( gases or liquids4 ,?is w appe> z ,i proce$4 #ah4 ,divisibility ( ,matt]4--,any visible portion ( matt] c be divid$ into p>ts4 ,ev5 if x be s small t y c see x only ) a p[]ful microscope1 x c\ld /ill be divid$ if y c\ld h an in/rum5t suffici5tly f9e = ! purpose4 ,divisibility1 !n1 is said to be a g5]al prop]ty ( matt]2 t is1 a prop]ty belong+ to all k9ds ( matt]4 #ai4 ,examples ( ,m9ute ,division ( ,matt]4--,!re are num]\s examples 9 :i* ! division ( matt] is c>ri$ f> beyond t :i* c be effect$ by any cutt+ in/rum5t4 ,"s ( ^! ,i w notice3 ,a gold-beat] c hamm] a gra9 ( gold into a leaf cov]+ a space ( fifty squ>e in*es4 ,s ?9 is x t x w\ld take #bhb1jjj ( su* leaves1 laid ^u ea* o!r1 to make ! ?ickness ( an in*4 ,& yet s ev5 & p]fect is ?is ?9 lay] ( gold1 t :5 x is laid ^u any surface 9 gild+ x has ! appe>ance ( solid gold4 ,a fifty million? "p ( ?is gra9 ( gold ?us hamm]$ out c be se5 by ! aid ( a microscope :i* magnifies ! diamet] ( an object t5 times4 ,b ! division ( gold is made ev5 m m9ute ?an ?is 9 ! manufacture ( ! wire ( gold-lace4 ,x is done 9 ?is way3 ,a b> ( silv] weigh+ #ahj ounces is cov]$ ) a lay] ( gold weigh+ an ounce4 ,x is !n drawn ?r\gh a s]ies ( holes 9 a /eel plate1 dim9i%+ 9 diamet]1 till x at l5g? comes out a v f9e wire #djjj feet long4 ,ea* foot ( x !n has only ! "o #djjj? "p ( ! ounce ( gold1 & yet ! silv] is well cov]$4 ,a soap-bubble is a beautiful example ( ! m9ute division ( matt]4 ,t ?9 wall :i* incloses ! air :i* y h bl[n into x is compos$ ( p>ticles ( ! soap & ( ! wat] m+l$ toge!r4 ,x is suppos$ to be less ?an "o million? ( an in* 9 ?ickness4 ,! ?read ( ! silk-worm is s m9ute t ! f9e/ sew+-silk is =m$ ( _m ( ^! ?reads twi/$ toge!r4 ,b ! spid] sp9s mu* m f9ely ?an ?is4 ,! ?read by :i* y see him lett+ himself d[n f any height is made up ( ab\t #fjjj ?reads or filam5ts1 ea* com+ f a sep>ate hole 9 8 sp9n+ ma*9e4 ,a qu>t] ( an ounce ( ! ?read ( a spid]'s web w\ld ext5d #djj miles4 ,a gra9 ( blue vitriol1 dissolv$ 9 a gallon ( wat]1 w make ! :ole blue4 ,su* a diffusion c\ld n be )\t an exce$+ly m9ute division ( ! p>ticles4 ,p]haps ! mo/ m9ute division ( matt] is exemplifi$ 9 odors4 ,a gra9 ( musk w sc5t a room = ye>s1 & yet h no p]ceptible loss ( weight4 ,b all ?is "t ! air is fill$ ) f9e p>ticles com+ f ! musk4 ,! microscope reveals to u _m wond]ful examples ( ! m9ut5ess ( ! p>ticles ( matt]1 bo? 9 ! vegetable & ! animal _w4 ,if y press a common puff-ball a du/ flies (f l smoke4 ,exam9$ ) a microscope1 ea* p>ticle ( ?is du/1 :i* is ! se$ ( ! plant1 is a p]fectly r\nd orange-color$ ball4 ,?is ball is ( c\rse made up ( v _m p>ticles1 arrang$ 9 ?is regul> =m4 ,beautiful examples ( v>i\s arrangem5ts ( ! m9ute p>ticles ( matt] we h 9 ! poll5 ( diff]5t plants1 z se5 ) ! microscope4 ,ea* p>ticle ( ! du/ :i* adh]es to y\r f+]s z y cat* a mo? is a scale ) f9e l9es ^u x regul>ly arrang$4 ,& if y look ?r\gh ! microscope at ! w+ ( ! mo?1 y w see1 :]e ! du/ is rubb$ (f1 ! atta*m5ts by :i* ! scales 7 held /&+ up f ! surface ( ! w+1 l nail-heads on a ro( :]e ! %+les h be5 torn (f4 ,! organization ( exce$+ly small animals1 z reveal$ by ! microscope1 furni%es u ) wond]ful examples ( ! m9ute division ( matt]4 ,a little ( ! du/ ( guano1 exam9$ ?r\gh a p[]ful microscope1 is se5 to conta9 multitudes ( %ells ( v>i\s %apes4 ,^! %ells are ! rema9s ( animalcules t liv$ 9 ! wat]1 _! de/9y seem+ to be 9 "p to furni% food to o!r animals l>g] ?an !mselves4 ,9 ! *alk =mations ( ! e>? are se5 multitudes ( su* %ells4 ,!y h be5 discov]$ ev5 9 ! glaz+ ( a visit+-c>d2 = !y are s small t ! f9e gr9d+ up ( ! *alk does n :olly de/roy !m4 ,!re are animals1 bo? 9 ! air & 9 ! wat]1 s small t x w\ld take millions ( !m to equal 9 bulk a gram ( s&1 & a ?\s& ( !m c\ld swim side by side ?r\gh ! eye ( a common-siz$ ne$le4 ,n[ 9 all ^! animals !re are organs1 con/ruct$ ( p>ticles ( matt]1 :i* are arrang$ 9 !m ) z mu* ord] & symmetry z 9 ! organs ( our bodies4 ,h[ m9ute !n mu/ ^! p>ticles be6 ,h[ d su* facts ext5d our views ( ! p[] ( ! ,deity6 ,! same p[] t m\ld$ ! e>?1 sun1 moon1 & ! :ole ho/ ( heav51 gave =m1 & life1 & motion to ! millions :i* sport 9 e sunbeam2 ! same eye t wat*es ! imm5se heav5ly bodies z !y move on 9 _! c\rse1 looks ^u "o & all ( ^! legions ( animals 9 e>?1 air1 & wat]1 ?\gh !y are unse5 by human eyes1 see+ t e p>ticle %all take its "r position1 s t ?is "p ( creation may ) all ! re/ be pron\nc$ v good2 & ! same b\ntiful h& t disp5ses ! means ( life & enjoym5t to ! millions ( ! human race1 =gets n to m9i/] to ! brief life & enjoym5t ( ea* "o ( ^! myriads ( animalcules1 ?\gh !y seem to be almo/ no?+ness itself4 #bj4 ,pores & ,spaces 9 ,matt]4--,9 all matt] !re are spaces ab\t ! p>ticles4 ,^? bodies :i* are call$ por\s h q l>ge spaces 9 !m4 ,b ev5 9 ^? :i* are n commonly consid]$ por\s ! p>ticles are by no means close toge!r4 ,a celebrat$ exp]im5t tri$ 9 ,flor5ce a long "t ago %[$ t !re are spaces among ! p>ticles ( s d5se a sub/ance z gold suffici5tly l>ge to let wat] ?r\gh !m4 ,a holl[ gold5 globe conta9+ wat] 0 subject$ to great pressure1 & its surface 0 b$ew$ ) ! wat] t came out ?r\gh ! pores ( ! gold4 ,9 all sub/ances 9 :i* !re are pores visible to ! nak$ eye1 or by ! aid ( ! microscope1 !re are o!r spaces or int]/ices among ! p>ticles ar\nd ! pores4 ,inde$1 x is suppos$ t !re is space ar\nd e ultimate p>ticle or atom1 & t no two ( ^! atoms are 9 actual contact4 ,! fact t sub/ances :i* h no pores c be compress$ into a small] space ?an !y usually occupy %[s t !re are spaces or int]/ices 9 !m4 ,solids c be ?us compress$1 "s m ?an o!rs4 ,b ! mo/ compressible sub/ances are ! gases & vapors4 ,! am\nt ( space betwe5 _! p>ticles mu/ be v l>ge to all[ ( s great compression4 ,illu/ration3 ,fig4 #a4 #ba4 ,space 9 ,gase\s ,sub/ances4--,we c h "s idea ( ! great am\nt ( space 9 a gase\s or a]i=m sub/ance by obs]v+ ! diff]5ce betwe5 wat] 9 its liquid & 9 its a]i=m /ate4 ,a cubic in* ( wat]1 :5 x becomes /eam1 occupies #afif times z mu* room z x did :5 x 0 wat]4 ,! diff]5ce 9 proportion is exhibit$ 9 ,fig4 #a1 ! inn] circle repres5t+ ! wat]1 & ! out] ! /eam into :i* x is conv]t$4 ,n[ ! wat] is n alt]$ at all 9 its nature by be+ *ang$ into /eam4 ,! p>ticles are simply put f>!r ap>t by ! heat1 & z soon z ! heat is )drawn !y come toge!r aga9 to =m wat]1 or1 9 o!r words1 ! /eam is cond5s$ into wat]4 ,x is pla91 !re=e1 t ! space betwe5 ! p>ticles is #afif times z great 9 /eam z x is 9 ! wat] f :i* ! /eam is made4 #bb4 ,solutions4--,:5 any sub/ance1 z sug> or salt1 is dissolv$ 9 wat]1 its p>ticles are diffus$ ?r\gh ! spaces t exi/ betwe5 ! p>ticles ( ! wat]4 ,s also :5 wat] evaporates 7 #ab71 ! p>ticles ( wat] are diffus$ ?r\gh ! spaces betwe5 ! p>ticles ( ! air4 ,9 l mann] are ! p>ticles f an odor\s sub/ance diffus$ 9 ^! spaces1 & ?us m+l$ ) ! p>ticles ( ! air !y are c>ri$ into ! no/rils1 & /rike ^u ! m9ute extremities ( ! n]ve ( smell4 #bc4 ,relation ( ,heat to ! ,spaces ( ,matt]4--,! v>iation 9 ! am\nt ( space betwe5 ! p>ticles ( matt] 9 any sub/ance g5]ally dep5ds on ! v>iation ( ! am\nt ( heat pres5t4 ,?us heat exp&s iron2 t is1 x increases ! spaces betwe5 ! p>ticles ( ! iron4 ,s also heat increases ! spaces betwe5 ! p>ticles ( m]cury1 & ?us makes x occupy m room 9 ! !rmomet]4 ,?is effect ( heat w be consid]$ m fully h]eaft]4 ,! g5]al views :i* ,i h giv5 ( ! con/itution ( matt] w ?r[ light ^u ! diff]5t qualities ( diff]5t sub/ances1 "s ( :i* ,i w notice4 #bd4 ,d5sity & ,r>ity4--,! d5sity ( a sub/ance dep5ds ^u ! quantity ( matt] x conta9s 9 a giv5 space4 ,! m d5se1 !re=e1 a sub/ance is ! great] is its weight4 ,a piece ( lead is =ty times heavi] ?an a piece ( cork ( ! same size4 ,m]cury is ne>ly f\rte5 times heavi] ?an an equal bulk ( wat]4 ,y see1 !n1 t d5sity mu/ dep5d on ! ne>ness ( ! atoms to ea* o!r4 ,9 s d5se a sub/ance z gold ! atoms are all v close toge!r2 9 wood !re are spaces1 "s ( :i* are s l>ge t y c see !m2 & 9 air1 /eam1 & ! gases !re is a great deal ( space among ! p>ticles 7 #ba71 s t we speak ( _! r>ity in/ead ( _! d5sity4 #be4 ,t5acity4--,! p[] ( hold+ toge!r1 t]m$ t5acity1 dep5ds on ! degree ( attraction betwe5 ! p>ticles4 ,by attraction ,i mean a disposition 9 p>ticles to come toge!r1 ?is disposition be+ manife/$ 9 opposition to any =ce t5d+ to draw !m ap>t4 ,i %all soon speak ( ?is m p>ticul>ly4 ,t5acity does n exi/ at all 9 gase\s sub/ances4 ,! p>ticles ( air & ( /eam1 = example1 %[ no disposition to cl+ toge!r2 t is1 h no t5acity4 ,?is prop]ty is weak 9 liquids4 ,x is only /rong en\gh 9 wat] to enable its p>ticles to hang toge!r 9 ! %ape ( a drop4 ,x is /rong 9 solids1 enabl+ _! p>ticles n only to hold toge!r 9 l>ge quantities1 b to hold up also heavy weights susp5d$ to !m4 ,x is /rong] 9 iron ?an 9 any o!r solid4 ,x is /rong] 9 wr\ght iron ?an 9 ca/ iron2 & /ronge/ ( all 9 /eel4 #bf4 ,comp>ative ,t5acity ( ,sub/ances4--,v>i\s metals & o!r sub/ances h be5 te/$ 9 ref]5ce to _! comp>ative t5acity4 ,x 0 done 9 ?is way3 ,wires 7 made ( ! metals1 all ( ! same size4 ,weights 7 susp5d$ to !m1 & additions 7 made to ! weights by little & little till ! wires broke4 ,! table und]nea? 0 made by plac+ aga9/ ea* metal ! greate/ weight t its wire w\ld hold3 ,ca/ /eel #acd p\nds4 ,be/ wr\ght iron #gj p\nds4 ,ca/ iron #ai p\nds4 ,copp] #ai p\nds4 ,silv] #aa p\nds4 ,gold #i p\nds4 ,t9 #e p\nds4 ,lead #b p\nds4 ,oak wood1 tri$ 9 ! same way1 0 f\nd to hold up #ab p\nds1 "o m p\nd ?an silv]4 ,"s animal sub/ances h great t5acity1 z ! ?read ( ! silk-worm1 hair1 wool1 & ! ligam5ts & t5dons ( our bodies & ( o!r animals4 #bg4 ,value ( ,t5aci\s ,sub/ances4--,! gradual discov]y1 says ,dr4 ,arnot1 ( sub/ances possess$ ( /rong t5acity1 & :i* man c\ld yet easily m\ld & apply to 8 purposes1 has be5 ( great importance to 8 progress 9 ! arts ( life4 ,! place ( ! hemp5 cordage ( ,european navies is /ill held 9 ,*9a by twi/$ canes & /rips ( bamboo2 & ev5 ! hemp5 cable ( ,europe1 s great an improvem5t on =m] usage1 is n[ rapidly giv+ way to ! m complete & commodi\s security ( ! iron *a9--( :i* ! mat]ial to our remote ance/ors exi/$ only z useless /one or e>?4 ,& :at a magnific5t spectacle is x1 at ! pres5t day1 to behold *a9s ( t5aci\s iron /ret*$ high across a *annel ( ! ocean1 z at ! ,m5ai ,/rait betwe5 ,anglesea & ,engl&1 & support+ an admirable bridge-road ( safety1 along :i* cr[d$ processions may p\r1 reg>dless ( ! deep bel[1 or ( ! /orm2 :ile %ips !re1 ) sails full-spread1 pursue _! c\rse unmole/+ & unmole/$4 #bh4 ,h>dness4--,?is prop]ty seems to dep5d ^u "s peculi> arrangem5t ( ! p>ticles ( matt]4 ,we %\ld suppose t ! d5se/ sub/ances w\ld be ! h>de/4 ,b x is n s4 ,iron is ! h>de/ ( ! metals1 b its p>ticles are n s close toge!r z ^? ( gold1 :i* is q a s(t metal4 ,& gold is five times z heavy z ! diamond1 :i* is s h>d z to cut glass easily4 ,common fl9t is h>d en\gh to scrat* glass1 b w n cut x l ! diamond4 ,illu/ration3 ,fig4 #b4 #bi4 ,flexibility & ,brittl5ess4--,if y b5d a flexible body z a piece ( wood1 z repres5t$ 9 ,fig4 #b1 x is obvi\s t ! p>ticles on ! upp] or convex side mu/ be put a little f>!r ap>t1 :ile ^? on ! "u or concave side are br\ght a little ne>] toge!r4 ,b ! wood does n break1 because ! p>ticles t are ?us mov$ a little ap>t /ill reta9 _! hold ^u ea* o!r4 ,?is is ! explanation ( :at we call flexibility4 ,on ! o!r h&1 ! p>ticles 9 a rod ( glass c n be put f>!r ap>t 9 ?is way4 ,!y are n actually 9 contact any m ?an ! p>ticles ( ! wood are 7 #bj71 b !y are 9 a fix$ relative position2 t is1 a position :i* c n be di/urb$ )\t a p]man5t sep>ation ( p>ticles4 ,if y attempt to b5d ! rod !re is no slight sep>ation ( _m p>ticles1 z 9 ! b5t wood1 b a full & p]man5t sep>ation 9 "s "o "p ( ! rod4 ,we call ! prop]ty on :i* ?is result dep5ds brittl5ess4 ,brittle sub/ances are g5]ally h>d4 ,glass1 :ile ! mo/ brittle ( all sub/ances1 is h>d en\gh to scrat* iron4 ,brittle sub/ances also h mu* t5acity4 ,a rod ( glass c hold up a heavy weight1 al?\gh a slight bl[ sudd5ly giv5 w\ld break x4 #cj4 ,flexible & ,brittle ,/eel4--,!re are two k9ds ( /eel1 flexible & brittle4 ,! /eel ( mo/ cutt+ in/rum5ts is brittle4 ,! /eel ( a sword-blade is q flexible1 & t ( a wat*-spr+ is s mu* s t we c w9d x up 9 a coil4 ,?is diff]5ce is ow+ to a diff]5ce 9 ! mode ( cool+ ! /eel4 ,if x be cool$ sudd5ly1 x is brittle2 if sl[ly1 x is flexible4 ,! process by :i* x is cool$ sl[ly is call$ anneal+4 ,! explanation ( all ?is is q pla94 ,! /eel be+ exp&$ by heat--t is1 its p>ticles be+ put f>!r ap>t ?an !y usually are--:5 !y are sudd5ly br\ght toge!r aga9 !y h n "t to arrange _! relative position prop]ly4 ,brittl5ess is !re=e ! result4 ,b1 on ! o!r h&1 :5 ! cool+ is effect$ gradually1 "t is giv5 = ! arrangem5t4 #ca4 ,temp]+ ( ,/eel4--,/eel sudd5ly h>d5$ is too brittle = common use4 ,a process call$ temp]+ is !re=e resort$ to = dim9i%+ ! brittl5ess4 ,! /eel is reheat$ aft] ! h>d5+1 & is !n all[$ to cool sl[ly4 ,! degree 9 :i* ! brittl5ess is less5$ dep5ds on ! degree ( heat to :i* ! /eel is subject$4 ,x c be entirely remov$ by a r$ heat1 = !n ! p>ticles h a full opportunity to readju/ !mselves2 & ! m ! heat comes %ort ( ?is po9t ! less ?or\gh w be ! adju/m5t1 because ! less p]fectly are ! p>ticles releas$ f _! sudd5ly-tak5 position4 ,9 less5+ ! brittl5ess we less5 h>dness also1 & !re=e ! temp]+ is v>i$ 9 diff]5t cases accord+ to ! degree ( h>dness :i* is desir$4 #cb4 ,anneal+ ( ,glass4--,glass is always anneal$4 ,if ?is 7 n done our glass vessels & w9d[s w\ld be exce$+ly brittle1 & w\ld !re=e be con/antly break+4 ,articles made ( glass are anneal$ by be+ pass$ v sl[ly inde$ ?r\gh a long ov5 :i* is v hot at "o end1 ! heat gradually less5+ t[>d ! o!r end4 ,illu/ration3 ,fig4 #c #cc4 ,pr9ce ,rup]t's ,drops4--,we h a /rik+ example ( brittl5ess induc$ by sudd5 cool+ 9 :at are call$ ,pr9ce ,rup]t's drops4 ,^! are made by dropp+ melt$ gre5 glass into cold wat]1 & !y are ( ! %ape repres5t$ 9 ,fig4 #c4 ,if y break (f ev] s small a bit ( ! po9t ( "o ( ^! drops1 ! :ole w at once %iv] to pieces4 ,t is1 ! sudd5 arrangem5t ( ! p>ticles is s slight & unnatural t ! di/urbance ( ! arrangem5t 9 a small "p suffices to de/roy ! arrangem5t ( ! :ole1 v mu* z a r[ ( bricks falls ov] f ! fall ( ! fir/ 9 ! r[4 ,mr4 ,f>raday says t ^! drops 7 n1 z is commonly suppos$1 inv5t$ by ,pr9ce ,rup]t1 b 7 fir/ br\ght to ,engl& by him 9 #affj4 ,!y excit$ mu* curiosity at t "t1 & 7 consid]$ a k9d ( miracle 9 nature4 ,b y see t ?is1 l _m o!r wond]s1 receives ) a little ?\ght an easy explanation4 #cd4 ,malleability & ,ductility4--,^? metals :i* c be hamm]$ into ?9 plates are call$ malleable4 ,gold furni%es u ) ! be/ illu/ration ( ?is prop]ty4 ,silv]1 copp]1 & t9 are q malleable4 ,mo/ ( ! o!r metals are v little s1 & "s ( !m are n at all1 break+ at ! fir/ bl[4 ,a sub/ance is said to be ductile :5 x c be drawn out into wire4 ,! pr9cipal metals t h ?is quality are plat9um1 silv]1 iron1 copp]1 & gold1 & 9 ! ord] 9 :i* ,i h nam$ !m4 ,melt$ glass is v ductile4 ,x c be drawn out 9 a v f9e ?read1 & :5 ?is ?read is cut & arrang$ 9 bran*es x resembles beautiful :ite hair4 ,9 hamm]+ metals into plates1 or draw+ !m into wire1 !re is a consid]able *ange ( relative position 9 ! p>ticles1 simil> to t :i* we h 9 fluids1 ?\gh no?+ l z free4 ,9 ?is *ange ( position ^? p>ticles t d rema9 9 close neighborhood h a rem>kable t5acity or attraction1 prev5t+ _! sep>ation4 ,9 weld+ two pieces ( iron1 :i* is done by ! blacksmi? by hamm]+ !m toge!r :5 r$-hot1 !re mu/ be en\gh movem5t among ! p>ticles to h ^? ( "o piece m+le some:at ) ^? ( ! o!r4 #ce4 ,compressibility4--,por\s sub/ances c be consid]ably compress$4 ,=ce appli$ to !m c br+ _! p>ticles ne>] toge!r1 mak+ !m to fill up 9 "p _! pores4 ,! mo/ famili> example y h ( ?is is 9 sponge4 ,! m por\s wood is ! m c x be compress$4 ,b ev5 su* d5se sub/ances z ! metals c be compress$ 9 "s degree2 t is1 ! int]/ices betwe5 _! p>ticles c be made small]4 ,m$als & co9s h _! figures & lett]s /amp$ ^u !m by pressure1 j z impressions are made ^u melt$ seal+-wax4 ,! heavy & quick pressure requir$ to d ?is actually compresses ! :ole piece ( ! h>d metal1 putt+ all ! p>ticles ne>] toge!r1 s t x occupies less space ?an x did be=e x 0 /amp$4 #cf4 ,incompressibility ( ,liquids4--,we %\ld suppose1 f ! fre5ess ) :i* ! p>ticles ( liquids move among ea* o!r1 & f ! spaces 7 #bb7 :i* exi/ among !m1 t ^! sub/ances c\ld be easily compress$4 ,b x is n s4 ,! heavie/ pressure is requir$ to compress !m ev5 9 a slight degree4 ,wat] c be compress$ s v little t practically x is reg>d$ z incompressible4 #cg4 ,influ5ce ( ,heat on ! ,bulk ( ,liquids4--,al?\gh ! int]/ices betwe5 ! p>ticles ( liquids c n be v>i$ by me*anical pressure1 !y c be by v>iations ( temp]ature4 ,liquids are dilat$ or exp&$ by heat2 t is1 _! p>ticles are put f>!r ap>t4 ,!y are contract$ or compress$ by cold2 t is1 _! p>ticles are br\ght ne>] toge!r by ! ab/raction ( heat4 ,! mo/ famili> example t we h is 9 ! !rmomet]4 ,! m]cury rises 9 ! tube :5 ! heat increases ! int]/ices betwe5 its p>ticles2 & x falls :5 ! loss ( heat all[s ! p>ticles to come ne> toge!r4 ,! same effects are se5 :5 alcohol is us$ 9 ! !rmomet]1 z is done 9 ! arctic regions1 because m]cury may freeze !re4 ,a !rmomet] ) wat] 9 x w\ld answ] if we wi%$ only to measure temp]atures betwe5 ! freez+ po9t & ! boil+ po9t ( wat]4 ,! expansive influ5ce ( heat w be p>ticul>ly treat$ ( h]eaft]4 #ch4 ,compressibility ( ,a]i=m ,sub/ances4--,a]i=m bodies are m compressible ?an any o!r sub/ances1 %[+ t 9 _! ord9>y condition !re is a great deal ( space among _! p>ticles4 ,:ile !y are ?us unlike liquids 9 compressibility1 !y are affect$ by heat 9 ! same way t liquids are4 ,illu/ration3 ,fig4 #d4 ,fig4 #e4 #ci4 ,ela/icity4--,closely alli$ ) ! compressibility ( matt] is its ela/icity4 ,we see ?is prop]ty /rik+ly exemplifi$ 9 ,india-rubb]4 ,x occasions ! reb\nd+ ( a ball ( ?is sub/ance :5 ?r[n d[n4 ,obs]ve fl[ exactly :at occurs 9 ?is case4 ,! ball z x meets ! resi/ance ( ! floor is flatt5$1 z repres5t$ 9 ,fig4 #d4 ,!n1 z x assumes ! r\nd %ape1 z se5 9 ,fig4 #e1 x pu%es d[nw>d ^u ! floor4 ,x is ?is sudd5 pu%+ d[nw>d t makes x reb\nd4 ,x is z if !re 7 a compress$ spr+ betwe5 ! ball & floor4 ,x may be lik5$ also to jump+4 ,:5 "o jumps he b5ds 8 limbs at ! ?igh & knee jo9ts1 & !n1 9 /raight5+ himself up1 gives a sudd5 pu%1 l t giv5 by ! ball z x assumes its r\nd %ape1 & s is ?r[n =w>d or upw>d1 accord+ to ! direction 9 :i* ! pu%+ =ce is made4 ,! same flatt5+ occurs 9 an ivory ball1 ?\gh n to ! same degree4 ,y c prove t x does occur by exp]im5t4 ,let a m>ble slab be wet & drop ! ball ^u x4 ,q a spot w be made dry by ! bl[ ( ! ball1 %[+ t x t\*$ m ( ! m>ble ?an x does :5 x is m]ely plac$ ^u x4 #dj4 ,ela/icity ,%[n 9 ,o!r ,ways4--,if a /ick be b5t1 z 9 ,fig4 #b1 z soon z ! b5d+ =ce is )drawn ! /ick becomes /raight aga9 f its ela/icity4 ,x is ?is ela/ic =ce ( ! b[1 /raight5+ x1 t spe$s ! arr[4 ,obs]ve 9 ?is case t :ile ! p>ticles on ! concave side ( ! b5t b[ are br\ght ne>] toge!r or compress$1 ^? on ! convex side are mov$ ap>t4 ,?is mov+ ap>t ( ! p>ticles is (t5 %[n 9 ,india-rubb]4 ,y c see h[ v f> ap>t p>ticles t are 9 ne> neighborhood may be c>ri$1 if y w /ick two p9s close toge!r 9 a /rip ( ,india-rubb] be=e y /ret* x4 #da4 ,degrees ( ,ela/icity 9 ,diff]5t ,sub/ances4--,"s sub/ances h s v little ela/icity t !y are practically consid]$ z hav+ none4 ,lead is "o ( ^!4 ,a rod ( lead :5 b5t rema9s s1 & a lead5 ball does n reb\nd4 ,:ile a]i=m sub/ances are ! mo/ compressible ( all1 !y are also ! mo/ ela/ic4 ,air compress$ returns to its usual condition ! mom5t t x is reliev$ f ! pressure1 & ) a =ce proportion$ to ! am\nt ( ! pressure4 ,s x is ) /eam & ! gases4 ,! v>i$ results ( ?is quality ( a]i=m sub/ances w claim our att5tion m p>ticul>ly 9 "s o!r p>ts ( ?is book4 #db4 ,def9ition ( ,ela/icity4--,y see f ! illu/rations t h be5 giv5 t ela/icity is t prop]ty ( matt] by :i* its p>ticles1 :5 br\ght ne>] toge!r or c>ri$ f>!r ap>t by any =ce1 return to _! usual condition :5 ! =ce is )drawn4 #dc4 ,usefulness ( ,v>iety 9 ,prop]ties ( ,matt]4--,! v>i\s prop]ties ( matt] br\ght to view 9 ?is *apt] are provid5tial adaptations to ! necessities ( man4 ,ea* sub/ance has ^? prop]ties :i* be/ fit x = 8 use4 ,iron1 = example1 design$ by ! ,creator to be bo? ! /ronge/ & mo/ ext5sively useful s]vant ( man among ! metals1 is !re=e provid$ 9 great abundance1 & has ^? /rong1 decid$1 & v>i\s qualities :i* fit x = ! s]vices x is to p]=m4 ,gold & silv]1 on ! o!r h&1 design$ = s]vices less ext5sive1 light]1 & 9 a great measure ornam5tal1 are provid$ 9 v mu* less quantity1 & h prop]ties admirably adapt+ !m to ! s]vices = :i* !y are s manife/ly int5d$4 ,! same c be sub/antially said ( all o!r sub/ances1 & especially ( ^? v abundant ones1 air & wat]4 ,& x may be rem>k$ also t ! +5uity ( man is cont9ually discov]+ new modes ( br++ ! v>i\s prop]ties ( matt] into 8 s]vice4 ,i w give b a s+le illu/ration--! temp]+ ( /eel4 ,?is discov]y1 says ,dr4 ,arnot1 is p]haps second 9 importance to few discov]ies :i* man has made2 = x has giv5 him all ! edge-tools & cutt+-in/rum5ts by :i* he n[ m\lds e o!r sub/ance to 8 wi%es4 ,a savage w "w = twelve mon?s ) fire & %>p /ones to fell a great tree & to give x ! %ape ( a canoe1 :]e a mod]n c>p5t]1 ) 8 tools1 c\ld accompli% ! object 9 a day or two4 ,,*apt] ,,iii4 ,,! ,,ess5tial ,,prop]ties ,,( ,,matt]4 #dd4 ,ext5sion4--,y c n conceive ( any portion ( matt]1 h[ev] small x may be1 t has n %ape or figure4 ,x may be s small z to appe> only z a po9t to ! nak$ eye1 b se5 ?r\gh ! microscope its %ape becomes obvi\s4 ,ev5 an atom mu/ h l5g?1 bread?1 & ?ickness1 ?\gh x be s small t we c n measure x1 nor see its %ape ) ! mo/ p[]ful microscopes4 ,ext5sion1 :i* is ! t]m commonly us$ to express ?is idea1 is !n an ess5tial prop]ty ( matt]2 t is1 x is a prop]ty ( :i* no =m or k9d ( matt] c be de/itute4 ,! di/9ction1 9 ?is respect1 betwe5 ?is prop]ty & ^? :i* ,i h be=e notic$ may be made obvi\s to y by an example4 ,h>dness is n an ess5tial quality ( matt]1 = "s k9ds ( matt] are de/itute ( x2 b no portion ( matt]1 h>d or s(t1 c be de/itute ( ext5sion or %ape4 ,! air is sometimes spok5 ( 9 common language z be+ %apeless4 ,?is is p>tly because x is invisible1 & p>tly because no portion or body ( air assumes any def9ite %ape4 ,b air is cont9ually =c$ into def9ite %apes by conf9em5t 9 rooms1 boxes1 etc42 & !n its ext5sion 9 diff]5t directions c be measur$ z accurately z ! ext5sion ( a solid c be4 ,& besides1 ! atoms ( :i* air is compos$ are und\bt$ly solid1 & we c n conceive ( _! exi/5ce )\t atta*+ to !m ! idea ( figure or ext5sion4 #de4 ,imp5etrability4--,9 common language "o sub/ance is said to p5etrate ano!r4 ,?us a ne$le p5etrates clo?1 a nail p5etrates wood1 etc4 ,b ?is is n /rictly true4 ,! ne$le does n g into ! clo?1 b goes betwe5 ! fibres ( x1 pu%+ !m to ! "o side & ! o!r4 ,s ! nail goes betwe5 ! fibres ( ! wood1 & n into !m4 ,x does n occupy ! same room t ! fibres d at ! same "t4 ,s1 also1 no atom ( matt] c p5etrate or g into any o!r atom4 ,x c only pu% x out ( ! way1 & !n occupy its place4 ,imp5etrability is !re=e said to be "o ( ! ess5tial qualities ( matt]4 ,?is means simply t no portion ( matt] c occupy ! same space ) ano!r portion ( matt] at ! same "t4 ,illu/ration3 ,fig4 #f4 ,illu/ration3 ,fig4 #g4 ,illu/ration3 ,fig4 #h4 #df4 ,illu/rations4--,_m illu/rations might be giv5 ( ?is prop]ty4 ,i w give a few4 ,if y press a tumbl] into wat] ) its op5 end d[nw>d1 y c n fill x ) wat]1 = ! air conf9$ 9 ! tumbl] prev5ts x f ris+4 ,x c n occupy ! same space ) ! air4 ,x fills1 inde$1 a portion ( ! tumbl]1 b ?is is because ! air is compressible4 ,if y introduce a glass funnel1 a1 ,fig4 #f1 into a j> ( wat]1 b1 ) y\r ?umb on its m\?1 c1 ! wat] w n rise to fill x4 ,b if y take y\r ?umb (f1 ! wat] w rise to ! level ( ! wat] outside ( ! funnel1 pu%+ up ! air be=e x4 ,if y h n a funnel1 a vial or bottle ) its bottom brok5 (f w answ] = ! exp]im5t4 ,! foll[+ is a v pretty exp]im5t1 illu/rat+ ! same po9t4 ,place a light$ tap]1 a1 ,fig4 #g1 on a l>ge flat cork 9 a j> ( wat]4 ,put ov] x an op5 j> or receiv]1 b1 hav+ a /op-cock1 c4 ,clos+ ! /op-cock1 press ! receiv] d[n into ! wat]1 & y w see ! tap] s9k ) x1 z repres5t$ 9 ! figure1 ! air prev5t+ ! wat] f ent]+ ! receiv]4 ,if n[ y op5 ! /op-cock ! wat] ru%es 91 ?ru/+ ! air upw>d1 & mak+ ! tap] to appe> z if ris+ out ( ! wat]4 ,! div+-bell (f]s a good illu/ration4 ,x consi/s ( a vessel1 a a1 ,fig4 #h1 %ap$ l a bell1 made suffici5tly heavy to s9k 9 wat]4 ,x is let d[n by a *a9 & cable1 z se5 9 ! figure4 ,! wat] does n ent] ! bell any f>!r ?an ! compressibility ( ! air p]mits x4 ,9 ord] t ! m5 9 x may rema9 "u wat] = "s "t fre% air is suppli$ by ! tube b1 x be+ =c$ d[n by a =c+-pump4 ,at ! same "t ! vitiat$ air c be let (f by a valve provid$ = t purpose4 ,!re are w9d[s 9 ! top ( ! bell to give ! requisite light = "w on ! sea's bottom4 ,treasures are (t5 recov]$ by ?is means :i* w\ld o!rwise be lo/4 ,y see a resemblance betwe5 ! div+-bell & ! arrangem5t 9 ,fig4 #g1 ! receiv] repres5t+ ! bell & ! light$ tap] ! m5 9 x4 #dg4 ,o!r ,illu/rations4--,if y drop a bullet into a tumbl] ( wat] x pu%es ! p>ticles to ! "o side & ! o!r1 & occupies ! room ?us made4 ,if y drop 9 sev]al !re is a manife/ rise ( ! wat]1 & y may drop 9 en\gh to make x ov]fl[4 ,! same ?+ is true ( ! f9e/ ne$le dropp$ 9 ! wat]--x does n p5etrate x1 b l ! bullet displaces "s ( its p>ticles & occupies _! room2 & y c make ! wat] ov]fl[ by dropp+ 9 _m ne$les4 ,we c truly say1 !n1 t wat] c n be p5etrat$ ev5 by a ne$le4 ,:5 any sub/ance1 z sug>1 is dissolv$ 9 wat]1 its p>ticles d n p5etrate ! wat]1 b g into ! spaces betwe5 its p>ticles4 ,s1 also1 :5 p>ticles f odor\s sub/ances are diffus$ 9 ! air1 !y are n really 9 ! air1 b are betwe5 its p>ticles4 #dh4 ,in]tia4--,matt] has no p[] to put itself 9 motion4 ,:5 x is mov$ x is mov$ by "s =ce :i* is ei!r outside ( ! matt] or is communicat$ to x 9 "s way4 ,:5 y\r arm is mov$ x is n ! matt] 9 y\r arm t is ! cause ( its motion4 ,x is caus$ by a =ce 9 y :i* ,i w n dwell ^u "h1 because ! subject belongs to ,physiology4 ,:5 air moves x is set 9 motion by "s =ce act+ ^u x1 z :5 y bl[ x f y\r lungs or move x ) a fan4 ,:5 ! w9d bl[s1 ! air is set 9 motion by heat & ! attraction ( ! e>?1 z w be expla9$ to y 9 ano!r "p ( ?is book4 ,i might multiply examples to any ext5t1 %[+ t matt] ( itself c n move4 ,?is prop]ty ( matt] is t]m$ in]tia4 #di4 ,in]tia ,%[n 9 ! ,inability ( ,matt] to ,/op its ,motion4--,matt]1 :5 once set 9 motion1 has no p[] to /op itself4 ,if x c\ld /op itself x c\ld n be said to be in]t4 ,& z x is in]t1 x w\ld1 :5 once set 9 motion1 keep on mov+ =ev] unless /opp$ by "s =ce4 ,:5 a /one falls to ! gr\nd1 x /ops simply because ! e>? /ops x4 ,if ! e>? 7 n 9 ! way1 ! /one w\ld move /raight on until x 7 /opp$ by some?+ else4 ,s1 also1 a /one t is ?r[n up 9 ! air w\ld keep on1 & soon be out ( sight1 & nev] return to ! e>?1 if x 7 n made to come d[n by =ces act+ ^u x4 ,"o ( ^! =ces is ! resi/ance ( ! air1 :i*1 f ! mom5t ! /one />ts1 is de/roy+ its motion4 ,ano!r =ce z con/antly op]at+ to ret>d ! /one is ! attraction1 or draw+ =ce1 ex]t$ by ! e>? ^u x4 ,?is p[]ful ?\gh unse5 =ce w be treat$ ( fully 9 ! next *apt]4 #ej4 ,matt] ,equally ,incl9$ to ,re/ & ,motion4--,x 0 =m]ly taught by philosoph]s t matt] is m incl9$ to re/ ?an to motion2 & ?is is ! popul> notion n[4 ,?is is because ! *ief causes t /op ! motions t we see f day to day--viz41 ! air & ! attraction ( ! e>?--are n visible4 ,= ?is reason1 until we inve/igate ! subject1 x seems to u t motion has a natural t5d5cy to /op1 or is sp5t1 z x is express$4 ,:5 friction has an ag5cy 9 arre/+ motion we see x pla9ly2 b ! common idea is1 t 9 ?is case ! motion is 9 "p sp5t & 9 "p de/roy$4 ,b 9 no case is motion sp5t1 b x is always de/roy$ by ob/acles4 ,! m ?or\ghly ^! are remov$1 ! long] w ! motion cont9ue2 & if !y 7 :olly remov$1 ! motion w\ld nev] cease4 ,p]petual motion1 !n1 is n 9 itself impossible2 = matt] has no m t5d5cy to /op mov+ :5 once put 9 motion1 ?an x has to beg9 motion :5 x is at re/4 ,all motion w\ld be p]petual if !re 7 n =ces oppos+ x4 ,if !re 7 only "o body 9 ! univ]se1 & t 7 set 9 motion1 x w\ld move =ev] ?r\gh empty space 9 a /raight l9e2 = !re is no matt] any :]e to resi/ its motion or to attract x away f its onw>d c\rse4 #ea4 ,divisibility4--,?\gh divisibility is a g5]al quality ( matt] 7 #ah71 x is n an ess5tial "o4 ,= if x be true t e portion ( matt] is compos$ ( atoms t rema9 :ole 7 #ad71 ?is prop]ty c n be said to belong to ^! atoms4 ,x is only ! bodies made up ( ^! atoms t c be divid$4 ,:5 we come to ! atoms !mselves ! division mu/ /op4 #eb4 ,weight4--,9 speak+ ( ! prop]ties ( matt] ,i h said no?+ ab\t weight1 al?\gh 9 ! popul> m9d ?is is ?\ght ( z be+ "o ( ! mo/ prom95t ( ! prop]ties ( "s k9ds ( matt]4 ,?is w be appropriately treat$ ( :5 ,i come to speak ( attraction1 = x is a m]e result ( attraction4 ,suffice x to /ate "h1 t ! weight ( a body is ! pressure occasion$ by ! attraction exi/+ betwe5 x & ano!r body4 ,if :5 a /one is rais$ f ! gr\nd ! attraction betwe5 x & ! e>? c\ld be de/roy$1 ! /one w\ld rema9 !re4 ,x w\ld n press d[n1 & s w\ld h no weight4 ,x is pla91 !re=e1 t weight1 s f> f be+ an ess5tial prop]ty ( matt]1 is n really a prop]ty at all4 ,x is only an effect ( a prop]ty--attraction4 ,if !re 7 only "o body 9 ! univ]se1 x w\ld h no weight1 = x w\ld press 9 no direction because !re is no?+ to attract x4 ,b z x is1 all matt] has weight1 = !re is o!r matt] to attract x4 ,,*apt] ,,iv4 ,,attraction4 #ec4 ,nature ( ,attraction4--,if y attempt to break a v t5aci\s solid sub/ance1 :y d y n succe$8 ,x is because ! p>ticles are s /rongly fa/5$ toge!r4 ,b h[8 ,by "s k9d ( cem5t or glue1 or by "s me*anical contrivances z nails or hooks8 ,no4 ,!y are fa/5$ toge!r by "s unse5 =ce4 ,we "k no?+ ( ! nature ( ?is =ce4 ,we "k only t x exi/s1 & we call x attraction4 ,! "n is a prop] "o1 = x simply expresses ! fact t "o p>ticle attracts or draws ano!r p>ticle t[>d itself4 #ed4 ,newton's ,idea ( ,attraction4--,x 0 /at$ 9 #bj t ! p>ticles ( matt]1 ev5 9 ! d5se/ sub/ances1 are n 9 actual contact1 b h spaces ar\nd !m4 ,n[ x 0 suppos$ by ,newton t !re is "s k9d ( e!real sub/ance p]vad+ all ^! spaces1 :i* causes ?is attraction betwe5 ! p>ticles4 ,he suppos$ also t ?is e!r 0 e :]e 9 space1 caus+ attraction betwe5 masses ( matt]4 ,b all ?is is m]e supposition1 & we "k n :e!r !re is ?is sort ( e!real glue keep+ ! univ]se toge!r1 or :e!r x is "s prop]ty 9 ! p>ticles !mselves t makes !m ?us attract ea* o!r4 ,b ! fact ( ! attraction we "k1 & we c obs]ve ! ph5om5a :i* x produces1 & discov] ! laws or rules by :i* ?is =ce is regulat$ 9 its action4 #ee4 ,attraction 9 ,solids4--,attraction is /rong] 9 "s solids ?an 9 o!rs4 ,! mason ) 8 tr[el easily divides a brick2 b he c n d ?is ) a piece ( granite1 = its p>ticles h a great] attraction = ea* o!r ?an ^? ( ! brick4 ,s a rap :i* w\ld break a glass di% w\ld n injure a copp] "o ( ! same ?ickness4 ,a weight t w\ld hang securely f an iron wire w\ld break a lead wire ( ! same size2 t is1 x w\ld te> ! p>ticles ap>t1 because !y are n /rongly attract$ to ea* o!r4 ,attraction has diff]5t modes ( action 9 diff]5t solids4 ,x !re=e fa/5s _! p>ticles toge!r 9 diff]5t ways1 & ?us produces all ! v>i\s qualities1 already notic$1 :i* are s useful to u--t5acity1 h>dness1 s(tness1 ductility1 flexibility1 etc4 #ef4 ,attraction 9 ,liquids4--,9 a liquid ! attraction betwe5 ! p>ticles is v feeble comp>$ ) t 9 solids4 ,! attraction ( ! p>ticles ( /eel is 9 /r5g? ab\t ?ree million times t ( ! p>ticles ( wat]4 ,we make ! e/imate 9 ?is way3 ,we f9d t a /eel wire w su/a9 a weight equal to #ci1jjj feet ( ! wire4 ,b a drop ( wat] hang+ to ! end ( a /ick c n be m ?an "o-six? ( an in* 9 l5g?2 t is1 wat] w hold toge!r by ! attraction ( its p>ticles only to ?is ext5t1 :i* is a little less ?an ! ?ree million? "p ( ! l5g? ( /eel wire :i* c\ld hang )\t break+4 #eg4 ,fre5ess ( ,movem5t ( ! ,p>ticles ( ,liquids4--,!re is "o prom95t *>act]i/ic ( liquids :i* is probably n entirely ow+ to ! feeble attraction ( _! p>ticles--,i mean ! fre5ess ) :i* ^! p>ticles are mov$ among ea* o!r4 ,?is is ow+ probably 9 "p to "s peculi> arrangem5t ( ! atoms 9 mak+ ! p>ticles ( a liquid4 ,i w illu/rate ?is 9 a co>se way4 ,if ! atoms ( lead 9 %ot 7 s arrang$ z to make irregul> jagg$ =ms1 !y c\ld n readily be mov$ among ea* o!r4 ,we suppose ! ultimate atoms ( a liquid to be s arrang$ 9 ! =mation ( p>ticles z to make !m n only r\nd b v smoo?4 ,h5ce comes ! great ease ) :i* !y circulate among ea* o!r4 ,illu/ration3 ,fig4 #i4 ,illu/ration3 ,fig4 #aj4 #eh4 ,globul> ,%ape ( ,drops ( ,liquids4--,z ! p>ticles ( a liquid move ?us freely among ea* o!r1 _! attraction disposes !m to assume a globul> or r\nd %ape4 ,! reason ( ?is c be made pla9 by ,figs4 #i & #aj4 ,! outside ( a p]fect sph]e is all at ! same di/ance f ! c5tre4 ,s all ! circumf]5ce ( a circle is at ! same di/ance f ! c5tre1 z repres5t$ 9 ,fig4 #i4 ,b ?is is n true ( all p>ts ( ! surface ( a cube or ( a squ>e3 a1 = example1 is f>!r f ! c5tre ?an b is4 ,n[ 9 a drop ( liquid all ! p>ticles are attract$ t[>d ! c5tre1 = 9 t l9e f ea* p>ticle lies ! l>ge/ numb] ( p>ticles to attract x4 ,?is c be made obvi\s by tak+ "s po9t 9 ! drop1 z repres5t$ 9 ,fig4 #aj1 & draw+ l9es f x ?r\gh ! c5tre & 9 o!r directions4 ,if a be ! po9t 9 ! drop1 x is pla9 t ! l9e f x ?r\gh ! c5tre is long] ?an a b or a c4 ,!re=e a p>ticle1 a1 w be attract$ t[>d ! c5tre r ?an 9 ! direction a b or a c1 because !re are m p>ticles 9 ! direction ( ! c5tre1 & ! m p>ticles !re are ! /rong] is ! attraction4 ,b ?is is n all4 ,! p>ticles 9 ! l9e a c1 t5d+ to make a g t[>d c1 are balanc$ by ! p>ticles 9 ! l9e a e1 t5d+ to make x g t[>d e4 ,! two l9es ( p>ticles !re=e toge!r t5d to make x g 9 a middle l9e betwe5 !m1 t is1 t[>d ! c5tre1 j z two /r+s pull+ equally1 ! "o to c & ! o!r to e1 w\ld make a body1 a1 move 9 a middle l9e betwe5 ^! two directions4 ,! same c be %[n ( ! two l9es ( p>ticles a b & a d1 & s ( any o!r two alike 9 situation on ea* side ( ! l9e ?r\gh ! c5tre4 ,! t5d5cy ( e p>ticle is1 !n1 to g t[>d ! c5tre1 & x w\ld g !re if !re 7 n p>ticles betwe5 to prev5t x4 ,y see h[ ?is w\ld op]ate 9 ! case ( ! p>ticles on ! surface ( ! drop4 ,z ^! are all /riv+1 z we may say1 9 ob$i5ce to attraction1 to get to ! c5tre1 none ( !m w be rais$ up into an angle or a po9t1 z w\ld be ! case if ! drop 7 9 ! %ape ( a cube4 ,if ?is %\ld be done x w\ld %[ t "s ( ! p>ticles 7 n z /rongly attract$ t[>d ! c5tre z o!rs are1 :i* is an impossibility4 #ei4 ,! ,globul> ,=m 9 ,diff]5t ,liquids4--,! disposition to =m a sph]e is se5 m di/9ctly 9 m]cury ?an 9 any o!r liquid4 ,if y drop a little ( x ^u a plate x sep>ates into globules1 :i* roll ab\t l %ot4 ,:y c n ! same ?+ be done ) wat]8 ,:y d ! drops ( wat] hang ^u ! w9d[-pane1 %[+ only 9 an imp]fect way _! disposition to ! globul> arrangem5t8 ,x is because ! p>ticles ( wat] h a great] attraction = o!r sub/ances1 & less attraction = ea* o!r1 ?an ! p>ticles ( ! quicksilv] h4 ,wat] sometimes exhibits its disposition to ! globul> =m 9 full on ! leaves ( "s plants1 & rolls ab\t 9 balls l m]cury4 ,?is is because !re is some?+ on ! surface ( ! leaf :i* repels r ?an attracts ! wat]4 ,if y put y\r f+]1 h[ev]1 on "o ( ^! drops1 x w spoil x1 & y\r f+] w be moi/5$1 because !re is an attraction betwe5 ! p>ticles ( y\r sk9 & ( ! wat]4 ,take ano!r illu/ration ( ?is diff]5ce 9 attraction4 ,if y drop a little oil ^u ! surface ( wat] x w float ab\t 9 r\nd drops4 ,?is is because ! wat] repels ! oil1 z ! surface ( "s k9ds ( leaves does wat]4 ,b :5 oil is spill$ ^u wood or clo? its p>ticles h s /rong an attraction = _! p>ticles t !y unite ) !m1 in/ead ( ga!r+ up into little r\nd companies z !y d on ! surface ( wat]4 #fj4 ,manufacture ( ,%ot4--,we h a beautiful example ( ! t5d5cy ( fluids to ! globul> arrangem5t 9 ! manufacture ( %ot4 ,! melt$ lead is p\r$ into a l>ge vessel 9 ! top ( ! %ot-t[]4 ,?is vessel has holes 9 its bottom1 f :i* ! metal falls 9 drops4 ,ea* drop1 z x :irls r\nd & r\nd 9 its fall1 takes ! globul> =m4 ,by ! "t t x rea*es ! end ( its j\rney1 ab\t two hundr$ feet1 x becomes s f> cool$ z to be solid1 & z x is receiv$ 9 a res]voir ( wat]1 its globul> =m is reta9$4 ,bullets c n be made 9 ?is way1 because a quantity ( melt$ lead suffici5t to make a bullet w n hold toge!r 9 a globul> =m4 #fa4 ,globul> ,=m ( ! ,e>? & ! ,heav5ly ,bodies4--,x is suppos$ t ! sun1 moon1 e>?1 & all ! heav5ly bodies 7 once 9 a liquid /ate1 & t !y owe _! globul> %ape to ?is fact4 ,z !y :irl$ on 9 ?is condition 9 _! c\rse1 ! diff]5t solids 7 gradually =m$1 & at l5g? !y acquir$ _! pres5t /ate4 ,h[ all ! mighty *anges c\ld be effect$ 9 our e>?1 conv]g+ x f a liquid into a body ) a solid cru/1 hav+ su* v>i\s sub/ances 9 x1 & s v>i\sly arrang$1 ) its depressions conta9+ wat]1 & ! :ole cov]$ ) its robe ( air fifty miles 9 ?ickness1 we c n und]/&4 ,& yet !re are "s portions ( ! process :i* *emi/ry & geology h reveal$ to u1 giv+ u "s glimpses ( ! wond]s :i*1 dur+ ! lapse ( ages1 ,god wr\ght 9 our e>? 9 prep>+ x = ! habitation ( man4 ,illu/ration3 ,fig4 #aa4 ,fig4 #ab4 #fb4 ,cry/allization4--,! arrangem5t ( ! p>ticles ( solid sub/ances is diff]5t f t ( liquids4 ,! t5d5cy "h is to /raight l9es & angles2 t is1 to cry/all9e =ms4 ,alum or common salt1 :5 x becomes solid f a solution1 =ms cry/als4 ,s also does sug>4 ,! cry/als ( diff]5t sub/ances are diff]5t4 ,9 ,fig4 #aa y h ! cry/al ( common salt1 & 9 ,fig4 #ab t ( alum4 ,we see ?is cry/all9e t5d5cy e :]e1 ev5 9 ! rude rocks & common /ones4 ,! rocks are dispos$ to exhibit regul> lay]s1 or columns1 or battlem5ts1 & always d s except :5 int]f]+ circum/ances prev5t4 ,& :5 y exam9e _! composition1 or t ( ! /one "u y\r feet1 y see ! same cry/all9e disposition 9 detail t y see 9 ! mass4 #fc4 ,cry/allization ( ,wat]4--,wat]1 :5 x *anges into a solid1 %[s ! same disposition1 ( :i* ! cry/als ( ! sn[ & ! fro/-"w on our w9d[s are famili> examples4 ,:5 sn[ =ms1 ! wat] ( ! cl\ds is sudd5ly cry/alliz$ by ! cold air1 ! p>ticles tak+ _! regul> places m readily & c]ta9ly ?an if !y 7 guid$ by intellig5ce1 because 9 ob$i5ce to an un]r+ law e/abli%$ by ! ,creator4 ,we sometimes h an example ( ?is sudd5 cry/allization ( wat] "u our eye4 ,! wat] 9 a pit*] may rema9 fluid1 al?\gh x is cool$ d[n to ! freez+ po9t1 & ev5 bel[ x1 if x be kept p]fectly /ill4 ,b on tak+ up ! pit*] ! wat] at once becomes fill$ ) a net-"w ( ice-cry/als4 ,! explanation is ?is3 ,! /illness ( ! wat] has prev5t$ its p>ticles f tak+ on ! new arrangem5t ne$$ = ! =mation ( ice2 b ! jo/l+ ( !m 9 tak+ up ! pit*] has s]v$ to make !m d x ?us sudd5ly4 ,illu/ration3 ,fig4 #ac4 #fd4 ,fro/ & ,sn[4--,! fro/-"w on our w9d[s is a wond]ful exhibition ( ! v>iety ( =ms t cry/allization c produce4 ,x sometimes pres5ts figures l leaves & fl[]s1 su* z we see *as$ on vessels ( silv]1 b mu* m delicate & beautiful4 ,s v>i$ & fanta/ic are ! =ms 9 :i* ^! wat]-cry/als are arrang$1 t x is v natural to ascribe !m1 z is done univ]sally 9 ! dialect ( ! nurs]y1 to ! +5uity ( a /range & tricksy _s4 ,e sn[-flake is a bundle ( little cry/als z regul> & beautiful z ! cry/als :i* y s mu* admire 9 a m9]alogical cab9et4 ,& !re is great v>iety 9 ! gr\p+ ( ^! cry/als4 ,y h "s specim5s ( ^! gr\ps 9 ,fig4 #ac z !y appe> on exam9+ !m ) ! microscope4 ,ov] six hundr$ diff]5t =ms h be5 enum]at$1 & a hundr$ h be5 del9eat$4 ,x is a v quick op]ation by :i* ! p>ticles ( wat] 9 ! cl\ds ?us m>%al !mselves1 z if by magic1 9 ^! regul> =ms4 ,b a quick] op]ation is t by :i* hail is =m$--s quick t ! p>ticles h n "t to set !mselves 9 ! cry/all9e arrangem5t1 b are huddl$ toge!r )\t ord]4 ,! brilliant & gli/5+ :it5ess ( ! sn[ is ow+ to ! reflection ( light f its m9ute cry/als4 ,9 ! arctic regions ! beauty ( ! sn[ is (t5 mu* great] ?an ) u4 ,! sn[ cry/als ( la/ night1 says ,capta9 ,m',cl9tock 9 8 ,discov]y ( ! ,fate ( ,sir ,john ,frankl91 7 extremely beautiful4 ,! l>ge/ k9d is an in* 9 l5g?2 its =m exactly resembles ! end ( a po9t$ fea!r4 ,/ell> cry/als two-t5?s ( an in* 9 diamet] h also fall52 ^! h six po9ts1 & are ! mo/ exquisite ?+s :5 se5 "u a microscope4 ,9 ! sun1 or ev5 9 moonlight1 all ^! cry/als gli/5 mo/ brilliantly2 & z our ma/s & rigg+ are abundantly cov]$ ) !m1 ! ,fox nev] 0 s gorge\sly array$ z %e n[ appe>s4 #fe4 ,ord] 9 ,nature4--,we see 9 ?is g5]al t5d5cy to cry/allization a /rik+ illu/ration ( ! fact t ,god is a ,god ( ord]4 ,disord]ly arrangem5t is nev] se5 except :]e !re is an obvi\s necessity = x4 ,& ev5 :5 !re is app>5t disord]1 a little exam9ation g5]ally %[s t ess5tially !re is ord]4 ,! rocks t give s mu* v>iety to sc5]y are n pil$ up 9 confusion1 & ord] has evid5tly reign$ 9 _! con/ruction4 ,pick up a common /one1 & on break+ x y w see ! cry/all9e arrangem5t 9 its int]ior4 ,nay1 m1 mu* ( ! v soil is made up ( sep>at$ & brok5 cry/als4 ,illu/ration3 ,fig4 #ad4 #ff4 ,p>ticles ,mu/ be v ,ne> to ,ea* ,o!r to ,adh]e4--,:y is x t :5 y h brok5 any ?+ made ( glass1 h[ev] accurately y may br+ ! two p>ts toge!r1 y c n make !m unite 9 "o aga98 ,x is simply because ! p>ticles ( sub/ances w n attract ea* o!r en\gh to be unit$ unless !y are br\ght v ne> toge!r4 ,n[ x is impossible to br+ ! p>ticles on ! two surfaces ( a brok5 piece ( glass z ne> toge!r z !y 7 be=e x 0 brok54 ,if y c\ld d s1 no crack w\ld be visible4 ,y c jo9 !m by "s k9d ( cem5t4 ,?is is because ! p>ticles ( ! cem5t1 :ile x is s(t1 c be ins9uat$ among ! p>ticles ( ! glass2 & ?us1 :5 x dries1 x becomes a bond ( union betwe5 ! p>ticles on ea* side ( ! brea*4 ,= ! same reason y c make ! cut surfaces ( "s yield+ sub/ances adh]e4 ,if y divide a piece ( ,india-rubb] ) a clean cut1 y c make ! two surfaces adh]e by press+ !m toge!r firmly4 ,! p>ticles 9 ?is case are n unyield+1 z ^? ( ! glass are1 & "s ( !m are !re=e br\ght into su* ne> neighborhood z to attract ea* o!r suffici5tly to unite toge!r4 ,s1 too1 if y cut two bullets s z to h a v smoo? flat surface on ea*1 y c make !m adh]e q /rongly by press+ !m toge!r1 especially if y give a little turn+ motion at ! same "t t y press1 = ?is w cause ! p>ticles on ! two surfaces to be some:at m+l$ toge!r4 ,if y h q l>ge balls ( lead ) h&les1 z repres5t$ 9 ,fig4 #ad1 x w require consid]able =ce to sep>ate !m :5 !y h be5 ?us press$ toge!r4 #fg4 ,o!r ,illu/rations4--,silv] & gold may be made to adh]e to iron by a v great & sudd5 pressure4 ,! iron mu/ be made v smoo?1 & ! silv] or gold plate v ?94 ,a p[]ful bl[ br+s ! p>ticles ( ! ?9 plate into su* ne>ness to ^? ( ! iron t union is effect$1 or1 9 o!r words1 t !y attract ea* o!r suffici5tly to be unit$4 ,s1 also1 a %eet ( t9 & "o ( lead c be made to adh]e s z to =m "o %eet by ! pressure ( ! roll]s ( a flatt+-mill4 ,two v smoo? panes ( glass laid "o ^u ano!r may h s _m p>ticles br\ght into great ne>ness z to occasion "s adhesion4 ,x w be slight1 h[ev]1 few comp>atively ( all ! p>ticles com+ ne> en\gh to adh]e1 = ! smoo!/ glass is full ( inequalities1 z may be se5 by ! microscope4 #fh4 ,/r5g? ( ,adhesion4--,9 no case d p>ticles come 9 actual contact 7 #bj71 & _! adhesion dep5ds on ! ne>ness ( _! neighborhood to ea* o!r4 ,! /r5g? ( union1 !n1 betwe5 two surfaces dep5ds on ! numb] ( p>ticles br\ght ne> en\gh to adh]e toge!r4 ,9 ! case ( ! two bullets or ! lead balls1 if all ! p>ticles ( ! two surfaces 7 ne> en\gh to adh]e1 ! lead w\ld be j z /rong at ! junction z any :]e else4 ,! reason t s /rong adhesion takes place betwe5 portions ( "s sub/ances :5 we s(t5 !m by heat is t ! p>ticles ( ! two s(t5$ ends are all br\ght ne> en\gh toge!r = adhesion4 ,?us ! two ends ( a brok5 /ick ( seal+-wax may be firmly unit$ by heat+ !m & !n press+ !m toge!r4 ,! same ?+ c be done ) glass4 ,:5 iron is weld$1 z x is t]m$1 "s hamm]+ is requir$ to make ! p>ticles ( ! two s(t5$ ends ( ! iron unite4 ,illu/ration3 ,fig4 #ae4 #fi4 ,attraction ,betwe5 ,solids & ,liquids4--,! attraction :i* solids & liquids h = ea* o!r furni%es u ) _m int]e/+ ph5om5a4 ,! adhesion ( drops ( wat] to glass & o!r solids is a famili> example ( ?is attraction4 ,if y dip y\r h& into wat]1 x is wet on tak+ x out1 because y\r sk9 has suffici5t attraction = ! wat] to reta9 "s ( x4 ,a t[el w reta9 m ( x = two reasons--) ! int]/ices betwe5 its fibres x pres5ts mu* m surface to ! wat]1 & x has none ( ! oily sub/ance :i* on y\r sk91 ?\gh be+ 9 small quantity1 s]ves some:at to repel ! wat]4 ,! attraction ( solids & fluids = ea* o!r is %[n v prettily 9 ! exp]im5t repres5t$ 9 ,fig4 #ae 7p4 #dg74 ,a piece ( wood is atta*$ by ! /r+1 a1 to "o end ( a balance1 & weights j suffici5t to balance x are plac$ 9 ! opposite scale4 ,if n[ ! wood is br\ght 9 contact ) ! wat] 9 ! vessel1 b1 x w require additional weight 9 ! scale to sep>ate ! wood f ! wat]4 ,illu/ration3 ,fig4 #af4 ,fig4 #ag4 ,illu/ration3 ,fig4 #ah4 ,illu/ration3 ,fig4 #ai4 #gj4 ,f>!r ,illu/rations4--,:5 y see /ems ( plants ris+ above ! surface ( /agnant wat] y w obs]ve t ! wat] is consid]ably rais$ ab\t !m4 ,?is is f ! attraction betwe5 !m & ! wat]4 ,= ! same reason wat] is n z high 9 ! middle ( a tumbl] z x is at ! sides4 ,if y imm]se a piece ( glass 9 wat]1 ! wat] w rise at its sides z repres5t$ 9 ,fig4 #af4 ,if y imm]se two toge!r1 z 9 ,fig4 #ag1 ! wat] w rise high] betwe5 ?an outside ( !m1 because ! p>ticles betwe5 are attract$ by two surfaces1 :ile ^? outside are attract$ only by "o4 ,x is = ! same reason t two m5 c raise a weight high] ?an "o ( !m c alone4 ,& if ! pieces ( glass be br\ght q ne> toge!r1 z 9 ,fig4 #ah1 ! wat] w be rais$ high] /ill1 because !re is less to be rais$ by ! two surfaces4 ,x is j z two m5 c raise a small weight high] ?an !y c a l>ge "o4 ,! same ?+ may be beautifully illu/rat$ 9 ?is way3 ,let two pieces ( glass1 z repres5t$ 9 ,fig4 #ai1 be imm]s$ 9 color$ wat]1 ) two ( _! edges jo9$ toge!r at ,a ,b1 ! opposite edges at ,e ,d ,c be+ sep>at$4 ,! height to :i* ! fluid rises w make a curv$ l9e1 ,a ,f ,c1 x be+ l[e/ at ! edges :i* are sep>at$1 & highe/ at ! edges :i* are jo9$ toge!r4 ,illu/ration3 ,fig4 #bj4 ,illu/ration3 ,fig4 #ba4 #ga4 ,rise ( ,liquids 9 ,tubes4--,= ! same reason t wat] rises high] betwe5 plates ( glass ?an outside1 s x w rise high] 9 a tube ?an x w outside ( x4 ,! diagram 9 ,fig4 #bj w make ?is cle>4 ,i repres5t 9 ?is a transv]se section ( a tube1 enl>g$ s t ! demon/ration may be pla94 ,we w take a p>ticle on ! inside & ! outside at equal di/ances f ! glass4 ,x is cle> t ! p>ticle a is n z ne> to z _m p>ticles ( ! glass z ! p>ticle b is4 ,! l9es drawn %[ ?is4 ,! longe/ l9es ext5d+ f ! p>ticles a & b to ! glass are equal 9 l5g?2 t is1 a e & a f are equal to b g & b h4 ,x is cle>1 !re=e1 t all ! glass betwe5 ! l9es at c & d is z ne> to ! p>ticle b z ! glass betwe5 ! l9es at e & f is to ! p>ticle a4 ,b ?is is n all4 ,! p>ticle b is ne> en\gh to all ! inside ( ! tube to be attract$ by x1 :ile v little attraction is ex]t$ ^u a by any "p ( ! glass beyond t :i* is includ$ betwe5 e & f4 ,! same diff]5ce c be %[n ) reg>d to all ! p>ticles on ! inside ( ! tube comp>$ ) ^? outside4 ,! =m] are ne>] to m p>ticles ( ! glass ?an ! latt]1 & !re=e are m /rongly attract$4 ,aga91 z ! ne>] ! plates ( glass are 7 #gj7 ! high] ! wat] rises betwe5 !m1 s ! small] ! tube is ! high] w ! wat] rise 9 x4 ,y c try ! exp]im5t z repres5t$ 9 ,fig4 #ba4 ,x is obvi\s t ! p>ticle b 7,fig4 #bj7 w\ld n be v /rongly attract$ by ! "p ( ! tube opposite if ! tube 7 a l>ge "o2 b x w\ld be if ! tube 7 v small1 = !n x w\ld be q ne> to t "p4 #gb4 ,capill>y ,attraction4--,! t]m capill>y 7d]iv$ f ! ,lat9 ^w capilla1 hair7 has be5 commonly appli$ to ! attraction exhibit$ "u ! circum/ances j notic$1 because x is mo/ obvi\s & 0 fir/ obs]v$ 9 tubes ( v f9e bore4 ,! same t]m is us$ :5 ! attraction is se5 9 ! ris+ or spread+ ( a liquid 9 int]/ices z well z 9 tubes4 ,?us capill>y attraction causes ! ris+ ( oil or burn+ fluid 9 ! wicks ( lamps4 ,! liquid goes up 9 ! int]/ices or spaces betwe5 ! fibres1 z x does 9 ! spaces ( tubes4 ,i w give "s o!r examples4 ,if y let "o end ( a t[el be 9 a b[l ( wat]1 ! o!r end ly+ ov] ^u ! table1 ! :ole t[el w become wet f ! spread+ ( ! wat] among ! fibres 9 ob$i5ce to capill>y attraction4 ,if y susp5d a piece ( sponge s t x m]ely t\* ! surface ( "s wat]1 or if y lay x 9 a plate ) wat] 9 x1 ! :ole sponge w become wet4 ,s1 too1 if y dip ! end ( a lump ( sug> 9 y\r tea1 & hold x !re a little "t1 ! :ole w be moi/5$4 ,9 v damp wea!r ! wood-"w 9 our h\ses swells f ! spread+ ( wat] 9 ! pores ( ! wood 9 ob$i5ce to capill>y attraction4 ,especially w ?is be s 9 basem5t rooms1 :]e ! wat] c g up f ! gr\nd 9 ! pores ( ! walls1 z well z f ! damp air4 ,9 wat]+ plants 9 pots1 if ! wat] be p\r$ into ! sauc]s1 x w pass up ?r\gh ! e>? by capill>y attraction4 ,= ! same reason plants & trees ne> /reams gr[ luxuriantly1 be+ abundantly suppli$ ) wat]1 :i* rises to _! roots ?r\gh ! pores ( ! soil4 ,! disposition ( wood to imbibe moi/ure 9 its pores has sometimes be5 made use ( v effectually 9 gett+ out mill/ones4 ,fir/ a l>ge block ( /one is hewn into a cyl9drical %ape4 ,!n grooves are cut into x all ar\nd :]e a sep>ation is desir$1 & wood5 w$ges are driv5 tightly into !m4 ,^! absorb moi/ure f ! dews & ra91 & !re=e swell s mu* z to split ! /one 9 ! direction ( ! grooves4 ,! blott] :i* y use furni%es an illu/ration ( capill>y attraction1 ! ink be+ tak5 up among ! fibres ( ! pap]4 ,ord9>y writ+ pap] w n answ] z a blott]1 because ! siz+ fills up ! int]/ices betwe5 ! fibres4 ,,*apt] ,v4 ,,gravitation4 #gc4 ,attraction ,betwe5 ,masses4--,i h ?us f> treat$ ( attraction z exi/+ betwe5 ! atoms or p>ticles ( matt] :5 !y are br\ght v ne> toge!r1 :i* is call$ ! attraction ( cohesion4 ,b x exi/s also betwe5 any portions ( matt] t are sep>ate f ea* o!r4 ,?us if two cork balls be plac$ on ! surface ( wat] ne> to ea* o!r1 _! attraction w soon br+ !m toge!r4 ,to h ! exp]im5t /rik+1 ! balls mu/ be v>ni%$1 t !y may glide easily ov] ! wat]4 ,bubbles ( glass w exhibit ! same attraction4 ,s1 also1 float+ pieces ( wood are apt to be f\nd toge!r2 & :5 a %ip is wreck$1 z soon z ! sea becomes calm ! p>ts ( ! wreck are 9 collections "h & !re4 ,n[ :5 a /one falls to ! gr\nd1 x does s = precisely ! same reason t ! two cork balls come toge!r 9 ! wat]4 ,! idea ( all :o h n be5 in=m$ on su* subjects is1 t ! /one comes to ! gr\nd because ! gr\nd is d[n & ! /one is up1 & !re is no?+ to support ! /one 9 ! air4 ,!y h no idea t "s p[] makes ! /one come d[n4 ,!re is su* a p[]1 & x is ! attraction :i* ! e>? & ! /one h = ea* o!r4 ,if y hold ! /one 9 y\r h&1 & ?us prev5t its fall+1 y simply resi/ a p[] :i* is pull+ x d[n4 ,if y c\ld 9 any way susp5d ! attraction ( ! e>? & ! /one = ea* o!r1 y c\ld let g ( ! /one1 & x w\ld rema9 j !re 9 ! air1 & w\ld n come d[n until ! attraction is re/or$4 #gd4 ,attraction ,mutual4--,! cork balls move t[>d ea* o!r because _! attraction is mutual4 ,s d ! e>? & /one really move t[>d ea* o!r = ! same reason4 ,z ! /one is drawn t[>d ! e>?1 s is ! e>? drawn t[>d ! /one4 ,b ! e>? is s l>ge a ?+ to be drawn t its motion is exce$+ly small--s small t practically x may be consid]$ z no?+4 #ge4 ,illu/ration4--,?is may be cle>ly illu/rat$ if we comp>e ! =ce ( attraction to ! =ce ( muscul> action4 ,suppose a man 9 a boat pulls on a rope :i* is made fa/ to a %ip ly+ loose at ! :>f1 & 9 ?is way draws 8 boat t[>d x4 ,he does n dream t he moves ! %ip at all2 b he 9 reality does1 = if in/ead ( "o boat a hundr$ or m pull ^u ! %ip1 !y w move x s mu* z to make ! motion app>5t4 ,9 ! case ( ! s+le boat1 ! %ip z really moves z :5 a hundr$ boats are pull+ on x1 b x is only ! "o hundr$? "p z mu*4 ,n[ let ! %ip repres5t ! e>?1 & ! little boat "s body1 z a /one1 attract$ by x4 ,! e>? & ! /one move t[>d ea* o!r1 j z ! %ip & ! boat d4 ,& if1 z we multipli$ ! numb] ( boats1 we %\ld multiply ! bulk ( ! /one till x is ( an imm5se size1 x w\ld h by its attraction a p]ceptible influ5ce ^u ! e>?'s motion4 ,obs]ve 9 reg>d to ! illu/ration1 t x makes no diff]5ce :e!r ! man be 9 ! boat or 9 ! %ip z he pulls4 ,9 ei!r case he ex]ts an equal =ce on ! %ip & ! boat1 mak+ !m to approa* ea* o!r4 ,s x is ) ! attraction betwe5 ! e>? & ! /one4 ,x is a =ce ex]t$ equally ^u bo?4 ,its effect on ! e>? is n manife/1 because x is s mu* l>g] ?an ! /one2 j z ! effect ( ! man's pull+ is n manife/ ^u ! %ip1 because x is s mu* l>g] ?an ! boat4 #gf4 ,proportion ( ! ,mutual ,motions ( ,attraction4--,let u pursue ! illu/ration a little f>!r4 ,if a man /& 9 a boat1 & pull a rope made fa/ to ano!r boat ( ! same size & weight1 bo? boats1 9 com+ toge!r1 w move ov] ! same space4 ,j s x is ) ! attraction betwe5 two bodies hav+ ! same quantities ( matt] or equal weights--!y attract ea* o!r equally1 & !re=e meet ea* o!r half way4 ,let n[ "o boat be t5 times z great & z heavy z ! o!r4 ,! small boat w\ld move t5 times z mu* z ! l>ge "o :5 ! man br+s !m toge!r by pull+ ! rope4 ,9 l mann]1 if a body "o-t5? z l>ge z ! e>? %\ld approa* x1 !y w\ld attract ea* o!r1 b 9 com+ toge!r ! body w\ld move t5 times z f> z ! e>? w\ld4 ,9 ! case ( fall+ bodies1 ev5 ?\gh !y may be ( great size1 ! e>? moves s slightly to meet !m t its motion is :olly imp]ceptible4 ,x has be5 calculat$ t if a ball ( e>? ! t5? "p ( a mile 9 diamet] 7 plac$ at ! di/ance ( a t5? "p ( a mile f ! e>?1 z ! e>? & ?is body w\ld be mov$ by _! attraction to meet ea* o!r1 ! motion ( ! e>? w\ld be only ! eighty ?\s&? ( a million? 7#a_/hj1jjj1jjj1jjj7 ( an in*4 #gg4 ,attraction ,univ]sal4--,! attraction ( :i* ,i h be5 speak+ exi/s betwe5 all bodies1 h[ev] di/ant !y may be f ea* o!r4 ,sun1 e>?1 moon1 & />s attract ea* o!r2 & 9 ob$i5ce to ?is attraction !y h a t5d5cy to come toge!r 9 "o great mass1 & w\ld d s if ano!r =ce act+ 9 opposition to ?is did n prev5t x4 ,?is =ce w be treat$ ( 9 ano!r "p ( ?is book4 #gh4 ,! ,tides4--,"o effect ( ! attraction betwe5 ! e>? & ! moon is q famili>4 ,i ref] to ! tides4 ,:5 ! tide rises x is because ! wat] ( ! ocean feels ! attract+ =ce ( ! moon4 ,! moon actually lifts ! wat] t[>d itself4 ,! attraction ( ! sun sometimes increases & sometimes dim9i%es ! tides1 accord+ to its position 9 relation to ! moon & ! e>?4 ,if ! l& 7 z movable z ! wat]1 or1 9 o!r words1 if its p>ticles 7 held toge!r by no /rong] attraction ?an ^? ( wat]1 !re w\ld be ! same motion t !re is 9 ! ocean ov] ! surface ( ! e>?1 z 9 its revolution successive portions ( x pres5t !mselves t[>d ! moon4 #gi4 ,mean+ ( ! ,^w ,gravitation4--,! attraction ?us exi/+ betwe5 diff]5t bodies ( matt] sep>at$ f ea* o!r is call$ ! attraction ( gravitation or gravity1 9 di/9ction f ! attraction ( cohesion treat$ ( 9 ! previ\s *apt]4 ,?is "n 0 giv5 to x because we h su* common examples ( its influ5ce 9 ! fall ( bodies to ! e>?4 ,!y are said to gravitate t[>d ! e>?4 ,& !y are said to d s by ! =ce or attraction ( gravitation or gravity4 ,! t]m t]re/rial gravitation is sometimes us$ 9 speak+ ( ! e>?'s attraction1 9 di/9ction f ! same ?+ 9 op]ation 9 o!r planets4 ,illu/ration3 ,fig4 #bb4 ,illu/ration3 ,fig4 #bc4 #hj4 ,attraction ,t[>d ! ,e>?'s ,c5tre4--,all bodies are attract$ t[>d ! c5tre ( ! e>?4 ,?is is because ! e>? is globul>1 z may be made cle> by ,fig4 #bb4 ,let ! circle repres5t ! e>?1 & a a body attract$ by x4 ,! l9es drawn f ! body to ! e>? repres5t ! attractive =ce ex]t$ by ! e>? ^u ! body4 ,x is obvi\s f ^! t !re is z mu* attraction on ! "o side ( ! l9e drawn f ! body to ! e>?'s c5tre z !re is on ! o!r4 ,! attractive =ce1 !n1 ( ! e>? z a :ole is ex]t$ ^u ! body 9 ! direction ( ?is middle l9e4 ,x t5ds to draw x1 !re=e1 t[>d ! c5tre4 ,if1 !re=e1 a weight be susp5d$ by a /r+1 ! l9e ( ! /r+ cont9u$ w\ld g to ! c5tre ( ! e>?4 ,?is be+ s1 x is cle> t two weights susp5d$ by two /r+s d n hang p]fectly p>allel to ea* o!r4 ,! diff]5ce is s slight 9 an ord9>y pair ( scales t x c n 9 any way be p]ceiv$4 ,b if x 7 possible to susp5d 9 ! heav5s a beam s long z to /ret* ov] a l>ge ext5t ( ! e>?'s circumf]5ce1 z repres5t$ 9 ,fig4 #bc1 ! scales atta*$ to x w\ld be v f> f hang+ p>allel to ea* o!r4 ,sub/ances susp5d$ 9 diff]5t p>ts ( ! globe are hang+ 9 diff]5t directions1 & ^? :i* are hung up by our fell[-m5 on ! opposite side ( ! e>?1 are hang+ directly t[>d u4 ,illu/ration3 ,fig4 #bd4 #ha4 ,up & ,d[n4--,all fall+ bodies fall t[>d ! c5tre ( ! e>?1 & ! same rem>ks c be made on ?is po9t t ,i h made 9 relation to susp5d$ weights4 ,up & d[n are m]ely relative t]ms--up be+ f ! c5tre ( ! e>?1 & d[n t[>d x4 ,z ! e>? moves r\nd on its axis1 ! same l9e ( direction :i* we call upw>d at "o "t is d[nw>d at ano!r4 ,?is may be illu/rat$ on ,fig4 #bd4 ,let ! circle repres5t ! circumf]5ce ( ! e>?4 ,9 ! daily revolution we pass ov] ?is :ole circle4 ,if we are at ,d at noon1 we are at ,e at six o'clock1 & at ,f at midnight4 ,if1 !re=e1 ! ball ,a be dropp$ f "s height at noon1 ! l9e 9 :i* x falls w be at "r angles to a l9e 9 :i* x w fall if y drop x f ! same height at six o'clock2 = ?is height w h mov$ 9 ?is "t f ,a to ,b4 ,if x be dropp$ f ! same height at midnight its l9e ( direction w be directly opposite to :at x 0 twelve h\rs be=e2 = ! height w h mov$ 9 t "t to ,c4 ,x is n always true t fall+ bodies t5d exactly t[>d ! c5tre ( ! e>?4 ,x is no?+ 9 ! c5tre t attracts !m1 b x is ! sub/ance ( ! :ole e>?2 & z ?is is irregul> 9 its d5sity & =m1 ! attraction w be irregul> also4 ,?us x is f\nd by accurate exp]im5t+ t a plumb l9e susp5d$ 9 ! neighborhood ( a m\nta9 is s attract$ by x t x w n hang exactly p>allel ) ano!r susp5d$ at "s di/ance f ! m\nta94 ,! diff]5ce is n1 h[ev]1 en\gh 9 any case to h any practical be>+4 #hb4 ,weight4--,i h said be=e 7 #eb7 t :at we call weight is n a prop]ty ( matt]1 b m]ely ! result ( a prop]ty1 ! attraction ( gravity4 ,?is ,i w n[ illu/rate4 ,if two bodies are fall+ to ! e>?1 & "o ( !m conta9s t5 times z _m p>ticles ( matt] z ! o!r1 t5 times z mu* =ce ( gravity is requir$1 & is actually ex]t$1 to br+ x to ! gr\nd4 ,?is w appe> pla9 to y if y be> 9 m9d t a body does n come to ! gr\nd because !re is no?+ to keep x !re1 b because x is drawn d[n by ! =ce ( attraction1 & !n comp>e ?is =ce to any o!r =ce1 z1 = example1 t ( muscul> action4 ,if y draw t[>d y two weights1 "o ( :i* is tw5ty times z heavy z ! o!r1 or1 9 o!r words1 has tw5ty times ! quantity ( matt] t ! o!r has1 y mu/ ex]t tw5ty times z mu* /r5g? on ! =m] z y d on ! latt]4 ,j s x is ) ! =ce ( attraction4 ,! e>? attracts or draws t[>d itself a body hav+ tw5ty times ! quantity ( matt] t ano!r has ) tw5ty times ! am\nt ( =ce4 ,& ! fir/ body w h tw5ty times ! weight ( ! o!r1 = x w make tw5ty times ! pressure ^u any ?+ t resi/s ! =ce ) :i* ! e>? draws x t[>d itself4 ,weight1 !n1 is ! am\nt ( ! pressure occasion$ by ! attraction exi/+ betwe5 ! e>? & ! body weigh$4 ,if y place a sub/ance 9 "o side ( a pair ( scales1 x goes d[n because ( ! attraction betwe5 x & ! e>?4 ,by plac+ weights 9 ! o!r side until ! scales are balanc$1 y f9d h[ mu* is ne$$ to c\nt]act ! d[nw>d pressure caus$ by ! attraction ( ! sub/ance & ! e>? = ea* o!r2 or1 9 o!r words1 y f9d out h[ mu* x weighs4 ,9 do+ ?is y use c]ta9 /&>d weights2 t is1 c]ta9 quantities ( matt] :i* h be5 agre$ ^u by mank9d1 & are call$ by c]ta9 names1 z p\nds1 ounces1 etc4 ,:5 a spr+ is us$ 9 weigh+1 ! spr+ has be5 tri$ by ^! /&>d weights1 & its scale has be5 m>k$ accord+ly4 #hc4 ,weight n ,fix$1 b ,v>iable4--,weight does n dep5d alone ^u ! d5sity ( ! body weigh$1 b also ^u ! d5sity ( ! e>?4 ,= ! attraction caus+ ! pressure :i* we call weight is a mutual attraction1 & is 9 proportion to ! quantities ( matt] 9 bo? ! body & ! e>?4 ,if1 !re=e1 ! d5sity ( ! e>? 7 increas$ twice1 ?ree times1 or f\r times1 ! weights ( all bodies w\ld be increas$ 9 ! same proportion2 t is1 ! =ce ) :i* ! e>? w\ld attract !m w\ld be twice1 ?ree times1 or f\r times z great z n[4 ,?is w\ld n be p]ceiv$ by any effect on balances1 = ! weights & ! articles weigh$ w\ld be alike increas$ 9 weight4 ,b x w\ld be p]ceiv$ 9 in/rum5ts t indicate ! weights ( bodies by _! influ5ce on a spr+4 ,^! w\ld disagree ) scales & /eely>ds j 9 proportion to ! increase ( ! e>?'s d5sity4 ,x w\ld be p]ceiv$ also 9 ! application ( muscul> & o!r =ces 9 rais+ & su/a9+ weights4 ,e /one w\ld require twice1 ?ree times1 or f\r times ! muscul> ef=t to raise x t x does n[4 #hd4 ,weight ,v>ies ) ,di/ance4--,! ne>] two bodies are to ea* o!r ! great] is _! attraction4 ,! ne>] a body is to ! e>? ! great] is ! attraction t presses x t[>d ! e>?2 9 o!r words1 ! great] is its weight4 ,! =ce ( gravity1 or weight1 is greate/1 !re=e1 j at ! surface ( ! e>?1 & x dim9i%es z we g up f ! e>?4 ,z we g f ! e>?1 ! =ce ( gravity less5s 9 su* a proportion t x is always inv]sely z ! squ>e ( ! di/ance f ! c5tre ( ! e>?4 ,i w expla94 ,if ! di/ance f ! c5tre ( ! e>? to its surface1 :i* is #djjj miles1 be call$ #a1 !n #djjj miles f ! e>? w\ld be call$ #b1 or twice z f> f ! c5tre1 & #hjjj miles f ! e>? w\ld be #c1 & s on4 ,! squ>es ( ^! numb]s w\ld be #a1 #d1 #i1 #af1 etc4 ,n[ z weight less5s s z to be inv]sely z ! squ>e ( ! di/ance1 a body weigh+ a p\nd on ! surface ( ! e>? w\ld weigh b a qu>t] ( a p\nd at ! di/ance ( #djjj miles1 & b ! n9? "p ( a p\nd at #hjjj miles4 ,a body weighs less on ! summit ( a high m\nta9 ?an x w\ld 9 ! valley bel[1 because x is f>!r away f ! great bulk ( ! e>?1 & !re=e is n s /rongly attract$4 ,! diff]5ce1 h[ev]1 is b small4 ,a man weigh+ two hundr$ & fifty p\nds 9 ! valley w\ld weigh b half a p\nd less if on ! summit ( a m\nta9 f\r miles high4 #he4 ,weight ,e ,:]e4--,i h spok5 ( weight only 9 relation to ! e>?4 ,b !re is weight 9 bodies e :]e1 = !re is attraction :]ev] !re is matt]4 ,! weight ( sub/ances on ! surface ( diff]5t heav5ly bodies v>ies accord+ to ! quantities ( matt] 9 ^? bodies4 ,z ! moon is mu* small] ?an ! e>?1 :at weighs a p\nd ) u w\ld weigh mu* less ?an a p\nd 9 ! moon4 ,& z ! sun is mu* l>g] ?an ! e>?1 :at is a p\nd ) u w\ld be mu* m ?an a p\nd !re4 ,if we knew ! exact d5sities ( ! sun & ! moon & ! e>?1 z well z _! size1 we c\ld e/imate exactly ! diff]5ce 9 ! weights :i* any body w\ld h 9 !m2 = ! attraction :i* causes ! pressure t we call weight is z ! quantity ( matt]1 & ! quantity ( matt] dep5ds on bo? d5sity & size4 #hf4 ,cohesion1 ,capill>y ,attraction1 & ,gravitation ! ,same4--,! attraction ( cohesion1 capill>y attraction1 & gravitation are only diff]5t modes ( action ( ! same p[]2 viz41 ! attraction :i* matt] e :]e has = matt]4 ,at fir/ ?\ght x w\ld appe> t !re is some?+ peculi> 9 ! attraction ( p>ticles :5 !y are br\ght toge!r s z to adh]e4 ,= if we take any sub/ance1 a piece ( glass1 = example1 its p>ticles seem to be held toge!r by an attraction va/ly /rong] ?an t attraction :i* incl9es diff]5t bodies to move t[>d ea* o!r4 ,if y break ! glass1 h[ev] closely y may press ! two pieces toge!r1 !y w n unite aga94 ,x w\ld seem1 at fir/ view1 t !re mu/ be "s peculi> arrangem5t ( ! p>ticles :i* is de/roy$ by break+ ! glass4 ,b we c readily acc\nt = ! facts 9 ano!r way4 ,! attraction betwe5 bodies ( matt] is ! great] ! ne>] we br+ !m toge!r4 ,! ne>]1 = example1 is ! moon to any portion ( ! e>?1 ! great] is ! attraction :i* x ex]ts1 z se5 9 ! tides2 & if x 7 mu* ne>] to ! e>? ?an x is1 our tides w\ld prove awfully de/ructive4 ,:at is true ( masses is also true ( ! p>ticles ( :i* !y are compos$4 ,?\gh _! attraction is comp>atively feeble :5 at a di/ance f ea* o!r1 x increases1 n 9 ! ari?metical b ! geometrical ratio 7 #hd71 z !y come ne>] toge!r2 s t :5 !y are exce$+ly ne> toge!r ! attraction is v p[]ful4 ,x mu/ be rememb]$ 9 reg>d to ! pieces ( brok5 glass t y c n br+ ! p>ticles on _! surfaces z ne> z !y 7 be=e ! glass 0 brok51 = ! crack does n disappe>4 ,& z ! attraction is inv]sely z ! squ>e ( ! di/ance1 a little di/ance mu/ make a great diff]5ce4 ,! p>ticles ( "s sub/ances y c br+ s ne> toge!r z to cause adhesion1 z y saw 9 ! case ( ! two bullets 7 #ff74 ,t _! adh]+ toge!r dep5ds m]ely ^u _! p>ticles be+ br\ght ne> to ea* o!r appe>s f ! fact1 t ! smoo!r y make ! surfaces ! m /rongly w !y adh]e4 ,& ! reason t liquids & semi-liquids adh]e s readily to solid sub/ances is1 t _! p>ticles1 mov+ freely among ea* o!r1 h ?us ! p[] ( arrang+ !mselves v ne> to ! p>ticles ( ! solid4 ,?us1 :5 a drop ( wat] hangs to glass1 all ! p>ticles ( wat] 9 t "p ( ! drop next to ! glass t\*1 or r are exce$+ly ne> to1 ! p>ticles ( ! glass4 #hg4 ,v>iety 9 ! ,results ( ,attraction4--,x is "o & ! same =ce1 !n1 :i* b9ds ! p>ticles ( a pebble toge!r1 & makes x fall to ! gr\nd--:i* m\lds ! te> & bids x trickle f its s\rce--:i* gives ! e>? & all ! heav5ly bodies _! globul> %ape1 &1 9 connection ) ano!r p[] h]eaft] to be notic$1 makes !m revolve 9 _! orbits4 ,h[ sublime ! ?\ght t ?is "o simple pr9ciple t gives =m to a drop ext5ds its influ5ce ?r\gh ! imm5sity ( space1 & s m>%als ! ho/ ( heav5 t1 )\t ! lea/ int]ruption or discord1 !y all hold on _! c\rse f ye> to ye> & f age to age6 ,x is ?us t ,omnipot5ce makes ! simple/ means to produce ! gr&e/ & mo/ multi=m results4 #hh4 ,opposition ,betwe5 ! ,modes ( ,attraction4--,al?\gh cohesion & gravitation are ess5tially ! same ?+1 we see !m cont9ually act+ 9 opposition to ea* o!r4 ,abundant illu/rations might be giv51 b1 ,i w cite only a few4 ,illu/ration3 ,fig4 #be4 ,fig4 #bf4 #hi4 ,:y ,pit*]s h ,lips4--,if y p\r wat] out ( a tumbl] !re is a /ruggle betwe5 ! attraction ( cohesion & gravitation = ! ma/]y--! attraction ( cohesion t5d+ to make ! wat] adh]e to ! tumbl]1 & run d[n its side1 z 9 ,fig4 #be1 & gravitation t5d+ to make x fall /raight d[n4 ,b :5 wat] is p\r$ out ( a pit*]1 z 9 ,fig4 #bf1 ! lip ( ! pit*] acts 9 favor ( ! attraction ( gravity2 = ! wat] w\ld h to turn a v %>p corn] to run d[n ! outside ( ! pit*] 9 ob$i5ce to ! attraction ( cohesion4 ,9 p\r+ wat] f a tumbl]1 we c (t51 by a quick movem5t1 ?r[ ! wat]1 z we may say1 into ! h&s ( gravity be=e ! attraction ( cohesion c get a *ance to turn x d[n ! tumbl]'s side4 ,if y c only make ! wat] beg9 to run f ! tumbl] )\t go+ d[n its side !re w be no difficulty2 = !re is an attraction ( cohesion betwe5 ! p>ticles ( ! wat]1 t5d+ to make !m keep toge!r1 :i* 9 ?is case acts aga9/ ! cohesion betwe5 ! wat] & ! glass1 & !re=e acts 9 favor ( gravitation4 ,x is cohesion t =ms ! drop on ! lip ( a vial z we drop m$ic9e--cohesion betwe5 ! p>ticles ( ! liquid1 & cohesion betwe5 ^! p>ticles & ^? ( ! glass4 ,x is gravitation1 on ! o!r h&1 t makes ! drop fall1 x becom+ s l>ge t ! =ce ( gravity ov]comes ! cohesion betwe5 ! drop & ! vial4 #ij4 ,size ,limit$ by ,gravity4--,7 x n = ! attraction ( gravity !re w\ld be no limit to ! size ( drops ( any liquid4 ,:5 ! drop rea*es a c]ta9 size1 x falls because x is s heavy2 or1 9 o!r words1 because ) its slight cohesion ! attraction ( ! e>? br+s x d[n4 ,n[ if ?is attraction c\ld be susp5d$1 & ! attraction ( cohesion left to act alone1 p>ticles ( wat] might be add$ to ! drop to any ext5t1 & !y w\ld cl+ !re4 ,y c see ! /ruggl+ betwe5 cohesion & gravitation v prettily illu/rat$ if y wat* ! drops ( ra9 on a w9d[-pane4 ,if two drops happ5 to be q ne> toge!r !y unite by attraction1 & !n1 be+ too l>ge to all[ ( its be+ reta9$ !re by cohesion 9 opposition to gravitation1 ! unit$ drop runs d[n4 ,if x meet ) no o!r drop x soon /ops1 because by cohesion "s portion ( x cl+s to ! glass all along its track1 & s at l5g? less5s x suffici5tly to all[ x to rema9 susp5d$ aga94 ,x is f ! influ5ce ( ! attraction ( gravitation t diff]5t k9ds ( liquids furni% drops ( diff]5t sizes1 ! heavi] giv+ small1 & ! light] l>ge ones4 ,?us y c drop f a vial a l>g] drop ( alcohol ?an ( wat]1 & a l>g] "o ( wat] ?an ( nitric acid4 ,y h ano!r illu/ration ( a simil> "* 9 ! adhesion ( *alk to a black-bo>d or any surface4 ,! *alk crayon itself c n adh]e1 = ! attraction ( ! e>? does n p]mit x4 ,b small quantities ( x c adh]e = ! same reason t wat] adh]es to surfaces 9 small quantities4 ,s also du/ cl+s to sides ( furniture1 ?\gh a lump ( dirt w\ld n4 ,illu/ration3 ,fig4 #bg4 ,illu/ration3 ,fig4 #bh4 #ia4 ,illu/rat$ 9 ,solid ,bodies4--,we c illu/rate ! limitation ( size 9 solid masses by ,figs4 #bg & #bh4 ,suppose t a & b1 ,fig4 #bg1 are two projections ( timb] f a po/1 b be+ twice z l>ge z a4 ,x is evid5t t b c n support twice z mu* weight z a1 = gravitation is dragg+ x d[nw>d f its atta*m5t to ! upright po/ ) twice ! =ce t x does a4 ,! case is /ill /rong] :51 z repres5t$ 9 ,fig4 #bh 7p4 #fd71 ! l>g] timb] is twice z long z ! small]4 ,"h d has f\r times ! bulk ( c4 ,b x c n support f\r times z mu* weight at its end1 n only because its own weight presses x d[nw>d1 b because half ( its weight is at a great] di/ance f ! place ( atta*m5t ?an ! small] beam is4 ,gravitation "h op]ates 9 opposition to cohesion 9 su* a way t ! project+ timb]1 if c>ri$ to a c]ta9 size1 w fall by its own weight1 ei!r break+ 9 two1 or te>+ away f its atta*m5t4 ,?is t5d5cy is v commonly resi/$ 9 build+s & o!r /ructures by braces1 z repres5t$ 9 ,fig4 #bi4 ,"h ! weight ( ! horizontal timb] at "s di/ance on ea* side ( a1 is made to press ^u ! upright po/ in/ead ( directly d[nw>d4 ,illu/ration3 ,fig4 #bi4 #ib4 ,f>!r ,illu/rations4--,! size ( bodies1 bo? animate & inanimate1 is limit$ by ! ,creator 9 ob$i5ce to ! pr9ciples above develop$4 ,?is is se5 9 ! fact t !re are no animals on ! l& to comp>e 9 size ) ! mon/]s ( ! deep4 ,a :ale does v well 9 ! wat]1 because he is buoy$ up by t elem5t2 b an animal z l>ge z a :ale c\ld n well exi/ on l&1 because gravitation w\ld act s /rongly 9 opposition to cohesion4 ,at lea/ x w\ld be necess>y1 9 ord] t he might walk ab\t1 or ev5 hold toge!r1 t 8 great bulk %\ld be made up ( v firm & t5aci\s mat]ials4 ,:5ev] any ?+ v l>ge or tall is to be support$1 its support is always broad & compos$ ( v cohesive mat]ials4 ,we see ?is exemplifi$ 9 ! massive trunks ( full-gr[n trees1 z comp>$ ) ! sl5d] trunks ( trees ( ! same k9ds 9 ! nurs]y4 ,we see x exemplifi$ 9 ! fact t ! highe/ m\nta9s are built ( ! h>de/ rocks1 :ile ! s(t *alk =mations are conf9$ to ^? ( small size4 ,!re is a limit to ! height ev5 ( ! granite m\nta9s 9 ! influ5ce ( gravity4 ,if c>ri$ mu* high] ?an !y are1 ! attraction ( ! e>?1 9 its opposition to cohesion1 w\ld te> !m ap>t 9 _! fissures1 or cause ! imm5se weight to cru% _! f\ndations4 ,9 ! moon1 :]e gravitation is less ?an on ! e>? 7 #he71 m\nta9s c be mu* high] )\t ^! results1 & accord+ly ! telescope %[s !m to be s4 ,9 ,jupit]1 on ! o!r h&1 :i* is mu* l>g] ?an ! e>?1 ! m\nta9s1 if !re be any1 c n rise to any great height1 & if !re be any liv+ be+s z l>ge z we are 9 t planet !y mu/ be made ( va/ly firm] mat]ials to prev5t _! be+ cru%$ by _! own weight4 #ic4 ,! ,above ,pr9ciples ,transgress$ by ,man4--,man (t5 transgresses ^! pr9ciples 9 8 /ructures4 ,= example1 a build+ settles because ! f\ndation is n /rong en\gh to be> ! sup]9cumb5t weight2 9 o!r words1 ! =ce ( gravitation is n suffici5tly tak5 into ! acc\nt4 ,:5 a v tall build+ is erect$1 ! l[] portions ought to be made ( v cohesive sub/ances4 ,firm granite is !re=e an appropriate mat]ial = ! l[] /ory ( tall brick build+s4 ,at lea/ %\ld ! walls ( ! l[] /ories ( su* build+s be made ?ick] ?an !y ord9>ily are1 to resi/ prop]ly ! =ce ( gravitation 9 ! weight above4 ,/ores int5d$ to be> mu* weight on _! floors are (t5 built )\t due reg>d to ! cohesive =ce requir$ to su/a9 ! weight4 ,long timb]s are sometimes support$ only at ! ends1 :5 _! own weight1 to say no?+ ( :at may be br\ght to press ^u !m1 requires t !y %\ld be support$ at o!r po9ts4 ,:ile 9 mod]n build+s ! timb]s are (t5 too small1 9 "s old build+s ! upp] timb]s are s heavy z to less5 r ?an increase ! /r5g? ( ! /ructure4 ,especially is ?is true ( ! unsightly beams :i* 9 "s anci5t h\ses we see ext5d+ along ! ceil+s above4 ,_m o!r examples c\ld be giv51 b ^! w suffice4 ,! practic$ eye1 9 look+ at a build+1 in/9ctively requires t e "p %\ld be se5 to be suitably support$4 ,a gall]y 9 a *ur*1 !re=e1 if )\t pill>s or braces f ! wall1 is displeas+ to su* an eye1 ev5 ?\gh !re may be really suffici5t support provid$ 9 ! mode ( /ructure4 ,! same c be said ( gall]ies support$ by sl5d] iron pill>s1 especially if !y be pa9t$ ( "s light color s z to look z if !y 7 wood r ?an iron4 ,= ! same reason porticoes )\t pill>s are unsightly4 ,s1 too1 ! eye in/9ctively looks = a suffici5t base to e pill> & pila/]4 ,! concealm5t ( ! base 9 any way1 or ! sub/itution ( any ?+ else = x1 is an unpleasant anomaly1 & yet su* anomalies are sometimes se5 ev5 9 exp5sive build+s4 #id4 ,attraction ( ,natural ,philosophy & ( ,*emi/ry4--,! attraction ( :i* ,i h treat$ 9 ?is & ! previ\s *apt]s is t :i* belongs to ,natural ,philosophy1 9 di/9ction f t ( ,*emi/ry4 ,its effects are only me*anical1 :ile ! attraction ( ,*emi/ry goes beyond ?is1 & affects ! composition ( sub/ances4 ,= example1 ! attraction betwe5 ! two gases1 oxyg5 & hydrog51 :i* makes !m unite to =m wat]1 belongs to ,*emi/ry2 :ile t :i* makes ! p>ticles ( wat] coh]e is 9 ! prov9ce ( ,natural ,philosophy4 ,,*apt] ,,vi4 ,,c5tre ,,( ,,gravity4 ,illu/ration3 ,fig4 #cj4 ,illu/ration3 ,fig4 #ca4 ,fig4 #cb4 #ie4 ,c5tre ( ,gravity ,illu/rat$4--,if y balance a rul] on y\r f+]1 z 9 ,fig4 #cj1 x is balanc$ because !re is j z mu* weight on "o side z on ! o!r4 ,n[ j ov] y\r f+]1 9 ! middle ( ! rul]1 !re is a po9t t we call ! c5tre ( gravity2 or1 9 o!r words1 ! c5tre ( ! weight ( ! rul]4 ,?is po9t is indicat$ 9 ! figure4 ,!re is z mu* ( ! weight ( ! rul] on ! "o side ( ?is po9t z on ! o!r1 & also z mu* above x z bel[ x4 ,if y\r f+] %\ld be a little to ! "o side or ! o!r ( ?is po9t1 ! rul] w\ld n be balanc$1 & w\ld fall4 ,:5 balanc$ x does n fall1 simply because ?is c5tral po9t is support$ by be+ directly ov] ! end ( ! f+]4 ,! weight ( ! rul]1 !n1 may be consid]$ practically z all be+ 9 t po9t1 = x is !re t is ex]t$ all ! d[nw>d pressure ( ! rul] z x is balanc$4 ,s1 also1 :5 ! rul] is balanc$ on ! f+]1 z repres5t$ 9 ,fig4 #ca 7p4 #fh71 ?is same c5tre ( gravity is directly ov] ! po9t ( ! f+]1 & is !re=e support$4 ,if x be to ! "o side or ! o!r1 z 9 ,fig4 #cb1 x is n support$1 & ! rul] !re=e falls4 ,y see1 !n1 t if a body be balanc$1 ! c5tre ( gravity is directly ov] ! po9t ( support4 ,if1 on ! o!r h&1 a body is susp5d$1 ! c5tre ( gravity is directly "u ! po9t ( support4 ,illu/ration3 ,fig4 #cc4 #if4 ,def9ition4--,if a plumb-l9e f ! c5tre ( gravity c\ld be ext5d$ into ! e>? x w\ld g directly to its c5tre4 ,! body may be consid]$ z mak+ all its pressure f its c5tre ( gravity 9 t direction1 9 ob$i5ce to ! attraction ( gravitation4 ,! be/ def9ition1 !n1 t we c give ( ! c5tre ( gravity is1 t x is t po9t 9 a body f :i* its pressure z a :ole t[>d ! c5tre ( ! e>? proce$s4 ,x is t po9t1 !re=e1 ! support ( :i* insures ! support ( ! :ole body4 ,& 9 speak+ ( ! weight ( a body1 or its d[nw>d pressure1 we may consid] all ! matt] compos+ x z collect$ or conc5trat$ 9 t po9t4 ,! body1 !re=e1 c be balanc$ 9 any position 9 :i* ?is po9t is support$1 z %[n 9 ,figs4 #cj & #ca4 ,& :5 a body is susp5d$1 x is at re/ only :5 ! c5tre ( gravity is directly "u ! po9t ( support4 ,?us1 if y h a circul> plate susp5d$ at ,e1 ,fig4 #cc1 x w n be at re/ :5 x is mov$ to ! "o side or ! o!r1 z repres5t$ by ! dott$ l9es1 b only :5 ! c5tre ( gravity1 c1 is directly "u ! po9t ,e4 ,illu/ration3 ,fig4 #cd4 ,fig4 #ce4 #ig4 ,h[ to ,f9d ! ,c5tre ( ,gravity ( a ,body4--,if y take a piece ( bo>d1 & susp5d x at ,a1 ,fig4 #cd1 & susp5d a plumb-l9e f ! same po9t1 ! c5tre mu/ be some:]e 9 t l9e4 ,b exactly at :at po9t x is y d n "k4 ,h[ w y asc]ta9 ?is8 ,m>k ! l9e ,a ,b on ! bo>d1 & susp5d ! bo>d by ano!r po9t1 z 9 ,fig4 #ce4 ,z ! c5tre ( gravity mu/ be some:]e 9 ! plumb-l9e z x n[ hangs1 ( c\rse x is at ,o1 :]e ! two l9es cross4 ,illu/ration3 ,fig4 #cf4 ,fig4 #cg4 #ih4 ,scales & ,/eely>ds4--,:5 two bodies are connect$ by a rod or b>1 ! c5tre ( gravity ( ! :ole is some:]e 9 ! connection4 ,if ! two bodies be equal 9 weight1 z 9 ,fig4 #cf1 ! c5tre ( gravity is exactly 9 ! middle ( ! rod1 z m>k$4 ,b if ! bodies are unequal1 z 9 ,fig4 #cg1 ! c5tre ( gravity is ne>] to ! l>g] body ?an to ! small]4 ,9 balanc+ a body 9 "o scale ) weights 9 ano!r1 y h a case p>allel to t ( ,fig4 #cf4 ,! c5tre ( gravity ( ! body weigh$1 ! weights1 & ! scales1 z a :ole1 is midway betwe5 ! scales1 at ! po9t ( support4 ,9 ! /eely>d y h ! heavy body to be weigh$ ne>] ! c5tre ( gravity ?an ! small weight is on ! long arm1 & s ! case is p>allel ) t ( ,fig4 #cg4 ,illu/ration3 ,fig4 #ch4 #ii4 ,! ,c5tre ( ,gravity ( a ,body n ,always 9 ! ,body ,itself4--,! c5tre ( gravity ( a holl[ ball ( uni=m ?ickness is n 9 ! sub/ance ( ! ball1 b x is 9 ! c5tre ( ! space 9 ! ball1 = ! l9e ( ! ball's d[nw>d pressure w\ld be f t po9t4 ,if ! ball _h a frame-"w 9 x1 z repres5t$ 9 ,fig4 #ch1 ! c5tre ( gravity w\ld obvi\sly be at ,a1 ! c5tre ( ?is frame-"w4 ,b if !re 7 no frame-"w1 & p]p5dicul> l9es 7 suppos$ to be drawn f diff]5t po9ts ( susp5sion1 ,c1 ,b1 ,d1 & ,e1 ^! w\ld int]sect at ! po9t ,a1 %[+ t ?is is ! c5tre ( gravity1 accord+ to ! rule = f9d+ x giv5 9 #ig4 ,s1 also1 ! c5tre ( gravity ( an empty box1 or an empty %ip1 w\ld be an imag9>y po9t 9 ! space inside4 ,9 a hoop x is ! c5tre ( ! hoop's circle4 ,illu/ration3 ,fig4 #ci4 #ajj4 ,! ,c5tre ( ,gravity ,seeks ! ,l[e/ ,po9t4--,! c5tre ( gravity always takes ! l[e/ place :i* ! support ( ! body w all[4 ,9 a susp5d$ body1 !re=e1 x is always directly "u ! po9t ( susp5sion4 ,to get to ! "o side or ! o!r ( ?is position x mu/ rise4 ,?is ! attraction ( gravity =bids1 & if by any =ce x is made to rise1 ?is attraction at once br+s x back4 ,?is is manife/ 9 ! case ( a susp5d$ ball1 ,fig4 #ci4 ,if ! ball be mov$ to b1 x w1 on be+ let g1 return to its fir/ position1 simply because its c5tre ( gravity1 9 ob$i5ce to ! e>?'s attraction1 seeks ! l[e/ place possible4 ,f in]tia 7 #di7 x moves beyond ?is po9t1 & cont9ues to vibrate back & =? = "s "t2 b :5 its motion is /opp$1 x hangs p]p5dicul>ly2 t is1 9 su* a way t its c5tre ( gravity %all h ! l[e/ possible position4 ,i add a few o!r illu/rations ( ! same po9t4 ,:5 a rock+-horse is at re/1 its c5tre ( gravity is directly ov] ! po9t at :i* x t\*es ! floor1 = ?us x has its l[e/ possible place4 ,if x be rock$1 ! c5tre ( gravity is mov$ to a high] po9t1 & = ?is reason x rocks back aga94 ,! same is se5 9 ! sw+1 ! cradle1 ! rock+-*air1 etc4 ,mo/ int]e/+ illu/rations ( ! same ?+ are f\nd 9 ! ,laggan1 or ,loggan ,/ones z !y are call$1 sev]al ( :i* are se5 on ! rugg$ p>ts ( ! ,briti% coa/4 ,an imm5se rock1 :i* has be5 loos5$ by "s convulsion1 re/s ) a slightly-r\nd$ base on ano!r rock :i* is flat1 & x is s nicely balanc$ t "o p]son alone c produce a p]ceptible rock+ motion 9 x4 ,i saw1 _m ye>s ago1 a l>ge rock ne> ,salem1 ,massa*usetts1 ?us situat$4 ,!re is "o also 9 ,great ,b>r+ton1 ,massa*usetts4 ,illu/ration3 ,fig4 #dj4 ,fig4 #da4 ,illu/ration3 ,fig4 #db4 ,illu/ration3 ,fig4 #dc4 #aja4 ,f>!r ,illu/rations4--,x is because ! c5tre ( gravity always seeks ! l[e/ place t an egg lies ^u its side4 ,:5 on its side1 ! c5tre ( gravity is at its l[e/ po9t1 z is manife/ f comp>+ ,fig4 #dj ) ,fig4 #da 7p4 #ga74 ,*ildr5 (t5 h a toy1 call$ a wit*1 :i* illu/rates ! same ?+ 9 ano!r way4 ,x is a piece ( light sub/ance1 z pi?1 ) a %ot fa/5$ 9 "o end4 ,x always /&s up on its load$ end1 & c n be made to lie d[n on its side1 because ! c5tre ( gravity w\ld n !n be at ! l[e/ po9t4 ,!re is an amus+ ,*9ese toy ( ! same k9d4 ,x is a figure ( a fat old woman1 ,fig4 #db1 load$ ) lead at ! bottom1 s t its c5tre ( gravity is at a4 ,if ! figure be ?ru/ ov] to "o side1 z %[n by ! dott$ l9es1 ! c5tre ( gravity is rais$1 & ! upright position is at once resum$4 ,if ! toy 7 n load$1 x w\ld lie 9 ! position repres5t$ 9 ,fig4 #dc1 j z ! egg lies on its side4 ,illu/ration3 ,fig4 #dd4 ,illu/ration3 ,fig4 #de4 ,fig4 #df4 ,illu/ration3 ,fig4 #dg4 #ajb4 ,curi\s ,exp]im5ts4--,y c n hang a pail ( wat] on a /ick laid ^u a table1 z repres5t$ 9 ,fig4 #dd1 = ! c5tre ( gravity is n support$4 ,b if y place ano!r /ick a z a brace1 9 ! mann] repres5t$ 9 ,fig4 #de 7p4 #gc71 s z to pu% ! pail "u ! table1 x w hang securely1 because ! c5tre ( gravity is n[ "u ! po9t ( susp5sion4 ,! explanation ( ! foll[+ exp]im5t is ! same3 ,run a l>ge ne$le ?r\gh a cork2 fa/5 to ! cork a =k1 & y c susp5d ! :ole on ! edge ( a table1 z se5 9 ,fig4 #df4 ,"h ! c5tre ( gravity is directly "u ! po9t ( susp5sion1 :i* is at ! po9t ( ! ne$le4 ,! same c be said ( ! v common toy repres5t$ 9 ,fig4 #dg4 ,! horse1 made ( v light mat]ial1 /&s securely1 because ! c5tre ( gravity ( ! :ole is 9 ! heavy ball1 :i* is "u ! po9t ( susp5sion4 ,if ! horse be made to rock back & =?1 ! c5tre ( gravity 9 ! ball moves 9 a curv$ l9e1 z 9 ! case ( a ball susp5d$ by a /r+ 7,fig4 #ci74 ,x is at its l[e/ place only :5 ! horse is at re/4 ,! hang+ ( a cane ) a hook-%ap$ h&le on ! edge ( a table is to be expla9$ 9 ! same way4 ,illu/ration3 ,fig4 #dh4 ,fig4 #di4 ,fig4 #ej4 ,illu/ration3 ,fig4 #ea4 ,illu/ration3 ,fig4 #eb4 #ajc4 ,/ability ( ,bodies4--,! firmness ) :i* a body /&s dep5ds ^u two circum/ances--! height ( its c5tre ( gravity1 & ! ext5t ( its base4 ,! l[] ! c5tre ( gravity1 & ! broad] ! base1 ! firm] does ! body /&4 ,a cube1 repres5t$ 9 ,fig4 #dh1 is m /able1 t is1 less easily turn$ ov]1 ?an a body %ap$ z ,fig4 #di1 because x has a l>g] base4 ,! contra/ is /ill great] betwe5 ,figs4 #dh & #ej4 ,! reason ( ! /ability ( a body ) a broad base is f\nd 9 ! fact1 t 9 turn+ x ov] ! c5tre ( gravity mu/ be rais$ m ?an 9 turn+ ov] "o ( a n>r[] base4 ,! curv$ l9es indicate ! pa?s ( ! c5tres ( gravity z ! bodies are turn$ ov]4 ,9 ! case ( a p]fectly r\nd ball1 ! base is a m]e po9t1 & !re=e ! lea/ t\* turns x ov]4 ,its c5tre ( gravity does n rise at all1 b moves 9 a horizontal l9e1 z %[n 9 ,fig4 #ea4 ,! pyramid is ! firme/ /ructure 9 ! _w1 because x possesses 9 ! highe/ degree ! two elem5ts--a broad base1 & a l[ position ( ! c5tre ( gravity4 ,on bo? ^! acc\nts ! c5tre ( gravity mu/ asc5d consid]ably :5 ! body is turn$ ov]1 z se5 9 ,fig4 #eb4 ,illu/ration3 ,fig4 #ec4 ,illu/ration3 ,fig4 #ed4 #ajd4 ,bodies n ,upright ,un/able4--,:5 a body does n /& upright1 its /ability is dim9i%$ simply because only a portion ( ! base is conc]n$ 9 its support4 ,9 ,fig4 #ec ! base is broad1 b ! body is s f> f be+ upright t ! c5tre ( gravity be>s ^u ! v extremity ( ! base on "o side1 z ! p]p5dicul> l9e f x indicates4 ,! lea/ jo/le w turn x ov]1 because ! c5tre ( gravity ne$ n asc5d ! lea/ :5 ?is is done4 ,y see1 !n1 t ! less upright a body is1 ! less ( ! base is ( s]vice 9 its support1 because ! f>!r is ! l9e ( direction ( ! d[nw>d pressure ( ! c5tre ( gravity f ! c5tre ( ! base4 ,! fam\s t[] ( ,pisa1 ,fig4 #ed1 "o hundr$ & ?irty feet high1 ov]hangs its base fifte5 feet4 ,x 0 und\bt$ly built int5tionally 9 ?is way to excite wond] & surprise1 = :at w\ld o!rwise h be5 a v unsafe /ructure is r5d]$ /able & safe by ! arrangem5t ( its mat]ials4 ,its l[] portion is built ( v d5se rock1 ! middle ( brick1 & ! upp] ( a v light por\s /one4 ,9 ?is way ! c5tre ( gravity ( ! :ole /ructure is made to h a v l[ position4 ,illu/ration3 ,fig4 #ee4 #aje4 ,famili> ,illu/rations4--,y see n[ ! explanation ( ! fact :i* common exp]i5ce tea*es e "o1 t ! tall] is a body1 & ! n>r[] its base1 ! m easily is x ov]turn$4 ,?is is exemplifi$ 9 ! two loads1 ,fig4 #ee4 ,! base is ! space includ$ by ! :eels4 ,! c5tre ( gravity is s high 9 ! tall load t a p]p5dicul> l9e drawn f x falls outside ( ! base if ! c>t come ^u a consid]able lat]al incl9ation ( ! road4 ,b ! small] load1 "u ! same circum/ances1 is p]fectly secure f ov]turn+4 ,a high c>riage is m easily ov]turn$ ?an a l[ "o1 = ! same reason4 ,a /age1 if load$ on its top1 is v unsafe on a r\gh road4 ,/ability is giv5 to articles ( furniture by mak+ _! bases broad & heavy1 z y see 9 tables support$ by a c5tral pill>1 c&le/icks1 lamps1 etc4 ,! tall *airs 9 :i* *ildr5 sit at table w\ld be v insecure if _! legs 7 n widely sep>at$ at ! bottom1 ?us wid5+ ! base ( support4 ,9 ! ladd]1 s commonly us$ n[ 9 pick+ fruit1 a broad base is furni%$ betwe5 ! foot ( ! ladd] & ! two /&>ds :i* are spread out to su/a9 its top4 ,illu/ration3 ,fig4 #ef4 ,fig4 #eg4 #ajf4 ,support ( ! ,c5tre ( ,gravity 9 ,animals4--,! base ( support :i* quadrup$s h1 viz41 ! space includ$ betwe5 _! f\r feet1 is q l>ge2 & ?is is "o reason t !y walk s soon aft] bir?4 ,a *ild does well t c walk at ! end ( t5 or twelve mon?s1 = ! support+ base is q small comp>$ ) t ( a quadrup$4 ,x consi/s ( ! feet & ! space betwe5 !m4 ,x requires skill1 !re=e1 9 ! *ild to manage ! c5tre ( gravity 9 /&+ & walk+1 & ?is is gradually acquir$4 ,if "o %\ld gr[ up )\t ev] /&+ on 8 feet1 he w\ld f9d1 z ! infant does1 t "s tra9+ is necess>y to enable him to d x4 ,x is on acc\nt ( ! smallness ( ! base furni%$ by ! feet t ! /atue ( a man is always made ) a l>ge base or p$e/al4 ,al?\gh we ex]t consid]able skill 9 walk+1 by no means s mu* is requisite z ! ,*9ese ladies mu/ put 9 ex]cise ) _! small feet4 ,/ill m skill is ex]cis$ by "o :o has two wood5 legs1 or "o :o walks on /ilts4 ,! base made by ! feet c be v>i$ mu* by _! position4 ,if ! toes be turn$ out & ! heels br\ght ne> to ea* o!r1 ! base w n be z l>ge z :5 ! feet are /raight =w>d & f> ap>t1 z is manife/ 9 ,figs4 #ef & #eg4 ,x is = ?is reason t ! *ild1 9 8 fir/ essays at /&+ & walk+1 in/9ctively manages 8 feet z 9 ,fig4 #ef4 ,illu/ration3 ,fig4 #eh4 ,illu/ration3 ,fig4 #ei4 ,illu/ration3 ,fig4 #fj4 ,fig4 #fa4 #ajg4 ,motions ( ! ,c5tre ( ,gravity 9 ,walk+4--,9 walk+1 ! c5tre ( gravity is alt]nately br\ght ov] "o foot & ! o!r1 & s moves 9 a wav+ l9e4 ,?is is v manife/ z y see p be=e y go+ d[n ! aisle out ( a *ur*4 ,:5 two are walk+ toge!r1 if !y keep /ep ! two wav+ l9es ( _! c5tres ( gravity run p>allel1 z 9 ,fig4 #eh1 & !y walk easily2 b if !y d n keep /ep ^! l9es run z 9 ,fig4 #ei1 & ! movem5t is bo? awkw>d & emb>rass+4 ,! l9e ( movem5t ( ! c5tre ( gravity is always slightly wav+ upw>d also1 z se5 9 ,fig4 #fj 7p4 #gh74 ,9 ! case ( a man ) wood5 legs ! l9e w\ld n be g5tly wav+1 b some:at angul>1 z repres5t$ 9 ,fig4 #fa4 ,illu/ration3 ,fig4 #fb4 ,fig4 #fc4 ,illu/ration3 ,fig4 #fd4 ,illu/ration3 ,fig4 #fe4 #ajh4 ,! ,c5tre ( ,gravity & ,attitudes4--,! object ( v>i\s attitudes assum$ "u diff]5t circum/ances is to keep ! c5tre ( gravity ov] ! base ( support4 ,a man ) a load on 8 back w\ld n assume ! position ( ,fig4 #fc1 b t ( ,fig4 #fb1 s t ! c5tre ( gravity ( 8 load may be directly ov] 8 feet4 ,s a man c>ry+ any ?+ 9 front leans backw>d1 z 9 ,fig4 #fd4 ,9 asc5d+ a hill a man appe>s to lean =w>d1 & 9 desc5d+ to lean backw>d2 b 9 fact he is 9 bo? cases upright 9 ref]5ce to ! pla9 on :i* ! hill /&s1 z may be se5 9 ,fig4 #fe4 ,a p]p5dicul> l9e drawn f 8 c5tre ( gravity /rikes ! gr\nd midway betwe5 ! feet1 t is1 9 ! middle ( ! base1 & if prolong$ w\ld g /raight to ! c5tre ( ! e>?4 ,:5 "o rises f a *air he draws 8 feet backw>d1 & !n b5ds 8 body =w>d to br+ ! c5tre ( gravity ov] ! feet4 ,unless ?is is done1 x is impossible to rise1 at lea/ delib]ately1 z y w f9d by try+ ! exp]im5t4 ,a man /&+ ) 8 heels close to a wall c n /oop =w>d & pick up any ?+1 = ! wall prev5ts him f mov+ any "p ( 8 body backw>d1 & !re=e :5 he /oops =w>d1 ! c5tre ( gravity be+ br\ght f> 9 advance ( ! base1 he loses 8 balance & falls4 ,a man :o did n und]/& ?is und]took to /oop 9 ?is way to pick up a purse conta9+ tw5ty gu9eas1 :i* he 0 to h if he succe$$1 ! =feiture 9 case ( failure be+ t5 gu9eas4 ,( c\rse 8 c5tre ( gravity made him lose 8 wag]4 #aji4 ,rope-,danc]s1 ,tops1 etc4--,great skill is exhibit$ by ! rope-danc] 9 support+ ! c5tre ( gravity4 ,simil> skill is se5 9 feats ( balanc+1 z1 = example1 9 balanc+ a long /ick upright on ! f+]4 ,9 ^! cases ! c5tre ( gravity is v little ( ! "t directly ov] ! po9t ( support4 ,x is kept 9 con/ant motion ne>ly b n q ov] ?is po9t1 ?is un/able equilibrium1 z x is call$1 be+ va/ly less difficult to ma9ta9 ?an /able equilibrium2 t is1 keep+ ! balance 9 "o unv>y+ position4 ,x is ! motion ( ! top t makes x to /& upright ^u its po9t--a v beautiful example ( un/able equilibrium4 ,! c5tre ( gravity revolves ar\nd a p]p5dicul> l9e1 at exce$+ly little di/ance f x at fir/1 b great] & great] z its motion becomes less rapid1 till at l5g? ! c5tre ( gravity gets s f> f ?is l9e t ! top falls4 ,= a simil> reason an intoxicat$ man may n be able to keep himself up if he und]take to /& /ill1 & yet may d s if he keep mov+4 ,z 9 ! case ( ! top1 8 c5tre ( gravity mu/ be kept 9 motion1 or he mu/ fall4 ,,*apt] ,,vii4 ,,hydro/atics4 #aaj4 ,:at ,hydro/atics ,tea*es4--,hydro/atics is t bran* ( ,natural ,philosophy :i* treats ( ! pressure & equilibrium ( liquids4 ,! ph5om5a :i* x br+s to view all results f ! influ5ce ( ! attraction ( ! e>? ^u liquids4 ,x is = ?is reason t ?is subject calls naturally = our consid]ation aft] exam9+ ! g5]al subject ( attraction1 z we h done 9 ! previ\s *apt]s4 ,9 ord] to und]/& fully ! ph5om5a ( ,hydro/atics1 y mu/ cont9ually be> 9 m9d ! two gr& *>act]i/ics ( liquids4 ,"o is1 t ! p>ticles move freely among ea* o!r 7 #i74 ,! o!r is1 t a liquid is almo/ entirely incompressible 7 #cf74 #aaa4 ,level ,surface ( ,liquids4--,x is ! influ5ce ( gravitation ^u liquids t gives !m a level surface :5ev] !y are n agitat$ by any cause4 ,obs]ve h[ ?is is4 ,a /ill body ( wat] y may consid] z be+ made up ( lay]s ( p>ticles4 ,ea* lay] w h all its p>ticles equally attract$ by ! e>?1 & mu/ !re=e be level4 ,if any ( ! p>ticles 7 less attract$ ?an _! neighbors !y w\ld rise1 z is ! case :5 heat is appli$1 z y w see h]eaft]4 ,:5ev] ! upp] lay]s ( ! p>ticles are di/urb$ by w9d or any o!r cause1 z soon z ! di/urbance ceases ! p>ticles w aga9 take _! places 9 level lay]s "u ! influ5ce ( gravitation4 #aab4 ,a ,comp>ison4--,! p>ticles ( wat] may be comp>$ to %ot4 ,if y h %ot 9 a vessel1 & !y are heap$ up 9 any portion ( ! surface1 on %ak+ ! vessel ^? t are highe/ w roll d[n1 & ! result w be a level surface4 ,!y w\ld d ?is )\t agitation if !y 7 z smoo? z ! p>ticles ( wat] are4 ,if we c\ld h a microscope /rong en\gh to di/+ui% ! %ape ( ! p>ticles ( wat]1 ! surface w\ld probably appe> l ! level surface ( %ot 9 a vessel4 ,b ! p>ticles ( wat] are s exce$+ly m9ute t ! surface ( wat]1 :5 entirely free f agitation1 is s smoo? z to con/itute a p]fect mirror1 (t5 fea/+ our eyes ) ano!r _w ( beauty z we look d[n into its quiet dep?s4 ,wat] 0 man's fir/ mirror1 & "o ( ! mo/ beautiful passages 9 ! ,p>adise ,lo/ is ! description ( ,eve's fir/ wak+ aft] h] creation at ! side ( a lake1 & see+ h] =m reflect$ 9 its smoo? wat]s4 ,illu/ration3 ,fig4 #ff4 #aac4 ,surface ( ,liquids n ,truly ,level4--,/rictly speak+1 ! surface ( a liquid is n level1 b r\nd+4 ,b x is s little s t x c n be p]ceiv$ unless we take into view a v l>ge surface1 z ! ocean4 ,"h x is v manife/1 = :5ev] a %ip comes into port ! fir/ ?+ se5 f ! %ore is ! topmo/ sail1 ! re/ ( ! %ip be+ conceal$ by ! wat] r\nd$ up betwe5 x & ! obs]v]4 ,?is is illu/rat$ 9 ,fig4 #ff4 ,at a ! %ip is j 9 sight1 :ile at b x is s ne> %ore t ! eye sees ! :ole ( x4 ,if ! e>? _h no elevations ( l&1 or if !re 0 wat] en\gh to cov] !m1 ! wat] w\ld make a p]fectly globul> cov]+ = ! e>?1 be+ held to x by ! =ce ( attraction4 ,! reason = ?is is precisely ! same z 0 giv5 9 #eh = ! disposition ( a drop ( liquid to take ! globul> =m4 ,z 9 t case1 s 9 ?is1 x c be demon/rat$ t ea* p>ticle is attract$ t[>d a common c5tre1 & t ?is w produce 9 ! freely-mov+ p>ticles a uni=mly r\nd$ surface4 ,:at c\ld ?us be %[n to be true if ! e>? 7 :olly cov]$ ) wat]1 is true ( ! portions ( wat] :i* n[ fill up ! depressions 9 ! e>?'s cru/2 & x c be p]ceiv$1 z %[n 9 ! fir/ "p ( ?is p>agraph1 9 ! case ( any ext5d$ portion ( x4 ,illu/ration3 ,fig #fg4 #aad4 ,_s-,level4--,:at we call a p]fectly level surface is1 !n1 "o all p>ts ( :i* are equally di/ant f ! c5tre ( ! e>?1 & is !re=e really a sph]ical surface4 ,b ! sph]e is s l>ge t any v small portion ( x may be consid]$ = all practical purposes a p]fect plane4 ,a hoop surr\nd+ ! e>? w\ld b5d eight in*es 9 e mile4 ,9 cutt+ a canal1 !re=e1 !re is a v>iation 9 ?is proportion f a /raight level l9e4 ,z ! v>iation is b an in* 9 an eigh? ( a mile1 x is ( no acc\nt 9 tak+ ! level = build+s4 ,levels are asc]ta9$ by :at is call$ a _s-level4 ,?is consi/s ( a clos$ glass tube1 ,fig #fg1 ne>ly fill$ ) alcohol4 ,! space n occupi$ by alcohol is occupi$ by air4 ,! tube is plac$ 9 a wood5 box = conv5i5ce & security1 !re be+ an op5+ 9 ! box at a4 ,n[ :5 ! box ) its glass tube is p]fectly level1 ! bubble ( air w be se5 9 ! middle at a2 b if "o end be high] ?an ! o!r1 ! bubble w be at or t[>d t end4 #aae4 ,riv]s4--,if a tr\gh be exactly level1 ! wat] w be ( ! same dep? at "o end z at ! o!r1 = ! surface ( ! wat] at bo? ends w be at ! same di/ance f ! c5tre ( ! e>?4 ,b raise up "o end1 & x is n[ deepe/ at ! o!r end4 ,if x 7 n s1 ! surface at ! two ends w\ld n be at ! same di/ance f ! c5tre ( ! e>?4 ,n[ if1 ) ! tr\gh ?us plac$1 wat] run 9 at ! upp] end & out at ! l[]1 y h exemplifi$ :at is tak+ place 9 all riv]s--! wat] is 9 con/ant motion f ! influ5ce ( gravitation1 caus+ x to seek to be on a level4 ,a v slight slope w give ! runn+ motion to wat]1 = ! p>ticles are s movable among ea* o!r t 9 ob$i5ce to gravity !y fl[ d[n ! incl9$ plane to seek a level4 ,?ree in*es declivity 9 e mile 9 a smoo? /raight *annel w make a riv] run at ! rate ( ab\t ?ree miles an h\r4 ,! ,ganges1 :i* receives its wat]s f ! ,himalaya ,m\nta9s1 9 runn+ #ahjj miles falls #hjj feet4 ,! ,magdal5a1 9 ,s\? ,am]ica1 falls only #ejj feet 9 runn+ #ajjj miles betwe5 two ridges ( ! ,&es4 #aaf4 ,h[ "s ,riv]s h be5 ,made4--,*anges are con/antly produc$ 9 ! e>? by ! disposition ( wat] to seek a level4 ,9 do+ ?is ! wat] c>ries solid sub/ances ( v>i\s k9ds f elevat$ places into depress$ ones1 t5d+ to fill up ! latt]4 ,new *annels are also sometimes made by ! wat]4 ,! boy :o makes a little pond ) 8 mud-dam1 & lets ! wat] ov]fl[ f x into ano!r pond on a l[] level1 z he sees a *annel work$ by ! wat] betwe5 ! two ponds becom+ l>g] & l>g]1 witnesses a fair repres5tation on a small scale ( "s ext5sive *anges :i* h 9 ages pa/ tak5 place 9 "s p>ts ( ! e>?4 ,x is suppos$1 & ) good reason1 t _m riv]s _h _! orig9 9 ! way above indicat$4 ,= example1 :]e ! ,danube runs its long c\rse !re 0 once a *a9 ( lakes4 ,^! becom+ connect$ toge!r by _! ov]fl[1 ! *annels cut betwe5 !m by ! wat] cont9ually became l>g]1 until at l5g? !re 0 "o long1 deep1 & broad *annel1 ! riv]1 :ile ! lakes became dry1 & con/itut$ ! f]tile valley ?r\gh :i* t noble riv] runs to empty into ! ,black ,sea4 ,x is said t a simil> process is manife/ly go+ on 9 ! ,lake ( ,g5eva1 ! outlet ( x becom+ cont9ually broad]1 :ile ! wa%+ f ! neighbor+ hills & m\nta9s is fill+ up ! lake4 ,t[ns t a c5tury ago lay directly ^u ! bord]s ( ! lake h g>d5s & fields n[ betwe5 !m & ! %ore2 & ,dr4 ,arnot says1 ,if ! t[n ( ,g5eva la/ long en\gh1 its inhabitants w h to speak ( ! riv] 9 ! neighbor+ valley1 in/ead ( ! picturesque lake :i* n[ fills x4 ,illu/ration3 ,fig4 #fh4 ,illu/ration3 ,fig4 #fi4 #aag4 ,canals4--,! managem5t ( ! locks ( a canal is 9 con=mity ) ! disposition ( wat] to seek a level4 ,a gr\nd view ( a lock & a "p ( two adjac5t locks is giv5 9 ,fig4 #fh4 ,! lock1 ,c1 has two pair ( flood-gates1 ,d ,d & ,e ,e4 ,! wat] 9 ,a is high] ?an 9 ,c1 b ! level is ! same 9 ,c & ,b1 because ! gates1 ,e ,e1 are op54 ,suppose n[ t !re is a boat 9 ! lock ,b t y wi% to get into ! lock ,a4 ,x mu/ be float$ into ! lock ,c1 & ! gates ,e ,e mu/ be clos$4 ,! wat] may n[ be made to fl[ f ! high] level1 ,a1 into ,c1 till ! level is ! same 9 bo? ,a & ,c4 ,b ?is c n be done by op5+ ! gates ,d ,d1 = ! pressure ( su* a height ( wat] 9 ! lock ,a w\ld make x difficult1 p]haps impossible1 to d ?is2 & besides1 if x c\ld be done1 ! rapid ru% ( wat] into ,c w\ld flood ! boat ly+ !re4 ,! dis*>ge is !re=e effect$ by op5+s 9 ! l[] "p ( ! gates ,d ,d4 ,^! op5+s are cov]$ by slid+ %utt]s1 :i* are rais$ by racks & p9ions1 z repres5t$ 9 ,fig4 #fi4 ,:5 ! wat] has become ( ! same level 9 ,a & ,c1 ! gates ,,dd c be easily op5$1 & ! boat may be float$ f ,c into ,a4 ,if a boat is to pass d[nw>d 9 ! locks1 ! process describ$ mu/ be rev]s$4 ,canals are also ext5sively us$ = supply+ wat] by side op5+s to turn wat]-:eels = ! work+ ( ma*9]y4 ,! wat] turns ! :eel by ! =ce :i* gravitation gives x z x desc5ds f ! level ( ! canal to ! level ( ! riv]4 ,illu/ration3 ,fig4 #gj4 ,illu/ration3 ,fig4 #ga4 #aah4 ,o!r ,illu/rations4--,we see ! t5d5cy ( fluids to be on ! same level 9 o!r ways4 ,9 a c(fee-pot ! liquid has ! same level 9 ! sp\t z 9 ! vessel itself1 :atev] may be its position1 z se5 9 ,fig4 #gj 7p4 #hf74 ,if x be turn$ up s f> t ! level ( ! fluid 9 ! vessel is high] ?an ! outlet ( ! sp\t1 ! fluid runs out4 ,if two res]voirs ( wat] be connect$ toge!r ! wat] w /& at ! same height 9 bo?1 :atev] ! di/ance betwe5 !m may be4 ,s1 also1 9 ! aqu$uct pipes t ext5d f a res]voir1 ! wat] w rise z high z ! surface ( ! wat] 9 ! res]voir itself4 ,if ! outlets ( ! pipes be l[] ?an ?is level ! wat] w run f !m1 z 9 ! case ( ! c(fee4 ,! cause ( ^! & simil> facts is ! same z t ( ! level surface 9 vessels & res]voirs--! action ( gravitation4 ,?is may be made pla9 by ,fig4 #ga4 ,let ! figure repres5t a vessel ) divisions ( diff]5t degrees ( ?ickness1 ^! divisions1 h[ev]1 n ext5d+ to ! bottom ( ! vessel4 ,wat] 9 ?is w\ld /& at ! same level 9 ! diff]5t ap>tm5ts1 j z x w\ld if ! vessel _h no su* divisions1 z repres5t$4 ,?is is simply because ! attraction ( ! e>? acts ^u ! wat] 9 ! same way ) ! divisions z )\t !m4 ,& y c see t x w make no diff]5ce :e!r ^! divisions be ?ick or ?91 or :e!r ! ap>tm5ts be ne>1 z y see "h1 or f> ap>t1 z !y are :5 bran* pipes ext5d f a res]voir4 ,a bran* pipe may be consid]$ z hav+ ! same relation to ! res]voir1 z "o ( ! n>r[ ap>tm5ts 9 ! figure has to ! re/ ( ! vessel4 ,! result is n at all affect$ by ei!r ! size or =m ( ! tubes t may be connect$ ) a common res]voir--a fluid w /& at ! same height 9 all4 ,?us we h1 9 ,fig4 #gb1 tubes ( v>i\s size & %ape1 a b c d e1 connect$ ) a res]voir1 r1 & if wat] be p\r$ into "o ( !m x w rise to ! same height 9 all1 j z 9 ! diff]5t ap>tm5ts ( ! vessel repres5t$ 9 ,fig4 #ga4 ,a man once ?\ght t he _h ga9$ ! great desid]atum1 p]petual motion1 by a vessel con/ruct$ z 9 ,fig4 #gc4 ,he reason$ 9 ?is way3 ,if ! vessel conta9 a p\nd ( wat]1 & ! tube only an ounce1 z an ounce c n balance a p\nd1 ! wat] 9 ! vessel mu/ be con/antly =c+ t 9 ! tube upw>d4 ,x !re=e mu/ con/antly run out ( ! outlet ( ! tube1 & z x fl[s into ! vessel ! circulation mu/ g on1 & ! only h9drance to its be+ a p]petual circulation w\ld be ! evaporation ( ! wat]4 ,he 0 conf\nd$ :5 he f\nd1 on p\r+ wat] into ! vessel1 t x /ood at precisely ! same level 9 ! vessel & ! tube4 ,illu/ration3 ,fig4 #gb4 ,illu/ration3 ,fig4 #gc4 #aai4 ,aqu$ucts4--,! anci5ts built aqu$ucts ( /one at imm5se exp5se1 9 "s cases spann+ valleys at great heights1 to supply _! cities ) wat]4 ,at ! pres5t day ! same object is effect$ at comp>atively small exp5se ) iron pipes laid "u gr\nd4 ,no matt] h[ mu* l[] ?an ! res]voir a valley cross$ by ! pipes may be1 ! wat] fl[+ ?r\gh !m w rise any :]e 9 _! bran*es to ! same height z x /&s 9 ! res]voir4 ,x is suppos$ by "s t ! anci5ts 7 n aw>e ( ?is fact2 b by o!rs t !y 7 aw>e ( x1 & built _! imm5se aqu$ucts because !y _h no mat]ial = con/ruct+ l>ge pipes4 ,illu/ration3 ,fig4 #gd4 #abj4 ,spr+s & ,artesian ,wells4--,! pr9ciples :i* ,i h develop$ 9 ! previ\s p>agraphs w expla9 ! ph5om5a ( spr+s1 common wells1 & ,artesian wells4 ,! cru/ ( ! e>? is l>gely made up ( lay]s ( diff]5t mat]ials1 z clay1 s&1 gravel1 *alk1 etc4 ,:5 ^! 7 =m$ !y 7 und\bt$ly horizontal1 b !y h be5 ?r[n up by convulsions ( nature 9 su* a way t !y pres5t e v>iety ( arrangem5t4 ,z "s ( ^! lay]s are mu* m p]vi\s to wat] ?an o!rs1 ! ra9 :i* falls & s9ks into ! gr\nd (t5 makes its way ?r\gh "o lay] ly+ betwe5 two o!rs :i* are imp]vi\s to wat]1 & s may make its appe>ance at a great di/ance f ! place ( its entrance1 & at a v diff]5t height4 ,h[ ?is expla9s ! ph5om5a ( spr+s1 common wells1 & ,artesian wells may be made cle> by ,fig4 #gd4 ,a ,a & ,b ,b ,b are design$ to repres5t por\s lay]s ( e>? ly+ betwe5 o!r lay]s :i* are imp]vi\s to wat]4 ,! wat] 9 ,a ,a w fl[ out at ,c1 mak+ :at is commonly call$ a spr+4 ,if we dig a well at ,f1 go+ d[n to ! por\s lay]1 ,b ,b ,b1 ! wat] w rise to ,g1 because ?is is on a level ) ! surface ( ! gr\nd1 ,h1 :]e ! supply ( wat] ent]s4 ,f ?is po9t x may be rais$ by a pump4 ,if ! well be dug at ,d1 ! wat] w rise n only to ! surface b to ,e1 because ?is is on a level ) ,h4 ,wat] is sometimes obta9$ "u su* circum/ances f v great dep?s4 ,9 ?is case ! por\s /ratum conta9+ ! wat] is rea*$ by bor+1 & !n we h :at is t]m$ an ,artesian well4 ,! "n comes f ,artois1 9 ,france1 :]e ?is op]ation 0 fir/ execut$4 ,!re is a celebrat$ well ( ?is sort 9 ,p>is ov] #ahjj feet deep1 & ! wat] rises #aab feet above ! surface4 ,m ?an #fjj gallons are dis*>g$ e m9ute4 ,london1 says ,dr4 ,arnot1 /&s 9 a holl[1 ( :i* ! fir/ or inn]mo/ lay] is a bas9 ( clay1 plac$ ov] *alk1 & on bor+ ?r\gh ! clay 7sometimes ( #cjj feet 9 ?ickness7 ! wat] issues1 & 9 _m places rises consid]ably above ! surface ( ! gr\nd1 %[+ t !re is a high] s\rce or level some:]e--probably among ! ,surry hills or ^? nor? ( ,london4 #aba4 ,pressure ( ,liquids 9 ,proportion to ,dep?4--,! pressure ( a fluid is 9 exact proportion to its dep?4 ,=1 z ! p>ticles are all "u ! influ5ce ( gravity1 ! upp] lay] ( !m mu/ be support$ by ! second1 & ^! two lay]s toge!r by ! ?ird1 & e lay] mu/ be> ! weight ( all ! lay]s above x4 ,! increase ( pressure at great dep?s produces ! mo/ /rik+ effects4 ,?us if an empty cork$ bottle be let d[n v deep at sea1 ei!r ! cork w be driv5 9 or ! bottle w be cru%$ 94 ,a g5tleman tri$ ! foll[+ exp]im5t3 ,he made a p9e-wood cork1 s %ap$ t x project$ ov] ! m\? all ar\nd4 ,he !n cov]$ ?is ) pit*1 & fa/5$ ov] ! :ole sev]al pieces ( t>paul94 ,! bottle1 ?us prep>$1 he let d[n to a great dep? by atta*+ to x a weight4 ,on rais+ x up he f\nd t x conta9$ ab\t half a p9t ( wat] /rongly impregnat$ ) pit*1 %[+ t ! pressure ( ! wat] =c$ wat] ?r\gh ! sev]al pieces ( t>paul91 ! pit*1 & ! pores ( ! wood5 cork4 ,:5 a %ip f\nd]s ne> l&1 ! pieces ( ! wreck1 z x breaks up1 float to ! %ore2 b :5 ! accid5t happ5s 9 deep wat]1 ! great pressure =ces wat] into ! pores ( ! wood1 & ?us makes x s heavy t no "p ( ! vessel w ev] rise aga94 ,:5 a man dives v deep he suff]s mu* f ! pressure on 8 *e/4 ,if we wat* a bubble ( air ris+ 9 wat] x is small at fir/1 b x gr[s l>g] z x approa*es ! surface1 because x su/a9s less pressure ?an :5 x 0 deep 9 ! wat]4 ,! =ce ) :i* a fluid is dis*>g$ f an op5+ 9 a vessel dep5ds on ! height ( ! fluid above ! op5+4 ,! diff]5ce 9 ?is respect betwe5 a full b>rel & "o ne>ly empty is v obvi\s4 ,mo/ fi%es1 probably1 c n be> ! pressure ( great dep?s1 & s are commonly f\nd on ! coa/1 or on banks1 z !y are call$1 9 ! mid/ ( ! ocean4 ,illu/ration3 ,fig4 #ge4 #abb4 ,sluice-,gates1 ,dams1 etc4--,! application ( ! above pr9ciples 9 ! con/ruction ( sluice-gates1 dams1 etc41 is a matt] ( great practical importance4 ,let u look at ?is4 ,z pressure 9 a fluid is always 9 proportion to ! height ( ! fluid above ! po9t ( pressure1 ! pressure ^u any portion ( ! side ( a vessel conta9+ a fluid mu/ be 9 proportion to its di/ance f ! surface2 or1 9 o!r words1 x is ! weight ( a column ( wat] ext5d+ f ?is portion to ! surface4 ,let ,a ,b ,c ,d 7,fig4 #ge7 repres5t a section ( a cubical vessel1 t is1 "o 9 :i* ea* side is ( ! same size ) ! bottom4 ,! pressure on ! po9t a1 9 ! l9e ,a ,b1 is t ( a column ( p>ticles1 ,a a4 ,b ,a a is equal to c b1 & c b is equal to b a4 ,!re=e b a may repres5t ! pressure on a4 ,9 ! same way x c be %[n t e d repres5ts ! pressure on d1 n m ! pressure on m1 ,c ,b t on ,b4 ,!re=e ! pressure on all ! po9ts 9 ,a ,b w be repres5t$ by l9es fill+ up all ! triangul> space ,a ,b ,c1 & ?is is half ( ,a ,b ,c ,d1 :i* repres5ts ! pressure on ! l9e ,c ,b4 ,x is cle>1 !n1 t z ! pressure on a v]tical l9e 9 ! side is half t on a l9e at "r angles to x 9 ! bottom1 ! pressure on ! :ole side is half t on ! :ole bottom4 ,illu/ration3 ,fig4 #gf4 ,we see f ! above demon/ration :y x is t a dam is built 9 ! =m repres5t$ 9 ,fig4 #gf4 ,we see1 also1 :y 9 ! mon/r\s vats 9 "s ( ! ,engli% brew]ies 7"s ( !m hold+ _m ?\s& b>rels7 ! hoops & o!r securities at ! l[] "p ( !m require to be made ( v great /r5g?4 ,x is manife/1 also1 t if a sluice-gate is to be kept %ut by a s+le support1 ?is mu/ be appli$ at "o ?ird ( ! di/ance f ! bottom1 !re be+ z mu* pressure1 z se5 by ,fig4 #ge1 on ! l[] ?ird z on ! upp] two ?irds ( ! gate4 #abc4 ,lat]al ,pressure 9 ,fluids4--,! pressure ( a liquid on ! side ( a vessel1 ( :i* ,i h spok5 above1 is a lat]al pressure1 & x is caus$ by ! d[nw>d pressure ( gravitation 9 ! liquid4 ,b h[8 ,! p>ticles ( a fluid are freely movable among ea* o!r1 & !re=e are ready to escape f pressure 9 any direction4 ,! p>ticles at a1 ,fig4 #ge1 press$ ^u by ! column ( p>ticles ext5d+ above !m to ! surface1 are ready to escape lat]ally1 & w\ld d s if !re 7 an op5+ made 9 ! vessel at t po9t4 ,b if ! vessel conta9$ a block ( ice1 fitt+ x z accurately z ! body ( wat]1 !re w\ld be no escape at ! op5+1 because ! p>ticles ( ! solid are s held toge!r t ! d[nw>d pressure ( ! e>?'s attraction occasions no lat]al pressure4 ,illu/ration3 ,fig4 #gg4 ,illu/ration3 ,fig4 #gh4 ,! mann] 9 :i* ! d[nw>d pressure ( ! e>?'s attraction causes lat]al pressure may be made cle> by ,figs4 #gg & #gh4 ,we w suppose t ! p>ticles ( solids & liquids are alike r\nd1 & t a solid diff]s f a liquid only 9 hav+ its p>ticles firmly unit$ by attraction4 ,let a1 b1 & c1 9 ,fig4 #gg1 repres5t ?ree p>ticles ( a solid4 ,z !y are unit$ firmly !y w h a unit$ pressure f ! c5tre ( gravity directly t[>d ! c5tre ( ! e>?1 z repres5t$ by ! arr[4 ,let n[ d1 e1 & f1 ,fig4 #gh1 repres5t ?ree p>ticles ( wat]4 ,^! be+ b v slightly coh]5t1 w make ea* an indep5d5t pressure t[>d ! e>?'s c5tre1 z indicat$ by ! arr[s4 ,x is pla9 t d t5ds to sep>ate e & f1 & w d s if !y are left free to move 9 a lat]al direction4 ,= example1 if e be at ! side ( a vessel1 & an op5+ be made !re1 ! d[nw>d pressure ( d w give e a lat]al movem5t1 =c+ x out ( ! op5+4 #abd4 ,ano!r ,view4--,to return to ,fig4 #ge1 obs]ve t ! lat]al pressure at any po9t 9 ! side ( a vessel1 z a1 is occasion$ :olly by ! d[nw>d pressure ( a v]tical column ( p>ticles ext5d+ f t po9t to ! surface4 ,! neighbor+ columns ( p>ticles h no?+ to d ) x4 ,! same ?+ is true 9 reg>d to any o!r po9t ei!r 9 ! l9e ,a ,b or ano!r l9e drawn on ! side ( ! vessel4 ,x is !re=e true ( ! :ole side1 t ! pressure ^u x is occasion$ alone by ! columns ( p>ticles t are 9 close proximity to ! side1 & n at all by ! o!r columns ( p>ticles 9 ! vessel4 ,! numb] ( ^! columns1 !re=e1 9 ! vessel1 or1 9 o!r words1 ! bread? ( ! body ( wat] 9 x1 makes no diff]5ce ) ! pressure on its side4 ,= ?is reason two flood-gates s little ap>t t a few hog%eads or ev5 pails ( wat] fill up ! space betwe5 !m1 are z mu* press$ ^u z !y w\ld be if a lake or an ocean ( wat] lay betwe5 !m4 ,x has be5 object$ to ! project ( digg+ a %ip canal betwe5 ! ,r$ ,sea & ! ,m$it]ranean1 t z ! wat] 9 ! =m] is tw5ty feet high] ?an 9 ! latt]1 x w\ld bur/ ?r\gh ! flood-gates ) su* =ce z to produce mo/ disa/r\s results4 ,b accord+ to ! pr9ciple :i* ,i h illu/rat$1 !re w\ld be no m dang] ( ?is ?an !re w\ld be if two ponds 7 unit$ by a canal1 9 "o ( :i* ! wat] is tw5ty feet high] ?an 9 ! o!r4 ,illu/ration3 ,fig4 #gi4 #abe4 ,pressure 9 ,liquids ,equal 9 all ,directions4--,we are n[ prep>$ to g a /ep f>!r4 ,! pressure occasion$ by gravitation 9 fluids op]ates equally 9 all directions :5 ! fluid is at re/4 ,t is1 any p>ticle ( a liquid is press$ equally 9 all directions4 ,if x 7 n s x w\ld n rema9 at re/1 b w\ld be mov$ 9 ! direction 9 :i* ! sup]ior pressure op]ates4 ,suppose t a1 ,fig4 #gi1 is a /ratum ( p>ticles 9 a vessel conta9+ wat] at re/4 ,! upw>d pressure on x be+ equal to ! d[nw>d pressure1 ! /ratum nei!r rises nor falls4 ,if a body ( liquid be di/urb$ by w9d or any o!r cause1 ^? p>ticles :i* are rais$ above ! common level 9 waves are press$ d[nw>d m ?an upw>d or lat]ally 9 ob$i5ce to ! action ( gravitation4 ,!y !re=e move d[nw>d1 pu%+ lat]ally & upw>d ! neighbor+ p>ticles1 till ! liquid rega9s its level surface & its /ate ( re/4 ,s1 also1 if any p>ticles become heat$ !y are light] ?an _! neighbor+ p>ticles1 & ! latt] be+ m /rongly attract$ ?an ! =m]1 pu% !m upw>d 9 ord] to take _! places4 ,:5 all ! liquid comes to h ! same temp]ature x is at re/1 ea* p>ticle hav+ an equal pressure ^u x 9 all directions4 ,illu/ration3 ,fig4 #hj4 #abf4 ,illu/rations4--,if a bladd] fill$ ) wat] be compress$ by ! h&1 ! wat] is press$ no m imm$iately "u ! h& ?an 9 any o!r "p ( ! bladd]1 & :]ev] an op5+ be made ! wat] w ru% out ) equal read9ess4 ,a hose-pipe z readily bur/s upw>d z 9 any o!r direction4 ,a l>ge cork1 if sunk 9 v deep wat]1 w be uni=mly r$uc$ 9 its dim5sions1 %[+ t x has be5 press$ equally on all sides4 ,9 ! exp]im5ts ) ! clos$ bottles 7 #aba71 ! result is ! same if ! bottle be s sunk z to h its m\? d[nw>d4 ,if two tubes1 %ap$ z 9 ,fig4 #hj1 be ?ru/ d[n into wat]1 ! wat] w rise ) equal facility 9 bo?1 al?\gh 9 ! /raight "o ! pressure :i* c>ries up ! wat] is :olly upw>d1 :ile 9 ! b5t "o x is at ! fir/ d[nw>d4 ,illu/ration3 ,fig4 #ha4 #abg4 ,upw>d ,pressure z ! ,dep?4--,x has be5 %[n t ! d[nw>d & ! lat]al pressures are z ! dep?4 ,! same is true ( ! upw>d pressure1 = x is produc$ by ! same cause--! attraction ( ! e>?4 ,let u look at ?is4 ,:y is any p>ticle ( a fluid press$ upw>d at all8 ,x is f ! /ruggle on ! "p ( ! neighbor+ p>ticles to get bel[ x4 ,& :y ?is /ruggle8 ,x is f ! attraction ( gravitation1 & s ! great] ?is attraction ! great] is ! upw>d z well z ! d[nw>d pressure4 ,! upw>d pressure !re=e diff]s at diff]5t dep?s z ! d[nw>d pressure does4 ,?us1 9 ,fig4 #ha1 ! upw>d pressure aga9/ ! lay] or /ratum ( p>ticles1 b1 is great] ?an t aga9/ a1 = ! same reason t ! d[nw>d pressure on b is great] ?an t on a4 ,b ! two pressures at b are equal1 & s are !y at a1 & !re=e ea* /ratum rema9s at re/4 ,illu/ration3 ,fig4 #hb #abh4 ,exp]im5ts4--,"s v neat exp]im5ts c be tri$1 %[+ t ! upw>d pressure v>ies ) ! dep?4 ,take a l>ge glass tube1 ,a ,b ,c ,d1 ,fig4 #hb1 & let !re be fitt$ to "o end a circul> plate ( brass1 :i* may be held !re by a /r+1 ,f4 ,?us arrang$1 plunge x q deep into wat]1 & y w f9d t y w n ne$ to hold on to ! /r+1 = ! brass disk w be held tight to ! tube by ! upw>d pressure ( ! wat]4 ,n[ draw up ! tube sl[ly1 & at l5g? ! disk w fall f ! end ( ! tube4 ,:y8 ,because ! end ( ! tube has come to a po9t :]e ! upw>d pressure ( ! wat] is less ?an ! d[nw>d pressure ( ! disk4 ,to h ?is exp]im5t succe$1 ! end ( ! tube :]e ! disk is appli$ mu/ be v ev5 & smoo?4 ,ano!r exp]im5t may be tri$ 9 ?is way4 ,tie to "o end ( a glass tube a piece ( ?9 ,india-rubb] or bladd]1 & fill ! tube p>tly ) wat]4 ,! ,india-rubb] w ( c\rse bulge out or be convex f ! weight ( ! wat]4 ,press ! clos$ end d[n a little way 9 a vessel ( wat]1 s t ! level 9 ! tube %all be above ! level 9 ! vessel4 ,! ,india-rubb] is /ill some:at convex1 because1 z ! upw>d pressure ^u x is 9 proportion to its di/ance f ! surface ( ! wat] outside ( ! tube1 x is n z great z ! pressure d[nw>d ( ! high] wat] 9 ! tube4 ,pu% ! tube n[ s f> d[n t ! level 9 ! tube is ! same ) t 9 ! vessel4 ,! ,india-rubb] is n[ flat1 because ! d[nw>d & upw>d pressures ^u x are equal1 j z w\ld be ! case ) a /ratum ( wat] 9 place ( x4 ,b press ! tube l[] d[n1 & ! ,india-rubb] bulges upw>d into ! tube1 because ! upw>d pressure is n[ great] ?an ! d[nw>d4 #abi4 ,great ,effects f ,small ,quantities ( a ,fluid4--,y are n[ prep>$ to und]/& ! explanation ( "s v /rik+ ph5om5a 9 ! pressure ( liquids4 ,if y take a p]fectly tight cask1 &1 fill+ x ) wat]1 screw into its top a long tube1 by p\r+ wat] into ! tube y c bur/ ! cask4 ,to und]/& ?is y mu/ be> 9 m9d two facts--t ! fluid 9 ! cask is n compressible1 & t its p>ticles move freely among ea* o!r4 ,any pressure1 !re=e1 ex]t$ ^u x is felt ?r\gh ! :ole ( x equally4 ,if ! tube1 says ,dr4 ,arnot1 h an area ( a =tie? ( an in*1 & conta9 :5 fill$ half a p\nd ( wat]1 ?is produces a pressure ( half a p\nd ^u e =tie? ( an in* all ov] ! int]ior ( ! cask2 :i* is m ?an a common cask c be>4 ,suppose a small res]voir ( wat] exi/s 9 ! side ( a m\nta9 :olly clos$ up1 & t wat] f a height above f9ds its way to x by a crevice1 x may by its pressure ev5 bur/ op5 ! side ( ! m\nta94 ,& x matt]s n h[ l>ge or small ! crevice may be1 = pressure 9 a liquid is only z ! height4 ,if ! res]voir be t5 y>ds squ>e & an in* deep1 & ! fissure lead+ to x be b an in* 9 diamet] & two hundr$ feet 9 height1 x is calculat$ t ! pressure ( ! wat] 9 ! fissure w\ld be equal 9 =ce to ! weight ( #ejjj tons4 ,illu/ration3 ,fig4 #hc4 #acj4 ,explanation4--,! mann] 9 :i* ^! effects are produc$ may be made cle> by ,fig4 #hc4 ,let ,a be a close vessel fill$ ) wat]1 & let a tube1 b1 be made fa/ 9 x1 ) a movable plug or pi/on at c4 ,if ! surface ( ! wat] be press$ ^u by ?is pi/on ) ! =ce ( a p\nd1 z ! wat] is incompressible & its p>ticles are freely movable among ea* o!r1 ! pressure w be ext5d$ equally ?r\gh all ! wat]1 & e portion ( ! vessel ( equal ext5t ) ! tube's op5+ at c w be press$ ^u ) ! =ce ( a p\nd4 ,if ano!r tube1 d1 ( ! same size 7 ins]t$ ) a pi/on1 i1 ! =ce ( a p\nd appli$ to ! pi/on c w\ld pu% upw>d ! pi/on i ) ! same =ce4 ,& if !re 7 sev]al pi/ons ( ! same size1 by pu%+ ^u "o ) ! =ce ( a p\nd !y w\ld all be press$ upw>d ) exactly ?is =ce4 ,f>!r1 if e be a tube five times z l>ge z b1 its pi/on1 n1 w be =c$ upw>d ) a pressure ( five p\nds by ! d[nw>d pressure ( a p\nd ^u c4 ,suppose n[ t a p\nd ( wat] 7 sub/itut$ = ! pi/on c1 ! o!r pi/ons w\ld be press$ upw>d z be=e4 ,& if all ! pi/ons be remov$1 ! p\nd ( wat] 9 b w press ! wat] up ! tube d ) ! =ce ( a p\nd1 & up ! tube e ) ! =ce ( five p\nds4 ,illu/ration3 ,fig4 #hd4 ,to make ?is /ill m cle> ,i w pres5t x 9 a little diff]5t =m4 ,let ,b1 ,fig4 #hd1 be a close vessel ) two tubes1 "o ( :i* is five times z l>ge z ! o!r4 ,if suffici5t wat] be p\r$ into ! vessel to occupy a "p ( ! tubes1 x w /& at ! same height 9 bo? tubes1 z indicat$4 ,if !re be a p\nd ( wat]1 !n1 9 ! tube c1 !re w be five p\nds 9 a4 ,n[ if ! five p\nds ( wat] 9 a made any m pressure on ! :ole body ( wat] 9 ,b ?an ! p\nd ( wat] 9 c does1 x w\ld press up ! wat] 9 c to a great] height4 ,b ?is is impossible1 z has be5 %[n 9 #aah4 ,obs]ve t ! five p\nds ( pressure 9 a is spread ov] five times ! area or ext5t ( surface t ! p\nd's pressure 9 c is4 ,if ! tube c h an area ( an in* squ>e1 ! wat] 9 x w ex]t a pressure ( a p\nd on e squ>e in* 9 ! vessel4 ,! wat] 9 a ex]ts a pressure ( five p\nds2 b x mu/ be rememb]$ t x does n press ) ?is =ce on e squ>e in*1 b on e space ( five squ>e in*es1 & t !re=e its pressure on e in* is ! same z t 9 ! tube c4 #aca4 ,hydro/atic ,p>adox4--,y see 9 ! ph5om5a & explanations giv5 above t a small quantity ( a fluid c1 "u c]ta9 circum/ances1 ex]t an enorm\s pressure4 ,?is fact has be5 call$ ! ,hydro/atic ,p>adox4 ,x does seem1 at fir/ view1 incr$ible or p>adoxical1 :5 "o ass]ts t a few ounces ( wat] c be made to raise weights ( hundr$s or ev5 ?\s&s ( p\nds4 ,b ! explanations :i* ,i h giv5 %[ y t !re is no unexpla9able my/]y 9 ! fact4 ,! cause ( x is ! same z t :i* gives a level surface to liquids2 viz41 ! =ce ( gravitation act+ ^u a sub/ance ^: p>ticles are freely movable among ea* o!r4 ,illu/ration3 ,fig4 #he4 #acb4 ,hydro/atic ,bell[s4--,! in/rum5t call$ ! ,hydro/atic ,bell[s is repres5t$ 9 ,fig4 #he4 ,x consi/s ( two circul> bo>ds1 ,a & ,b1 unit$ toge!r by /rong lea!r1 & hav+ a tube1 ,c1 ?r\gh :i* wat] c be p\r$ into x4 ,! am\nt ( weight :i* c be su/a9$ on ! bell[s )\t =c+ ! wat] out ( ! tube dep5ds on ! size ( ! bell[s4 ,if ! area ( ! tube is only "o ?\s&? ( t ( ! top ( ! bell[s1 a p\nd ( wat] 9 ! tube w balance a ?\s& p\nds' weight on ! bell[s4 ,x is = ! same reason t 9 ,fig4 #hd "o p\nd ( wat] 9 ! tube c balances five p\nds 9 a4 ,z ! weight presses ^u ! top z a :ole1 x is ! same z if !re 0 a vessel ( ! same size ) ! bell[s re/+ ^u x & conta9+ a ?\s& p\nds ( wat]4 ,! wat]1 9 t case1 w\ld /& at ! same height 9 ! vessel & ! tube4 ,?is %[s t ! ,hydro/atic ,p>adox is only "o ( ! exemplifications ( ! great fact t a fluid1 f ! influ5ce ( gravitation1 seeks to be on a level4 ,x is ! wat] 9 ! bell[s seek+ to be on a level ) t 9 ! tube t causes ! upw>d pressure su/a9+ ! weight4 ,:5 ! weight on ! bell[s is less ?an is requir$ to balance ! wat] 9 ! tube1 ! weight c be rais$ cont9ually by p\r+ wat] into ! tube4 ,b obs]ve t al?\gh ! lift+ =ce be s /rong1 x is v sl[ 9 its op]ation4 ,if ! comp>ative areas ( ! tube & ! bell[s be z above suppos$1 ! wat] mu/ fall 9 ! tube t5 in*es 9 rais+ ! weight ! "o hundr$? "p ( an in*4 ,illu/ration3 ,fig4 #hf4 #acc4 ,bramah's ,hydro/atic ,press4--,! pr9ciples :i* ,i h elucidat$ h be5 appli$ by ,mr4 ,bramah 9 8 ,hydro/atic ,press4 ,?is consi/s ( a small metallic =c+-pump1 ,fig4 #hf1 9 :i* ! wat]1 a1 is pump$ up by ! pi/on1 s1 work$ by ! lev]1 c b d1 & =c$ into a /rong & l>ge cyl9d]1 ,a4 ,9 ?is cyl9d] is a /\t pi/on1 ,s1 hav+ a flat head1 ,p1 above4 ,betwe5 ?is plate & ano!r1 ,r1 is plac$ ! body1 ,w1 :i* is to be compress$4 ,x is obvi\s t ! pressure ex]t$ w be 9 proportion to ! diff]5ce betwe5 ! size ( ! pump1 a1 & ! cyl9d]1 ,a1 j z 9 ! case ( ! bell[s1 x dep5d$ on ! diff]5ce betwe5 ! areas ( ! tube & ( ! top ( ! bell[s4 ,9 ! press ! =ce ( a pump is sub/itut$ = ! pressure ( a v high column ( wat]1 simply because x is m conv5i5t4 ,?is press is ( great s]vice 9 ! me*anic arts4 ,x is us$ 9 press+ pap]1 clo?1 hay1 cotton1 etc4 ,x has also be5 rec5tly us$ 9 rais+ enorm\s weights4 ,! tubes ( ! celebrat$ bridge ov] ! ,/raits ( ,m5ai 7 rais$ by a ma*9e con/ruct$ on ?is pr9ciple4 ,,*apt] ,,viii4 ,,specific ,,gravity4 #acd4 ,nature ( ! ,subject4--,we n[ come to a v int]e/+ subject1 :i* is at lea/ intimately connect$ ) ,hydro/atics1 if x may n be consid]$ a "p ( x4 ,! pr9ciples :i* h be5 develop$ 9 ! *apt] on ,hydro/atics 9 relation to liquids are to be appli$ "h to v>i\s k9ds ( sub/ances4 ,& z we proce$ y w see t all ! ph5om5a br\ght to view 9 ?is *apt] are to be ref]r$ to ! same cause ) ^? ( ! previ\s *apt]2 viz41 ! attraction ( gravitation4 #ace4 ,specific ,gravity ,def9$4--,be=e proce$+ ) ! inve/igation ,i w give y ! def9ition ( specific gravity4 ,! specific gravity ( any sub/ance is its weight z comp>$ ) ! same bulk or volume ( o!r sub/ances4 ,wat] is tak5 z a /&>d1 & its specific gravity is = conv5i5ce call$ #a4 ,m]cury1 !n1 is said to h a specific gravity ( #ac4e1 = x is ?irte5 & a half times z heavy z ! same volume ( wat]4 ,x is easy to see h[ ! specific gravities ( diff]5t fluids may be asc]ta9$4 ,"o mode1 & ! mo/ obvi\s "o1 is to weigh 9 a vessel equal quantities ( !m4 ,9 :at way ! specific gravities ( solids are asc]ta9$ w be expla9$ 9 ano!r "p ( ?is *apt]4 #acf4 ,action ( ,gravity on ,solids 9 a ,liquid4--,! reason t a v heavy sub/ance1 z a /one1 s9ks 9 wat] is simply t ! e>? attracts x m /rongly ?an x does ! wat]1 & s drags ! /one d[n ?r\gh x4 ,if ! /one lay ^u a bladd] fill$ ) wat]1 x w\ld press ^u x ) ! =ce ) :i* x is attract$ by ! e>?4 ,b :]e wat] is n ?us conf9$1 ! /one ?ru/s its p>ticles to ! "o side & ! o!r till x gets to ! bottom4 ,x is ! attraction ( gravity1 also1 t makes light sub/ances1 z wood & cork1 rise 9 wat]4 ,9 ?is case ! wat] is attract$ by ! e>? m /rongly ?an ! wood or cork1 & s gets bel[ x1 & 9 s do+ pu%es ! light] sub/ance up above itself4 ,illu/ration3 ,fig4 #hg4 ,b y w obs]ve t ! wood1 on ris+ 9 ! wat]1 does n come completely out ( x & lie ^u ! surface1 b a "p ( x rema9s imm]s$ 9 ! wat]4 ,! explanation ( ?is w furni% y ) ! key to ! und]/&+ ( _m v int]e/+ facts4 ,suppose t half ( a block ( wood1 ,a1 ,fig4 #hg1 weigh+ a p\nd1 is above ! surface ( wat]4 ,z x is attract$ to ! e>? ) ! =ce ( a p\nd1 x has pu%$ to ! "o side & ! o!r j a p\nd ( wat]1 & tak5 its place4 ,x is drawn d[n t[>d ! e>? ) ! same =ce ) ! p\nd ( wat] on ei!r side ( x1 b or c4 ,if x 7 attract$ any m ?an ) ! =ce ( a p\nd1 t is1 if x weigh$ m ?an a p\nd1 x w\ld displace m ?an a p\nd ( wat]4 ,if x 7 ( j ! same weight ) ! same volume ( wat]1 x w\ld displace a volume ( wat] equal to itself2 x w\ld be :olly imm]s$1 & w\ld /ay any :]e 9 ! wat]1 :]ev] y plac$ x1 because x is attract$ by ! e>? ) ! same =ce t ! same bulk ( wat] is4 ,illu/ration3 ,fig4 #hh4 #acg4 ,f>!r ,explanation4--,suppose wat] 9 a vessel divid$ into equal portions ( a p\nd ea*1 z repres5t$ 9 ,fig4 #hh4 ,n[ suppose t ! portion a %\ld at once *ange into solid ice )\t at all alt]+ its bulk or weight4 ,x w\ld n move f its position1 because x is attract$ by ! e>? precisely z mu* z :5 x 0 wat]1 & z mu* z is ea* ( ! equal portions ( wat] ar\nd x4 ,b z wat] on becom+ ice does really increase 9 bulk1 & !re=e become light]1 ?is block ( ice w\ld rise s t a "p ( x w\ld be above ! surface4 ,illu/ration3 ,fig4 #hi4 ,! light] a sub/ance is t is imm]s$ 9 wat]1 ! m !re w be ( x above ! surface4 ,take two blocks ( wood ( diff]5t weights ?\gh ( ! same size4 ,suppose ! heavie/ "o1 ,a1 ,fig4 #hi1 is "o ?ird light] ?an ! same bulk ( wat]4 ,"o ?ird ( x w be above ! surface4 ,if ! o!r1 ,b1 is half ! weight ( wat]1 half ( x w be above ! surface4 ,we %\ld say1 !n1 t ! specific gravity ( ! wood 9 ! fir/ block is two ?irds ( t ( wat]1 & ! specific gravity ( ! wood 9 ! second is "o half t ( wat]4 #ach4 ,illu/rations4--,!re are _m int]e/+ facts t illu/rate ! pr9ciples :i* ,i h develop$4 ,a /one is lift$ mu* m easily 9 wat] ?an 9 air1 because ( ! support af=d$ by ! upw>d pressure ( ! wat]4 ,a boy w (t5 wond] :y he c lift a v heavy /one to ! surface1 b c get x no f>!r4 ,:5 a bucket ( wat] is drawn up a well mu* less ex]tion is requir$ to raise x ?r\gh ! wat] ?an ?r\gh ! air aft] x em]ges f ! wat]4 ,:ile x is 9 ! wat] y raise only ! bucket itself1 ! wat] 9 x hav+ no weight1 be+ su/a9$ by ! wat] ar\nd x4 ,b :5 x comes to ! air y h ! weight ( ! wat] add$ to t ( ! bucket4 ,:5 a p]son lies 9 a ba? = "s "t1 on rais+ 8 arm f ! wat] x seems to be v heavy4 ,! reason is1 t x has _h = s long a "t ! support ( ! wat] t :5 x is lift$ into ! air ! want ( ?is support is s5sibly felt1 j z we p]ceive ! diff]5ce betwe5 rais+ a bucket ( wat] ?r\gh wat] & rais+ x ?r\gh air4 ,x is said t ,ar*im$es took 9 ! full idea ( ! pr9ciples ( specific gravity z 8 limbs felt ! liquid support ( a ba?1 & s ov]joy$ 0 he ) ! discov]y1 t he ran home cry+ out all ! way1 6 6--,i h f\nd x6 ,i h f\nd x6 ,x 0 a rational joy1 = he _h f\nd a pr9ciple ( imm5se value to sci5ce & to ! _w4 #aci4 ,boats & ,life-,boats4--,a boat ( iron w float ) z mu* ( x out ( wat] z "o ( wood ( ! same size1 provid$ t ! iron be made s ?9 t ! boat is n heavi] ?an ! wood5 "o4 ,= :at is x t floats8 ,n ! iron or wood1 b a wood5 or iron boat fill$ ) air4 ,if x 7 fill$ ) wat] in/ead ( air x w\ld s9k1 ! specific gravity ( ! mat]ials ( :i* x is built be+ on ! :ole ( great] specific gravity ?an wat]4 ,life-boats h 9 _! /ructure ei!r a l>ge quantity ( cork or air-tight vessels ( t9 or copp]1 & 9 ?is way !y are made s light t !y w float ev5 :5 fill$ ) wat]4 ,z ! weight ( a body c be e/imat$ f ! quantity ( wat] :i* x displaces1 we c v readily e/imate ! weight ( ! load ( a canal-boat1 z its =m is s simple & regul>4 ,9 ord] to d ?is we mu/ fir/ "k h[ f> ! boat s9ks 9 ! wat] :5 empty1 or1 9 o!r words1 h[ mu* wat] x displaces4 #adj4 ,specific ,gravity ( ,animals4--,birds h a mu* less specific gravity ?an animals t walk1 9 ord] t !y may m\nt up easily 9 ! air4 ,_! light fea!rs increase greatly _! bulk1 z y may see :5ev] a bird is /ripp$ ( !m4 ,besides ?is1 ! bones are holl[ & communicate ) ! lungs4 ,birds t swim1 z ducks1 swans1 etc41 h s small a specific gravity--t is1 are s l>ge 9 proportion to _! weight--t b a small "p ( ! body is "u wat]1 & ! motion ( _! feet is n requir$ at all to su/a9 !m1 b only1 l ! action ( o>s1 to propel !m along4 ,insects are ( small specific gravity1 ^? t fly ! mo/ swiftly be+ ! lighte/4 ,fi%es are v ne>ly ( ! same specific gravity ) wat]1 & h5ce require b little muscul> ef=t to move ab\t 9 _! elem5t4 ,!y are assi/$ mu* 9 ris+ & fall+ by a contrivance by :i* !y c in/antane\sly alt] _! specific gravity4 ,!y h an air-bladd]1 :i* !y c dilate or contract at pleasure4 ,:5 dilat$1 ! bulk ( ! fi% is increas$ & 8 specific gravity less5$1 & he rises easily & at once4 ,by compress+ x he z readily s9ks4 #ada4 ,specific ,gravity ( ! ,human ,body4--,! human body1 :5 ! *e/ is fill$ ) air1 is s mu* light] ?an wat] t x w float ) ab\t half ! head above ! surface4 ,a k ( ?is fact1 ) prop] pres5ce ( m9d1 might ord9>ily save p]sons f dr[n+2 = if ! body be put 9 ! prop] position1 ! feet d[nw>d & ! head ?r[n backw>d1 ! nose & m\? w be out ( ! wat]4 ,s little is requir$ 9 ! way ( support to keep ! :ole head out ( wat]1 t p]sons :o c n swim are (t5 sav$ f dr[n+ by cat*+ hold ( v small pieces ( wood4 ,an o> w\ld support half a doz5 m51 if !y w\ld be satisfi$ ) keep+ only ! head out ( wat]2 b if ea* "o /ruggle to get 8 :ole body ^u ! o>1 !y may all be lo/4#a ,a life-pres]v] is a great aid 9 pres]vation f dr[n+1 = x dim9i%es ! specific gravity ( ! body4 ,x is commonly an air-tight bag fa/5$ r\nd ! upp] "p ( ! body1 :i* c be fill$ by bl[+ into x ?r\gh a pipe :i* has a valve 9 x4 ,on ! great riv]s ( ,*9a1 says ,dr4 ,arnot1 :]e ?\s&s ( p f9d x m conv5i5t to live 9 cov]$ boats ^u ! wat] ?an 9 h\ses on ! %ore1 ! y\ng] male *ildr5 h a holl[ ball ( "s light mat]ial atta*$ con/antly to _! necks1 s t 9 _! frequ5t falls ov]bo>d !y are n 9 dang]4 ,:5 a p]son is dr[n$ ! body s9ks because 9 ! /ruggle mu* ( ! air 9 ! lungs is lo/1 j z ! fi% s9ks :5 8 air-bladd] is contract$4 ,x is1 h[ev]1 s little heavi] ?an wat] aft] ?is is done1 t x v readily rises :5 any gas is produc$ 9 x by putrefaction4 ,x is a common popul> notion t fir+ cannon ov] ! wat] w raise ! dr[n$4 ,b x c produce no effect1 unless p]haps ! agitation caus$ by ! concussion may ha/5 a v little ! ris+ ( a body :i* f comm5c+ putrefaction is ab\t to rise4 ,9 wad+ a riv] ! feet press ^u ! bottom ) only a =ce equal to ! weight ( half ! p]son's head1 ?is be+ ! diff]5ce betwe5 ! weight ( ! body & ! weight ( ! same bulk ( wat]4 ,n[ ?is pressure is n suffici5t to give a sure foot+ aga9/ ev5 a mod]ate curr5t4 ,_m p]sons h be5 dr[n$ f ignorance ( ?is fact4 ,a man c>ry+ a load may (t5 =d a riv] safely :]e )\t a load to press him d[n1 & ?us give him a sure foot+1 he w\ld be c>ri$ d[n ! /ream4 ,s a man may walk 9 deep wat] ^u brok5 glass ) impunity4 ,illu/ration3 ,fig4 #ij4 #adb4 ,h[ to ,asc]ta9 ! ,specific ,gravity ( ,solids4--,x results f ! upw>d pressure ( wat] t a body weighs less 9 wat] ?an 9 air4 ,take a piece ( gold or any o!r sub/ance1 a1 ,fig4 #ij 7p4 #ajg71 & weigh x susp5d$ z y see f "o ( ! scales4 ,introduce ! gold n[ into a cup ( wat]1 & y w f9d t a "p ( ! weight mu/ be tak5 f ! opposite scale to pres]ve ! balance4 ,! weight :i* y take f ! scale w be ! weight ( a quantity ( wat] equal 9 bulk to ! piece ( gold2 = ! imm]s$ body is support$ ) a =ce equal to ! weight ( ! wat] x displaces 7 #acg74 ,by comp>+1 !re=e1 its weight 9 wat] ) its weight 9 air we det]m9e its specific gravity4 ,?us if a lump ( gold weigh n9ete5 ounces1 & on be+ weigh$ 9 wat] weighs eighte51 x w prove t gold is n9ete5 times z heavy z wat]4 ,& if a lump ( copp] weigh n9e ounces 9 air & eight 9 wat]1 x is n9e times z heavy z wat]4 ,call+ wat]1 !re=e1 #a1 ! specific gravity ( gold is #ai1 & ( copp] #i4 ,x is obvi\s t a body ( ! same specific gravity ) wat] w\ld weigh no?+ :5 imm]s$ 9 wat]1 = x w\ld be support$ ) an upw>d pressure precisely equal to its own weight1 j z ! same bulk ( wat] is4 ,a p\nd ( wat]1 !re=e1 w weigh no?+ 9 wat]4 ,! exp]im5t c easily be tri$4 ,weigh a glass bottle1 susp5d$ on "o arm ( ! scale-beam1 & !n put a p\nd ( wat] 9 x4 ,on imm]s+ x 9 wat] x w be balanc$ if y take out ! p\nd weight 9 ! opposite scale4 #adc4 ,ar*im$es & ! ,cr[n4--,hi]o1 ,k+ ( ,syracuse1 /ipulat$ = a cr[n ( pure gold4 ,b suspect+ ! mak] ( x ( adult]at+ ! gold1 he call$ ^u ,ar*im$es to detect ! impo/ure4 ,he did x 9 ?is way3 ,he procur$ two lumps ( gold & silv] ( ! same weight ) ! cr[n1 & obs]v$ ! quantity ( wat] :i* ea* displac$4 ,he !n tri$ ! cr[n1 & f\nd t x displac$ less ?an ! silv] & m ?an ! gold1 & !re=e conclud$ t x 0 an alloy ( ! two metals4 ,all ?is 0 sugge/$ to him by 8 exp]i5ce 9 ! ba?1 ref]r$ to 9 #ach4 ,illu/ration3 ,fig4 #ia #add4 ,h[ to ,asc]ta9 ! ,specific ,gravity ( ,liquids4--,!re are sev]al modes ( asc]ta9+ ! specific gravities ( diff]5t liquids4 ,! in/rum5t call$ a ,hydromet] furni%es ! mo/ common mode4 ,?is is us$ *iefly 9 det]m9+ ! quality ( _s4 ,! m alcohol & ! less wat] _s conta9s ! less is its specific gravity4 ,! ,hydromet] consi/s ( two bulbs ( glass1 ,a ,b1 ,fig4 #ia1 ) a sl5d] /em1 ,c1 :i* is graduat$4 ,9 ! l[] bulb are a few %ot or a little m]cury1 to give ! in/rum5t its prop] weight1 & to make its c5tre ( gravity to be 9 ! l[] "p4 ,! light] ! fluid to be te/$ is ! l[] w ! in/rum5t s9k 9 x4 ,?is is a v accurate in/rum5t1 detect+ ! slighte/ adult]ation 9 spirits4 ,dr4 ,arnot tells an amus+ /ory ( ! detection ( a ,*9ese trad] 9 liquors4 ,he _h sold a quantity ( liquor to ! purs] ( a %ip1 av]r+ x to be ( ! same quality ) a sample :i* he _h giv5 him4 ,! purs] tri$ x ) 8 ,hydromet]1 & f\nd x to be ( great] specific gravity ?an ! sample4 ,! ,*9ese promptly d5i$ ! fraud2 b on be+ told ! exact quantity ( wat] :i* he _h add$1 he 0 s mu* conf\nd$ t he imm$iately confess$ 8 guilt1 & made ample am5ds4 ,:5 ! ,hydromet] 0 %[n to him he (f]$ a l>ge price = :at appe>$ to him to be a magical in/rum5t1 =esee+ t x w\ld be ( great advantage to him 9 8 bus9ess4 ,9 ,switz]l& & 9 ! nor? ( ,italy1 :]e ! peasants br+ _! milk to a common dairy1 & are all[$ a quantity ( *eese at ! end ( ! season 9 proportion to ! am\nt ( milk :i* !y h br\ght1 a ,hydromet] is us$ to te/ ! quality ( ! milk4 ,!re is a propriety 9 ?is1 n only z a safe-gu>d aga9/ adult]ation1 b because !re is a diff]5ce ( quality 9 ! milk ( diff]5t c[s1 "s giv+ a mu* m wat]y milk ?an o!rs4 #ade4 ,c5tre ( ,gravity 9 ,float+ ,bodies4--,! same pr9ciples :i* apply to ! c5tre ( gravity 9 bodies /&+ on a firm basis apply also to float+ bodies4 ,t ! c5tre ( gravity may be l[ 9 a load$ vessel ! heavy "p ( ! c>go is put und]nea?1 & g5]ally balla/ ( /one or iron is necess>y = ! same purpose4 ,9 l>ge flat-boats1 ! base ( support be+ ext5sive1 !re is n ! same ne$ ( tak+ c>e t ! c5tre ( gravity be l[4 ,if a %ip be lad5 9 "p ) an article :i* w dissolve 9 wat]1 !re is mu* dang]1 if ! %ip %\ld leak1 t ?is portion ( ! c>go %all be dissolv$ & be pump$ out ) ! bilge-wat]1 ?us alt]+ ! trim ( ! vessel1 or remov+ ! c5tre ( gravity f ov] ! middle l9e1 & br++ x too f> =w>d1 or c>ry+ x too f> back1 mak+ ! %ip :olly unmanageable4 ,f\r l>ge ,engli% %ips1 9 "p load$ ) saltpetre1 7 suppos$ to be lo/ f ?is cause 9 #ahji (f ! ,isle ( ,france4 ,! imm5se ice-isl&s1 or iceb]gs1 :i* float ab\t 9 summ] 9 ! pol> regions1 by melt+ irregul>ly (t5 *ange ! place ( _! c5tre ( gravity1 & 9 turn+ ov] pres5t "o ( ! mo/ sublime spectacles 9 nature4 ,a m\nta9 ( ice1 ext5d+ high 9 ! air & deep 9 ! sea1 sudd5ly turns ov]1 & produces a roll+ ( ! ocean :i* is (t5 felt at ! di/ance ( _m leagues4 ,,*apt] ,,ix4 ,,pneumatics4 #adf4 ,:at ,pneumatics ,tea*es4--,z ,hydro/atics treats ( ! pressure & equilibrium ( liquids1 ,pneumatics treats ( ! same 9 air & ! gases1 or a]i=m sub/ances4 ,! "n comes f ! ,greek ^w 1 mean+ air1 brea?1 _s4 ,illu/ration3 ,fig4 #ib4 #adg4 ,air ,mat]ial & has ,weight4--,t air is a mat]ial sub/ance has be5 already prov$ to y1 = x 0 %[n 9 #df t x has imp5etrability1 "o ( ! ess5tial prop]ties ( matt]4 ,x has ext5sion also1 = bodies ( air c be obta9$ 9 v>i\s %apes conf9$ 9 vessels1 s t we c speak ( cubes & sph]es ( air2 & besides1 ! ultimate atoms 7 #ae7 ( air mu/ h %ape or ext5sion4 ,t air has weight c be prov$ by weigh+ x z y w\ld any o!r sub/ance4 ,let a holl[ globe1 ,a1 ,fig4 #ib1 hav+ a neck ) a /op-cock1 ,b1 be empti$ ( air & weigh$4 ,if n[ y op5 ! /op-cock1 & s let 9 ! air1 ! o!r beam ( ! scale w rise1 because ! globe is heavi] ?an x 0 be=e4 ,! additional weight requir$ to make ! scales balance w indicate ! weight ( ! air :i* ! globe conta9s4 ,x is "o eight hundr$? 7#a_/hjj7 ( ! weight ( ! same volume ( wat]4 ,h[ ! globe c be empti$ ( ! air w be %[n 9 ano!r "p ( ?is *apt]4 #adh4 ,air ,attract$ by ! ,e>?4--,! weight ( ! air is simply ! result ( ! attraction ( ! e>? 7 #eb74 ,air is attract$ by ! e>? j z wat] is2 & ! wat] takes its place bel[ air because x is attract$ m /rongly ?an ! air4 ,x is f ! attraction ( ! e>? t air desc5ds into any holl[ spot 9 ! e>? :5 wat] is remov$ f x4 ,x takes ! place ( ! remov$ wat] because f ! influ5ce ( attraction x gets z ne> to ! e>? z possible4 ,if y put into a vial m]cury1 wat]1 & oil1 ! m]cury w be at ! bottom1 because x is m /rongly attract$ by ! e>? ?an ! o!r fluids4 ,! wat] w be next1 !n ! oil1 & la/ly1 ov] all1 !re is air1 t be+ less attract$ ?an any ( ! o!r sub/ances4 ,x is ?is attraction ( ! air by ! e>? t gives u ! *ief ph5om5a ( ,pneumatics4 #adi4 ,:y ,"s ,?+s ,fall & ,o!rs ,rise 9 ,air4--,mo/ sub/ances fall 9 air = ! same reason t v heavy sub/ances s9k 9 wat]4 ,!y fall because ! e>? attracts !m m /rongly ?an x does ! air4 ,! reason t "s sub/ances rise 9 air is precisely ! same z t giv5 9 #acf = ! ris+ ( sub/ances 9 wat]4 ,! air be+ attract$ m /rongly ?an !y are pu%es !m up to get bel[ !m1 z cork or wood is pu%$ up by wat]4 ,?us a balloon fill$ ) hydrog5 gas rises 9 air = ! same reason t a bladd] fill$ ) air rises 9 wat]4 ,s1 also1 smoke rises 9 air1 j z oil rises 9 wat]4 ,illu/ration3 ,fig4 #ic4 #aej4 ,?ickness ( ! ,e>?'s ,air-,cov]+4--,! air makes a cov]+ = ! e>? ab\t fifty miles deep4 ,if ! e>? 7 repres5t$ by a globe a foot 9 diamet]1 ! air might be repres5t$ by a cov]+ a t5? ( an in* 9 ?ickness4 ,! l9e a1 ,fig4 #ic1 gives u ! curve ( ! surface ( su* a globe1 & ! space betwe5 a & b repres5ts ! comp>ative ?ickness ( ! cov]+ ( air4 ,?is is asc]ta9$ by calculation f ! pressure ( ! air ^u ! e>?4 ,x is j z ! dep? ( wat] may be calculat$ f ! pressure :i* x makes4 ,we d n take ?is mode ( asc]ta9+ ! dep? ( wat]1 because we c measure x f ! surface by s\nd+4 ,b we %\ld be oblig$ to adopt x if we liv$ at ! bottom ( wat]1 z we d at ! bottom ( ! sea ( air4 #aea4 ,h[ ! ,air-,cov]+ ,adh]es to ! ,e>?4--,! e>? flies on 9 its ye>ly j\rney ar\nd ! sun at ! rate ( #aajj miles p] m9ute1 & yet x holds on to ?is loose airy robe by its attractive =ce1 s t n an atom ( x escapes into ! surr\nd+ e!r4 ,( itself x is dispos$ to escape2 & x w\ld d s1 & be diffus$ ?r\gh space1 if ! attraction ( ! e>? = x 7 susp5d$4 ,=1 unlike liquids1 ! air has no disposition to keep toge!r2 t is1 !re is no attraction betwe5 its p>ticles4 ,on ! o!r h&1 !re is a repulsion1 s t !y are dispos$ to keep f> ap>t1 & are kept toge!r only by pressure4 ,x is ! pressure ( ! e>?'s attraction t keeps !m toge!r to ! ext5t ( fifty miles all ar\nd x4 #aeb4 ,compressibility ( ,air4--,9 look+ at ! influ5ce ( gravitation ^u air1 x mu/ be rememb]$ t air is v compressible1 :ile wat] is v ne>ly incompressible4 ,:ile1 !re=e1 9 a body ( wat] ! p>ticles are v little ne>] toge!r at ! bottom ?an at ! surface1 ! p>ticles ( ! air are mu* ne>] toge!r close to ! e>? ?an !y are f> away f x4 ,= z all ! p>ticles ( ! air are attract$ or drawn t[>d ! e>?1 ^? bel[ are press$ toge!r by ! weight ( ^? above4 ,! air is !re=e ?9n] z we g up f ! surface ( ! e>?1 & 9 ! out] regions ( ! sea ( air x is too ?9 to support life4 ,ev5 at ! tops ( v high m\nta9s1 or ! heights sometimes rea*$ by balloons1 disagreeable effects are (t5 exp]i5c$ f ! ?9ness ( ! air4 ,! air has be5 comp>$1 9 reg>d to its v>y+ d5sity at diff]5t heights1 to a heap ( loose compressible sub/ance2 z1 = example1 cotton-wool1 :i* is q light at ! top1 b is press$ m & m toge!r z y g t[>d ! bottom4 ,hydrog5 gas has only "o fifte5? ! weight ( air at ! surface ( ! e>?2 & !re=e ! hydrog5 balloon rises till x rea*es a height :]e ! air is s ?9 t ! balloon is ( ! same weight ) an equal bulk ( air1 & !re x /ops4 #aec4 ,9 :at ,a]i=m ,sub/ances & ,liquids are ,alike4--,y h se5 9 #cf & #ch h[ ! air & gases diff] f liquids4 ,b 9 "o v important respect !y are alike1 viz41 ! movability ( _! p>ticles4 ,h5ce pressure is 9 air1 z well z 9 wat]1 equal 9 all directions1 s t 9 ! exp]im5t ) ! bladd]1 9 #abf1 x makes no diff]5ce 9 ! result :e!r !re be wat] or air 9 x4 ,= ! same reason pressure is z ! dep? 9 a]i=m sub/ances z 9 liquids1 & ! laws ( specific gravity apply to ! "o z well z to ! o!r4 ,y are n[ prep>$ to und]/& ! results ( ! action ( gravitation ^u air & ! gases2 or1 9 o!r words1 ! pr9cipal ph5om5on ( ,pneumatics4 #aed4 ,pressure ( ! ,atmosph]e4--,! am\nt ( ! pressure ( ! atmosph]e is v readily e/imat$1 ! mode ( do+ :i* ,i w speak ( 9 ano!r "p ( ?is *apt]4 ,x presses ) a weight ( fifte5 p\nds on e squ>e in*4 ,suppose t y ext5d y\r outspread h& horizontally 9 ! air4 ,y feel no pressure ^u x1 b !re is a pressure ( "s two or ?ree hundr$ p\nds ( air ^u x4 ,if y\r h& be five in*es long & ?ree broad x pres5ts a surface ( fifte5 squ>e in*es1 on e "o ( :i* ! atmosph]e is press+ ) ! weight ( fifte5 p\nds4 ,t is1 !re is a pressure on ! upp] surface ( y\r h& ( a column ( air weigh+ #bbe p\nds4 ,s1 also1 on ! lid ( a box only ?irty in*es squ>e1 !re is a pressure ( #ac1ejj p\nds4 ,! :ole pressure on ! body ( a man ( common size is ab\t fifte5 tons4 ,b :y is x t ! lid ( ! box is n brok5 91 y\r h& n borne d[n1 & y\r body n cru%$8 ,x is simply f ! fact1 %[n 9 ! previ\s *apt] 9 reg>d to liquids1 & 9 ?is 9 reg>d to a]i=m sub/ances1 t ! pressure is equal 9 all directions4 ,! lid & ! outspread h& are !re=e balanc$ by an upw>d pressure equal to ! d[nw>d1 & ! body has ! pressure on all sides ! same4 ,if ! air c\ld be remov$ f )9 ! box ! lid w\ld be cru%$ 92 if f "u ! h&1 t w\ld be borne d[n2 & if f "o side ( ! body1 ! body w\ld be =c$ viol5tly 9 t direction till x met ) an oppos+ pressure4 ,b besides ?is equal pressure ( ! air on all sides1 !re is air )9 ! pores & int]/ices ( all bodies t are n v d5se1 & its p>ticles are subject to ! same laws z are ^? on ! outside4 ,all ?is c be made cle> to y by ! air-pump4 ,illu/ration3 ,fig4 #id4 #aee4 ,air-pump4--,9 ,fig4 #id y h a repres5tation ( an air-pump z commonly arrang$4 ,at a a are two pump-b>rels1 ! pi/ons 9 :i* are work$ by means ( ! h&le1 b4 ,^? pumps are v nicely made1 & ! frame-"w1 d e d e1 to :i* !y are atta*$1 is v /rong & firm1 s t ! pumps may "w ev5ly4 ,!re is a l>ge1 smoo?1 metallic plate1 f4 ,at c is a bell-%ap$ glass vessel1 close at ! top1 b op5 at ! bottom1 ! edge ( :i* is gr\nd v true1 s t x may fit exactly on ! metallic plate4 ,9 ! middle ( ! plate is an op5+ :i* leads to ! pump-b>rels1 & x is ?r\gh ?is t ! air is pump$ out ( ! glass receiv]1 c4 ,if we wi% to let ! air 9 aft] we h pump$ x out we loos5 ! screw at g1 = f ! op5+ "h is a passage to ! op5+ 9 ! middle ( ! plate4 ,illu/ration3 ,fig4 #ie4 ,! op]ation ( ! air-pump c be made cle> by ! plan 9 ,fig4 #ie4 ,b "o pump-b>rel1 a1 is repres5t$1 ) a pi/on1 c1 work+ 9 x4 ,9 ! pi/on !re is a valve1 i1 op5+ upw>d1 & also "o at b1 9 ! beg9n+ ( ! passage lead+ to ! c5tre ( ! plate :]e is ! receiv]1 d4 ,! work+ ( ! in/rum5t is ?us3 ,if ! pi/on be =c$ d[n1 ! air "u x1 be+ compress$1 w close ! valve at b1 & w ru% upw>d ?r\gh ! valve i 9 ! pi/on4 ,let ! pi/on n[ be rais$2 ! resi/ance ( ! air above x w close ! valve i1 :ile ! valve b w be op5$ by ! air ru%+ f ! receiv]1 d1 ?r\gh ! passage1 e1 to fill ! space betwe5 ! pi/on & b4 ,y see1 !n1 t e "t t ! pi/on is drawn up air passes out ( ! receiv] ?r\gh ! valve b into ! space betwe5 ?is valve & ! pi/on4 ,none ( ?is air :i* has pass$ out c g back aga91 = ! mom5t t y press ^u x by =c+ d[nw>d ! pi/on ! valve b is %ut d[n1 & ! air escapes f ! pressure by pass+ out ?r\gh ! valve i4 ,ea* "t1 !re=e1 t y "w ! pi/on up & d[n y pump out "s ( ! air f ! receiv]2 & if y pump = "s "t !re w be exce$+ly little air left 9 x1 & t w ( c\rse be diffus$ ?r\gh\t ! receiv]4 ,x w be ?91 l t 9 ! upp] regions ( ! atmosph]e4 ,illu/ration3 ,fig4 #if4 ,fig4 #ig4 ,illu/ration3 ,fig4 #ih4 #aef4 ,exp]im5ts4--,:5 ! receiv] is full ( air x c be mov$ ab\t on ! plate easily1 & c be lift$ f x4 ,b "w ! pumps a few /rokes & y w f9d t ! receiv] is firmly fa/5$ to ! plate1 = ! air )91 be+ made ?91 presses ) little =ce comp>$ ) ! air outside4 ,if ! pumps be work$ = "s "t no =ce c\ld release ! receiv] f ! pressure )\t break+ x4 ,b loos5 ! screw1 g1 & ?us let ! air 91 & ! equality ( ! pressure on ! outside & inside is at once re/or$4 ,take (f n[ ?is l>ge receiv]1 & place a small glass j>1 op5 at bo? ends1 on ! plate1 ) ! h& cov]+ ! upp] op5+1 z repres5t$ 9 ,fig4 #if4 ,on exhau/+ ! air ! h& is s firmly press$ into ! glass t x requires consid]able =ce to dis5gage x f ! pressure4 ,if we tie a piece ( bladd] or ,india rubb] ov] ?is j>1 z 9 ,fig4 #ig1 & !n pump out ! air1 ! bladd] at fir/ is press$ 9 z repres5t$1 & if we pump on x at l5g? bur/s ) a l\d report4 ,x w\ld make no diff]5ce 9 ! result ( ! exp]im5t if ! j> 7 %ap$ z 9 ,fig4 #ih1 = ! pressure is ! same 9 all directions4 ,! resemblance betwe5 air & liquids 9 ?is respect may be illu/rat$ ?us3 ,suppose t a flat fi% cov]s ) "o ( its sides ! end ( ! tube ( a pump4 ,he feels no uncom=table pressure1 because ! wat] 9 ! pump & t bel[ x press equally ^u him4 ,if1 n[1 ! pressure ( ! wat] 9 ! pump c\ld be sudd5ly tak5 (f by ! pi/on1 ! fi% w\ld be press$ upw>d into ! tube1 z ! bladd] is press$ upw>d 9 ,fig4 #ih1 or d[nw>d 9 ,fig4 #ig1 or z ! h& is press$ d[nw>d 9 ,fig4 #if4 ,! ,magdeburg ,hemisph]es1 ,fig4 #ii1 illu/rate v impressively ! pressure ( ! atmosph]e4 ,!y consi/ ( two hemisph]es ^: edges at ,a fit v accurately ^u ea* o!r4 ,! air is exhau/$ ?r\gh ! /em :]e y see ! /op-cock1 & !n ! h&le ,b is screw$ on4 ,! =ce requir$ to pull ^! hemisph]es ap>t dep5ds ^u ! ext5t ( _! surface4 ,9 ! fam\s exp]im5t at ,magdeburg1 9 #afed1 by ,otto von ,gu]icke1 ! inv5tor ( ! air-pump1 two /rong hemisph]es ( brass ( a foot 9 diamet] 7 employ$1 & x requir$ ! =ce ( ?irty horses to sep>ate !m4 ,9 ,fig4 #ajj y see a receiv] ) an op5+ at ! top4 ,cem5t$ 9 ?is op5+ is a wood5 cup1 a1 t]m9at+ 9 a cyl9drical piece1 b4 ,if m]cury be p\r$ into ! cup1 on exhau/+ ! air f ! receiv] ! m]cury w be =c$ ?r\gh ! pores ( ! wood by ! ext]nal air1 & w fall 9 a silv] %[]4 ,a tall j>1 c1 is plac$ !re to receive x1 to prev5t any ( x f go+ d[n into ! op5+ 9 ! metallic plate4 ,illu/ration3 ,fig4 #ii4 ,illu/ration3 ,fig4 #ajj4 ,illu/ration3 ,fig4 #aja4 #aeg4 ,! ,suck]4--,! boy's suck] illu/rates ! pressure ( ! air4 ,x is simply a circul> piece ( lea!r ) a /r+ fa/5$ to its c5tre1 z se5 9 ,fig4 #aja4 ,:5 ! lea!r is moi/5$ & press$ ^u a smoo? /one1 on pull+ ! /r+ a vacuum is made betwe5 ! middle ( ! lea!r & ! /one1 & ! lea!r adh]es by its edges to ! /one1 j z ! receiv] adh]es to ! plate ( ! air-pump :5 ! air is pump$ out4 ,!re are _m animals t h contrivances ( a simil> "*4 ,! gecko & ! cuttle-fi% furni% int]e/+ examples1 z notic$ 9 my ,natural ,hi/ory1 pages #aih & #cbj4 ,snails1 limpets1 etc41 adh]e to rocks by a l arrangem5t4 ,"s fi%es d ! same4 ,!re is "o fi% call$ ! remora1 t atta*es itself by suck]s to ! side ( "s l>ge fi% or a %ip1 & ?us enjoys a f9e ride ?r\gh ! wat]1 )\t any ex]tion on 8 "p4 ,9 all su* cases x is wat] in/ead ( air t makes ! pressure1 b ! pr9ciple is ! same4 ,flies & "s o!r insects c walk up a smoo? pane ( glass1 or along ! ceil+ ov]-head1 because _! feet h contrivances ak9 to ! boy's suck]4 ,! h9d-feet ( ! walrus are con/ruct$ some:at l ! feet ( ! fly1 enabl+ ?is huge animal to g up smoo? walls ( ice4 ,illu/ration3 ,fig4 #ajb ,illu/ration3 ,fig4 #ajc4 ,illu/ration3 ,fig4 #ajd4 #aeh4 ,d5sity ( ! ,air ,dep5d5t ^u ,pressure4--,! fact t ! degree ( ! d5sity ( ! air is dep5d5t on pressure has be5 already %[n 9 #aeb4 ,! same ?+ c be %[n 9 v>i\s ways ) ! air-pump4 ,if a small bladd]1 p>tly fill$ ) air1 ,fig4 #ajb1 & load$ ) a weight s z to s9k 9 wat]1 be plac$ 9 a j> ( wat]1 & ! :ole be set "u ! receiv] ( ! air-pump1 on exhau/+ ! air ! bladd] w swell out ) ! exp&$ air 9 x1 & w rise z se5 9 ! figure4 ,! reason is1 t ! pressure be+ tak5 (f ! surface ( ! wat]1 ! bladd] be>s only ! pressure ( ! wat]1 & n t ( ! air ) ! wat]1 & s ! air 9 x exp&s & becomes less d5se4 ,if an ,india-rubb] bag be p>tly fill$ ) air1 ,fig4 #ajc 7p4 #aai71 & put "u ! receiv]1 on exhau/+ ! air1 ! surr\nd+ pressure be+ ?us tak5 (f f ! bag1 ! air 9 x becomes exp&$1 t is1 r>efi$4 ,= ! same reason1 if a vessel ) soap-bubbles 9 x be plac$ "u ! receiv]1 on pump+ out ! air ! bubbles w become mu* enl>g$4 ,a v pretty exp]im5t illu/rat+ ! same ?+ may be tri$ 9 ?is way4 ,let an egg ) a hole made 9 its small end be susp5d$ 9 a receiv]1 z repres5t$ 9 ,fig4 #ajd1 a w9e-glass be+ b5ea? x4 ,on exhau/+ ! air ! egg w all run out ( ! %ell into ! w9e-glass1 & !n1 on admitt+ ! air1 x w run back aga9 into ! %ell4 ,! explanation is ?is3 ,!re is air 9 ! l>ge end ( ! egg4 ,z soon z ! pressure ( air is tak5 (f f all ab\t ! egg ! air 9 ! egg exp&s1 =c+ out ! cont5ts2 b :5 ! air is admitt$ into ! receiv] ! air 9 ! egg is at once cond5s$ into its =m] small bulk by ! surr\nd+ pressure4 ,illu/ration3 ,fig4 #aje4 ,illu/ration3 ,fig4 #ajf4 #aei4 ,hydro/atic ,balloon4--,! philosophical toy repres5t$ 9 ,fig4 #aje illu/rates v beautifully ! influ5ce ( pressure ^u ! d5sity ( ! air4 ,! balloon 9 ! j> ( wat] is ( glass1 ) a small orifice at its l[] "p4 ,c>e mu/ be tak5 9 putt+ wat] 9 ! balloon to h j en\gh to make x ( a little less specific gravity ?an wat]4 ,9 t case x w be at ! top ( ! j>1 ) a v little ( its top above ! surface ( ! wat]4 ,n[ tie a piece ( ,india-rubb] clo? ov] ! top ( ! j>1 & ! app>atus is complete4 ,on press+ ^u ! ,india rubb] ! balloon w g d[n 9 ! j>1 & on tak+ (f ! pressure x w rise4 ,! explanation is ?is3 ,! pressure ^u ! ,india rubb] is felt ?r\gh ! :ole body ( ! wat] 9 ! j>1 & =ces a little m wat] into ! orifice ( ! balloon1 cond5s+ ! air t is !re4 ,! balloon consequ5tly becomes heavi]1 & has a great] specific gravity ?an wat]1 & s9ks 9 x4 ,b :5 ! pressure is tak5 (f1 ! cond5s$ air 9 ! balloon1 by its ela/icity1 returns to its =m] bulk1 expell+ ! surplus wat] j introduc$1 & ! balloon1 becom+ !re=e z light z be=e1 rises4 ,grotesque figures ( glass may be manag$ 9 ! same way4 ,! ,c>tesian image1 ,fig4 #ajf1 is an example4 ,?is has air 9 its upp] "p1 a1 & wat] up to c d4 ,:5 pressure is made on ! ,india rubb] m wat] is =c$ into ! image ?r\gh ! tail1 b1 & x goes d[n l ! balloon1 to rise aga9 :5 ! pressure is tak5 (f4 ,illu/ration3 ,fig4 #ajg4 ,illu/ration3 ,fig4 #ajh4 #afj4 ,air 9 ,sub/ances4--,i h said t !re is air 9 ! pores & int]/ices ( wood1 fle%1 & a great v>iety ( sub/ances4 ,9 all ^! cases ! pres5ce ( ! air c be made manife/ by tak+ (f ! pressure ( ! surr\nd+ air1 & ?us all[+ ! air 9 ^! sub/ances to exp&4 ,if an egg be plac$ 9 a j> ( wat]1 ,fig4 #ajg1 "u ! receiv] ( an air-pump1 on exhau/ion be+ made air-bubbles w con/antly rise 9 ! wat] f ! egg4 ,s1 too1 a glass ( port]1 ,fig4 #ajh1 w h its surface cov]$ ) foam1 ! c>bonic acid gas 9 x escap+ freely :5 ! pressure ( ! air ^u x is tak5 (f4 ,! same ?+ may be se5 to "s ext5t ev5 9 wat]1 = x always conta9s "s air4 ,= ! same reason a %rivel$ apple1 ) ! pressure ( ! air tak5 f x1 w become plump & fair1 b w %r9k at once to its %rivel$ /ate :5 ! air is admitt$ into ! receiv]4 #afa4 ,ela/icity ( ! ,air4--,all ! ph5om5a cit$ 9 #aeh1 #aei1 & #afj exhibit ! ela/icity ( ! air4 ,x is f ?is prop]ty t x is always dispos$ to exp&4 ,x w d s :5ev] pressure is tak5 f x1 or :5 x c ov]come pressure to :i* x is subject$4 ,?is prop]ty is mo/ /rik+ly exhibit$ :5 ! air is mu* cond5s$ by pressure4 ,& ! great] ! cond5sation ! /rong] is ! expansive or ela/ic =ce4 ,illu/ration3 ,fig4 #aji4 #afb4 ,! ,cond5s]4--,9 ,fig4 #aji y h ! plan ( an in/rum5t call$ ! ,cond5s]4 ,9 ,a ,b1 a cyl9d]1 moves ! pi/on1 ,p4 ,air is admitt$ to ! cyl9d] at ,f1 & into ! receiv]1 ,v1 at ,g4 ,! valve at ,f prev5ts any air f escap+ f ! cyl9d]1 & ! valve at ,g prev5ts x f escap+ f ! receiv]4 ,! op]ation ( ! in/rum5t is ?is3 ,if ! pi/on be press$ d[nw>d1 ! press$ air 9 ! cyl9d] %uts ! valve ,f & op5s ,g1 & s ent]s ! receiv] ,v4 ,if n[ ! pi/on be rais$1 air ru%es 9 at ,f to fill ! space 9 ! cyl9d]4 ,x c n come f ,v1 because ! valve ,g is %ut by its pressure4 ,by work+ ! pi/on = "s "t y c get a body ( air into ,v ( v great d5sity4 ,y see t ?is in/rum5t is ! v opposite ( ! air-pump4 ,9 ! receiv]1 ,v1 y h cond5s$ air1 :ile 9 ! receiv] ( ! air-pump y h r>efi$ air4 ,if y comp>e ! two in/rum5ts y w see t ! opposite results are ow+ to diff]5t arrangem5t ( ! valves4 ,illu/ration3 ,fig4 #aaj4 #afc4 ,! ,gasomet]4--,gas is di/ribut$ 9 pipes f ! gasomet] at ! gas factory by ! ag5cy ( ! ela/icity occasion$ by cond5sation "u pressure4 ,! app>atus1 ,fig4 #aaj 7p4 #abb71 consi/s ( a l>ge r\nd vessel1 ,g1 op5 bel[1 & sunk 9 a l>g] vessel ( wat]1 w4 ,we w suppose ! vessel1 ,g1 to be full ( wat]4 ,gas is introduc$ into x ?r\gh ! pipe1 p r1 ! gasomet] ris+ z x fills ) ! gas4 ,p is a weight balanc+ ! gasomet]1 & s p]mitt+ x to rise z ! gas ent]s4 ,! gasomet] be+ fill$1 ! gas is to be di/ribut$4 ,= ?is purpose weights are put ^u ! gasomet]1 s t ! gas may be compress$4 ,"u ?is pressure x by its ela/icity seeks = m room1 & obta9s x by escap+ ?r\gh ! pipe o b c4 ,z ! pressure on ! gas ne$s to be regulat$1 !re is sometimes a gauge1 h i1 atta*$1 :i* %[s ! am\nt ( ! pressure4 ,x is a b5t tube ) wat] 9 ! b5d4 ,y see at once t ! great] ! pressure ^u ! gas ! high] w ! wat] be 9 ! bran*1 h1 ( ! gauge4 ,illu/ration3 ,fig4 #aaa4 #afd4 ,air-,guns & ,pop-,guns4--,^! illu/rate ! ela/icity ( cond5s$ air4 ,! air-gun is con/ruct$ 9 ?is way3 ,a receiv]1 l ,v1 ,fig4 #aji1 is made s t y c screw x on & (f f ! in/rum5t4 ,aft] be+ *>g$ ) cond5s$ air x is screw$ ^u ! gun1 its /em communicat+ ) ! b>rel4 ,9 ord] to dis*>ge ! gun !re is a contrivance connect$ ) ! trigg] = rais+ ! valve1 ,g1 s t "s ( ! cond5s$ air may ent] ! b>rel4 ,on do+ s1 x by its sudd5 expansion rapidly =ces out ! cont5ts4 ,! pr9ciple on :i* ! common pop-gun op]ates is ! same4 ,!re is air conf9$ betwe5 ! two corks1 a & b1 ,fig4 #aaa 7p4 #abc74 ,z ! rod1 ,r1 is pu%$ quickly 91 ! cork b is c>ri$ ne>] to a1 s t ! air betwe5 !m is cond5s$4 ,) ! cond5sation ! expansive =ce is increas$2 & :5 x becomes s great t ! cork a c no long] resi/ x1 x ?r[s ! cork out1 & s quickly z to occasion ! popp+ s\nd4 #afe4 ,p[d] & ,/eam4--,! explosion ( p[d] furni%es a good illu/ration ( ! expansive =ce ( cond5s$ air or gases4 ,^! gases are produc$ s sudd5ly f ! p[d] t at ! in/ant !y are 9 a v cond5s$ /ate1 & !re=e exp& p[]fully4 ,s1 also1 /eam has p[] 9 proportion to its cond5sation4 ,:5 =m$ "u ! conf9em5t ( a boil]1 on be+ all[$ to escape x exp&s ) great =ce4 ,! application ( ! expansive p[] ( /eam w be treat$ ( p>ticul>ly 9 ano!r "p ( ?is book4 ,illu/ration3 ,fig4 #aab4 #aff4 ,ret>dation by ,cond5s$ ,air 9 ,gunn]y4--,:5 a ball is fir$ x is con/antly ret>d$ 9 its flight by ! resi/ance ( ! air1 = x has to pu% ! air away on e side 9 ord] to make its way ?r\gh x4 ,( c\rse1 !n1 ! m cond5s$ ! air is ! great] is ! resi/ance4 ,n[ x is cond5s$ air t ! ball is oblig$ to remove2 = z x goes =w>d x1 by its rapid pressure1 cond5ses ! air directly be=e x4 ,& ! m rapid is its flight ! great] is ! cond5sation1 & !re=e ! great] ! resi/ance4 ,besides1 ! ret>d+ effect is increas$ by ! t5d5cy to a vacuum beh9d ! ball4 ,all ?is c be made cle> by ,fig4 #aab4 ,let ,b be a ball go+ v rapidly 9 ! direction indicat$ by ! arr[1 ! cl\d repres5t+ ! cond5s$ air be=e x1 & ! space includ$ 9 ! two l9es ! vacuum beh9d x4 ,x is obvi\s t ! m rapidly ! ball goes ! less readily is ! air press$ out ( ! way1 & !re=e ! m x is cond5s$ 9 front ( ! ball4 ,at ! same "t ! m rapid is ! ball ! less readily does ! air close up beh9d x1 & !re=e ! great] is ! t5d5cy to a vacuum !re4 ,= ^! reasons !re is m ret>d+ influ5ce ex]t$ by ! air ^u a ball 9 ! fir/ "p ( its c\rse ?an 9 its latt] "p4 ,illu/ration3 ,fig4 #aac4 ,illu/ration3 ,fig4 #aad4 ,illu/ration3 ,fig4 #aae4 #afg4 ,pressure ( ! ,air on ,liquids4--,if y plunge a tumbl] into a vessel ( wat]1 & turn+ x ov] hold x s t its op5 "p is j "u ! surface1 x w rema9 full4 ,! reason is t ! weight ( ! air press+ ^u ! surface ( ! wat] 9 ! vessel prev5ts ! wat] 9 ! tumbl] f pass+ d[nw>d4 ,n[ if y introduce a b5t tube "u ! tumbl]1 z 9 ,fig4 #aac1 & bl[ ?r\gh x1 ! air t y =ce up into ! tumbl] presses ! wat] d[n1 tak+ its place4 ,t is1 ! pressure ( ! air acts 9 opposition to ! pressure ( ! air outside ^u ! surface ( ! wat] 9 ! vessel4 ,y take a j>1 a1 ,fig4 #aad1 & fill+ x ) wat]1 turn x ov] ) its op5 end d[nw>d1 ! wat] w rema9 9 ! j>4 ,y h "h a repres5tation ( ! pneumatic tr\gh us$ by ! *emi/ 9 collect+ gases4 ,to fill ! j> a ) gas he puts ! m\? ( ! retort f :i* ! gas issues "u ! j> a1 & ! gas pass+ upw>d expels ! wat]1 z ! wat] is expell$ by ! brea? f ! tumbl] 9 ,fig4 #aac4 ,9 ,fig4 #aae 7p4 #abe7 is repres5t$ an exp]im5t :i* %[s n only t ! pressure ( ! air su/a9s ! column ( wat] 9 ! cases cit$ above1 b also t x makes no diff]5ce 9 :at direction ?is pressure is ex]t$4 ,take a l>ge tube1 a1 clos$ at "o end & op5 at ! o!r1 & fill x ev5 full ) wat]4 ,place1 n[1 a piece ( writ+-pap] ov] its m\?1 & c>efully inv]t ! tube1 z se5 9 ! figure4 ,! pap] w rema91 & ! wat] w n run out4 ,x is ! pressure ( ! air t su/a9s ! wat]1 & ! pap] only s]ves to ma9ta9 ! surface ( ! wat] unbrok54 ,if ! pap] 7 n !re ! p>ticles ( ! air w\ld ins9uate !mselves among ^? ( ! wat]1 & pass upw>d 9 ! tube4 ,y c try ?is exp]im5t ) a w9e-glass1 & may ev5 succe$ ) a tumbl]4 ,we see 9 ^! exp]im5ts ! reason t a liquid w n run f a b>rel :5 x is tapp$1 if !re be no v5t-hole above1 unless !re be s l>ge an op5+ made z to let ! air "w its way 9 bubbles among portions ( ! liquid4 ,x is ?is entrance ( ! air t causes ! gurgl+ s\nd 9 p\r+ a liquid f a bottle4 #afh4 ,am\nt ( ,atmosph]ic ,pressure4--,if1 in/ead ( ! j> a1 9 ,fig4 #aad1 y h a tube ?irty-f\r feet high1 & clos$ at ! top1 situat$ z ! j> a is1 x w rema9 full ( wat]4 ,if ! tube be long] ! wat] w /& only at ?irty-f\r feet1 leav+ a vacuum above x4 ,x makes no diff]5ce :at ! size ( ! tube is2 ! result w be ! same 9 all cases4#b ,t is1 a column ( wat] ?irty-f\r feet high c be su/a9$ by ! pressure ( ! atmosph]e4 ,x is easy1 !re=e1 to e/imate ! weight or pressure ( ! air4 ,! pressure ( ! column ( wat] is f\nd to be fifte5 p\nds to ! squ>e in* ( its base1 & ?is1 ( c\rse1 is ! am\nt ( pressure or weight ( ! atmosph]e :i* x balances4 ,m]cury is ?irte5 & a half times z heavy z wat]1 & !re=e ! air w su/a9 a column ( x only ab\t ?irty in*es 9 height4 ,illu/ration3 ,fig #aaf4 #afi4 ,b>omet]4--,! weight ( ! atmosph]e v>ies to "s ext5t at diff]5t times1 & ! b>omet] is an in/rum5t = measur+ ^! v>iations4 ,x is con/ruct$ on ! pr9ciples develop$ 9 ! previ\s p>agraphs4 ,9 ,fig4 #aaf is a repres5tation ( ! in/rum5t4 ,a ,b is a glass tube ab\t #cd or #ce in*es long1 clos$ at "o end4 ,x has be5 fill$ ) m]cury1 & !n inv]t$ 9 a cup ( ! same liquid1 ,c4 ,! vacuum above ! m]cury is call$ ! ,torricellian vacuum1 f ,torricelli1 an ,italian1 :o fir/ develop$ ! pr9ciples ( ! in/rum5t4 ,! m]cury g5]ally1 z /at$ 9 #afh1 /&s at ab\t ! height ( ?irty in*es4 ,b x v>ies f ?is ) ! wea!r4 ,:5 ! wea!r is bright & cle> ! air is heavi] ?an ?is1 &1 press+ ^u ! m]cury 9 ! vessel1 =ces x up high] 9 ! tube4 ,b :5 a /orm is com+ ! air is apt to be light]1 & !re=e press+ less /rongly on ! m]cury 9 ! vessel1 ! m]cury 9 ! tube falls4 ,! b>omet] is ( great s]vice1 especially at sea1 9 af=d+ ! sailor w>n+ ( an approa*+ /orm4 ,an incid5t is relat$ by ,dr4 ,arnot :i* /rik+ly illu/rates its value 9 ?is respect4 ,he 0 at sea 9 a ,s\!rn latitude4 ,z ! sun set aft] a beautiful aft]noon ! capta9 =esaw dang]1 al?\gh ! wea!r 0 p]fectly calm1 = ! m]cury 9 ! b>omet] _h sudd5ly fall5 to a rem>kable degree4 ,he gave hurri$ ord]s to ! wond]+ sailors to prep>e ! %ip = a /orm4 ,sc>cely _h ! prep>ations be5 made :5 a trem5d\s hurricane bur/ ^u ! %ip1 te>+ ! furl$ sails to tatt]s1 & disabl+ ! ma/s & y>ds4 ,if ! b>omet] _h n be5 obs]v$ ! %ip w\ld h be5 :olly unprep>$1 & %ipwreck1 ) ! loss ( all on bo>d1 w\ld h be5 ! result4 ,a wat]-b>omet] c\ld be made1 b x w\ld be an unwieldy ?+1 = ! tube mu/ be ov] #cd feet long4 ,besides1 x w\ld n answ] 9 v cold wea!r1 z ! wat] w\ld freeze4 ,s %ort a column ( ! heavy fluid1 m]cury1 balances ! weight ( ! atmosph]e t a b>omet] made ) ?is is ( v conv5i5t size2 & !n !re is no dang] ( ! m]cury's freez+1 except 9 ! extreme cold ( ! ,arctic regions4 #agj4 ,b>omet] a ,measur] ( ,heights4--,! atmosph]e1 z /at$ 9 #aeb1 dim9i%es regul>ly 9 d5sity z we g upw>d4 ,! rate ( ?is dim9ution has be5 accurately asc]ta9$1 & !re=e we c e/imate heights by ! am\nt ( pressure on ! m]cury 9 ! b>omet]4 ,at a height ( #ejj feet ! b>omet] w be half an in* l[] ?an 9 ! valley bel[4 ,at ! summit ( ,mont ,blanc x /&s b half z high z at its foot1 indicat+ a height ( #ae1jjj feet4 ,du ,luc1 9 8 fam\s balloon asc5sion f ,p>is1 saw ! b>omet] at "o "t /&+ at ab\t twelve in*es1 %[+ an elevation ( #ba1jjj feet4 #aga4 ,relation ( ! ,air's ,pressure to ! ,boil+ ,po9t4--,wat] heat$ to #bab degrees ( ,fahr5heit boils1 t is1 x becomes vapor4 ,n[ if wat] be heat$ on ! summit ( a high m\nta9 x boils be=e x arrives at ?is degree ( temp]ature4 ,on ! top ( ,mont ,blanc x boils at #ahj degrees1 t is1 #cb degrees bel[ ! boil+ po9t ( wat] at ! foot ( ! m\nta94 ,?is is because ! pressure ( ! air acts 9 opposition to ! *ange ( wat] 9 to vapor1 & ! less ! pressure is ! less heat w be requir$ to vaporize ! wat]4 ,we may illu/rate ?is influ5ce ( ! pressure ( air ^u boil+ by ! foll[+ exp]im5t4 ,let a cup ( e!r 7:i* boils at #ih degrees7 be plac$ "u ! receiv] ( an air-pump4 ,on r>efy+ ! air by ! pump ! e!r w boil4 ,! g5]al effect ( pressure ^u boil+ may be prettily illu/rat$ by ano!r exp]im5t4 ,boil "s wat] 9 a ?9 flask ov] a _s-lamp4 ,bl[ out ! lamp1 &1 cork+ ! flask tightly1 let ! boil+ cease4 ,if1 n[1 y p\r "s cold wat] ov] ! flask ! boil+ w comm5ce aga9 ) consid]able =ce4 ,:y8 ,because y cond5se ! /eam :i* is ov] ! wat] by ! application ( cold1 & ?us take (f ! pressure4 ,!n1 aga91 if1 :ile ! wat] is boil+1 y p\r hot wat] ov] ! flask1 ! boil+ ceases1 because ! heat favors ! accumulation ( /eam1 & !re=e r5ews ! pressure on ! surface ( ! wat]4 ,y c see f :at has be5 /at$ t mo/ liquids h ! liquid =m because ( ! pressure ( ! atmosph]e ^u !m4 ,if !re 7 no atmosph]e1 e!r1 alcohol1 ! volatile oils1 & ev5 wat]1 w\ld fly (f 9 vapor2 & ! e>? w\ld be envelop$ 9 a vapor\s robe1 = ! p>ticles ( ! vapors w\ld be held to ! e>? by attraction1 j z ! p>ticles ( ! air are n[1 #aea4 ,illu/ration3 ,fig4 #aag4 #agb4 ,syphon4--,! pressure ( air ^u fluids is beautifully exemplifi$ 9 ! op]ation ( ! syphon4 ,?is in/rum5t is simply a b5t tube hav+ "o bran* long] ?an ! o!r4 ,its op]ation is %[n 9 ,fig4 #aag4 ,! tube hav+ be5 fir/ fill$ ) ! liquid1 has its %ort] bran* 9 ! liquid ( ! vessel ,a1 :i* is to be empti$1 & ! o!r 9 ! vessel ,b1 :i* is to receive ! liquid4 ,z y see x "h1 ! op5+ ( ! long bran* is bel[ ! surface ( ! liquid 9 ,b4 ,x is manife/1 !re=e1 t ! air presses equally ^u ! surfaces 9 bo? vessels1 t5d+ to support ! fluid 9 ! tube1 j z ! fluid is support$ 9 ! j> 9 ,fig4 #aad4 ,b1 not)/&+ ^! equal pressures1 ! liquid runs up ! tube f ,a1 & d[n its long] bran* into ,b4 ,:y is ?is8 ,z ! pressure ( a column ( fluid is z its height1 !re is great] pressure or weight 9 ! long] bran* ?an 9 ! o!r2 & x is ?is diff]5ce 9 weight t causes ! fl[ f ,a into ,b ?r\gh ! syphon4 ,! diff]5ce 9 ! columns 9 ! two bran*es is n ! diff]5ce 9 l5g? ( ^! bran*es1 b ! di/ance betwe5 ! levels ( ! fluid 9 ,a & ,b1 t is1 ! di/ance f a to b4 ,! op]ation1 !n1 ( ! in/rum5t is ?is4 ,!re is a con/ant t5d5cy to a vacuum at ,c1 ! b5d ( ! tube1 f ! influ5ce ( gravitation on ! excess ( fluid 9 ! long bran* ov] t 9 ! %ort "o4 ,?is t5d5cy is con/antly c\nt]act$ by ! rise ( fluid 9 ! %ort bran*1 x be+ =c$ up by ! pressure ( ! air ^u ! surface ( ! fluid 9 ,a4 ,illu/ration3 ,fig4 #aah4 ,if ! syphon 7 s plac$ t ! surface ( ! liquid 9 ,a is precisely on a level ) t 9 ,b1 z repres5t$ 9 ,fig4 #aah1 ! liquid w\ld rema9 at re/1 = z pressure is z ! height1 #aba1 & ! pressures on ! two surfaces are equal1 !re w\ld be an exact balance4 ,b let ! surface 9 ,b be 9 ! lea/ l[] ?an 9 ,a & ! fl[ w beg94 ,& ! great] ! di/ance betwe5 ! two levels ! m rapid w be ! fl[1 = ! great] w be ! influ5ce ( gravitation 9 ! long bran*4 ,illu/ration3 ,fig4 #aai4 ,aga91 if ! end ( ! long bran* ( ! syphon be free1 z 9 ,fig4 #aai 7p4 #acj71 ! syphon w op]ate 9 ! same way1 = ! air1 press+ 9 all directions equally1 t5ds to support ! column ( fluid 9 ! long bran* by a direct upw>d pressure1 b is prev5t$ f do+ s by ! excess ( fluid 9 x above :at is 9 ! %ort] "o4 ,! op]ation ( ! syphon is commonly repres5t$ 9 ?is way2 b ,i h giv5 fir/ ! arrangem5t 9 ,fig4 #aag1 9 ord] t y might m cle>ly see ! pr9ciple ( ! in/rum5t4 ,illu/ration3 ,fig4 #abj4 #agc4 ,uses ( ! ,syphon4--,! syphon is us$ *iefly = dis*>g+ liquids f "o b>rel or vessel into ano!r4 ,= conv5i5ce1 x is (t5 con/ruct$ aft] ! plan ( ,fig4 #abj4 ,to ! long bran*1 ,b ,c1 is atta*$ ! tube ,,ed4 ,x is us$ 9 ?is way3 ,! end ( ! %ort bran*1 ,a1 be+ introduc$ into ! liquid to be drawn (f1 y place y\r f+] ^u ,c1 & aft] fill+ ! syphon by suction at ,e1 y remove ! f+] & let ! liquid run4 ,! syphon has sometimes be5 us$ to dra9 pits & m9es4 ,x ( c\rse c nev] be us$ :]e ! elevation ov] :i* ! tube is to b5d is ov] #cd feet f ! surface ( ! wat] to be dis*>g$1 = !n ! air w\ld n press ! wat] up to ! b5d ( ! syphon4 ,illu/ration3 ,fig4 #aba4 #agd4 ,cup ( ,tantalus4--,?is cup1 ,fig4 #aba1 has a syphon 9 x1 ! %ort bran*1 b1 op5+ into ! cup1 & ! long bran*1 d1 hav+ its outlet 9 ! bottom4 ,z y p\r wat] into ! cup x w rema9 !re until y p\r en\gh 9 to cov] ! b5d ( ! syphon4 ,z soon z ?is is done1 ! syphon be+ fill$1 ! wat] sudd5ly fl[s out f ! outlet1 a1 ( ! long bran*4 ,illu/ration3 ,fig4 #abb4 #age4 ,int]mitt+ ,spr+s4--,! op]ation ( an int]mitt+ spr+ is ess5tially ! same ) t ( ! cup ( ,tantalus4 ,y h a repres5tation ( su* a spr+ 9 ,fig4 #abb4 ,!re is a cavity 9 a hill1 suppli$ ) wat] f a passage above4 ,!re is also a passage f x :i* takes a b5d upw>d l a syphon4 ,n[ :5 ! wat] 9 ! cavity is l[ x w n run out f ! syphon-l *annel2 b :5 ! cavity becomes fill$ above ! level ( ! b5d ! wat] w at once fl[ out1 j z x does f ! cup ( ,tantalus z soon z ! b5d ( its syphon is cov]$4 ,illu/ration3 ,fig4 #abc4 #agf4 ,pumps4--,9 ,fig4 #abc y h a plan ( a common pump4 ,a tube1 ,c ,d1 ext5ds d[n into ! well1 ,w4 ,above ?is is ! b>rel ( ! pump1 ,a ,b1 9 :i* ! pi/on works up & d[n4 ,!re is a valve1 ,f1 9 ! pi/on1 & ano!r1 ,e1 at ! bottom ( ! b>rel4 ,bo? ( !m op5 upw>d4 ,we w suppose t ! pump is entirely empty ( wat]4 ,if1 n[1 ! pi/on desc5d1 ! valve ,e %uts d[n1 & ,f op5s1 lett+ ! press$ air betwe5 ! pi/on & ,e pass upw>d4 ,see :at w happ5 :5 ! pi/on rises4 ,! air above ! pi/on c n get bel[1 = its pressure w %ut ! valve ,f4 ,b !re w be a t5d5cy to a vacuum bel[ ! pi/on z x rises1 & ! air w g up ?r\gh ! valve ,e to fill up ! space4 ,b :y does ! air rise8 ,because ( ! pressure ( ! air ^u ! surface ( ! wat] 9 ! well4 ,?is =ces up 9 ! pump ! wat] & ! air above x1 j 9 proportion z ! d[nw>d pressure 9 ! pump is less5$4 ,if ! pump+ be cont9u$ all ! air w soon be expell$1 ! wat] foll[+ x & fl[+ out at ! op5+1 ,g4 ,x is obvi\s t ! pump w be useless if ! valve ,e be ov] #cd feet above ! surface ( ! wat] 9 ! well1 z ! pressure ( ! atmosph]e w n su/a9 a column ( wat] high] ?an ?is4 #agg4 ,suction4--,9 common language1 ! op]ation ( ! pump is attribut$ to :at is call$ a pr9ciple ( suction1 z if !re 0 a draw+ up ( ! wat]4 ,b ! wat]1 y see1 is n drawn1 b =c$1 up4 ,s x is ) all op]ations ( a simil> "*4 ,9 suck+ up a fluid ?r\gh a tube ! fluid is =c$ up1 because ! pressure d[nw>d 9 ! tube is remov$4 ,b h[ is x remov$8 ,x is done by a movem5t ( ! tongue d[nw>d f ! ro( ( ! m\?1 ?us caus+ a t5d5cy to a vacuum1 z ! upw>d movem5t ( ! pi/on 9 ! pump causes ?is t5d5cy "u x4 ,to fill ! space made by ! movem5t ( ! tongue ! air is =c$ up ! tube1 ! liquid foll[+2 &1 z 9 ! case ( ! pump :5 ! air is all expell$1 ! liquid w beg9 to dis*>ge into ! m\?4 ,illu/ration3 ,fig4 #abd4 #agh4 ,=c+-,pump4--,! =c+-pump is con/ruct$ diff]5tly f ! common pump4 ,its plan is giv5 9 ,fig4 #abd4 ,x has a pipe1 ,c ,d1 & a b>rel1 ,a ,b1 l ! common pump4 ,x has also ! valve ,e at ! bottom ( ! b>rel4 ,b x has no valve 9 ! pi/on4 ,connect$ ) ! b>rel is ano!r pipe1 ,f ,g1 f :i* ! wat] issues4 ,?is has a valve1 ,h1 op5+ upw>d4 ,! op]ation ( ! pump is obvi\s4 ,z ! pi/on is drawn up ,e op5s & ,h %uts1 & :5 x is =c$ d[n ,e %uts & ,h op5s4 ,illu/ration3 ,fig4 #abe4 #agi4 ,fire-,eng9e4--,! fire-eng9e has commonly two =c+-pumps1 ) a contrivance = mak+ ! wat] issue 9 a uni=m /ream4 ,?is contrivance c be expla9$ 9 ,fig4 #abe4 ,! dis*>g+ pipe1 ,l ,m1 ext5ds d[n into a l>ge vessel1 ,i ,k1 :i* is fill$ ) air4 ,! uni=mity ( ! /ream dep5ds ^u ! ela/ic =ce ( compress$ air1 z y w see if ,i expla9 ! op]ation ( ! ma*9e4 ,:5 ! wat] is =c$ ?r\gh ! op5+ ,h1 x rises to ! level ,n ,o1 compress+ ! air 9 ,i ,k1 = ! tube ,l ,m is too small to all[ all ! wat] to escape t comes f ! l>g] tube1 ,h ,e4 ,n[ ! mom5t t ! pi/on ceases to =ce ! wat] ?r\gh ,h1 ! ela/ic =ce ( ! compress$ air op]ates1 %utt+ d[n ! valve ,h1 & =c+ ! wat] up ,l ,m4 ,! result1 y see1 is a cont9u\s =c+ up ( ! wat] ?r\gh ?is tube1 & !re=e a uni=m /ream4 ,,*apt] ,x4 ,,motion4 #ahj4 ,univ]sality ( ,motion4--,! _w is full ( motion4 ,! ris+ & sett+ ( ! sun1 ! *anges ( ! seasons1 ! fall+ ( ! ra91 ! runn+ ( riv]s into ! ocean1 ! asc5t ( wat] into ! air by evaporation1 ! w9d mov+ 9 sil5ce or ru%+ on 9 its might1 are famili> examples ( motion con/ant & e :]e pres5t4 ,b ) all ?is motion1 sometimes 9 conflict & (t5 v>iable1 ord] & regul>ity reign4 ,! causes ( motion1 ?\gh v>i\s 9 _! op]ation1 are kept by ! ,creator f produc+ confusion & disorganization by a few simple laws1 :i* regulate ! movem5ts bo? ( atoms & ( worlds4 ,! pr9cipal ( ^! causes ,i w n[ briefly notice4 #aha4 ,causes ( ,motion4--,attraction is ! mo/ univ]sal ( ! causes ( motion 9 ! univ]se4 ,:ile x b9ds atom to atom1 x also b9ds sy/em to sy/em ?r\gh\t ! imm5sity ( space2 & :ile x makes ! /one fall to ! gr\nd1 x moves ! c\ntless orbs =ev] onw>d 9 _! c\rses4 ,x is ?is :i* causes ! tides to fl[ & ! riv]s to run d[n _! slopes to ! ocean1 & ?us by keep+ up ! nev]-end+ motion ( wat] all ov] ! e>? 9 seas1 lakes1 riv]s1 & ! millions ( little /reamlets1 diffuses life & beauty ov] ! vegetable _w1 & gives to man ! va/ res\rces :i* we see develop$ 9 ! numb]less applications ( wat]-p[] & navigation4 ,heat p]vades all matt]1 & is e :]e unit+ its influ5ce ) ! o!r causes ( motion4 ,x is heat t produces all ! motions ( ! air1 t]m$ w9ds4 ,x is heat t causes ! rise ( ! wat] all ov] ! e>? 9 evaporation1 s t x may be collect$ 9 cl\ds1 aga9 to desc5d to moi/5 ! e>? & keep ! ev]-fl[+ riv]s full4 ,heat appli$ to wat] gives to man "o ( 8 be/ means ( produc+ motion 9 ma*9]y4 ,! ag5cies :i* ,*emi/ry reveals to u are ev] at "w caus+ motion among ! p>ticles ( matt]2 & ?\gh !y g5]ally "w 9 sil5ce1 !y sometimes %[ !mselves 9 trem5d\s explosions1 & 9 convulsions ( nature4 ,busy life is e :]e produc+ motion1 m especially 9 ! animal _w4 ,x gives to ! myriads ( animals1 great & small1 t sw>m ! e>? n only ! p[] ( mov+ !mselves1 b also ! p[]1 to "s ext5t1 ( mov+ ! mat]ial _w ar\nd !m4 #ahb4 ,action & ,reaction ,equal4--,:5 any ( ! causes ( motion act1 ! action is met by an opposite & equal reaction4 ,if1 = example1 a bl[ be giv51 an equal bl[ is receiv$ 9 return4 ,= ?is reason1 if "o 9 runn+ hits 8 head aga9/ ! head ( ano!r bo? are equally hurt4 ,:5 a *ild knocks 8 head aga9/ a table1 !re is s\nd philosophy 9 ! common say+ t he has giv5 ! table z good a bl[ z he has receiv$1 ?\gh x may af=d him no com=t4 ,_m v int]e/+ illu/rations ( ?is law ( motion sugge/ !mselves1 ( :i* ,i w give a few4 ,illu/ration3 ,fig4 #abf4 ,a swimm]1 press+ ! wat] d[nw>d & backw>d ) 8 h&s & feet1 is c>ri$ along =w>d & upw>d by ! reaction ( ! wat]4 ,& 9 ?is case1 z 9 e o!r1 ! great] ! action ! great] is ! reaction2 9 o!r words1 ! m /rongly he presses ) 8 h&s & feet1 ! m rapidly is he borne along by ! reaction ( ! wat] aga9/ ! pressure4 ,a boat advances 9 proportion to ! =ce ) :i* ! o>s press aga9/ ! wat]4 ,s ! rapidity ( a /eamboat dep5ds on ! =ce ) :i* ! paddles drive ! wat] a/]n4 ,birds rise 9 ! air by ! reaction ( ! air aga9/ _! w+s z !y are press$ d[nw>d4 ,a sky-rocket pursues its rapid flight because a l>ge quantity ( gase\s matt] issues f its l[] end1 &1 be+ resi/$ by ! reaction ( ! air1 by its pressure ?r[s ! rocket upw>d4 ,s if a %ip fire guns f ! /]n its advance w be accel]at$1 b if f ! b[ x w be ret>d$4 ,:5 a broadside is fir$ ! %ip incl9es to ! o!r side4 ,9 ,fig4 #abf 7p4 #acf7 is repres5t$ ! plan ( ,b>k]'s mill4 ,x consi/s ( a cyl9d]1 c1 arrang$ 9 a frame 9 su* a way t x c revolve on ! po9t ^u :i* x re/s4 ,wat] runs into x by a tube1 p1 & escapes by ! bran*es1 a & d4 ,^! are s arrang$ t ! reaction ^u ! issu+ wat] makes ! cyl9d] revolve rapidly1 caus+ ! ends ( ! bran*es to :irl ar\nd z indicat$ by ! dott$ l9es & arr[s4 ,if a spr+ be compress$ betwe5 two equal bodies1 x w ?r[ !m (f ) equal velocities4 ,if !y are unequal1 ! velocity ( ! small] body w be great] ?an t ( ! l>g]1 & 9 proportion to its smallness4 ,= ?is reason1 :5 a ball issues f a cannon1 ?\gh ! cannon & ! ball are equally act$ ^u by ! ela/ic or expansive =ce ( ! gases set free by light+ ! p[d]1 ! gun is mov$ b v little because ! =ce is diffus$ ?r\gh s l>ge a mass1 :ile ! ball be+ s mu* small] moves ) great velocity4 ,:5 a volcano ?r[s /ones f its crat] ! e>? may be comp>$ to ! cannon1 ! /ones to ! ball1 & ! explosive mat]ials ?r[+ ! /ones to ! explod+ p[d] project+ ! ball4 ,z ! cannon is mov$ z mu* z ! ball1 s is ! e>? mov$ z mu* z ! /ones1 ! only reason t x does n move z f> & z rapidly z ! /ones be+ t ! =ce is diffus$ ?r\gh s l>ge a bulk4 ,^! examples illu/rate v well ! relation ( action & reaction1 = :5ev] !re is an action ( "o body ^u ano!r x is z if a spr+ 7 betwe5 ! two bodies1 act+ equally ^u bo?4 ,:5 a man jumps f ! gr\nd x is z if a spr+ 7 compress$ betwe5 him & ! e>?1 & ?is exp&+ moves ! e>? exactly z mu* z x does ! man4 ,he really kicks ! e>? away f him4 ,! motion ( ! e>? is n obvi\s because x is diffus$ ?r\gh s l>ge a mass4 ,! case is p>allel to t ( ! ball & cannon4 ,! same =ce is ex]t$ ^u ! man & ! e>?1 b ! man1 l ! ball1 moves ! mo/1 & 9 proportion to 8 comp>ative smallness4 ,s :5 a bird hops f ! gr\nd1 ! e>? moves z really z ! bird4 ,if ! bird hop f a twig1 y p]ceive t ! twig is mov$ by ! press+ d[n ( ! bird z x rises4 ,:5 x />ts f ! gr\nd x ex]ts ! same d[nw>d pressure1 & moves ! e>? z really z 9 ! o!r case x did ! twig4 #ahc4 ,in]tia ,%[n 9 ! ,communication ( ,motion4--,:at is meant by ! in]tia ( matt] y h already le>n$ 9 #dh4 ,?is prop]ty is exemplifi$ 9 ! communication ( motion to any body1 or1 9 o!r words1 9 sett+ x 9 motion4 ,( ?is ,i w give "s illu/rations4 ,:5 ! sails ( a vessel are fir/ spread to ! w9d ! vessel does n move swiftly at once1 = "s "t is requir$ = ! =ce appli$ to ov]come ! in]tia ( s l>ge a mass1 & to put x 9 rapid motion4 ,horses make a great] ef=t to />t a load ?an !y d to keep x 9 motion aft] x is />t$4 ,if "o be /&+ up 9 a c>riage1 & ! horses />t (f sudd5ly1 he falls backw>d1 because 8 body1 f its in]tia1 does n readily & at once p>take ( ! motion ( ! c>riage4 ,if a p]son />t =w>d quickly ) a wait] fill$ ) glasses 9 8 h&s1 ! glasses w slide backw>d4 ,s if a p]son />t quickly f 8 *air ) a cup ( tea 9 8 h&1 ! tea w be ?r[n backw>d ^u him4 ,y see f ! =ego+ illu/rations t x requires "s "t to communicate motion to any body4 ,i w give "s illu/rations ( ?is fact ( a m /rik+ "*4 ,if a ball be ?r[n aga9/ an op5 door x w move ! :ole door1 & p]haps %ut x2 b ! same ball if fir$ w pass ?r\gh ! door )\t mov+ x p]ceptibly4 ,9 ! latt] case its velocity is s great t !re is n "t en\gh to communicate motion to ! :ole door1 & x moves only t "p ( x ) :i* x comes 9 contact4 ,a bullet ?r[n ) b little =ce aga9/ a w9d[ w crack a :ole pane ( glass2 b if %ot f a pi/ol x m]ely makes a r\nd hole4 ,s1 also1 a cannon-ball hav+ a great velocity may pass ?r\gh ! side ( a %ip1 do+ p]haps comp>atively little damage1 :ile "o mov+ ) mu* less velocity may d va/ly m damage by spl9t]+ ! wood to a consid]able ext5t4 ,= ! same reason a rapid ball hitt+ a p]son may occasion less suff]+ & d less h>m ?an a sl[ ball2 = a rapid ball kills m]ely ! p>ts :i* x t\*es1 leav+ ! fle% ar\nd 9 a s\nd /ate1 :ile ! sl[ ball bruises ov] a l>ge space4 ,if a l>ge pit*] fill$ ) "s heavy liquid be quickly tak5 up ! h&le w break1 leav+ ! pit*] beh9d4 ,l>ge di%es are (t5 brok5 9 ?is way :5 heavily load$4 #ahd4 ,in]tia ,%[n 9 ! ,disposition ( ,motion to ,cont9ue4--,( ?is ,i w cite "s illu/rations4 ,z 9 ! case ( ! %ip1 9 ! fir/ illu/ration 9 #ahc1 x takes "t to communicate motion to ! :ole %ip1 or1 9 o!r words1 to ov]come its in]tia1 s :5 ! %ip is once 9 rapid motion x does n /op sudd5ly :5 ! sails are tak5 d[n1 b its in]tia t5d+ to keep x mov+ is gradually ov]come by ! resi/ance ( ! wat]4 ,if "o be /&+ up 9 a c>riage 9 motion1 & ! horses sudd5ly /op1 he w be ?r[n =w>d1 = 8 body has a motion 9 common ) ! c>riage1 & f in]tia is dispos$ to g on :5 ! c>riage /ops4 ,:5 y /rike y\r foot aga9/ any ?+ to get ! sn[ (f1 y give ! foot & ! sn[ a common motion toge!r1 !n arre/+ ! motion ( ! foot1 ! sn[ f in]tia passes on4 ,! same ?+ is illu/rat$ 9 /rik+ a book aga9/ any ?+ to get ! du/ (f4 ,if a %ip /rike ^u a rock e ?+ on bo>d :i* is loose is da%$ =w>d4 ,! e>? z x revolves on its axis has a velocity at ! equator ( ab\t #ajjj miles an h\r4 ,if ?is revolution %\ld be sudd5ly arre/$ e ?+ loose on its surface1 hav+ acquir$ ! motion ( ! e>?1 w\ld be at once ?r[n ea/w>d1 j z ! furniture1 etc41 on bo>d %ip are da%$ =w>d :5 x is /opp$ by runn+ aga9/ a rock4 ,all ! h\ses1 & monum5ts1 & /ructures ( e k9d w\ld fall pro/rate ea/w>d4 ,all ! cities on our ,atlantic coa/ w\ld be plung$ into ! ocean2 & :ile ! wat]s w\ld leave ! we/]n %ores ( ! ,atlantic1 !y w\ld ov]fl[ its ea/]n %ores1 & deluge ! cont95t ( ,europe1 z wat] 9 a vessel on bo>d a %ip t _h /ruck an ob/acle w\ld be ?r[n =w>d ov] its side4 ,illu/ration3 ,fig4 #abg4 #ahe4 ,an ,eque/rian ,feat4--,9 ! feat repres5t$ 9 ,fig4 #abg ! only ex]tion made by ! rid] is to raise himself suffici5tly to pass ov] ! cord1 & he comes d[n aga9 ^u ! horse's back1 simply because ( ! motion :i* he has 9 common ) ! horse1 8 feet go+ 9 ! pa? repres5t$ by ! dott$ l9e4 ,if he %\ld attempt to ?r[ himself =w>d1 z 9 leap+ f ! gr\nd1 he w\ld g too f>1 & p]haps /rike ^u ! horse's neck in/ead ( 8 back4 ,skill 9 jump+ f a mov+ c>riage consi/s 9 mak+ prop] all[ance = ! =w>d motion :i* is _h 9 common ) ! c>riage4 ,mo/ p]sons are apt to ov]do ! matt]1 & s come to ! gr\nd pro/rate1 & ) m viol5ce ?an is necess>y4 #ahf4 ,a ,case 9 ,c\rt4--,a da%+ "y man driv+ a light phaeton ran aga9/ a heavy c>riage4 ,8 fa!r 0 induc$ by 8 son's repres5tations to prosecute ! driv] ( ! c>riage = driv+ too fa/4 ,a k ( motal in]tia v readily decid$ ! case4 ,! son & 8 s]vant bo? decl>$ t ! %ock ( ! c>riage 0 s great aga9/ ! phaeton t !y 7 ?r[n ov] ! horses' heads4 ,!y ?us prov$ !mselves guilty ( ! fa/ driv+1 = x 0 _! own rapid motion t ?rew !m out :5 ! phaeton 0 /opp$ by runn+ aga9/ ! c>riage4 ,! foll[+ case is a p>allel "o4 ,if two boats1 ! "o ( l>ge size sail+ sl[ly up /ream1 ! o!r a small "o sail+ rapidly d[n1 run aga9/ ea* o!r1 a man /&+ 9 ! b[ ( ! "o go+ d[n w be ?r[n mu* f>!r =w>d ?an "o /&+ 9 ! b[ ( ! o!r4 #ahg4 ,c\rse ( ,bodies ,?r[n into ! ,air4--,x results f ! pr9ciple t ,i h illu/rat$ t :5 any body1 z a /one1 is ?r[n1 z we say1 /raight upw>d1 x does n1 9 reality1 g up or come d[n p]p5dicul>ly4 ,if x did x w\ld come d[n at a great di/ance f u4 ,suppose x takes two seconds = x to g up & to rea* ! gr\nd4 ,if we are at ! equator1 9 t two seconds we move f ! po9t :]e we ?rew up ! /one ne>ly #cjjj feet ea/w>d1 & !re=e if ! /one rose & fell p]p5dicul>ly x w\ld fall #cjjj feet we/w>d ( u4 ,:y1 in/ead ( ?is1 does x fall at our feet8 ,because t :5 ?r[n into ! air x has n only ! upw>d motion giv5 by ! h&1 b also ! =w>d motion ( ! e>?4 ,x is a case simil> to t ( ! rid] 9 ,fig4 #abg1 ! horse repres5t+ ! surface ( ! e>? & ! rid] ! /one4 ,= ! same reason a man on bo>d ( a /eamboat1 ?\gh x move fifte5 miles an h\r1 tosses up 8 ball or orange & cat*es x z well z if he 7 on l&4 ,?is he c\ld n d if bo? he & 8 orange did n h ! same =w>d motion t ! boat does4 ,s1 also1 if a man fall f a ma/-head he rea*es ! deck at ! foot ( ! ma/ :5 ! vessel is sail+ rapidly1 j z he w\ld if x 7 ly+ /ill at ! :>f4 ,if he did n by in]tia reta9 ! =w>d motion :i* he _h 9 common ) ! vessel he w\ld fall at "s di/ance beh9d ! ma/4 #ahh4 ,! ,e>? & ! ,atmosph]e4--,! air be+ held to ! e>? by attraction1 #aea1 x has a motion 9 common ) ! e>?4 ,x revolves ) ! e>? j z ! tire ( a :eel revolves ) ! :eel4 ,?is be+ s1 our w9ds are no?+ b slight v>iations ( ?is con/ant rapid :irl ( ! a]ial coat+ ( ! e>?4 ,if ! atmosph]e 7 sudd5ly to /op :irl+ r\nd ) ! e>? we %\ld move ?r\gh x ) a velocity ( #aejj feet a second2 & ! de/ructive effect ^u u w\ld be ! same z x w\ld 7 ! e>? /&+ /ill :ile ! air mov$ ov] its surface ) ?is fe>ful velocity4 ,a wise man1 n reflect+ t ! atmosph]e mov$ ) ! e>?1 propos$ ris+ 9 a balloon1 & wait+ till ! c\ntry to :i* he wi%$ to g %\ld be pass+ "u him4 #ahi4 ,motion & ,re/4--,?\gh we use ! t]m re/ 9 opposition to motion1 x is obvi\s f "s ( ! illu/rations giv5 t re/ is m]ely a relative t]m1 = n a p>ticle ( matt] 9 ! univ]se is at re/4 ,?\gh :5 we are sitt+ /ill we call ourselves at re/1 we are mov+ e h\r1 by ! revolution ( ! e>? on its axis1 #ajjj miles ea/w>d1 & #fh1jjj miles 9 our annual j\rney r\nd ! sun4 ,:y1 !n1 are we s ins5sible to ^! rapid motions8 ,x is p>tly because ! motions are s uni=m1 b *iefly because all ?+s ar\nd u1 our h\ses1 trees1 & ev5 ! atmosph]e1 are mov+ along ) u4 ,if we 7 mov+ along alone1 ev5 at a sl[ rate1 :ile all ^! objects 7 /&+ /ill1 we %\ld be consci\s ( our motion1 z we are :51 z we ride along 9 a c>riage1 we see ! objects at ! road-side n mov+ along ) u4 #aij4 ,a ,comp>ison4--,! above c be made m cle> & impressive by a famili> comp>ison4 ,a man on bo>d ( a /eamboat1 by conf9+ 8 att5tion to ?+s )9 ! boat1 may1 aft] a :ile1 be almo/ unconsci\s ( ! boat's mov+1 if ! wat] be smoo?1 ?\gh ! boat may be go+ at ! rate ( fifte5 miles an h\r4 ,if he be read+ 9 ! cab9 he w ?9k z little ( 8 motion z he w\ld 7 he read+ 9 8 p>lor at home4 ,if he %\ld be bl9dfold$1 & turn$ ar\nd a few times1 x w\ld be impossible = him to tell ! direction 9 :i* ! boat is go+4 ,n[ x is ) a man on ! e>? z x is ) ! man 9 ! boat4 ,he is unconsci\s ( ! motion ( ! e>? = ! same reason t ! man 9 ! boat is unconsci\s ( ! boat's motion4 ,all objects ar\nd him are mov+ along ) him1 z ! objects ar\nd ! man 9 ! cab9 ( ! boat are mov+ along ) him4 ,we c c>ry ! p>allel f>!r4 ,:ile ! man sits 9 ! cab9 he kn[s n h[ fa/ ! boat moves1 nor ev5 :e!r x moves at all4 ,he mu/ look out to decide ?is1 & ev5 !n he may n be able to tell :e!r ! boat moves1 or :e!r he m]ely sees ! wat] runn+ by x4 ,we (t5 are actually deceiv$ 9 ?is respect4 ,a /eamboat /ruggl+ aga9/ w9d & wave may appe> to ^? on bo>d to be advanc+ :5 x is really /ation>y1 or ev5 :5 x is los+ gr\nd4 ,s :5 we look at ! sun we "k n :e!r x is ! sun or ! e>? t is mov+4 ,m]e vision1 )\t reason+ on ! subject1 leads "o to ?9k t x is ! sun t moves4 ,= ! same reason1 if a *ild %\ld be plac$ 9 a c>riage = ! fir/ "t )\t see+ ! horses1 b ) its eyes fix$ on objects at ! road-side1 he w\ld probably ?9k t all ! f5ces & trees & rocks & h\ses are 9 motion4 #aia4 ,absolute & ,relative ,motion4--,! motion ( a body is said to be absolute :5 x is consid]$ )\t relation to ! position ( any o!r body4 ,its motion is said to be relative :5 x is mov+ ) respect to "s o!r body4 ,absolute re/ is unkn[n1 = no body 9 ! univ]se is kn[n to be )\t motion4 ,b a body may be relatively at re/1 t is1 9 a fix$ relative position to o!r bodies4 ,e body is 9 a /ate ( absolute motion1 & yet x may be 9 a /ate ( relative re/4 ,all objects t appe> to u to be at re/ h a v rapid absolute motion4 ,!y appe> to be at re/ m]ely because !y h ! same rapidity & direction ( absolute motion t we h ourselves4 ,& all ! motions :i* are app>5t to ! eye are only slight diff]5ces 9 ! common absolute motions1 ( :i*1 ?\gh !y are s exce$+ly rapid1 we are entirely unconsci\s4 ,?us1 if ,i /& /ill1 & ano!r at my side walks at ! rate ( ?ree miles an h\r ea/w>d1 we bo? ( u h a common absolute motion ( #ajjj miles 9 e h\r1 & he m]ely adds ?ree miles to 8 ?\s&--,i move #ajjj miles1 & he #ajjc4 ,s if ,i sit /ill 9 my p>lor1 & my fri5d travels ea/w>d at ! rate ( #bj miles an h\r1 ,i move e h\r #ajjj miles1 & he #ajbj4 ,& if he travel we/w>d at ?is rate he really travels sl[] ?an ,i d--he has an absolute motion ea/w>d ( #ihj miles1 & ,i ( #ajjj4 ,at ! same "t we are bo? :irl+ on 9 our annual j\rney ar\nd ! sun at ! rate ( #fh1jjj miles an h\r4 #aib4 ,ob/acles to ,motion4--,z motion is naturally dispos$ to cont9ue 7 #di & #ahd71 :5ev] x is /opp$ x does n sp5d itself1 b is /opp$ by ob/acles4 ,! pr9cipal ( ^! ob/acles are3 gravitation2 ! resi/ance ( oppos+ sub/ances--solids1 liquids1 & gases2 & friction4 ,:5 a /one is ?r[n into ! air its upw>d motion is gradually de/roy$ by ! attraction ( ! e>? & ! resi/ance ( ! air4 ,obs]ve1 n[1 :y x desc5ds4 ,x is f ! action ( "o ( ! causes :i* arre/$ its upw>d flight--! attraction ( ! e>?4 ,9 its desc5t x is ret>d$ by ! resi/ance ( ! air1 z x 0 9 its asc5t4 ,?is ret>dation is v obvi\s 9 ! case ( sub/ances :i* pres5t a l>ge surface to ! air1 z a fea!r4 ,a small piece ( lead w outweigh _m fea!rs1 & !re=e1 z its quantity ( matt] is s mu* great] 9 proportion to its surface ?an t ( a fea!r1 x w fall to ! gr\nd mu* m quickly4 ,t ?is is ow+ :olly to ! resi/ance ( ! air c be prov$ ) ! air-pump4 ,illu/ration3 ,fig4 #abh4 ,suppose t y h a tall receiv]1 ,fig4 #abh1 on ! air-pump1 & a piece ( lead & a fea!r are plac$ at its upp] "p 9 su* a way t !y c be made to fall at ! same in/ant4 ,exhau/ ! air1 & !n let !m fall4 ,!y w g d[n side by side1 z repres5t$ by ! figure1 & rea* ! bottom ( ! receiv] at ! same "t1 because !re is no air !re to resi/ ! progress ( ! fea!r4 ,! toy call$ ! wat]-hamm] illu/rates ! same ?+4 ,:5 wat] falls ?r\gh ! air ! resi/ance ( ! air t5ds to sep>ate its p>ticles1 z we see 9 ! fall+ ( wat] ?r[n up by a f\nta94 ,9 ! wat]-hamm]1 :i* is a clos$ tube conta9+ a little wat] & no air1 :5 ! wat] is made to fall f "o end to ! o!r1 z !re is no air to divide x1 x falls z "o mass1 & gives a %>p s\nd l ! bl[ ( a hamm]4 ,an in/rum5t ess5tially l ?is c be made ) a ?9 glass flask4 ,put a little wat] 9 x1 &1 aft] heat+ x to boil+ ov] a _s-lamp1 cork ! flask tightly1 & !n leave ! wat] to cool4 ,z all ! space above ! wat] 0 fill$ ) /eam :5 ! flask 0 cork$1 x is a vacuum n[ t ! /eam is cond5s$4 ,illu/ration3 ,fig4 #abi4 #aic4 ,relation ( ,bulk to ! ,resi/ance ( ,liquids & ,gases4--,y h already se51 9 #aib1 t ! m surface a body has 9 proportion to its weight ! great] is ! resi/ance ( ! air to its motion4 ,?is tru?1 :i* applies to liquids z well z to airs or gase\s sub/ances1 expla9s ! fact t small bodies meet ) proportionately m resi/ance ?an l>ge ones4 ,! body ,b1 ,fig4 #abi1 y see is made up ( eight cubes ( ! size ( ! cube a1 t is1 x has eight times ! quantity ( matt] t a has4 ,n[ if ,b 7 mov+ ?r\gh air or wat]1 any ( its sides pu%+ ! wat] be=e x w\ld meet ) only f\r times ! resi/ance t a side ( a w\ld1 = its surface is only f\r times z l>ge1 & yet ! body is eight times z l>ge z a4 ,& ! great] ! diff]5ce ( size ! great] is ! diff]5ce ( resi/ance4 ,if ,b 7 a cube tw5ty-sev5 times z l>ge z a x w\ld meet ) only n9e times z mu* resi/ance4 ,y see "h ! reason t %ells & cannon-balls c be ?r[n mu* f>!r ?an bullets & small %ot4 ,! sportsman does n ?r[ away 8 %ot by fooli%ly aim+ at birds at great di/ances1 & yet %ells & l>ge cannon-balls c be ?r[n ! di/ance ( sev]al miles4 ,! diff]5ce is n 9 ! degree ( velocity :i* ! p[d] produces1 b 9 ! resi/ance ( ! air4 ,x is = ! same reason t ra9 falls ) great] rapidity ?an drizzl+ mi/4 ,z liquids & a]i=m sub/ances resi/ solids 9 motion 9 proportion to ! am\nt ( surface :i* ! solids pres5t to !m1 s also :5 !y /rike aga9/ solids !y cause motion 9 !m 9 proportion to ! am\nt ( surface act$ ^u4 ,?us a viol5t w9d c\ld n move a lump ( t91 b c\ld bl[ along a %eet ( x1 or te> up a ro(+ ( x if x got b5ea?4 ,s cl\ds ( s& are rais$ into ! air 9 ! des]ts ( ,africa1 al?\gh ! p>ticles are ( ! same mat]ial z /ones1 & !re=e h ! same specific gravity4 ,= ! same reason du/1 fea!rs1 ! d[n & poll5 ( fl[]s1 etc41 are bl[n ab\t1 al?\gh !y are heavi] ?an ! air4 ,a pebble is mov$ m easily by a curr5t ( wat] ?an a /one1 because x has a l>g] surface1 9 proportion to its weight1 to be act$ ^u by ! wat]4 ,= ! same reason s& is mov$ m easily ?an pebbles1 & f9e mud ?an s&1 ?\gh /ones1 pebbles1 s&1 & mud may all be ( ! same mat]ial4 ,?is expla9s :y y w f9d mud :]e ! curr5t is sl[1 s& :]e x is fa/]1 pebbles & /ones :]e x is /ill fa/]1 & :]e ! curr5t is exce$+ly rapid y f9d no?+ b l>ge rocks--s&1 pebbles1 & /ones n be+ able to resi/ its =ce4 ,= ! same reason1 9 ! process ( w9n[+1 ! *aff is c>ri$ away by ! w9d2 :ile ! gra91 pres5t+ less surface 9 proportion to its weight to be act$ ^u by ! air1 falls to ! floor4 ,9 all ! above cases ! mov+ wat] or air may be consid]$ z act+ 9 opposition to ! attraction ( ! e>?1 ! latt] pull+ ! sub/ance d[n to ! e>?1 & ! =m] pu%+ x away f ! e>?4 ,( c\rse1 ! m surface ! wat] or air has to pu% ^u ! great] is ! effect2 & x is to be rememb]$ t ! attraction ( gravity is z ! quantity ( matt]1 )\t any reg>d to am\nt ( surface 9 ! body attract$4 ,illu/ration3 ,a ,b ,c ,d ,fig4 #acj4 #aid4 ,relation ( ,=ce to ,velocity4--,x w\ld seem at fir/ ?\ght t ! motion produc$ 9 any body mu/ be 9 exact proportion to ! =ce produc+ x2 t is1 t twice ! =ce :i* produces a giv5 velocity w\ld d\ble t velocity1 & ?ree times w\ld treble x1 etc4 ,?is is true :]e !re are no ob/acles to motion1 z 9 ! case ( ! heav5ly bodies mov+ 9 _! orbits4 ,b 9 all motions "h ^u ! e>? !re are ob/acles2 & z reaction is always equal to action1 ! great] ! velocity ! great] is ! reaction ( ! ob/acle4 ,if1 !re=e1 y increase ! velocity ( any body1 y n only h to communicate m motion to x1 b y mu/ ov]come also ! increas$ reaction4 ,! rate ( increase ( =ce = increas$ velocities has be5 v accurately asc]ta9$4 ,?is ,i w expla94 ,a boat mov+ f ,b to ,a1 ,fig4 #acj1 we w suppose1 displaces a quantity ( wat] repres5t$ by ! space betwe5 ! two l9es ext5d+ f ,b to ,a4 ,n[ if x move f ,b to ,c1 x displaces twice ! bulk ( wat] ,b ,c2 & z x is displac$ 9 ! same "t t ,b ,a 01 ea* p>ticle is displac$ ) twice ! velocity4 ,d\ble ! =ce is requir$ to displace a d\ble portion ( wat]1 & to d ?is ) d\ble ! velocity ! =ce mu/ be d\bl$ aga94 ,s if ! boat is made to move ?ree times z f> 9 ! same "t1 t is f ,b to ,d1 ?ree times ! quantity ( wat] is displac$1 & ea* ( ^! ?ree portions1 ,b ,a1 ,a ,c1 & ,c ,d1 is displac$ ) ?ree times ! velocity4 ,! =ce requir$1 !n1 to d ?is is n9e times t requir$ to c>ry ! boat f ,b to ,a 9 ! same "t4 ,x is pla91 !re=e1 t ) velocities repres5t$ by ! numb]s #a1 #b1 #c1 #d1 etc41 ! =ces requisite to produce ^! velocities mu/ be z ! squ>es ( ^! numb]s2 viz41 #a1 #d1 #i1 #af1 etc4 ,?is law is a v important "o 9 a practical po9t ( view4 ,= example1 x %[s u h[ mu* l>g] a quantity ( coal is requir$ to produce 9 /eamboats a high velocity ?an a mod]ate "o4 ,its application too to ! sci5ce ( gunn]y is important4 #aie4 ,relation ( ,%ape to ,velocity4--,! resi/ance ( air or wat] to a flat surface is great] ?an to a convex "o1 because ! latt] readily turns ! p>ticles to ! "o side & ! o!r4 ,s1 also1 a concave surface is resi/$ mu* m ?an a flat "o1 because ! p>ticles ( ! air or wat] c n s easily escape sideways4 ,fi%es are ( a sp9dle-l & sl5d] %ape1 t !y may h z little resi/ance z possible f ! wat]4 ,x is = ?is reason t a fi% has no neck1 = if x _h "o ! upp] portion ( its body w\ld1 f ! resi/ance ( ! wat] /rik+ aga9/ x1 prove a s]i\s imp$im5t to rapidity ( motion4 ,mank9d h 9 "s measure imitat$ ! %ape ( fi%es 9 _! boats & %ips4 ,boats :i* are int5d$ to be> light burd5s & g swiftly are made v long & n>r[4 ,! webb$ feet ( wat]-f[ls1 :5 !y are mov$ =w>d1 are fold$ up s z to meet ) z little resi/ance z possible2 b :5 !y are mov$ backw>d !y are spread out s z to press aga9/ ! wat] a broad concave surface4 ,= ! same reason ! w+s ( a bird are made convex upw>d & concave d[nw>d2 & :5 x moves its w+ upw>d x makes x cut ! air some:at edgewise1 b 9 mov+ x d[nw>d x presses directly ) ! :ole concave surface4 #aif4 ,friction4--,friction is g5]ally an ob/acle to motion4 ,:5 we roll a ball1 ! m r\gh is ! surface on :i* we roll x ! great] is ! friction & ! soon] is ! ball /opp$4 ,friction less5s ! rapidity ( motion 9 ma*9]y1 & to prev5t ?is z f> z possible oil+ & o!r exp$i5ts are employ$4 ,b sometimes friction is a cause ( motion1 z1 = example1 ! friction ( ! driv+-:eels ( a locomotive ^u ! rails4 ,9 ?is case ! :eel pu%es backw>d on ! rail at ea* successive po9t ( contact4 ,to make ?is cle>1 suppose a common :eel is depriv$ ( its rim & is made to revolve on ! ends ( its spokes4 ,! end ( ea* spoke gives a backw>d pu% z x /rikes ! gr\nd4 ,n[ ! rim ( a :eel makes ! same pu%es1 b !y are m num]\s--!y are cont9u\s1 be+ made by all ! successive po9ts 9 ! rim4 ,sometimes ! rails ( a railroad are too smoo? f fro/ or "s o!r cause1 & !n s& is ?r[n ^u !m to give ! locomotive a />t4 ,! s& s]ves to prev5t ! :eels f slid+ by enabl+ !m to get "s hold ^u ! rails 9 _! backw>d pu%es4 #aig4 ,friction ( ,liquids 9 ,tubes4--,s easily does wat] fl[ along t we %\ld n at fir/ view suppose t x w\ld be delay$ mu* f friction z x passes ?r\gh pipes or along *annels4 ,b ! ret>d+ influ5ce is consid]able4 ,an in* tube #bjj feet long1 ly+ horizontally connect$ ) a res]voir1 w dis*>ge wat] n "o qu>t] z fa/ z an in* orifice 9 ! side ( ! res]voir4 ,sudd5 turns 9 a pipe %\ld be avoid$1 because !y occasion s mu* friction aga9/ ! sides ( ! pipe & among ! p>ticles ( wat] by di/urb+ ! regul>ity ( ! curr5t4 ,9 ! entrance ( ! art]ies into ! bra91 9 ord] to prev5t ! blood f fl[+ too rapidly into ?is organ1 !re are sudd5 turns 9 ! art]ies to ret>d ! blood2 & 9 graz+ animals1 z !re is special dang] t ! blood w fl[ too freely to ! bra9 z ! head is held d[n 9 eat+1 !re is a special provision to prev5t ?is 9 a net-"w ( art]ies4 ,if ! art]ies ( ! bra9 9 su* animals 7 /raight tubes !y w\ld cont9ually be dy+ ( conge/ion ( ! bra9 or ( apoplexy4 ,illu/ration3 ,fig4 #aca4 ,friction 9 a small pipe is great] 9 proportion to its size ?an 9 a l>ge pipe4 ,9 a pipe an in* 9 diamet] wat] w n move m ?an "o-fif? z fa/ z 9 a tube two in*es 9 diamet]4 ,?is may be made cle> by ,fig4 #aca1 9 :i* is repres5t$ ! area ( a small tube inside ( ! area ( a tube ( twice its diamet]4 ,suppose ! effect ( ! friction 9 ! l>ge tube to ext5d 9 to a4 ,9 ! small "o x w ext5d 9 z f>1 t is1 to b4 ,b e a is ab\t five times z long z e b1 s t !re is full five times z mu* wat] cle> ( friction 9 ! l>ge tube z !re is 9 ! small] "o4 ,illu/ration3 ,fig4 #acb4 #aih4 ,friction 9 ,/reams4--,! ret>d+ effect ( friction is v obvi\s 9 brooks & riv]s4 ,! wat] 9 ! middle ( a /ream runs mu* m rapidly ?an x does ne> its banks4 ,:5 a riv] is v %all[ at its sides ! wat] !re sc>cely moves1 ?\gh 9 ! middle ! wat] may be runn+ at a rapid rate4 ,a tide1 !re=e1 fl[+ up a riv]1 moves m freely ne> its banks ?an x does 9 ! middle ( ! /ream1 because x meets ) less resi/ance !re f ! d[nw>d curr5t4 ,wat] moves less rapidly at ! bottom ( a riv] ?an x does at ! surface4 ,= ?is reason1 if a /ick be s load$ at "o end z to /& upright 9 wat]1 9 ! curr5t ( a riv] its upp] end w be c>ri$ along fa/] ?an its l[] end1 & !re=e x w incl9e =w>d1 z 9 ,fig4 #acb4 ,z ! sea rolls 9 ov] a bea*1 ea* wave at l5g? p\rs ov] its cre/ & breaks1 because ! l[] "p ( ! wave is ret>d$ by friction on ! bea*4 ,7 x n = ! con/ant ret>dation ( friction at ! sides & bottom ( riv]s1 & at _! b5ds1 ^? riv]s :i* h _! rise at a consid]able height above ! level ( ! sea w\ld acquire an imm5se velocity4 ,?us ! ,rhone1 draw+ its wat]s f #ajjj feet above ! level ( ! ocean1 w\ld p\r !m =? ) ! velocity ( wat] :i* _h fall5 p]p5dicul>ly ! same height1 t is1 at ! rate ( #agj miles an h\r1 did n friction cont9ually dim9i% ! velocity4 #aii4 ,waves4--,waves are g5]ally =m$ by ! friction ( air ^u wat]4 ,obs]ve h[ !y are =m$4 ,z soon z any portion ( wat] is rais$ above ! g5]al surface x t5ds by gravity to fall to a level ) ! wat] ar\nd x1 & 9 do+ s ! portion next to x is =c$ upw>d1 =m+ ano!r wave2 & s "o wave produces ano!r1 ea* "o be+ small] ?an ! prec$+1 till at l5g? ! motion is :olly lo/4 ,?is is always ! process :5 ! cause ( ! motion is a s+le impulse1 z :5 a /one is dropp$ into ! wat]4 ,b :5 ! waves are produc$ by a succession ( impulses1 z :5 w9d makes !m1 !y are mo/ly ( ! same size4 ,x is q a common notion t ! wat] moves z rapidly z ! waves appe> to d2 b ! wat] really rema9s ne>ly /ation>y1 ris+ & fall+1 :ile m]ely ! =m ( ! wave advances4 ,! same wave is made up cont9ually ( a succession ( diff]5t portions ( wat]1 or r x is a succession ( diff]5t waves4 ,?is is v well illu/rat$ by ! wav+ ( a rope or c>pet4 ,9 an op5 sea a wave slopes regul>ly on ei!r side2 b :5 x comes ne> ! %ore1 = ! reason giv5 9 #aih1 x gr[s m & m ne>ly p]p5dicul> on ! side t[>d ! %ore1 till at l5g? x falls ov]1 & if x be v l>ge ! ro> ?us caus$ by its break+ is he>d to a great di/ance4 #bjj4 ,height ( ,waves4--,s awful1 says ,dr4 ,arnot1 is ! spectacle ( a /orm at sea t x is g5]ally view$ ?r\gh a m$ium :i* biases ! judgm5t2 & l(ty z waves really are1 imag9ation pictures !m l(ti] /ill4 ,n[ no wave rises m ?an t5 feet above ! ord9>y sea-level1 :i*1 ) ! t5 feet t its surface aft]w>d desc5ds bel[ ?is1 gives tw5ty feet = ! :ole height f ! bottom ( any wat]-valley to an adjo9+ summit4 ,?is proposition is easily v]ifi$ by a p]son :o tries at :at height on a %ip's ma/ ! horizon rema9s always 9 sight ov] ! top ( ! waves--all[ance be+ made = accid5tal incl9ations ( ! vessel1 & = h] s9k+ 9 ! wat] to mu* bel[ h] wat]-l9e1 at ! "t :5 %e rea*es ! bottom ( ! holl[ betwe5 two waves4 ,! spray ( ! sea1 driv5 along by ! viol5ce ( ! w9d1 is ( c\rse mu* high] ?an ! summit ( ! liquid wave2 & a wave1 com+ aga9/ an ob/acle1 may da% to a great elevation above x4 ,at ! ,eddy/one ,light-h\se1 :5 a surge breaks :i* has be5 gr[+ "u a /orm all ! way across ! ,atlantic1 x da%es ev5 ov] ! lant]n at ! summit4 #bja4 ,mom5tum4--,! mom5tum ( a body is its =ce :5 9 motion4 ,9 e/imat+ ! mom5tum ( any body two ?+s mu/ be consid]$--its velocity1 & its quantity ( matt] or weight4 ,a bullet fir$ f a gun has a va/ly great] =ce1 or p[] ( ov]com+ ob/acles1 ?an "o ?r[n by ! h&1 f its great] velocity4 ,n[ suppose ! weight or quantity ( matt] to be increas$ t5 times1 & t x moves ) ! same velocity z be=e1 x w h t5 times z mu* =ce z be=e1 & w ov]come t5 times z great an ob/acle4 ,= ?is reason a small /one dropp+ ^u a man's head may d b little h>m1 :ile "o t5 times z l>ge1 fall+ f ! same height1 may /un & p]haps kill him4 ,b if ! l>ge /one c\ld fall ) only "o-t5? ( ! velocity ( ! small "o1 ! effect ( bo? w\ld be ! same4 ,let ?is example illu/rate ! rule = calculat+ ! mom5tum ( mov+ bodies1 viz41 multiply ! quantity ( matt] into ! velocity3 ,let ! weight ( ! small /one be #a ounce1 & t ( ! l>ge "o #aj ounces4 ,if !y fall f a height ( #af feet ! =ce ) :i* ! l>ge "o w /rike w be express$ by #afj 7#afaj71 t ( ! small "o by #af 7#aaf74 ,suppose1 n[1 t by "s =ce 9 addition to gravity ! small "o c\ld be made to move t5 times z fa/ z ! l>ge "o1 ! =ce ) :i* x w\ld /rike w\ld be equal to t ( ! l>ge "o1 & w\ld be express$ by ! numb] #afj4 ,illu/ration3 ,fig4 #acc4 ,i w illu/rate ?is 9 ano!r way4 ,let a & b1 ,fig4 #acc1 be two balls ( clay ( equal size hang+ ov] a graduat$ arc4 ,n[ if b be let fall f ! top ( ! arc1 #f1 on /rik+ aga9/ a x gives half ( its motion to a1 & !y bo? move on toge!r4 ,b h[ f> w !y g8 ,to #c1 on ! o!r side ( ! arc4 ,:y8 ,let ! quantity ( matt] 9 ea* ball be call$ #a1 & ! motion ( b #f4 ,! mom5tum w !re=e be #f4 ,n[ ! mom5tum ( ! two toge!r w be ! same aft] ! bl[ z t ( b 0 be=e x4 ,b ! quantity ( matt] is twice z great1 & mu/ be call$ #b4 ,!re=e ! motion mu/ be repres5t$ z #c1 to make ! mom5tum #f 7#bc74 ,b suppose t b is twice z l>ge z a4 ,fall+ f #f1 its mom5tum w\ld be repres5t$ by #ab 7#bf74 ,aft] x has /ruck a1 ! mom5tum ( ! two toge!r w\ld be ! same z t ( b be=e ! /roke2 b ! quantity be+ #c1 ! motion w\ld be repres5t$ by #d4 ,!y w\ld !re=e move to #d on ! arc4 #bjb4 ,examples4--,a few examples illu/rat+ mom5tum z be+ comp\nd$ ( quantity ( matt] & velocity w suffice4 ,if a musket-ball ( an ounce weight 7 s mu* sp5t z to move ) only a velocity ( a foot 9 a second1 its =ce w\ld be s small t if x hit any "o x w\ld d no h>m4 ,b a cannon-ball weigh+ a ?\s& ounces mov+ at ?is sl[ rate w\ld h a v great =ce--equal1 9 fact1 to ! mom5tum ( an ounce ball mov+ #ajjj feet 9 a second4--,if a plank pu% a man's foot aga9/ a :>f he w sc>cely feel x2 b if ! plank1 in/ead ( be+ alone1 is "o ( a ?\s& planks fa/5$ toge!r 9 a raft1 & ! :ole move ) ! same velocity1 ! =ce w be increas$ a ?\s&-fold1 & ! plank w cru% ! foot4 ,s1 also1 if ! "o plank :5 alone %\ld move a ?\s& times z fa/ z ! :ole raft1 ! same result w\ld foll[4--,s s(t a sub/ance z a c&le c be fir$ ?r\gh a bo>d f ! mom5tum giv5 to x by an imm5se velocity4--,p]haps !re is no bett] example ( ! great =ce giv5 to a sub/ance by an enorm\s velocity ?an we h 9 ! w9d4 ,s light a ?+ is air t p ?9k ( x z almo/ no?+4 ,b let x be set 9 rapid motion1 & ! velocity gives to x a =ce1 a mom5tum1 :i* w drive %ips ^u ! %ore1 ?r[ ov] build+s1 & te> up trees by ! roots4 ,9 ?is la/ example we see beautifully illu/rat$ ! mean+ ( ! expression quantity ( motion4 ,9 ! mov+ air ea* p>ticle does its %>e ( ! "w 9 ! de/ructive effects m5tion$4 ,ea* p>ticle1 !re=e1 may be consid]$ z a res]voir ( motion1 & ! quantity ( motion 9 any case dep5ds ^u ! quantity :i* ea* p>ticle has & ! numb] ( ! p>ticles4 #bjc4 ,production ( ,great ,velocities4--,:5 !re are no ob/acles to motion great velocities may be produc$ by a s+le impulse4 ,?us at ! beg9n+ ! ,creator gave a s+le impulse to ea* ( ! heav5ly bodies1 produc+ enorm\s velocities1 :i* cont9ue unalt]$ ye> aft] ye> & age aft] age1 because ^! bodies fly 9 _! orbits ?r\gh space :]e !re is no resi/ance ( any ?+ l air to ret>d ! motion4 ,b 9 all ! motions t we see ar\nd u !re are ob/acles cont9ually ret>d+ !m2 & !re=e no v rapid motion is produc$ by any s+le impulse1 b a succession ( impulses is requir$ to accumulate suffici5t mom5tum s to ov]come ! ob/acles z to secure a great velocity4 ,i w give a few examples 9 illu/ration4 ,"o ( ! be/ examples we h 9 ! fall ( bodies to ! e>?4 ,y "k t ! great] ! elevation f :i* a body falls ! great] is its velocity1 & !re=e ! great] ! =ce ) :i* x /rikes4 ,:y is ?is8 ,if x fell because ( a s+le impulse mak+ x g t[>d ! e>?1 ?is w\ld n be ! case1 & if !re 7 no air 9 ! way ! velocity w\ld be uni=m2 b ! resi/ance ( ! air w\ld ret>d ! velocity1 s t if a numb] ( bodies %\ld receive ! same impulse at diff]5t elevations1 ! "o ! f>!/ (f w\ld be ! mo/ ret>d$1 & !re=e come d[n sl[] ?an all ! re/4 ,9 ?is case1 ! high] ! elevation f :i* a man %\ld fall ! less w\ld be ! injury4 ,b a body does n come to ! gr\nd by a s+le impulse1 b by a succession ( impulses1 or r a cont9u$ impulse4 ,e mom5t t ! body is com+ d[n x is drawn ^u by ! attraction ( ! e>?1 & ?is cont9u$ action ( ! cause ( ! motion makes x cont9ually increase 9 rapidity4 ,x is on ! same pr9ciple ( cont9u$ action t a man lifts 8 hamm] high :5 he wi%es to inflict a heavy bl[4 ,9 ?is case bo? gravitation & ! muscul> p[] ( ! arm ex]t _! =ce on ! hamm] ?r\gh ! :ole space4 ,a horse 9 kick+ does ! same ?+1 & by ! great l5g? ( ! leg ! velocity giv5 to ! foot by ?is cont9u$ action ( ! muscles is v great4 ,an arr[ is n %ot by a s+le mom5t>y impulse ( ! b[-/r+1 b ! /r+1 by foll[+ x ?r\gh a consid]able space1 gives x a cont9u$ impulse4 ,! action ( gunp[d] ^u a bullet issu+ f a gun is app>5tly an in/antane\s & s+le impulse1 b x is n really s4 ,! great velocity giv5 to ! bullet is giv5 to x by ! cont9u$ impulse ( ! expansive =ce ( gases produc$ f ! p[d]1 & x !re=e dep5ds mu* on ! l5g? ( ! b>rel4 ,if ?is be %ort1 ! =ce ( ! p[d] is n conf9$ long en\gh to ! bullet to give x a great velocity4 #bjd4 ,arre/ ( ,great ,velocities4--,z a cont9u$ =ce is requir$ to produce great velocities1 s a cont9u$ resi/ance is necess>y to arre/ !m4 ,x is by ! gradual or cont9u$ resi/ance ( ! air t ! motion ( a cannon-ball is de/roy$4 ,n[ if in/ead ( ?is gradual resi/ance any h>d sub/ance1 z a block ( granite1 7 oppos$ to ! progress ( ! ball1 x w\ld be at once brok5 asund]4 ,we see !n ! reason t a h>d sub/ance ( mod]ate ?ickness does n (f] s effectual a resi/ance to a body mov+ v rapidly z "s sub/ance ( a m yield+ k9d & ( great] bulk4 ,= example1 a bale ( cotton w arre/ a ball :i* w\ld pass ?r\gh a plank1 = ! cotton yield+ easily p]mits ! =ce ( ! ball to be felt & resi/$ by a l>g] bulk1 :ile ! wood1 n yield+1 opposes b a small portion ( its :ole bulk to ! =ce ( ! ball1 & !re=e does n arre/ x2 9 o!r words1 ! mom5tum ( ! ball is communicat$ to a mu* l>g] quantity ( matt] 9 ! cotton ?an 9 ! wood4 ,^! pr9ciples af=d a ready explanation ( a feat :i* is sometimes p]=m$4 ,a man lies ^u 8 back1 &1 hav+ an anvil c>efully plac$ ^u 8 *e/1 all[s "s "o to /rike a heavy bl[ ) a hamm] ^u ! anvil1 & no injury is receiv$4 ,:y8 ,because ! mom5tum or =ce ( ! hamm] is diffus$ ?r\gh\t ! bulk ( ! anvil1 & !n aga9 ?r\gh ! bulk ( ! yield+ *e/4 ,! man takes good c>e to h 8 lungs well fill$ ) air at ! mom5t ( ! bl[1 = ?is increases ! bulk & ela/icity ( ! *e/1 & ?us promotes ! diffusion ( ! mom5tum4 ,if ! bl[ ( ! hamm] 7 receiv$ directly ^u ! *e/ great injury w\ld be done1 = ! =ce w\ld n[ be sp5t ^u "o small spot alone4--,! pr9ciples above elucidat$ are appli$ by m5 in/9ctively 9 _! common labors & ef=ts4 ,y see a man cat*+ bricks t are toss$ to him4 ,z he receives ! bricks into 8 h&s he lets 8 h&s & ! bricks move toge!r a little way1 s t he may gradually arre/ ! motion ( ! bricks4 ,to d x sudd5ly w\ld give him a pa9ful lesson on mom5tum4 ,s :5 a man jumps f a height he does n come to ! gr\nd 9 a /raight position4 ,?is w\ld cause a sudd5 & !re=e a pa9ful arre/ ( ! motion ( ! :ole body4 ,to avoid ?is he comes to 8 feet ) all ! great jo9ts ( 8 body b5t1 s t ! diff]5t portions approa* ! gr\nd successively1 8 head hav+ its motion arre/$ la/4 ,illu/ration3 ,fig4 #acd4 #bje4 ,communication ( ,motion 9 ,ela/ic ,bodies4--,mom5tum is transf]r$ f "o body to ano!r v diff]5tly 9 ela/ic f :at x is 9 non-ela/ic bodies4 ,z y saw 9 #bja1 :5 "o non-ela/ic body /rikes ^u ano!r ! mom5tum is divid$ betwe5 !m1 & bo? move on toge!r4 ,n[ if a & b1 ,fig4 #acc1 7 ela/ic bodies1 z ivory balls1 & b %\ld be let fall aga9/ a1 x w\ld give all its mom5tum to a4 ,!re=e b w\ld /op1 & a w\ld move on to ! same height f :i* b came4 ,! reason is1 t ! velocity lo/ by b & receiv$ by a is j d\ble :at x w\ld be if ! balls 7 non-ela/ic4 ,= ! same reason1 if a & b1 be+ ela/ic1 meet ea* o!r f equal heights on ! arc1 !y w bo? reb\nd1 & return to ! same heights f :i* !y came4 ,b if non-ela/ic !y simply de/roy ea* o!r's mom5tum & /op4 ,! effect produc$ 9 ! =m] case is j twice z great z 9 ! latt]1 z y may see by reckon+ on ! arc4 ,= ! same reason1 too1 if y h a r[ ( ela/ic balls1 z 9 ,fig4 #acd1 & let a fall f ! po9t i ^u b1 x w /op !re2 & communicat+ all its mom5tum to b1 ?is mom5tum w pass f b to c1 & s on ?r\gh all ! r[ ( balls to e1 ! la/ "o1 :i* w fly (f to ! po9t h1 at ! same height ) i1 ! po9t f :i* a fell4 ,if b be held /ill1 & a be let fall ^u x1 a w reb\nd to ! height f :i* x fell1 = !n ! compress$ ela/ic spr+ 7 #ci7 ( ea* ball1 z b is immovable1 communicates all ! motion to a4 ,x is = ?is reason t an ela/ic ball1 on be+ ?r[n aga9/ any ?+ fix$1 reb\nds4 ,if :at x is ?r[n aga9/ be p]fectly ela/ic x reb\nds ) a =ce equal to t ) :i* x is ?r[n4 ,illu/ration3 ,fig4 #ace4 #bjf4 ,reflection ( ,motion4--,if an ela/ic body be ?r[n p]p5dicul>ly ^u a surface x reb\nds 9 ! same pa? 9 :i* x is ?r[n4 ,b if x hit ! surface obliquely x is ?r[n (f or reflect$ 9 a diff]5t direction4 ,?us a ball ?r[n f b ^u c1 ,fig4 #ace 7p4 #aeh71 w return 9 ! l9e drawn to b4 ,b if x be ?r[n f d x w be reflect$ 9 ! l9e c a4 ,n[ ! angle d c b1 call$ ! angle ( incid5ce1 is always equal to b c a1 ! angle ( reflection4 ,! same1 y w f9d 9 o!r p>ts ( ?is book1 is true ( s\nd & light & heat4 #bjg4 ,uni=mity ( ,motion4--,s9ce motion1 :5 once begun1 is dispos$ to cont9ue unless arre/$ by ob/acles1 x is naturally uni=m bo? 9 its velocity & its direction4 ,i w speak n[ only ( velocity4 ,suppose a body to be set 9 motion1 & to meet ) no opposition f friction1 or ! resi/ance ( air1 or attraction1 x w\ld move on =ev]1 & ) ! same velocity ) :i* x began4 ,n[ precisely ^! circum/ances we h 9 ! motion ( ! heav5ly bodies 9 _! orbits4 ,!y are1 x is true1 "u ! influ5ce ( attraction1 b 9 su* a way1 z y w soon see1 z n to int]f]e ) ! uni=mity ( _! motion4 ,7 x n = ?is uni=mity we %\ld h no regul>ity ( times & seasons4 ,x is only by ! uni=m motion ( ! e>? r\nd ! sun1 & r\nd its own axis1 t we c calculate = to-morr[1 or next week1 or next ye>4 ,if ^! motions 7 irregul> x w\ld ?r[ confusion into all our calculations = ! future & all our recollections ( ! pa/4 ,we c measure "t by no?+ else b regul> motion1 & 7 !re no regul> motion we %\ld h m]ely ! v inaccurate measure furni%$ by our s5sations4 ,to measure "t ) accuracy we take "s great & ext5sive uni=m motion z our /&>d4 ,?us1 ! revolution ( ! e>? ar\nd ! sun we take z "o division ( "t1 & call x a ye>4 ,we obs]ve t dur+ ?is "t x :irls ar\nd on its own axis #cfe times1 & ! "t occupi$ by ea* ( ^! revolutions we call a day4 #bjh4 ,! ,p5dulum4--,v>i\s modes ( measur+ "t h be5 adopt$ by mank9d4 ,at fir/ "t 0 inaccurately divid$ by m]ely obs]v+ ! sun4 ,b aft] a :ile man resort$ to v>i\s contrivances to measure %ort p]iods ( "t ) accuracy4 ,all ( ^! dep5d ^u ! uni=mity ( motion alone4 ,! sun-dial measures "t by ! uni=m movem5t ( ! %ad[ on its face1 caus$ by ! uni=m movem5t ( ! e>? 9 relation to ! sun4 ,! h\r-glass measures "t by ! uni=m fall ( s& produc$ by ! attraction ( gravity4 ,! be/ measurem5t ( "t is by ! comp>atively mod]n inv5tion ( clocks & wat*es1 9 :i* "t is divid$ into v m9ute p]iods by ! uni=m motion ( ! p5dulum or ! balance-:eel4 ,! p5dulum furni%es an int]e/+ example ( motion kept up by ! influ5ce ( gravity4 ,x 0 n till ! "t ( ,galileo1 less ?an ?ree c5turies ago1 t its op]ation 0 und]/ood & appropriat$ to ! measurem5t ( "t4 ,he obs]v$ t *&eli]s hang+ f l(ty ceil+s vibrat$ v long & uni=mly aft] !y 7 accid5tally agitat$1 & ! ?\ght ( ! philosoph] evolv$ f ?is ph5om5on ! mo/ important results4 ,?\gh x _h be5 be=e m5's eyes 9 "s %ape or o!r s9ce ! creation1 x 0 res]v$ = ,galileo to obs]ve its significance1 & ! result is t ! p5dulum has become man's "t-keep] ov] ! :ole e>?4 ,illu/ration3 ,fig4 #acf4 #bji4 ,explanation ( its ,op]ation4--,a p5dulum consi/s commonly ( a ball or weight at ! end ( a rod susp5d$ s z to vibrate ) little friction at ! po9t ( ! susp5sion4 ,let a b1 ,fig4 #acf1 repres5t su* a p5dulum4 ,:5 x is at re/ x makes a plumb-l9e hang+ t[>d ! c5tre ( ! e>?4 ,if x be rais$ to c & be left to fall1 ! =ce ( gravity w n only c>ry x to b1 b1 by ! accel]at$ velocity or accumulat$ mom5tum :i* x gives x 9 its desc5t1 x w c>ry x to d4 ,! same w\ld be true ( its return f d4 ,& x w\ld vibrate =ev] 9 ?is way if x c\ld be entirely fre$ f ! resi/ance ( ! air & friction4 ,b1 z x is1 ! p5dulum left to itself gradually loses its motion f ^! ob/acles4 ,9 ! common clock ! (fice ( ! weight is to c\nt]act ! influ5ce ( ^! ob/acles1 & keep ! p5dulum vibrat+4 ,9 ! wat* ! ma9spr+ p]=ms ! same (fice to ! balance-:eel4 ,illu/ration3 ,fig4 #acg4 ,! times ( ! vibrations ( a p5dulum are ne>ly equal :e!r ! arc x describes be great or small4 ,= :5 ! vibration is a l>ge "o ! velocity :i* ! p5dulum acquires 9 fall+ is great] ?an :5 ! vibration is ( small ext5t4 ,! reason is t ! high] x rises ! m /eep is ! beg9n+ ( its desc5t4 ,?us a c1 ,fig4 #acg1 is /eep] ?an c b4 ,illu/ration3 ,fig4 #ach4 ,fig4 #aci4 #baj4 ,gridiron ,p5dulum4--,! long] a p5dulum is ! long] "t does its vibration occupy4 ,x requires a p5dulum ( ! l5g? ( a little ov] ?irty-n9e in*es to vibrate seconds4 ,cold wea!r1 by contract+ ! p5dulum1 makes x vibrate quick] ?an 9 summ]1 & s makes ! clock g fa/]4 ,v>i\s contrivances h be5 resort$ to 9 ord] to c\nt]act ! v>iation ( l5g? 9 p5dulums by heat & cold1 b :at is call$ ! gridiron p5dulum is ! be/4 ,9 ?is p5dulum an +5i\s use is made ( ! fact t heat exp&s brass ne>ly twice z mu* z x does /eel4 ,a simple =m ( ?is p5dulum is giv5 9 ,fig4 #ach4 ,! middle rod is made ( brass1 & ! side rods1 b & c1 ( /eel4 ,suppose t ! brass rod exp&s or increases 9 l5g? half an in*4 ,! rod c w\ld be drawn upw>d by x1 & ! rod b d[nw>d1 ea* "o qu>t] ( an in*2 b ?is effect is c\nt]act$ by ! expansion ( ea* /eel rod1 :i* is half t ( ! brass1 t is1 "o qu>t] ( an in*4 ,! ball d1 !re=e1 always reta9s ! same di/ance f ! po9t ( susp5sion1 e4 ,9 ,fig4 #aci y h a gridiron p5dulum ( a m comp\nd "*1 a "p ( ! b>s be+ /eel1 & a "p brass4 #baa4 ,motion ,dispos$ to be ,/raight4--,:5 a body is set 9 motion1 if x be left to itself--t is1 if no?+ int]f]e ) its motion--x w move 9 a p]fectly /raight l9e4 ,x requires "s int]f]5ce f "s =ce to b5d ! motion4 ,y w readily see f ! views :i* ,i h giv5 y t !re nev] is any motion t is1 /rictly speak+1 /raight1 because e motion is 9 "s measure comp\nd2 t is1 ea* cause ( motion is modifi$ 9 its action by o!r causes ( motion4 ,b we c approximate v ne>ly to /raight motion by mak+ "o cause prepond]ate v mu* ov] o!r causes4 ,?is ,i w illu/rate4 ,if we fire a bullet horizontally f a gun x is act$ ^u by ?ree =ces3 ! propulsive =ce ( ! p[d]1 ! resi/ance ( ! air1 & ! attraction ( ! e>?4 ,! action ( ! second ( ^! is 9 direct opposition to ! fir/1 & !re=e only ret>ds ! motion1 & does n t5d at all to turn x f its /raight c\rse4 ,?is is se5 9 ! fact t ! ball is turn$ nei!r to ! "r h& nor to ! left4 ,b ! ?ird =ce t5ds to make ! ball b5d its c\rse t[>d ! gr\nd4 ,x does ?is f ! in/ant t ! ball leaves ! gun ?r\gh\t its flight1 b s slightly t practically we c consid] ! ball z go+ /raight = %ort di/ances4 ,:5 we take a long range we mu/ make all[ance = ?is b5d+ d[n ( ! motion4 ,accord+ly1 = ! sake ( precision1 a d\ble sight is provid$ 9 mod]n guns1 z se5 at ,a & ,b1 ,fig4 #adj4 ,?is y see secures ! po9t+ ( ! gun a little above ! level ( ! object aim$ at1 t level be+ indicat$ by ! dott$ l9e4 ,illu/ration3 ,fig4 #adj4 ,illu/ration3 ,fig4 #ada4 ,! great] is ! propulsive =ce ! m ne>ly to a /raight l9e is ! pa? ( ! propell$ body4 ,?is may be se5 v cle>ly 9 ,fig4 #ada1 repres5t+ ! issu+ ( wat] at diff]5t po9ts f a vessel4 ,z pressure 9 a liquid is z dep?1 #aba1 ! =ce ) :i* ! wat] is ?ru/ out is great] at ,c ?an at ,b1 & at ,d ?an at ,c4 ,! issu+ /ream1 !re=e1 is mo/ ne>ly /raight at ! l[e/ po9t1 ,d4 ,! motion ( projectiles1 ?us allud$ to1 w be m p>ticul>ly notic$ f>!r on4 ,illu/ration3 ,fig4 #adb4 ,illu/ration3 ,fig4 #adc4 #bab4 ,comp\nd ,/raight ,motion4--,we call t motion comp\nd :i* is produc$ by two or m =ces act+ ^u ! body4 ,?is may be /raight or curv$4 ,i w fir/ speak ( ! /raight4 ,if a man attempt to r[ a boat /raight across a riv]1 ! po9t :i* he w rea* w n be directly opposite to t f :i* he />t$1 b bel[4 ,two =ces act ^u ! boat3 ! curr5t t5d+ to c>ry x /raight d[n ! /ream1 & 8 r[+ t5d+ to c>ry x /raight across4 ,! boat w g 9 nei!r ( ^! directions1 b 9 a l9e betwe5 !m4 ,let ,a ,b1 ,fig4 #adb1 repres5t ! bank ( ! riv]1 f :i* he />ts at ,a1 ) ! b[ ( ! boat po9t+ to ,c1 on ! opposite bank4 ,suppose n[ t 9 ! "t t x takes him to r[ across ! curr5t w\ld c>ry him d[n to ,b if he did n r[ at all4 ,he w 9 ?is "t1 by ! two =ces toge!r1 rea* ! po9t ,d1 opposite to ,b1 8 c\rse be+ ! l9e ,a ,d4 ,s if ! w9d bl[ ^u a vessel 9 su* a way z to c>ry x ea/w>d1 & a curr5t is pu%+ x s\?w>d1 ! vessel w run 9 a middle l9e1 viz41 s\!a/4 ,= ! same reason if a boy kick a foot-ball already 9 motion1 x w n be c>ri$ 9 ! direction 9 :i* he kicks x1 b 9 a l9e betwe5 t direction & ! direction 9 :i* its =m] motion 0 c>ry+ x4 ,9 swimm+1 fly+1 r[+1 etc41 we h examples ( comp\nd motion1 ! middle l9e betwe5 ! directions ( ! =ces always be+ tak5 by ! body mov$4 ,illu/ration3 ,fig4 #add4 ,illu/ration3 ,fig4 #ade4 ,if we take ,fig4 #adb1 illu/rat+ ! movem5t ( ! boat1 & draw two l9es1 "o f ,a to ,c & ! o!r f ,b to ,d1 we %all h ! p>allelogram ,a ,c ,d ,b1 ,fig4 #adc1 9 :i* ! l9e ,a ,c repres5ts ! =ce ( ! r[+1 ,a ,b ! =ce ( ! curr5t1 & ,a ,d ! pa? ( ! boat4 ,y see1 !n1 t if we wi% to f9d 9 :at direction & h[ f> 9 a giv5 "t a body act$ ^u by two =ces w move1 we are to draw two l9es 9 ! direction ( ^! =ces1 & ( a l5g? 9 proportion to ! di/ances to :i* !y w\ld move x 9 t "t2 !n by draw+ two l9es p>allel to ^! we %all h a p>allelogram1 & ! diagonal ( ?is w repres5t ! di/ance & ! c\rse ( ! mov+ body4 ,if a body be act$ ^u by two equal =ces & at "r angles to ea* o!r1 ! figure describ$ w be a squ>e1 z y see 9 ,fig4 #add4 ,if !y v>y f be+ at "r angles to ea* o!r ! figure w v>y 9 ! same proportion f ! squ>e figure1 z se5 9 ,figs4 #ade & #adf4 ,9 ! ?ree figures ,a ,b & ,a ,d repres5t ! two =ces1 & ,a ,c ! result+ motion4 ,y obs]ve by ^! diagrams t ! ne>] ! two =ces come to be+ 9 ! same direction ! f>!r w !y move ! body4 ,illu/ration3 ,fig4 #adf4 ,illu/ration3 ,fig4 #adg4 ,y see ?is 9 ! diff]5t l5g?s ( ! diagonals 9 ,fig4 #add & ,fig4 #adf4 ,! m ne>ly1 !re=e1 ! w9d co9cides ) ! curr5t ! m rapidly w a vessel be c>ri$ along be=e ! w9d4 ,:51 on ! o!r h&1 ! angle at :i* two =ces act ^u a body is mu* great] ?an a "r angle1 !y w propel x b a small di/ance4 ,?us if two =ces act on a body 9 ! directions ,d ,a & ,d ,c1 ,fig4 #adg1 !y w move x only ! di/ance repres5t$ by ! diagonal ,d ,b4 ,?is diagram repres5ts ! motion ( a vessel sail+ almo/ directly aga9/ a curr5t by a w9d ! =ce ( :i* is equal to t ( ! curr5t1 :ile ,fig4 #adf repres5ts ! motion ( a vessel :]e w9d & curr5t be+ ( equal =ce v ne>ly co9cide4 ,9 ! above diagrams ,i h suppos$ ! =ces to be equal2 b ! same tru? c be %[n 9 reg>d to unequal =ces z se5 9 ,fig4 #adc4 #bac4 ,curv$ ,motion4--,no s+le impulse c produce a curv$ motion4 ,nei!r c two or m impulses communicat$ at "o "t4 ,9 bo? ( ^! cases ! motion w\ld be 9 a /raight l9e4 ,curv$ motion may be produc$ by two =ces1 "o ( :i* gives x a s+le impulse1 & ! o!r acts ^u x cont9u\sly4 ,a famili> example y h 9 a ball :irl$ ar\nd at ! end ( a /r+4 ,y c give x an impulse1 & !n1 hold+ x 9 y\r h&1 let x :irl4 ,"h ! impulse y give ! ball is "o =ce1 & ! t5sion ( ! /r+ is ! o!r1 ! latt] act+ cont9u\sly4 ,y\r h& hold+ ! end ( ! /r+ is ! c5tre ab\t :i* ! motion revolves2 ! impulse :i* y h giv5 ! ball t5ds to make x fly away f ! c5tre 9 a /raight l9e1 & h5ce is call$ ! c5trifugal =ce2 ! t5sion ( ! /r+ keeps x f ?us fly+ (f1 & s is call$ ! c5tripetal =ce4 ,:5 ! e>?1 at ! creation1 0 put 9 motion x w\ld h mov$ 9 a p]fectly /raight l9e1 7 x n con/antly drawn t[>d ! sun by attraction1 ! cont9u\s action ( ?is latt] =ce be+ ! same z ! t5sion ( ! /r+ 9 ! case ( ! :irl+ ball4 ,! =ce ( attraction1 !n1 is ! c5tripetal =ce ( ! e>?1 & ! impulse :i* 0 giv5 to x by ! ,creator 9 ! beg9n+ is its c5trifugal =ce2 &1 balanc$ betwe5 ^! two =ces1 ! e>? & all ! heav5ly bodies move uni=mly onw>d 9 _! orbits4 ,! c5trifugal =ce y see 9 ^! illu/rations is simply ! t5d5cy ( motion to a /raight l9e f ! in]tia ( matt]2 & ?is is con/antly c\nt]act$ by ! c5tripetal =ce4 ,illu/ration3 ,fig4 #adh4 #bad4 ,illu/rations ( ,c5trifugal ,=ce4--,:5 a wet mop is :irl$ ! wat] flies (f 9 e direction by its c5trifugal =ce4 ,on ! same pr9ciple a dog1 com+ out ( ! wat]1 %akes (f ! wat] by a semi-rot>y motion4--,:5 a susp5d$ bucket ( wat] is turn$ swiftly ar\nd ! wat] rises high on its sides1 & leaves a holl[ 9 ! middle4 ,x is ! t5d5cy to fly away f ! c5tre ( motion t causes ?is4--,l>ge :eels1 revolv+ ) great velocity1 h be5 brok5 by ! c5trifugal =ce ( its p>ticles1 & h5ce ! necessity ( hav+ su* :eels made v /rong4 ,! imm5se gr9d/ones us$ 9 gun-factories h sometimes be5 brok5 ?r\gh 9 ! middle1 or h fl[n into pieces f ! same cause4--,a man rid+ horseback on turn+ a %>p corn] incl9es 8 body t[>d ! corn]1 to avoid be+ ?r[n (f by ! c5trifugal =ce4 ,s1 9 ! feats ( ! circus1 a man /&+ on a horse runn+ at full spe$ ar\nd ! r+ incl9es 8 body /rongly inw>d1 z y see 9 ,fig4 #adh 7p4 #afg74 ,! horse also in/9ctively incl9es 9 ! same direction = ! same reason4 ,if ! rid] f9ds himself 9 dang] ( fall+1 by mak+ ! horse g a little fa/]1 ?us add+ to ! c5trifugal =ce1 ! difficulty is reliev$4--,! c5trifugal =ce is made use ( 9 mill+4 ,! gra9 is admitt$ betwe5 two circul> /ones by a hole 9 ! c5tre ( ! upp] "o1 & z ! /one revolves x con/antly moves t[>d ! circumf]5ce1 & !re escapes z fl\r4 ,illu/ration3 ,fig4 #adi4 #bae4 ,b5ds 9 ,riv]s4--,we see ! op]ation ( ! c5trifugal =ce 9 ! b5ds ( riv]s4 ,:5 a b5d has once comm5c$ 9 a riv] x is apt to increase1 = z ! wat] sweeps along ! out] bank ( ! b5d x presses /rongly aga9/ x1 j z ! wat] 9 ! :irl$ bucket1 #bad1 presses aga9/ its sides1 by its c5trifugal t5d5cy1 or1 9 o!r words1 its t5d5cy to assume a /raight motion4 ,( c\rse ! result is a we>+ away ( ?is out] bank1 & 9 proportion to ! loos5ess ( ! mat]ial ( :i* x is compos$ & ! velocity ( ! riv]'s curr5t4 ,& :5 "o b5d is =m$ ano!r is apt to =m bel[1 b 9 an opposite direction4 ,! wat]1 by sweep+ along ! b5d a1 ,fig4 #adi1 is direct$ by x t[>d ! opposite bank at b1 & makes a b5d !re also4 ,illu/ration3 ,fig1 #aej4 ,x is 9 ?is way t a riv]1 runn+ ?r\gh a loose soil1 ! ,mississippi1 = example1 acquires a v s]p5t9e c\rse4 ,z ! wat] 9 ! :irl$ bucket rises ar\nd ! sides1 s 9 ! riv] ! wat] w be high] aga9/ ! bank a ?an on ! opposite side4 ,eddies & :irlpools are produc$ on ! same pr9ciples1 :5 wat] is oblig$ to turn quickly ar\nd "s project+ po9t4 ,if a curr5t 7 mov+ swiftly along ! %ore a t[>d ! po9t b1 ,fig4 #aej1 x w\ld be direct$ outw>d by ! resi/ance ( ?is projection1 & s a depression w\ld be left at c1 j beh9d x1 & ?is depression w\ld be surr\nd$ by a revolv+ edge ( wat]4 ,illu/ration3 ,fig4 #aea4 #baf4 ,application ( ! ,c5trifugal ,=ce 9 ! ,arts4--,mu* use is made ( ! c5trifugal =ce 9 ! arts1 b ,i w give b two examples4 ,9 ! art ( pott]y ! clay is made to revolve on a :irl+ table1 ! workman at ! same "t giv+ ! clay su* %ape z he *ooses ) 8 h&s & v>i\s in/rum5ts4 ,9 do+ ?is he con/antly has ref]5ce to ! c5trifugal =ce1 giv+ ! table a velocity proportion$ to ! am\nt ( ?is =ce :i* is ne$$ 9 ea* /age ( ! op]ation4 ,! mo/ beautiful application ( ?is =ce t ,i h ev] witness$ is 9 ! manufacture ( common w9d[-glass4 ,! glass-bl[] ga!rs up on ! end ( 8 iron tube a quantity ( ! melt$ glass1 & bl[s x out into a l>ge globe4 ,:5 x is ( suffici5t size & ?9ness he places x on a re/1 z y see 9 ,fig4 #aea 7p4 #afi74 ,a second man n[ comes ) a rod hav+ "s melt$ glass on ! end1 & atta*es ?is to ! globe at a po9t opposite to t :]e ! tube ( ! fir/ man is jo9$ to x4 ,!re n[ comes a boy1 &1 giv+ ?is tube a quick bl[1 sev]s its connection ) ! globe1 leav+ a hole 9 ! globe :]e ! glass breaks out4 ,! second man1 hav+ ! globe atta*$ to 8 rod1 c>ries x to a blaz+ furnace1 & re/+ ! rod on a b> at its m\?1 puts ! globe directly into ! flame4 ,! glass is soon s(t5$1 & he :irls ! globe cont9ually ar\nd4 ,! hole 9 ! globe enl>ges by ! c5trifugal =ce1 & at l5g? by ?is =ce ! globe is *ang$ into a flat1 circul> disk4 ,panes ( glass :i* are call$ bull's-eyes are cut f ! c5tres ( ^! disks4 ,illu/ration3 ,fig4 #aeb4 #bag4 ,/eam-,gov]nor4--,! op]ation ( ! c5trifugal =ce is beautifully exemplifi$ 9 ?is regulator ( ! /eam-eng9e4 ,x consi/s ( two heavy balls1 ,fig4 #aeb1 susp5d$ by b>s f a v]tical axis1 ! b>s be+ connect$ to ! axis by h+es4 ,! b>s h also a h+$ connection at _! l[] ends ) two small] b>s1 & ^! latt] h a simil> connection ) a coll> t slides up & d[n on ! axis4 ,n[ ! fa/] ! axis turns ! f>!r ! balls fly out f x1 f ! c5trifugal =ce1 & ! high] ! coll> slides up on ! axis4 ,f ! coll> ext5ds1 z y see1 a lev]4 ,?is is connect$ ) a valve 9 ! /eam-pipe1 & s regulates ! am\nt ( /eam t ent]s ! work+ "p ( ! eng9e4 ,! object ( ?is +5i\s contrivance is to make ! eng9e regulate its own velocity4 ,:5 x is n work+ too fa/ ! valve 9 ! /eam-pipe is wide op54 ,b ! mom5t t x works too rapidly ! balls ext5d out f> f ! axis1 s t ! coll> rises1 & by ! lev] p>tly closes ! valve4 ,less /eam1 !re=e1 c come to ! eng9e1 & ! eng9e work+ 9 consequ5ce less rapidly1 ! balls fall aga91 op5+ ! valve4 ,y see1 !n1 t ! regulation ( ?is valve by ! gov]nor effectually prev5ts ! action ( ! eng9e f becom+ too rapid4 ,illu/ration3 ,fig4 #aec4 ,illu/ration3 ,fig4 #aed4 #bah4 ,%ape ( ! ,e>? ,influ5c$ by ! ,c5trifugal ,=ce4--,if ! pott] %\ld make a ball ( s(t clay revolve rapidly ar\nd on a /ick run ?r\gh x1 ! ball w\ld bulge out at ! middle1 :]e ! c5trifugal =ce is greate/1 & w\ld be flatt5$ at ! ends :]e ! /ick runs ?r\gh x4 ,?is is precisely :at has happ5$ to ! e>?4 ,at ! equator1 :]e ! c5trifugal =ce is greate/1 x has bulg$ out ab\t ?irte5 miles1 :ile x is flatt5$ at ! poles4 ,?is %ape 0 ( c\rse assum$ be=e ! e>? became solid4 ,9 ,fig4 #aec we h ! %ape ( ! e>? repres5t$1 ,n ,s be+ ! pol> diamet]1 & ,e ,e' ! equatorial diamet]4 ,! t5d5cy to take ?is %ape f ! c5trifugal =ce may be illu/rat$ by ! in/rum5t repres5t$ 9 ,fig4 #aed4 ,x consi/s ( a set ( circul> hoops ( brass1 ) an axis1 b a4 ,! hoops are fa/5$ to ! axis at a1 b are left free at b4 ,by a little ma*9]y at ! top !y c be made to revolve rapidly1 & bulg+ out at ! sides by ! c5trifugal =ce1 !y slide d[n on ! axis at b4 ,illu/ration3 ,fig4 #aee4 #bai4 ,projectiles4--,i h already spok5 ( projectiles 9 #baa4 ,y saw !re t any body1 z a cannon-ball1 :i* is project$ horizontally1 falls to ! e>? 9 a curv$ l9e4 ,two =ces act on ! ball2 viz41 ! projectile =ce giv5 by ! p[d] & ! =ce ( gravitation4 ,! =ce ( gravity be+ always ! same1 ! %ape ( ! curve :i* ! project$ body describes mu/ dep5d on ! =ce ) :i* x is project$4 ,?is is v /rik+ly exemplifi$ 9 ! curves describ$ by ! diff]5t /reams ( wat] 9 ,fig4 #ada4 ,b :e!r ! projectile =ce be great or small1 ! mov+ body ?r[n horizontally w 9 e case rea* ! gr\nd 9 ! same "t4 ,?us if two cannons /& side by side on a height1 "o ( :i* w s5d a ball a mile & ! o!r half a mile1 ! two balls1 if fir$ toge!r1 w rea* ! gr\nd at ! same in/ant1 ?\gh at fir/ ?\ght x w\ld seem t ! ball :i* travels twice z f> z ! o!r w\ld take a long] "t to d x 94 ,?is is because ! horizontal =ce ( ! ball does n oppose 9 ! lea/ ! d[nw>d =ce ( gravity4 ,if x 7 ?r[n upw>d in/ead ( horizontally1 ! projectile =ce w\ld be oppos$ to gravity1 & 9 proportion z ! direction came ne> to be+ v]tical4 ,z horizontal =ce does n int]f]e ) ! action ( ! =ce ( gravity1 x foll[s t a ball dropp$ at ! in/ant at :i* ano!r is fir$ w rea* ! gr\nd at ! same in/ant t ! fir$ ball does4 ,?is c be made cle> by ,fig4 #aee4 ,suppose x takes ?ree seconds = a ball to fall f ! top ( a t[] to its foot4 ,9 ! fir/ second x falls to a4 ,! ball project$ horizontally f ! cannon1 be+ op]at$ ^u by ! same =ce ( gravity1 w fall j z f>1 & w be on a level ) x at b4 ,bo? balls fall f>!r & f>!r ea* second1 bo? be+ accel]at$ 9 ! same degree because x is done by ! same =ce4 ,! project$ ball w rea* d :5 ! fall+ ball is at c1 & ! pla9 at f :5 ! fall+ ball is at e1 ! foot ( ! t[]4 ,! same holds true 9 all cases4 ,a bullet dropp$ f a level ) ! b>rel ( a gun1 p>adoxical z x may seem1 w fall to ! gr\nd no soon] ?an "o :i* is %ot f ! gun4 ,illu/ration3 ,fig4 #aef4 #bbj4 ,all ,fall+ ,bodies really ,project$4--,:5 a body falls f any height1 x does n1 z y h already se5 9 #ahg1 fall 9 a /raight l9e1 z x appe>s to d4 ,x falls 9 a curv$ l9e1 =1 l all projectiles1 x is act$ ^u by a horizontal =ce z well z ! =ce ( gravity4 ,b :at is ?is horizontal =ce8 ,x is ! motion :i* ! body has 9 common ) ! e>? 9 its rotation on its axis4 ,9 ?is rotation ! height f :i* ! body falls goes to ! ea/w>d #aejj feet 9 a second4 ,if1 !re=e1 ! body did n p>take ( ! motion ( ! e>?1 & w5t to ! gr\nd 9 a /raight l9e 9 a second1 x w\ld be :5 x rea*$ ! gr\nd #aejj feet we/w>d f ! foot ( ! height f :i* x fell4 ,b x does p>take ( ! e>?'s motion1 & goes ea/w>d z fa/ z ! height does1 & s describes ! curv$ l9e ( a projectile4 ,suppose a ball falls f a height ,a1 ,fig4 #aef1 & 9 a second ( "t t height passes to ,c4 ,! =w>d or projectile =ce w\ld t5d to c>ry ! ball to ,c1 & ! =ce ( gravity w\ld t5d to c>ry x to ,b4 ,b bo? =ces act+ toge!r1 x pursues a middle pa?1 & ?is pa? is a curv$ l9e1 because "o ( ! =ces is a cont9u$ =ce1 #bac4 ,= ! same reason1 if a ball be dropp$ f a railway c> 9 motion1 & x takes a second = x to fall1 x w be at ! end ( t second j "u t "p ( ! c> f :i* x fell4 ,al?\gh ! c> may h mov$ a consid]able di/ance1 ! dropp$ ball1 p>tak+ ( its motion1 goes along ) x 9 its fall4 ,s a ball dropp$ f a ma/-head :5 a %ip is 9 motion goes along ) ! %ip 9 its fall4 ,! ball 9 ea* ( ^! cases describes 9 its fall a curv$ l9e4 #bba4 ,motion 9 ,orbits4--,:y is x1 let u ask1 t a cannon-ball %ot horizontally f "s great height w n revolve ar\nd ! e>? l ! moon4 ,x has ! same two =ces act+ ^u x z ! moon has--viz41 a projectile =ce1 & ! attraction ( ! e>?--& bo? ball & moon describe a curve 9 _! motion4 ,b ! curve ( ! ball b5ds to ! e>?1 :ile t ( ! moon ev] sweeps ar\nd ! e>?4 ,:y is ?is8 ,fir/1 !re is ! resi/ance ( ! air cont9ually ret>d+ ! velocity ( ! ball4 ,b1 secondly1 ev5 if ! ball c\ld be project$ f an elevation suffici5tly high to be outside ( ! atmosph]e1 ! =ce ( ! projection w\ld n be great en\gh4 ,we "k1 f ! rate ( progress ( ! heav5ly bodies 9 _! orbits1 t x w\ld require an imm5se velocity to keep ! ball f be+ br\ght to ! e>? by its attraction4 ,! ,creator ( ^! worlds1 :5 he laun*$ !m into _! orbits1 gave !m precisely t impulse :i* is ne$$ to balance ! c5tripetal =ce ( attraction1 & s !y pursue a middle c\rse betwe5 ! two directions 9 :i* ^! two =ces t5d to c>ry !m4 ,& z _! velocities h nev] be5 ret>d$ by ! resi/ance ( air or any o!r sub/ance1 !y h be5 ev] ! same f ! beg9n+4 ,,*apt] ,,xi4 ,,! ,,me*anical ,,p[]s4 #bbb4 ,ma*9es n ,s\rces ( ,p[]4--,! ,me*anical ,p[]s1 z !y are t]m$1 are six 9 numb]--viz41 ! ,lev]1 ! ,:eel & ,axle1 ! ,incl9$ ,plane1 ! ,screw1 & ! ,w$ge4 ,!y are n1 /rictly speak+1 p[]s2 =1 z y w see 9 ! c\rse ( our inve/igation1 !y are m]ely means ( apply+ p[] to advantage1 & are n 9 reality s\rces ( p[]4 ,! true s\rces ( p[] are ! causes ( motion treat$ ( 9 #aha4 ,! in/rum5t or ma*9e c n create p[]1 & ! only use ( all ! v>iety ( tools & ma*9]y is to enable u to apply p[] 9 su* a mann]1 ) su* a velocity1 & 9 su* a direction1 z to effect ! objects :i* we h 9 view4 ,! t]m ,me*anical ,p[]1 !n1 is n /rictly prop] z appli$ to ^? contrivances :i* commonly h ?is "n2 b ! t]m is 9 s g5]al use t x w\ld n be well to alt] x4 ,e in/rum5t1 h[ev] simple & insignificant1 & e ma*9e1 h[ev] l>ge or complicat$1 is an example ( "s "o ( ! six ,me*anical ,p[]s1 or ( a comb9ation ( !m4 ,i w proce$ to consid] ea* ( ^! sep>ately4 ,9 do+ ?is c]ta9 t]ms w be us$ :i* ,i w fir/ expla94 ,p[] is ! =ce by :i* a ma*9e or in/rum5t is mov$4 ,weight is ! resi/ance to be ov]come4 ,if ! resi/ance be 9 "s o!r =m ?an t ( weight x is call$ te*nically by ?is "n4 ,s :at is call$ ,p[] may be 9 ! =m ( weight4 ,! fulcrum is ! po9t on :i* ! in/rum5t or ma*9e is support$ :ile x is 9 motion4 #bbc4 ,! ,lev]4--,! ,lev] is ! mo/ simple ( all ! ,me*anical ,p[]s1 & is !re=e 9 univ]sal use4 ,?\gh ! savage makes use ( b few tools 9 comp>ison ) ! civiliz$ man1 he uses ! lev] almo/ con/antly 9 "s =m or o!r4 ,! w$ge is ! only "o ( ! o!r ,me*anical ,p[]s t he uses to any great ext5t4 ,lev]s are ( ?ree k9ds1 :i* ,i w notice sep>ately4 ,illu/ration3 ,fig4 #aeg4 ,illu/ration3 ,fig4 #aeh4 #bbd4 ,lev] ( ! ,fir/ ,k9d4--,9 ! lev] ( ! fir/ k9d ! fulcrum or prop is betwe5 ! weight & ! p[]4 ,! common cr[-b> or h&-spike is a famili> example1 z se5 9 ,fig4 #aeg--! /one1 ,s1 or o!r heavy body to be mov$ be+ ! weight1 ! /one or block ( wood1 ,f1 on :i* ! b> re/s be+ ! fulcrum1 & ! pressure ( ! h&1 ,h1 ! p[]4 ,! ne>] ! fulcrum is to ! weight1 or ! f>!r is ! p[] f ! fulcrum1 ! great] is ! =ce ( ! lev]4 ,?is may be illu/rat$ on ,fig4 #aeh4 ,"h ! %ort arm ( ! lev]1 z x is call$1 ,c ,w1 is "o eigh? ( ! l5g? ( ! long arm1 ,a ,c4 ,if ! weight hang+ at ! end ( ! %ort arm be #gb p\nds1 a weight ( #i p\nds1 or ! =ce ( a h& am\nt+ to ?is1 w balance x at ! end ( ! long arm4 ,b if ! p[] %\ld be appli$ at only f\r times ! di/ance f ! fulcrum at :i* ! weight is1 !n x w\ld require a =ce ( #ah p\nds to balance ! #gb p\nds on ! %ort arm4 ,simil> v>iations c be made by alt]+ ! l5g? ( ! %ort arm4 ,! p[] & ! weight w balance ea* o!r if ! weight multipli$ by ! l5g? ( ! %ort arm1 & ! p[] multipli$ by ! l5g? ( ! long arm1 give equal products4 #bbe4 ,scales & ,/eely>ds4--,9 ! common scale-beam we h a lev]1 ! two arms ( :i* are equal1 & !re=e equal weights susp5d$ at ! ends balance4 ,if !y be n exactly equal1 a heavi] weight w be necess>y on ! %ort] arm ?an on ! long]4 ,! inequality w injure ! buy] if ! prop be too ne> ! scale 9 :i* ! weights are plac$1 & ! sell] if x be too ne> t :i* holds ! article to be sold4 ,any diff]5ce c be easily detect$ by *ang+ ! places ( ! article & ! weights4 ,:5ev] *eat+ is practic$ by ! false balance1 x is ( c\rse done 9 a small way1 to avoid any obs]vation by ! eye ( ! inequality ( ! two arms ( ! scale-beam1 & ! weight ( ! scale hang+ f ! %ort] arm is made a little great] ?an t ( ! o!r1 s t !y may balance4 ,scales may be r5d]$ v accurate by mak+ ! fulcrum or pivot ( h>d5$ /eel1 & ( a w$ge %ape1 ) a %>p edge1 9 ord] to avoid friction z mu* z possible4 ,! /eely>d diff]s f ! scale-beam 9 hav+ ! arms ( diff]5t l5g?s4 ,! pr9ciples on :i* ?is in/rum5t is con/ruct$ 7 develop$ 9 :at ,i said ( ,fig4 #aeh4 ,:5 ei!r ) ! balance or ! /eely>d two weights balance ea* o!r ! c5tre ( ! weights & ! app>atus tak5 toge!r is j ov] ! fulcrum1 #aie4 ,we see 9 ?is ! reason t x is necess>y to h ! prop ne> ! l>ge weight :5 we wi% to balance x by a small "o4 #bbf4 ,o!r ,examples4--,scissors are d\ble lev]s ( ! fir/ k9d4 ,! fulcrum is ! rivet1 ! weight or ! resi/ance to be ov]come is ! article to be cut1 & ! p[] is appli$ to ! long arms ( ! lev]s by ! f+]s4 ,) l>ge %e>s h>d sub/ances c be cut4 ,ev5 plates ( iron are cut l pap] by %e>s :i* are work$ by a /eam-eng9e4--,p9c]s are d\ble lev]s4 ,! h+e1 or rivet1 is ! fulcrum4--,! common hamm]1 z us$ 9 draw+ nails1 is a good example ( ! p[] ( ?is k9d ( lev]4 ,?\gh crook$1 x acts 9 ! same way ) a /raight lev]4 ,! fulcrum is ! po9t on ! bo>d :]e ! hamm] re/s1 & ?is is betwe5 ! resi/ance to be mov$1 ! nail1 & ! p[]1 t is1 ! h& :i* grasps ! h&le4 ,illu/ration3 ,fig4 #aei4 #bbg4 ,no ,ga9 ( ,p[] 9 ?is ,lev]4--,i w n[ illu/rate ! tru? t !re is no ga9 or sav+ ( p[] 9 ?is lev]1 ?\gh at fir/ ?\ght x w\ld seem t !re is4 ,let a b1 ,fig4 #aei1 repres5t a lev]1 & e its fulcrum4 ,let ! arm a e be twice z long z e b4 ,a p\nd1 !re=e1 susp5d$ f a w balance two p\nds at b4 ,if1 n[1 :5 ! weights are susp5d$1 ! long arm be rais$ s t ! lev] %all be 9 ! position repres5t$ by ! l9e c d1 & !n let g1 ! "o p\nd at c1 balanc+ ! two p\nds at d1 w br+ ! lev] aga9 to ! position a b4 ,x w be p]ceiv$ t ! end ( ! long arm ( ! lev] moves ?r\gh ! space a c1 :i* is l>g] ?an b d1 ?r\gh :i* ! end ( ! %ort arm moves1 9 ! same "t4 ,! "o-p\nd weight1 9 fact1 falls two feet 9 rais+ ! two-p\nd weight "o foot1 & x moves twice z f> z a "o-p\nd weight susp5d$ at i w\ld4 ,if a "o-p\nd weight c\ld raise a two-p\nd weight )\t ?us mov+ ?r\gh twice z mu* space we might !n say t !re is an actual ga9 ( p[] 9 ! lev]4 ,b x evid5tly makes no diff]5ce :e!r "o p\nd moves ?r\gh two feet or two p\nds ?r\gh "o foot2 ! =ce is ! same 9 bo? cases4 ,= ! mom5tum or =ce ( a mov+ body is 9 proportion to its weight & velocity1 #bja2 & !re=e ! p\nd weight1 mov+ ?r\gh two feet1 has z mu* mom5tum z ! two-p\nd weight mov+ ?r\gh "o foot 9 ! same "t4 ,! small weight does ! same am\nt ( "w t ! l>g] "o w\ld by mov+ twice z f> 9 ! same "t z ! l>g]1 j z a boy1 :o c>ries a load half z l>ge z a man1 w d z mu* "w z ! man if he c>ry x twice z fa/4 ,illu/ration3 ,fig4 #afj4 #bbh4 ,! ,see-,saw4--,we see ! same ?+ illu/rat$ 9 ! see-saw1 ,fig4 #afj4 ,! man1 be+ mu* heavi] ?an ! boy1 is ne>] ! prop1 & z !y move up & d[n ! boy passes ov] a mu* l>g] space ?an ! man1 describ+ an arc 9 a mu* l>g] circle4 #bbi4 ,ar*im$es's ,lev]4--,ar*im$es said t if he c\ld h a lev] long en\gh & a prop /rong en\gh he c\ld move ! _w by 8 own weight4 ,b he did n ?9k h[ f> he w\ld h to move to d ?is1 f ! va/ diff]5ce betwe5 8 weight & ! weight ( ! e>?4 ,he w\ld h requir$1 says ,dr4 ,arnot1 to move ) ! velocity ( a cannon-ball = millions ( ye>s to alt] ! position ( ! e>? by a small "p ( an in*4 #bcj4 ,an ,analogy4--,y w rememb] t 9 ! case ( ! ,hydro/atic ,p>adox1 ! ,hydro/atic ,bell[s1 & ,bramah's ,press 7 #aca1 #acb1 & #acc71 great effects are produc$ by a small p[]4 ,b ?is small p[] has to execute an ext5sive motion 9 ord] to produce ^! effects4 ,?us1 z /at$ 9 #acb1 if ! area ( ! top ( ! ,hydro/atic ,bell[s be "o ?\s& times ! area ( ! tube1 ?\gh ! wat] p\r$ into ! tube w raise a v great weight on ! bell[s1 ! wat] 9 ! tube mu/ fall t5 in*es 9 rais+ ! weight ! hundr$? "p ( an in*4 ,s :5 ! pressure ( ! h& on ! long arm ( a lev] moves a great weight1 z a heavy /one1 ! weight is mov$ b a little1 :ile ! ext5t ( ! h&'s motion is comp>atively v great4 ,illu/ration3 ,fig4 #afa4 ,illu/ration3 ,fig4 #afb4 #bca4 ,lev] ( ! ,second ,k9d4--,9 ! second k9d ( lev] ! weight is betwe5 ! fulcrum & ! p[]1 z y see 9 ,fig4 #afa4 ,! same rule ( equilibrium applies "h z 9 ! case ( ! lev] ( ! fir/ k9d4 ,! #gb p\nds ( weight c be su/a9$ by #h p\nds ( p[]1 because ! p[] acts on ! lev] at #i times ! di/ance f ! fulcrum t ! weight does1 = #agb #ih4 ,! common :eel-b>r[1 ,fig4 #afb 7p4 #ahj71 is an example ( ?is k9d ( lev]4 ,! po9t at :i* ! :eel presses on ! gr\nd is ! fulcrum1 & ! weight is ! load1 its d[nw>d pressure f its c5tre ( gravity be+ indicat$ at ,m4 ,( c\rse ! ne>] ! load is to ! fulcrum ! easi] x is1 on />t+1 to raise ! h&les4 ,! cr[-b> c be us$ z a lev] ( ?is k9d :5 its po9t is plac$ beyond ! weight to be rais$4 ,! *ipp+-knife1 ,fig4 #afc1 is ano!r example4 ,! end1 ,f1 atta*$ to ! bo>d1 is ! fulcrum1 ! h& press+ at ,p ! p[]1 & ! resi/ance ( ! sub/ance ,r1 :i* is to be cut1 is ! weight4 ,nut-crack]s h a simil> arrangem5t4 ,9 %utt+ a door by pu%+ x ne> its edge we move a lev] ( ?is k9d4 ,! h+e is ! fulcrum1 & ! weight is betwe5 ?is & ! h&4 ,illu/ration3 ,fig4 #afc4 ,we see1 !n1 ! reason t ! slight pu% ( a h& %utt+ ! door may ev5 cru% a f+] :5 caught 9 x at ! side :]e ! h+es are4 ,! f+] is a resi/ance s ne> ! fulcrum t ! p[] mov+ ?r\gh a great space acts ^u x ) imm5se =ce4 ,! same explanation applies to ! sev]e bite ( ! f+] :5 x is caught 9 ! h+e ( a pair ( tongs4 ,! o> ( a boat is a lev] ( ?is k9d1 ! weight to be mov$ be+ ! boat1 :i* is betwe5 ! p[]1 ! h& ( ! r[]1 & ! fulcrum1 ! resi/+ wat]4 ,illu/ration3 ,fig4 #afd4 #bcb4 ,lev] ( ! ,?ird ,k9d4--,9 ! ?ird k9d ( lev] ! p[] is betwe5 ! fulcrum & ! weight1 z se5 9 ,fig4 #afd4 ,9 ! fir/ two k9ds ( lev] ! p[] may be less ?an ! weight1 b 9 ?is ! p[] mu/ always be great] ?an ! weight4 ,?is lev] has1 !n1 no me*anical advantage1 z t expression is commonly us$4 ,apply+ ! same rule "h z 9 ! o!r lev]s1 see :at is ! result4 ,if ! weight1 z 9 ,fig4 #afd1 be #i times z f> f ! fulcrum z ! p[] is1 x w require a p[] equal to a weight ( #fdh p\nds to su/a9 a weight ( #gb p\nds1 = #igbafdh4 ,illu/ration3 ,fig4 #afe4 #bcc4 ,examples4--,:5 a man puts 8 foot aga9/ ! end ( a ladd]1 & raises x by tak+ hold ( "o ( ! r\nds1 ! ladd] is a lev] ( ?is k9d4 ,x is evid5t t he sp5ds 8 =ce ^u x at a great me*anical disadvantage1 = ! p[] is appli$ mu* ne>] to ! fulcrum ?an ! weight ( ! ladd]1 tak5 z a :ole1 is4 ,if y pu% a door to by plac+ y\r h& v ne> ! h+es1 y d n %ut x z easily z :5 y take hold ( x at its edge4 ,9 ! fir/ case x is a lev] ( ! ?ird k9d1 & ! h& moves ?r\gh a small space1 & !re=e mu/ ex]t a consid]able =ce2 :ile 9 ! latt] case ! door is a lev] ( ! second k9d1 & ! h&1 mov+ ?r\gh a great] space1 puts =? less =ce4 ,:5 we use a pair ( tongs we use a pair ( lev]s ( ! ?ird k9d4 ,!y are an in/rum5t 9 :i* conv5i5ce r ?an p[] is ne$$4 ,we c n grasp any ?+ v firmly ) !m because ! p[] is s mu* ne>] to ! fulcrum ?an ! weight to be lift$4 ,= ?is reason a p9* ) ! ends ( ! tongs is no?+ comp>$ ) "o 9 ! h+e4 ,! mo/ beautiful example ( ?is lev] we h 9 ! mov+ app>atus ( animals4 ,take1 = example1 ! pr9cipal muscle :i* b5ds ! elb[1 z repres5t$ 9 ,fig4 #afe 7p4 #ahb74 ,?is comes d[n f ! %\ld] 9 front ( ! bone ( ! arm1 & is ins]t$ j bel[ ! elb[-jo9t into "o ( ! bones ( ! =e>m4 ,x pulls ^u ! =e>m v ne> ! fulcrum1 :i* is ! elb[-jo9t1 & s acts at a great me*anical disadvantage4 ,! object ( ?is arrangem5t is to secure quickness ( movem5t1 :i* is "h1 z 9 almo/ all muscul> motions1 ( m importance ?an great /r5g?4 ,:5 great weights are lift$ ! fact t ! muscles act at su* me*anical disadvantage makes ! exhibition ( p[] wond]ful4 ,illu/ration3 ,fig4 #aff4 ,illu/ration3 ,fig4 #afg4 #bcd4 ,comp\nd ,lev]s4--,:5 sev]al lev]s are connect$ toge!r we call ! :ole app>atus a comp\nd lev]4 ,let ea* ( ! lev]s 9 ,fig4 #aff be #c in*es long1 ! long arms be+ #b in*es1 & ! %ort ones #a in*4 ,"o p\nd at ,a w1 accord+ to ! rule1 balance #b at ,b1 & #b at ,b w balance #d at ,c1 & #d at ,c w balance #h at ,d4 ,!re=e #a p\nd at ,a w balance #h p\nds at ,d4 ,& y see t an equilibrium is effect$ :5 ! p[] is to ! weight z ! product ( all ! %ort arms is to ! product ( all ! long arms4 ,! comp\nd lev] is us$ 9 weigh+ heavy loads--z hay1 coal1 etc4 ,y h a repres5tation ( ! arrangem5t 9 ,fig4 #afg4 ,! load1 ,w1 /&s on a plat=m1 ,a ,b1 :i* re/s ^u two lev]s1 ,e ,d & ,e ,c4 ,! long arms ( ^! lev]s are ,e ,g & ,e ,f1 & ! %ort arms are ,g ,d & ,f ,c4 ,! ends ( ! long arms press ^u ! fulcrum ( ! lev]1 ,h ,i4 ,! pressure is n[ transmitt$ f ! end ( ! long arm by ! rod1 ,i ,k1 to a small lev]1 ,k ,l1 :]e a small weight or p[]1 ,p1 balances ! weight ( ! heavy load1 ,w4 ,! two objects secur$ by ?is arrangem5t are accuracy & ! occupation ( a small space4 ,illu/ration3 ,fig4 #afh #bce4 ,:eel & ,axle4--,! me*anical p[] next 9 simplicity to ! lev] is ! ,:eel & ,axle4 ,! mo/ famili> applications ( ?is p[] we see 9 draw+ wat] & 9 rais+ heavy articles 9 /ores4 ,! pr9ciple ( ?is p[] is ! same z t ( ! lev]1 z may be %[n 9 ,fig4 #afh1 :i* repres5ts a section ( ! :eel & axle4 ,! p[]1 ,p1 hangs by a cord :i* goes r\nd ! :eel1 & ! weight1 ,w1 by a cord ar\nd ! axle4 ,we may consid] ! p[] z pull+ on a lev] repres5t$ by ,a ,b1 ! long arm ( :i* is ,a ,c1 & ! %ort arm ,b ,c4 ,y see t ! :eel & axle1 !n1 may be view$ z a con/ant succession ( lev]s1 & x is !re=e sometimes call$ ! p]petual lev]4 ,& ! same rule ( equilibrium applies "h z 9 ! simple lev]4 ,illu/ration3 ,fig4 #afi4 #bcf4 ,w9dlass4--,9 ! common w9dlass ! p[] is appli$ to a w9* or crank1 ,d ,c ,b1 ,fig4 #afi1 in/ead ( a :eel4 ,9 e/imat+ ! p[] ( ?is arrangem5t ,b ,c mu/ be consid]$ ! long arm ( ! lev]1 & half ( ! diamet] ( ! axle1 ,b ,a1 z its %ort arm4 ,illu/ration3 ,fig4 #agj4 ,illu/ration3 ,fig4 #aga4 #bcg4 ,cap/an4--,9 ! cap/an1 repres5t$ 9 ,figs4 #agj & #aga1 ! axle is 9 a v]tical position4 ,! top ( x is pi]c$ ) holes1 into :i* lev]s are introduc$4 ,9 ,fig4 #agj y see ! in/rum5t z x is commonly us$ 9 mov+ build+s4 ,sometimes horse-p[] is appli$ at ! ends ( ! lev]s4 ,great p[] is ex]t$ by ?is in/rum5t2 b we h ! same fact "h z 9 all cases :]e a small =ce produces a great effect--! effect is sl[1 & ! =ce passes ov] a great space 9 produc+ x4 ,! mov+ ( a build+ a foot requires _m circuits ( ! horse ar\nd ! axle4 ,fig4 #aga gives u ! cap/an z x is commonly on bo>d %ip4 ,! head ( x is circul>1 ) _m holes = lev]s1 s t _m m5 c "w toge!r 9 rais+ a heavy an*or4 ,illu/ration3 ,fig4 #agb4 #bch4 ,fusee ( a ,wat*4--,9 ! fusee ( a wat* we h a :eel & axle ( a peculi> con/ruction4 ,:5 we w9d up a wat* ! *a9 is w\nd ar\nd ! spiral pa?-way on ! fusee1 ,b1 ,fig4 #agb1 & at ! same "t ! spr+ is coil$ up tightly 9 ! r\nd box1 ,a4 ,! spr+1 9 gradually uncoil+ itself1 turns ?is r\nd box ar\nd1 & ?us pulls ^u ! *a91 c1 mak+ ! fusee to revolve1 & s give motion to o!r p>ts ( ! ma*9]y4 ,n[ ! spr+1 9 its ef=t to uncoil1 acts /ronge/ at fir/2 & !re=e if ! fusee 7 ( uni=m size ! wat* w\ld g fa/e/ :5 fir/ w\nd up1 & g gradually sl[] z x run d[n4 ,?is difficulty is obviat$ by giv+ ! p[] a small :eel to pull on at fir/1 & gradually enl>g+ ! :eel z ! spr+ uncoils4 ,?is is because1 9 ord] to produce a c]ta9 effect on a giv5 weight by a p[]1 ! less ! p[] is ! long] mu/ be ! arm ( ! lev] on :i* ! p[] acts4 ,illu/ration3 ,fig4 #agc4 ,illu/ration3 ,fig4 #agd4 ,fig4 #age4 #bci4 ,! ,pulley4--,! ?ird me*anical p[] is ! ,pulley4 ,pulleys are fix$ or movable4 ,9 ,fig4 #agc y h a fix$ pulley4 ,!re is no me*anical advantage 9 ?is pulley1 = its action may be conceiv$ ( z ! action ( successive lev]s ( equal arms1 ,b ,f & ,a ,f1 & !re=e equilibrium requires an equality ( ! p[] & weight4 ,b ?is pulley is (t5 a great conv5i5ce4 ,= example1 a man c raise himself or "s weight to any desir$ elevation1 z se5 9 ,fig4 #agd4 ,x is us$ also 9 effect+ desc5ts4 ,) two fix$ pulleys a horizontal =ce may be us$ 9 rais+ a weight v]tically1 z se5 9 ,fig4 #age4 ,9 us+ a fix$ pulley ei!r "o or ! o!r ( two objects is atta9$--apply+ =ce :]e we c\ld n o!rwise apply x1 & *ang+ ! direction ( its application4 ,illu/ration3 ,fig4 #agf4 #bdj4 ,movable ,pulley4--,y h a repres5tation ( a movable pulley 9 ,fig4 #agf 7p4 #ahf74 ,x is evid5t "h t ! =ce ( ! weight is equally divid$ betwe5 ! cords1 ,a ,b1 s t ! cord ,b1 ext5d+ ov] ! fix$ pulley1 ne$s to h a weight1 ,p1 b half ( ! weight ,w to balance x4 ,a movable pulley is sometimes call$ a runn]1 & a fix$ pulley is commonly connect$ ) x1 9 ord] to give ! desir$ direction to ! =ce4 ,_m pulleys are (t5 connect$ toge!r 9 v>i\s ways1 z se5 9 ,fig4 #agg4 ,x is easy to e/imate 9 su* cases ! relation ( ! p[] to ! weight on ! pr9ciples develop$ 9 relation to ! lev]4 ,if1 = example1 9 ! sy/em ( pulleys on ! left1 ! weight be #cf p\nds1 ! two cords ( ! fir/ pulley w ea* su/a9 a weight ( #ah p\nds1 ^? ( ! next pulley ea* #i p\nds1 & ^? ( ! next ea* #d p\nds4 ,! weight ,w !n w be balanc$ by ! weight ,p if x weigh #d p\nds4 ,illu/ration3 ,fig4 #agg4 ,illu/ration3 ,fig4 #agh4 #bda4 ,incl9$ ,plane4--,! f\r? me*anical p[] is ! ,incl9$ ,plane4 ,?is be+ a v simple contrivance is mu* us$1 especially :5 heavy bodies are to be rais$ only a small height1 z 9 gett+ l>ge boxes & hog%eads into /ores4 ,! me*anical advantage ( ! incl9$ plane may be illu/rat$ on ,fig4 #agh4 ,! l9e ,a c repres5ts an incl9$ plane4 ,if a weight be drawn up ?is plane x is rais$ only ! height ,b c4 ,a small] p[] is requisite to draw ! weight up ! plane ?an to raise x p]p5dicul>ly2 & ! p[] necess>y w be ! less ! long] ! plane4 ,a p[] :i* w\ld balance a weight on an incl9$ plane w\ld be to ! weight z ! height ( ! plane to its l5g?4 ,?us if ,a c be twice z long z ,b c1 a weight ( f\r p\nds on ! plane may be balanc$ by a two-p\nd weight susp5d$ by a cord pass+ f ! weight ov] ! summit ( ! plane4 ,a flight ( /airs is an incl9$ plane 9 reg>d to ! pr9ciple on :i* ! asc5t is effect$1 ! projections 9 x be+ = ! purpose ( af=d+ a sure foot+ 9 mak+ ! asc5t or ! desc5t4 ,s likewise hog%eads are let d[n ! /eps ( a cell>-way by ropes1 & x makes no diff]5ce 9 ! pr9ciple ( ! op]ation :e!r ! /eps h or h n planks laid along !m4 ,x is suppos$ t ! imm5se /ones 9 ! pyramids & o!r massive ,egyptian /ructures 7 put into _! position by means ( ! incl9$ plane4 ,roads1 :5 !y are n level1 are incl9$ planes1 & ! /eep] ! incl9ation ! m p[] is requir$ to draw a load up ! road4 ,great mi/akes 7 =m]ly made 9 c>ry+ roads too frequ5tly ov] high hills4 ,besides fail+ to take advantage ( ! pr9ciples ( ! incl9$ plane1 9 _m cases ! horse 9 go+ ov] a hill passes ov] q z mu* space z he w\ld if ! road 7 made to g r\nd ! base ( ! hill1 & sometimes ev5 m4 ,if ! hill 7 a p]fect hemisph]e1 a road ov] x w\ld be j equal 9 l5g? to a road ar\nd its base to ! opposite po9t4 ,illu/ration3 ,fig4 #agi4 #bdb4 ,! ,w$ge4--,?is is ! fif? ( ! me*anical p[]s4 ,x may be consid]$ z two incl9$ planes plac$ ) _! bases toge!r1 z se5 9 ,fig4 #agi4 ,inde$1 sometimes ! w$ge has "o side only incl9$1 x be+ only half ( ! ord9>y w$ge4 ,! diff]5ce betwe5 ! incl9$ plane & ! w$ge 9 op]ation is1 t 9 ! fir/ ! incl9$ plane is fix$1 & ! weight is made to move up along its surface1 :ile 9 ! latt] ! weight1 t is1 ! resi/ance1 is /ation>y1 & ! surface ( ! plane is made to move along ^u x4 ,! p[] ( ! w$ge is e/imat$ j z ! p[] ( ! incl9$ plane is1 t is1 by comp>+ ! ?ickness ( ! w$ge ) ! l5g? ( its side4 ,! less ! ?ickness ( ! w$ge comp>$ ) its l5g?1 obvi\sly ! m p[]ful is ! w$ge z a p5etrat+ in/rum5t4 ,! w$ge is us$ = splitt+ blocks ( wood & /one1 = produc+ great pressures1 = rais+ heavy bodies1 etc4 ,all cutt+ & pi]c+ in/rum5ts1 knives1 razors1 axes1 ne$les1 p9s1 nails1 etc41 act on ! pr9ciple ( ! w$ge4 #bdc4 ,! ,screw4--,?is is ! six? me*anical p[]4 ,! pr9ciple ( x is ess5tially t ( ! incl9$ plane4 ,! ?read runn+ ar\nd ! screw is an incl9$ plane :i* is spiral in/ead ( /raight1 & s is also ! correspond+ "p 9 ! nut an incl9$ plane runn+ 9 ! opposite direction4 ,9 ! common screw ! nut is fix$1 & ! screw is made to play up & d[n 9 x2 b sometimes ! screw is fix$1 & ! nut is made to play ar\nd x4 ,! screw acts l a w$ge1 & has ! same relation to a /raight w$ge t a road w9d+ up a hill has to a /raight road ( ! same l5g? & rise4 ,especially does ! comp>ison hold :5 ! screw is =c$ into wood2 ! w$ge goes /raight into ! wood1 b ! edge ( ! screw's ?read ent]s ! wood spirally4 ,illu/ration3 ,fig4 #ahj4 ,to e/imate ! =ce ( ! screw we comp>e ! l5g? ( "o turn ( ! ?read ar\nd x ) ! height to :i* ! ?read rises 9 go+ r\nd4 ,let a b1 ,fig4 #ahj1 repres5t "o turn ( ! ?read1 & b c ! height to :i* x goes4 ,x is cle> f ! figure t ! pr9ciple :i* applies to ! incl9$ plane & to ! w$ge applies "h also4 ,z ! less is ! height ( ! plane ! easi] x is = a weight to be drawn up x2 & z ! less is ! dep? ( ! w$ge ! less is x resi/$2 s1 also1 ! less ! height ( ! turn ( ! screw's ?read ! easi] is x to move ! screw1 & ! great] is ! =ce :i* x ex]ts4 ,h5ce ! prodigi\s p[] ( a screw ) a ?read :i* rises v sl[ly 9 its spiral turns4 ,screws are mu* us$ :5 great pressure is requir$1 z 9 press+ oils & juices f vegetable sub/ances1 9 compress+ cotton into bales1 9 br++ toge!r ) firm grasp ! jaws ( ! vice1 etc4 ,9 turn+ ! screw a b> is us$1 s t we h 9 ?is in/rum5t ! comb9$ advantages ( ! screw & ! lev]4 ,t y may h "s idea ( ! p[] ( ^! two in/rum5ts act+ toge!r ,i w suppose a case4 ,let ! weight to be rais$ by a screw be #aj1jjj p\nds4 ,let a turn ( ! screw be #aj in*es long1 & ! rise be b "o in*4 ,!n1 s f> z ! screw is conc]n$1 ! p[] requisite to raise ! #aj1jjj p\nds w be #ajjj--! ratio ( ! height ( ! ?read's turn to its l5g?4 ,b ! p[] ( ! lev] is yet to be e/imat$4 ,let ! l5g? ( ! lev]1 pass$ ?r\gh ! head ( ! screw s t x is equal on ea* side1 be #cj in*es4 ,! diamet] ( ! screw is ab\t ?ree in*es1 or "o-t5? ( ! diamet] ( ! circle describ$ by ! end ( ! lev]4 ,x w n[ take b a p[] ( #ajj p\nds to raise ! weight1 ! ratio ( ! radius ( ! screw to half ! l5g? ( ! lev]4 #bdd4 ,truly b ,?ree ,me*anical ,p[]s4--,! ,:eel & ,axle1 y h se51 is m]ely a modification ( ! ,lev]1 & ! ,w$ge & ! ,screw are modifications ( ! ,incl9$ ,plane4 ,! ,me*anical ,p[]s are1 !n1 9 reality b ?ree--! ,lev]1 ,pulley1 & ,incl9$ ,plane4 ,& ^! are ! elem5ts ( all ma*9]y1 f ! simple/ tool t is us$ = ! mo/ common purposes to ! mo/ complicat$ & p[]ful eng9e :i* ! +5uity ( man ev] design$4 ,! pr9ciple ^u :i* a p9 is %ap$ is id5tical ) t ( ! w$ge1 by :i* l>ge masses are cleft 9 two2 & ! in/rum5t by :i* ! f9e/ textures are cut by delicate f+]s is arrang$ on ! same pr9ciple ) ^? v>i$ contrivances by :i* imm5se weights are rais$ by a comp>atively small p[]1 viz41 ! pr9ciple ( ! lev]4 #bde4 ,friction 9 ,ma*9]y4--,y h se51 z we h proce$$1 t ! ,me*anical ,p[]s1 ?\gh ?us nam$1 d n g5]ate p[]4 ,s f> f ?is1 !re is really a loss ( p[] 9 _! use1 *iefly f friction4 ,9 rais+ a weight1 = example1 directly by ! h&1 !re is no loss f ?is cause2 b if y use a pulley y h ! friction ( ! cord ^u x1 & a loss ( p[] 9 proportion to ! am\nt ( friction4 ,9 "s cases ! loss ( p[] f ?is cause is s great z to call = a consid]able v>iation f su* calculations z we h made 9 ?is *apt] 9 reg>d to ! relations ( p[] & weight 9 ma*9]y4 ,9 ! op]ations ( ! screw friction has a great influ5ce 9 dim9i%+ ! p[] ( ! in/rum5t4 #bdf4 ,! ,real ,advantages ( ! ,me*anical ,p[]s4--,if !re is !n no sav+1 b a loss ( p[] 9 tools & ma*9]y1 :at1 let u inquire1 are _! advantages8 ,if "o man c d alone by ! aid ( "s in/rum5t :at w\ld o!rwise require ! ex]tion ( _m m51 ?\gh he be sl[ 9 do+ x1 yet x is a great advantage4 ,?us "o man c ) a lev] move a /one :i* p]haps x w\ld require ?irty m5 to move )\t x1 & ?\gh x take him ?irty times z long1 x saves him ! tr\ble ( gett+ a company ( m5 to help him4 ,s if a man c raise 8 goods by a :eel & axle to ! upp] l(t ( 8 /ore1 ?\gh he raise !m sl[] ?an sev]al m5 w\ld lift !m directly by ropes1 x is an advantage to him1 z x saves ! hir+ ( a company ( labor]s4 ,a few m5 by a cap/an c raise an an*or :i* c\ld be rais$ )\t x only by a l>ge company ( m54 ,ano!r advantage (t5 is t !re may be int]vals ( re/ 9 apply+ ! =ce )\t any loss4 ,?is is obvi\s 9 ! case ( ! pulley1 b /ill m s 9 ! case ( ! screw4 ,x is friction 9 bo? ^! cases :i* enables ! workman to re/4 ,x saves to him all t he has ga9$ by oppos+ any t5d5cy to slip back4 ,we see ! same ?+ 9 ! w$ge4 ,:5 ?is is driv5 into wood1 x rema9s because x is prev5t$ f return+ by ! friction ( ! wood aga9/ its sides4 ,x is ! same cause :i* holds a nail 9 its place1 & opposes any ef=t to draw x out4 ,9 driv+ ! w$ge ! workman c h z long int]vals z he pleases betwe5 8 bl[s1 because friction saves all t is ga9$4 ,?is effect is v well exemplifi$ 9 ! cap/an1 ,fig4 #agj4 ,x requires b little ex]tion ( ! man :o sits !re to hold ! rope1 because ! few turns ( x ar\nd ! axle prev5t its slipp+ easily4 ,a ?ird advantage :i* (t5 att5ds ! use ( tools & ma*9es is t =ce may be made to produce motion at v>i\s di/ances1 9 v>i\s directions1 & 9 v>i\s degrees ( velocity4 ,?us z to di/ance1 a man /&+ on ! gr\nd c raise a weight to ! top ( a h\se by a pulley4 ,s1 also1 a wat]-:eel may by ! connections ( ma*9]y produce motion at consid]able di/ances f x4 ,!n z to direction1 horizontal motion may be conv]t$ into v]tical1 rot>y into /raight1 etc4 ,! velocity ( motion is g5]ally v>i$ by cog-:eels4 ,?us a :eel ( #fj cogs revolv+ once 9 a m9ute1 play+ on a :eel ( #aj cogs1 w make x revolve once 9 #f seconds4 ,illu/ration3 ,fig4 #aha4 ,ano!r advantage ( tools & ma*9es is t !y secure a bett] mode ( apply+ p[] ?an we o!rwise c\ld h4 ,?us :5 sev]al m5 are pull+ on a rope mu* p[] is lo/ by _! pull+ irregul>ly1 a difficulty :i* is remov$ by ! pulley4 ,! same c be said ( apply+ pressure by ! screw4 ,"o man presses m /eadily1 & !re=e m effectually1 ?an fifty m5 w\ld )\t ! screw4 ,! arrangem5ts ( tools & ma*9es are s made z to provide conv5i5t ways ( apply+ our /r5g?4 ,an in/rum5t1 = example1 = mov+ a weight by h& is s %ap$ z to hold ! weight well1 & also to af=d a good h&le = ! h& to grasp4 ,! common claw hamm] is a v good illu/ration4 ,we grasp ! nail by an iron claw1 ) ! h&le we c apply n m]ely ! =ce ( ! h&1 b t ( ! :ole arm1 & !n we h ! imm5se lev] p[] ( ! in/rum5t4 ,we h a good illu/ration ( conv5i5ce 9 an in/rum5t1 9 :at is call$ a ,lewis1 repres5t$ 9 ,fig4 #aha4 ,x is us$ = rais+ blocks ( /one 9 build+4 ,x has ?ree p>ts1 ,a ,b ,c4 ,x is us$ 9 ?is way3 ,a hole is made 9 ! upp] "p ( ! block ( /one to be rais$ 9 %ape l ! in/rum5t2 !n ,a & ,c are ins]t$1 & ,b is pu%$ 9 betwe5 !m4 ,) ! r+1 ,d1 bolt$ ?r\gh ! in/rum5t ! /one is rais$ to its place by ! ord9>y ma*9]y4 ,! pr9ciple ( ! in/rum5t1 y see1 is t ( ! w$ge4 #bdg4 ,man a ,tool-,mak+ ,animal4--,?\gh !re is no actual sav+ ( p[] 9 ! tools & ma*9es :i* man uses1 yet s great are ! advantages :i* he reaps f !m1 t m ?an two ?\s& ye>s ago a philosoph] ?\ght t man c\ld n be bett] di/+ui%$ f brutes ?an by call+ him a tool-mak+ animal4 ,if ! di/9ction 0 s /rik+ 9 ! "t ( ,ari/otle1 :5 tools & ma*9es 7 s few 9 numb] & s rudely contriv$1 & s few ( ! s\rces ( p[] 7 appropriat$ by man to 8 use1 h[ mu* m /rik+ is x n[1 ) all ! v>iety & p]fection ( in/rum5ts & ma*9]y1 & ) ! ev]-ext5d+ appropriation ( ! s\rces ( p[] furni%$ by ! elem5ts4 ,! p[] :i* air & wat] & gravitation give is appli$ con/antly ) m & m v>iety & effect2 & ! appropriation ( t mighty s\rce ( p[]1 /eam1 is :olly a mod]n inv5tion4 ,,*apt] ,,xii4 ,,s\nd4 #bdh4 ,:at ,s\nd is4--,s\nd is su* a vibration ( sub/ances z c1 on be+ transmitt$ to ! e>1 act ^u ! s5se ( he>+4 ,i say su* a vibration1 because !re may be vibrations :i* w n produce ! s5sation ( s\nd1 ,vibrations :i* are ei!r v sl[ or v quick w n d x4 ,?us if a plate ( metal or a /r+ make less ?an #ae or m ?an #dh1jjj vibrations 9 a second1 no effect is produc$ ^u ! e>4 ,! capacity ( he>+ diff]s1 h[ev]1 9 diff]5t p]sons1 s t al?\gh few c he> vibrations :i* are beyond ! range :i* ,i h m5tion$1 !re are _m ^: capacity falls mu* )9 x ei!r at "o end or bo? ends ( ! scale4 ,! range = animals is n ! same z t = man4 ,?us ! lion & ! elephant c he> a s\nd :5 ! vibrations are too infrequ5t to make any impression ^u our e>s2 :ile small animals h a susceptibility 9 ! organ ( he>+ = vibrations s quick t we c n he> !m1 & at ! same "t are n susceptible to ! sl[] vibrations4 ,h[ f> ! range v>ies 9 diff]5t animals has n be5 asc]ta9$ to any ext5t4 ,illu/ration3 ,fig4 #ahb4 #bdi4 ,! ,vibration ( ,s\nd+ ,bodies ,manife/ to ! ,s5ses4--,if we place ! h& ^u a l>ge bell t has be5 /ruck we c feel ! vibration4 ,if we /rike "o ( ! ends ( a tun+-=k ^u "s h>d body we c see ! vibration1 z repres5t$ 9 ,fig4 #ahb by ! dott$ l9es4 ,if we look 9 ^u ! /r+s ( a piano z x is play$1 ! vibration ( ! l>g] /r+s is v obs]vable to ! eye4 ,if we rub ! edge ( a dr9k+-glass s z to produce a musical s\nd1 ! wat] :i* is 9 x w be ?r[n into waves f ! vibration ( ! glass4 ,illu/ration3 ,fig4 #ahc4 #bej4 ,w9d ,in/rum5ts4--,9 w9d in/rum5ts1 z ! flute1 horn1 etc41 x is ! vibration ( ! body ( air 9 ! in/rum5t :i* causes ! s\nd4 ,9 ! common t9 :i/le or bird-call1 ,fig4 #ahc1 ! s\nd is produc$ by ! vibration imp>t$ to ! conta9$ air by ! impulse ( ! brea? ?r\gh ! orifice1 ,b4 ,illu/ration3 ,fig4 #ahd4 #bea4 ,an ,analogy4--,! vibration ( a s\nd+ body is mu* l t ( a p5dulum4 ,! end ( ! tun+-=k1 ,fig4 #ahb1 on be+ /ruck passes to b1 & 9 return+ passes by ! po9t ( re/1 ,a1 z ! p5dulum does1 & rea*es a4 ,s1 also1 if a /r+1 ,a ,b1 ,fig4 #ahd1 be drawn aside to ,d1 z x flies back to ,c x w by its in]tia pass on to ,e1 & s w cont9ue to vibrate back & =? = "s "t4 ,! same rule also applies to ! ext5t ( ! vibrations "h z 9 ! case ( ! p5dulum1 #bji4 ,! quickness ( ! vibration is n at all affect$ by its wid?4 ,! f>!r ! /r+1 ,a ,b1 is drawn to "o side ! great] w be ! =ce ) :i* x w return1 & h5ce x w arrive at its position on ! o!r side ( ! middle l9e z soon :5 drawn f> away f ?is l9e z x w\ld if drawn b little away4 ,! same ?+ is true ( ! vibrations or waves ( air1 ?\gh x c n s easily be made pla9 to y4 #beb4 ,h[ ! ,s5sation ( ,s\nd is ,produc$4--,! vibration ( a s\nd+ body is transmitt$ to ! e> ord9>ily ?r\gh ! air1 & !re /rikes ^u a little drum1 a membrane at ! bottom ( ! ext]nal cavity ( ! e> j l a common drum-head4 ,"h ! vibration ( ! air is communicat$ to ?is drum1 & f ?is to a *a9 ( v small bones4 ,f ! la/ ( ^! bones x is transmitt$ to ano!r v small drum1 & f ?is to a fluid 9 "s v complicat$ passages 9 ! mo/ solid bone 9 ! body4 ,^! may be call$ ! halls ( audi5ce4 ,9 ! fluid conta9$ 9 !m are spread out ! bran*es ( ! n]ve ( he>+1 :i* receive ! impression ( ! vibration1 & transmit x to ! bra91 :]e ! m9d takes k ( x4 ,obs]ve t ! vibration1 transmitt$ fir/ ?r\gh ! air1 !n ?r\gh ! drum1 !n ! *a9 ( bones1 !n ano!r drum to a fluid1 /ops at ! fluid4 ,:at is transmitt$ f ?is to ! bra9 by ! n]ve we "k n1 & s we call x an impression4 #bec4 ,s\nd ,transmitt$ ?r\gh ,v>i\s ,sub/ances4--,9 ord9>y he>+ s\nd1 z y h se51 is transmitt$ ?r\gh v>i\s sub/ances be=e ! vibration arrives at ! liquid 9 ! halls ( audi5ce4 ,b s\nd ne$ n take ?is c\rse 9 all cases to arrive at ! n]ve ( he>+4 ,if1 = example1 y place a wat* betwe5 y\r tee?1 ! s\nd w g ?r\gh ! solid tee? & ! bones ( ! jaw directly to ! halls ( audi5ce by a %ort cut1 in/ead ( go+ r\nd ?r\gh ! out] e>-passage to ! drum1 & s ?r\gh ! *a9 ( bones4 ,fi%es 9 he>+ receive ! vibration ?r\gh wat]4 ,if y place y\r e> at ! end ( a timb]1 :ile "s "o scrat*es ) a p9 at ! o!r end1 y he> ! s\nd di/9ctly1 = ! vibration is transmitt$ ?r\gh ! timb]2 z 9 ! case ( ! wat* betwe5 ! tee?1 x goes ?r\gh ! solid bone4 ,illu/ration3 ,fig4 #ahe4 #bed4 ,s\nd n ,transmitt$ ?r\gh a ,vacuum4--,z s\nd is a vibration ( "s sub/ance x c n be transmitt$ ?r\gh absolute space4 ,?is c be prov$ by an exp]im5t ) ! air-pump1 z repres5t$ 9 ,fig4 #ahe4 ,! app>atus 9 ! receiv] is s arrang$ t ! bell1 a1 c be /ruck by press+ d[n a slid+ rod1 h4 ,if x be /ruck be=e ! air is exhau/$ ! s\nd is he>d ?r\gh ! glass4 ,b ! m y exhau/ ! air ! fa9t] w be ! s\nd2 & at l5g?1 if y keep on pump+1 x c n be he>d at all4 ,! same exp]im5t c be tri$ ) a music-box4 ,x is f ! ?9ness ( ! air on high m\nta9s1 & at ! great heights rea*$ by balloons1 t all s\nds are s fa9t4 ,! report ( a pi/ol fir$ (f on top ( ,mont ,blanc is a m]e crack comp>$ ) its report :5 fir$ 9 ! valley bel[4 #bee4 ,motion ( ! ,heav5ly ,bodies )\t ,noise4--,s\nd is (t5 he>d at a v great di/ance on ! e>?4 ,! s\nd ( an eruption ( a volcano has be5 he>d 9 "o case at ! di/ance ( #igj miles4 ,b suppose t ! same s\nd %\ld occur at ! same di/ance f ! e>?1 t is1 ov] #ijj miles beyond ! atmosph]e t enrobes ! e>?1 no inhabitant ( our _w c\ld he> x1 = ! same reason t y d n he> ! bell r++ 9 an exhau/$ receiv]4 ,if1 !re=e1 any s\nd1 h[ev] l\d1 %\ld be giv5 =? by any ( ! heav5ly bodies we c\ld n he> x4 ,! c\rse ( ^! bodies 9 _! orbits is noiseless1 because !y meet ) no resi/ance f any sub/ance4 ,bodies pass+ rapidly ?r\gh our atmosph]e cause s\nd1 f ! resi/ance :i* ! air gives to _! passage4 ,! :izz+ ( a ball is an example ( ?is4 ,x is ! passage ( ! electric fluid ?r\gh ! air :i* produces ! ?und]4 ,b ! heav5ly bodies1 hav+ no su* resi/ance1 make no s\nd 9 _! c\rse1 ?\gh _! velocity be s imm5se4 ,9 ! expressive language ( ! ,bible1 _! voice is n he>d4 #bef4 ,velocity ( ,s\nd4--,! velocity ( s\nd v>ies 9 diff]5t m$ia4 ,?us x passes ?r\gh wat] f\r times z rapidly z x does ?r\gh air4 ,dr4 ,frankl91 ) 8 head "u wat]1 he>d di/9ctly ! s\nd ( two /ones /ruck toge!r 9 ! wat] at ! di/ance ( m ?an half a mile4 ,s\nd passes ?r\gh solids mu* m easily1 & !re=e m rapidly1 ?an ?r\gh liquids4 ,?us its velocity ?r\gh copp] is twelve times & ?r\gh glass sev5te5 times great] ?an ?r\gh air4 ,if y place y\r e> aga9/ a long brick wall at "o end1 & let "s "o /rike ^u ! o!r end1 y w he> two reports1 ! fir/ ?r\gh ! wall & ! second ?r\gh ! air4 ,indians are 9 ! habit ( asc]ta9+ ! approa* ( _! enemies by putt+ ! e> to ! gr\nd4 ,:5 ! eruption ( a volcano is he>d at a great di/ance ! s\nd comes ?r\gh ! solid e>? r ?an ?r\gh ! air4 ,! ready transmission ( s\nd ?r\gh solids furni%es u ) a v valuable means ( exam9+ diseases ( ! lungs & he>t4 ,! s\nds occasion$ by ! movem5t ( ! air 9 ! lungs & by ! action ( ! he>t are v di/9ctly he>d ?r\gh ! solid walls ( ! *e/4 #beg4 ,measurem5t ( ,di/ances by ,s\nd4--,x makes no diff]5ce ) ! velocity ( s\nd :e!r x be l\d or n4 ,?us ! s\nds ( a b& ( music at a di/ance all rea* y\r e> at ! same "t1 ! s\nds ( ! in/rum5ts t c sc>cely be he>d keep+ exact pace 9 ! air ) ! s\nds ( ! l\de/4 ,s1 also1 ! velocity ( s\nd is uni=m ?r\gh\t its :ole c\rse1 be+ j z rapid :5 x is ab\t to die away z x 0 :5 x began4 ,x is f ?is uni=mity 9 ! velocity ( s\nd t we c e/imate ! di/ance ( ! object by :i* any s\nd is made4 ,we d x by a comp>ison betwe5 light & s\nd4 ,s\nd moves at ! rate ( #aabj feet 9 a second4 ,n[ light moves #aib1jjj miles a second1 & !re=e1 = all ord9>y di/ances on ! e>?1 we ne$ make no all[ance ( "t = light 9 comp>ison ) s\nd4 ,if we see1 !n1 ! op]ation by :i* a s\nd is produc$ we c e/imate its di/ance f u by ! l5g? ( "t :i* elapses betwe5 :at we see & :at we he>4 ,9 ?is way we c e/imate v accurately ! di/ance ( a cannon t we see fir$1 or ! di/ance ( a fla% ( lightn+4 #beh4 ,l\dness ( ,s\nd4--,! l\dness ( s\nd dep5ds ^u ! wid? ( ! vibrations produc+ x4 ,! h>d] y /rike ! end ( ! tun+-=k1 ,fig4 #ahb1 ! f>!r w x vibrate ! "o way & ! o!r1 & ! l\d] w be ! s\nd4 ,! same ?+ is true ( ! /r+s ( a piano4 ,a r\nd bell1 :5 x is /ruck1 t5ds 9 its vibration to take an oval =m1 & ! ext5t ( its vibration back & =? z x does ?is gov]ns ! l\dness ( ! s\nd4 ,z s\nd passes f ! s\nd+ body ! vibration gradually less5s1 & at l5g? dies away4 ,x is l ! successive vibrations or waves ( wat] produc$ by dropp+ a /one 9 x4 ,! l\d] ! s\nd is ! l>g] are ! fir/ vibrations1 & ! f>!r w ! vibrations ext5d1 z 9 wat] a l>ge /one dropp$ into x w produce l>g] waves ?an a small "o1 & ! waves w ext5d ov] a great] space4 #bei4 ,diffusion ( ,s\nd4--,:5 !re is no h9drance s\nd spreads equally 9 all directions4 ,x is 9 ?is respect ) ! vibrations or waves ( air z x is ) ! waves ( wat] :5 a /one is dropp$ into x4 ,light is also diffus$ 9 ! same mann]1 z y w see 9 ano!r *apt]4 ,illu/ration3 ,fig4 #ahf4 #bfj4 ,reflection ( ,s\nd4--,z waves ( wat] /rik+ aga9/ any object b\nd (f1 s x is ) ! vibrations or waves ( s\nd4 ,& ! same is true ( ?is z ( all motion1 z /at$ 9 #bjf1 t ! angle ( incid5ce is equal to ! angle ( reflection4 ,! reflection ( s\nd is ! cause ( e*oes4 ,9 ord] t an e*o be p]fect ! s\nd mu/ be reflect$ back to ! e> f "s plane surface ( "s size4 ,sometimes :5 !re are successive plane surfaces ( rocks along a riv] !re are successive e*oes4 ,?us 9 ,fig4 #ahf 7p4 #bjj7 is repres5t$ a locality on ! ,rh9e :]e a s\nd is reflect$ at successive places1 #a1 #b1 #c1 #d4 ,! roll+ ( ?und]1 ?\gh sometimes caus$ by ! diff]5t di/ances ( p>ts ( ! same fla% ( lightn+1 is commonly ow+ to reflections ( ! s\nd among ! cl\ds4 ,f ?is cause ! report ( a cannon is m apt to be a roll+ s\nd :5 !re are cl\ds above ?an :5 ! sky is cle>4 ,s\nd is cont9ually reflect$ 9 e v>iety ( direction f ob/acles ) :i* x meets4 ,?us 9 a room x is reflect$ f ! walls & f all ! objects 9 ! room2 & ! m v>i$ are ! surfaces ! m v>i$ & confus$ are ! reflections4 ,y "k t a voice has a v diff]5t s\nd 9 a room :5 x is empty f :at x has :5 ! room is fill$ ) an audi5ce4 ,inde$1 a bl9d speak] c e/imate v ne>ly ! size ( 8 audi5ce by ! s\nd ( 8 own voice4 ,! explanation is1 t ) a full audi5ce ! surfaces = reflection are va/ly multipli$1 & s deprive ! s\nd ( ! %>p & r++ "* :i* is giv5 to x by reflection f comp>atively few surfaces :i* are plane & firm4 ,! effect produc$ by an audi5ce ^u ! voice ( ! speak] is q analog\s to t ( muffl+ ^u ! s\nd ( a drum4 ,illu/ration3 ,fig4 #ahg4 #bfa4 ,:isp]+ ,gall]ies4--,! reflection ( s\nd f curv$ surfaces gives u "s int]e/+ ph5om5a4 ,! waves ( s\nd 9 be+ reflect$ f a concave surface are ga!r$ toge!r to "s po9t4 ,if ! surface be a p]fectly sph]ical "o1 & ! s\nd issue f ! c5tre1 ! reflection w be f all po9ts to ! c5tre4 ,b suppose ! concave surface h ! curve ( an ellipse1 z repres5t$ 9 ,fig4 #ahg4 ,?is1 in/ead ( hav+ a c5tre1 has two foci1 c & g4 ,n[ if a s\nd proce$ f "o focus1 c1 ! waves ( s\nd1 z repres5t$ by ! l9es c d1 c e1 c f1 c h1 w all be reflect$ to ! o!r focus1 g2 s t if a p]son speak 9 a v l[ tone or ev5 :isp] at c1 he may be he>d di/9ctly by ano!r at g1 ?\gh p]sons at o!r po9ts may he> no?+4 ,we may h ?is result ) a curv$ wall ext5d+ ev5 sev]al hundr$ feet2 & su* /ructures are call$ :isp]+ gall]ies4 ,if 9 "o ( ^! gall]ies a p]son /&+ 9 "o focus speak l\dly he w be he>d by o!rs at any po9t by ! direct waves ( s\nd2 b ! reflect$ s\nd w be add$ to ! direct 9 ! case ( "o /&+ at ! o!r focus4 ,illu/ration3 ,fig4 #ahh4 ,illu/ration3 ,fig4 #ahi4 #bfb4 ,conc5tration ( ,s\nd4--,x is by ! reflection ( s\nd t x c be conc5trat$ 9 v>i\s ways4 ,?us 9 us+ a speak+-trumpet ! waves ( s\nd1 in/ead ( mov+ 9 all directions z soon z !y escape f ! m\?1 are reflect$ by ! sides ( ! in/rum5t t[>d a c5tral l9e z repres5t$ 9 ,fig4 #ahh4 ,! waves or vibrations1 be+ ?us conc5trat$ h m int5sity & are ?r[n to a great] di/ance ?an if !y issu$ directly f ! m\?4 ,s a speak+-tube1 conf9+ ! vibrations1 c>ries ! voice to di/ant p>ts ( a build+4 ,= ! same reason ! voice c be he>d mu* f>!r ?r\gh a n>r[ /reet ?an 9 an op5 space4 ,s1 also1 a speak] c be he>d m di/9ctly 9 a hall ?an :5 address+ an audi5ce ( ! same size 9 ! op5 air4 ,! s\nd+-bo>d1 once s fa%ionable 9 *ur*es1 0 really ( consid]able s]vice 9 prev5t+ ! escape ( ! vibrations ( ! voice ( ! prea*] upw>d1 & direct+ !m d[nw>d ^u ! audi5ce4 ,9 ! he>+-trumpet1 ,fig4 #ahi1 ! vibrations are collect$ 9 ! broad op5 end ( ! in/rum5t1 & by reflection are ?r[n toge!r into a n>r[ compass be=e !y ent] ! e> to /rike ^u ! drum4 ,we (t5 in/9ctively make ! palm ( ! h& act z an e>-trumpet :5 we d n he> di/9ctly4 ,_m animals h ! ext]nal e>s movable1 s t !y c direct _! concave surface t[>d ! po9t f :i* !y wi% to he>4 ,su* e>s are movable e>-trumpets4 #bfc4 ,diff]5ce ,betwe5 a ,musical ,s\nd & a ,noise4--,! diff]5ce betwe5 a musical s\nd & a noise is v analog\s to ! diff]5ce betwe5 a cry/al & ! same sub/ance de/itute ( ! cry/all9e arrangem5t4 ,9 bo? !re are vibrations1 b 9 ! musical s\nd !y h p]fect regul>ity1 :ile 9 a noise ! vibrations are irregul>1 & !re is confusion4 ,inde$ s regul> are ! vibrations ( musical s\nds t ! rules & pr9ciples ( music h all ! rigid exactness ( ma!matics4 #bfd4 ,h[ ,diff]5t ,notes are ,produc$4--,! quick] is ! vibration ! high] is ! note4 ,?us a %ort & small /r+ on a viol9 or 9 a piano gives a high] note ?an a long & l>ge /r+1 because its vibrations are quick]4 ,! t5sion ( ! /r+ also has an influ5ce1 ! note be+ rais$ by increas+ ! t5sion4 ,9 tun+ a viol9 ! "r pit* is giv5 to ea* /r+ by less5+ or increas+ ! t5sion by means ( ! screws to :i* ! /r+s are atta*$4 ,9 play+ ^u x v>i\s notes are made ^u ea* /r+ by %ort5+ ! vibrat+ portion m or less by pressure ( ! f+]4 ,illu/ration3 ,fig4 #aij4 ,9 w9d in/rum5ts ! note dep5ds on ! l5g? & size ( ! column ( air conta9$ 9 !m4 ,?is may be illu/rat$ by an organ-pipe1 ,fig4 #aij 7p4 #bjc74 ,x is "o ( ! pipes ( :at is call$ ! flute-/op4 ,x is con/ruct$ v mu* l a boy's will[ :i/le4 ,! air f ! bell[s ( ! organ ent]s at ,p1 & causes a vibration ( ! :ole column ( air 9 ! pipe1 ! s\nd issu+ at t4 ,9 ! upp] end is a movable plug1 s1 by :i*1 9 tun+1 ! note ( ! pipe is regulat$4 ,if ! note be too grave ?is plug is pu%$ d[nw>d1 s z to %ort5 ! column ( air4 ,x is f diff]5ce 9 rapidity ( vibration t a l>ge bell gives a grav] note ?an a small "o4 ,s1 too1 :5 musical s\nds are produc$ by pass+ ! moi/5$ f+]s ov] ! edges ( glass vessels1 ! l>g] ! vessel ! grav] is its note4 ,a tumbl] w give a grav] note ?an a w9e-glass4 #bfe4 ,human ,voice4--,! pr9ciples :i* ,i h develop$ 9 relation to musical in/rum5ts apply to ! voice4 ,! musical in/rum5t ( man1 by :i* ! voice is produc$1 is conta9$ 9 a v small compass4 ,x is t box at ! top ( ! ?roat commonly call$ ,adam's apple4 ,across ?is1 f front to re>1 /ret* two %eets ( membrane1 leav+ a space betwe5 _! edges4 ,9 our ord9>y brea?+ ^! membranes are relax$1 & ! space betwe5 _! edges is consid]able1 to all[ ! air to pass 9 & out freely4 ,b :5 we speak or s+ ^! membranes1 or vocal *ords1 z !y are t]m$1 are put into a t5se /ate by muscles pull+ ^u !m1 & ! op5+ betwe5 !m is less5$4 ,! voice is produc$ by ! air t is =c$ out f ! lungs1 :i*1 /rik+ on ! *ords1 causes !m to vibrate4 ,! ne>] _! edges are toge!r1 & ! m t5se !y are1 ! high] is ! note4 ,! s\nds are produc$ precisely z ^? ( ! olian h>p are1 ! air caus+ 9 ! "o case a vibration ( /r+s1 & 9 ! o!r ( edges ( membranes4 #bff4 ,h>mony4--,:5 notes1 on be+ s\nd$ at ! same "t1 are agreeable to ! e>1 !y are said to h>monize4 ,n[ ?is h>mony dep5ds on a c]ta9 relation betwe5 ! vibrations4 ,! m simple is ! relation ! great] is ! h>mony4 ,= example1 if we take ! fir/ note1 t]m$ ! fundam5tal note1 ( :at is call$ ! scale 9 music1 x h>monizes bett] ) ! octave ?an ) any o!r ( ! eight notes1 because = e vibration 9 x !re are j two 9 ! octave4 ,take 9 contra/ ) ! octave ! second note4 ,"h to e eight vibrations ( ! fir/ note we h n9e ( ! second1 & ! consequ5ce is a discord :5 !y are s\nd$ toge!r4 ,! diff]5ce betwe5 ! two cases is ?is3 ,9 ! fir/ case ! comm5cem5t ( e vibration 9 ! fundam5tal note co9cides ) ! comm5cem5t ( e second vibration 9 ! octave4 ,b 9 ! o!r case !re is a co9cid5ce at only e eigh? vibration ( ! fir/ note ) e n9? ( ! second4 ,next to ! octave1 ! mo/ agreeable h>mony ) ! fundam5tal note is t ( ! fif? note ( ! scale4 ,"h we h ?ree vibrations to e two ( ! fir/ note1 & s e second vibration 9 ! fir/ note co9cides ) e ?ird vibration ( ! fif?4 ,next comes ! h>mony ( ! f\r?1 !re be+ "h a co9cid5ce at e ?ird vibration ( ! fundam5tal note4 ,! m frequ5t1 y see1 are ! co9cid5ces betwe5 ! vibrations ! great] is ! h>mony4 ,9 ! ?ree cases j /at$ ! co9cid5ce is 9 ! fir/ at ! comm5cem5t ( e vibration ( ! fundam5tal note1 9 ! second case at ! comm5cem5t ( e second vibration1 & 9 ! ?ird at ! comm5cem5t ( e ?ird vibration4 #bfg4 ,! ,diatonic ,scale4--,9 ord] t y may see ! relative numb]s ( ! vibrations = ea* ( ! notes ,i w give !m = ! :ole scale4 ,!y are z foll[s3 #a #i_/h #e_/d #d_/c #c_/b #e_/c #ae_/h #b ,c ,d ,e ,f ,g ,a ,b ,c4 ,accord+ to ?is ! note ,d has n9e vibrations to e eight vibrations ( ,c1 ,e has five to e f\r ( ,c1 etc41 ! octave ,c hav+ j twice ! numb] ( vibrations t ! fundam5tal note ,c has4 ,y h "h express$ ! proportion betwe5 ! numb]s ( vibrations 9 ! diff]5t notes4 ,suppose1 !n1 t y "k ! numb] ( vibrations 9 a second t ,c1 ! fundam5tal note1 has1 y c readily calculate ! numb] ( vibrations ( ea* ( ! o!r notes4 ,x is done by multiply+ ! numb] :i* ,c has by ! fractions ov] ! o!r notes4 ,?us if ! numb] ( vibrations 9 a second 9 ! fundam5tal note be #abh1 by ?is process we make ! vibrations ( all ! notes to be ?us3 ,c ,d ,e ,f ,g ,a ,b ,c #abh #add #afj #agj #aib #bac #bdj #bef4 ,!re are really b sev5 notes 9 :at is call$ ! diatonic scale1 ! eigh? note1 ,c1 be+ truly ! fir/ ( sev5 o!r notes above1 hav+ relations to ea* o!r simil> to ^? ( ! notes bel[1 & con/itut+ ano!r octave4 ,s we may h sev]al octaves1 "o above ano!r4 ,x is int]e/+ to obs]ve t ! proportionate l5g?s ( /r+s requir$ to produce ! eight notes ( ! scale h an exact num]ical relation1 b ! rev]se ( t ( ! numb]s ( ! vibrations4 ,?us if y h eight /r+s ( ! same size1 _! vibrat+ l5g?s requir$ = ! notes are z foll[s3 ,c ,d ,e ,f ,g ,a ,b ,c #a #h_/i #d_/e #c_/d #b_/c #c_/e #h_/ae #a_/b4 ,= ! notes ( ! octave above ! l5g?s are ?us3 ,c ,d ,e ,f ,g ,a ,b ,c #a_/b #d_/i #b_/e #c_/h #a_/c #c_/aj #d_/ae #a_/d4 #bfh4 ,unison4--,9 tun+ in/rum5ts s z to make !m h>monize ! result is obta9$ :5 ! correspond+ p>ts ( ! in/rum5ts h ! same numb] ( vibrations4 ,?us ! /r+ 9 "o viol9 t gives any p>ticul> note mu/ vibrate j ! same numb] ( times 9 a second t ! /r+s giv+ ! same note 9 o!r viol9s d1 or x w n be 9 p]fect unison ) !m4 ,! same is true ( o!r /r+s = o!r notes1 & also ( ! correspond+ p>ts ( all k9ds ( in/rum5ts :i* are to be play$ toge!r4 ,:51 9 tun+ in/rum5ts toge!r1 x is said t a /r+ ( a viol91 = example1 is too flat1 ! difficulty is t x does n vibrate ) suffici5t rapidity1 & x is !re=e screw$ up to make its note %>p en\gh1 z x is express$1 to be 9 unison ) ! note ( ! correspond+ /r+s or p>ts ( o!r in/rum5ts4 #bfi4 ,my/]ies ( ,s\nd & ,he>+4--,!re are _m ?+s ( a my/]i\s "* 9 relation bo? to s\nd & ! mann] 9 :i* x causes ! s5sation ( he>+4 ,i w b>ely notice b two ( ^!4 ,! effect1 or r ! *a9 ( effects1 result+ 9 he>+ is :olly me*anical1 until we come to ! n]ve ( he>+1 :i* bran*es out ) m9ute fibrils 9 ! halls ( audi5ce ( ! int]nal e>4 ,x is m]ely a s]ies ( vibrations4 ,n[ h[ x is t ! m]e agitation ( a fluid inclos$ 9 h>d bone c communicate ?r\gh f9e :ite fibres to ! bra91 & ?r\gh t to ! m9d1 ! idea t we h ( all ! v>i\s s\nds t are produc$1 is a great my/]y4 ,all t we "k is t ! n]ve is ! m$ium ( ! communication1 b ( ! mann] 9 :i* x p]=ms its (fice we "k absolutely no?+4 ,aga91 :ile x is suffici5tly my/]i\s t ?is in=mation c ?us be giv5 to ! m9d :5 "o s\nd aft] ano!r communicates its vibration to ! liquid 9 ! e>1 ! my/]y is greatly enhanc$ :5 v>i\s s\nds come to ! e> at "o & ! same "t4 ,to get a di/9ct idea ( ! v comp\nd & wond]ful "* ( ! process ( he>+ 9 su* a case we w suppose t a full b& ( music is play+1 & at ! same "t m+l$ ) its s\nds !re are v>i\s o!r s\nds he>d1 "s ( !m p]haps discordant4 ,:at a div]sity ( vibrations we h "h6 ,we h ! sl[ vibrations produc$ 9 ! grave notes1 & ! quick vibrations ( ! high] ones1 all travel+ toge!r ?r\gh ! air to ! e>1 & ea* pres]v+ its di/9ctive "*4 ,& m ?an ?is1 aft] !y arrive at ! e> !y are communicat$ unalt]$ ?r\gh ! drum1 ! *a9 ( bones1 ! second drum1 & ! liquid :]e ! n]ve is1 s t a correct report ( ea* ( all ! notes is giv5 ?r\gh ! n]ve to ! m9d4 ,!n1 too1 if !re be any discord its vibration travels along ) ! re/1 & s d ! vibrations ( o!r s\nds1 z ! ro>+ ( ! w9d1 ! report ( cannon1 & ! noise ( ! p4 ,& besides all ?is1 9 ! multiplicity ( ! vibrations ?us transmitt$ ?r\gh s _m diff]5t sub/ances ! m9d gets a true report ( ! comp>ative l\dness ( ! s\nds1 & ev5 ( _! "*1 s t ! s\nds ( drum1 fife1 trumpet1 etc41 are all accurately di/+ui%$4 ,9 view ( su* wond]s h[ significant is ! "q1 ,he t plant$ ! e>1 %all he n he>8 ,,*apt] ,,xiii4 ,,heat4 #bgj4 ,heat & ,cold4--,9 common language we speak ( heat & cold z two di/9ct & opposite ?+s4 ,t ?is is n /rictly correct may be %[n by ! foll[+ exp]im5t3 ,take ?ree vessels1 & fill ! fir/ ) ice-cold wat]1 ! second ) hot wat]1 & ! ?ird ) tepid wat]4 ,if y place y\r "r h& 9 ! fir/ & ! left 9 ! second1 & let !m rema9 a little "t1 on tak+ !m out & plung+ !m toge!r into ! ?ird vessel1 ! wat] 9 x w feel w>m to ! "r h& & cold to ! left4 ,s ! air ( a cell> seems w>m to y 9 w9t] & cold 9 summ] 9 contra/ ) ! air outside4 ,= ! same reason wat] ( a temp]ature t w\ld ord9>ily be refre%+ly cool to u seems w>m :5 drank aft] eat+ ice-cream4 ,x is manife/1 !n1 t !re is no fix$ divid+-l9e betwe5 heat & cold4 ,!re is1 9 fact1 no su* ?+ z cold4 ,sub/ances are cold f be+ depriv$ ( heat2 & no sub/ance ev] has all its heat tak5 f x4 ,sir ,humphrey ,davy prov$ t !re is heat 9 ice by rubb+ two pieces toge!r 9 a v cold room4 ,!y 7 gradually melt$4 ,n[ ?is 0 n done by ! air1 = t 0 at a temp]ature bel[ ! freez+ po9t4 ,! heat :i* melt$ ! ice came f ! ice itself by means ( ! rubb+4 #bga4 ,nature ( ,heat4--,!re are two !ories 9 reg>d to ! nature ( heat4 ,"o is t heat is an impond]able 7 #af71 & ( c\rse a v subtile sub/ance1 :i* p]vades all matt]4 ,its p>ticles are suppos$ to repel ea* o!r /rongly1 & h5ce !y h a t5d5cy to diffuse !mselves1 & to sep>ate ! p>ticles ( matt] f ea* o!r4 ,x is 9 ?is way t !y are suppos$ to occasion ! expansion ( sub/ances4 ,! o!r supposition1 :i* is mo/ commonly receiv$1 is t heat is a vibration ( ! p>ticles ( bodies1 & t x passes f ^! to bodies less w>m ?r\gh a subtile fluid call$ e!r1 suppos$ to fill all space4 ,y see t if ?is be ! true !ory1 !re is "s analogy betwe5 heat & s\nd4 ,illu/ration3 ,fig4 #aia4 #bgb4 ,s\rces ( ,heat4--,! pr9cipal ( ! s\rces ( heat on our e>? is ! sun1 ?\gh t body is n9ety-five millions ( miles di/ant f u4 ,z ! heat1 9 travel+ all ?is long j\rney1 is becom+ m & m diffus$2 or1 9 o!r words1 z its rays are all ! way sep>at+ f ea* o!r m & m1 we c h no conception ( ! conc5trat$ heat t exi/s 9 ! sun itself4 ,we c1 h[ev]1 approximate to ! idea by obs]v+ ! effects ( heat :5 "s ( its sep>at$ rays are ga!r$ to a po9t by a p[]ful l5s1 z repres5t$ 9 ,fig4 #aia4 ,a l5s :i* conc5trat$ ! heat t5 ?\s& times melt$ plat9um1 gold1 qu>tz1 etc41 9 a few seconds4 ,& z ! heat at ! sun is suppos$ to be ?irty times m conc5trat$ ?an ?is1 none ( ! mo/ solid sub/ances ( our e>? w\ld rema9 solid if !y 7 !re1 b w\ld be "s ( !m liquid1 & o!rs ev5 9 a /ate ( vapor4 ,! heat :i* ! sun con/antly radiates to ! e>? p]vades all sub/ances1 produc+ motion1 & awak5+ life e :]e1 s t1 9 ! expressive language ( ! ,bible1 ,!re is no?+ hid f ! heat !re(4 ,ano!r s\rce ( heat is )9 ! e>? itself4 ,x has be5 f\nd z we g d[n into ! e>? !re is a con/ant increase ( temp]ature ! f>!r we g4 ,?is int]nal heat is attribut$ 9 "p to subt]ranean fires & v>i\s *emical actions4 ,we see "h & !re ext]nal evid5ces ( ! op]ation ( ^! causes 9 ! eruptions ( volcanoes1 ! boil+ spr+s1 ! jets ( /eam & sulphure\s vapors1 etc4 ,b t ! heat 9 our e>? :i* comes f ^! subt]ranean s\rces is small comp>$ ) t :i* comes f ! sun1 is se5 9 ! fact t ! rate ( increase ( heat at great dep?s is mu* less ?an x is ne>] ! surface4 ,?is w\ld seem to %[ t al?\gh fires )9 ! e>? may h consid]able influ5ce 9 heat+ its cru/1 on :i* we live1 x d]ives ! mo/ ( its heat f ! sun1 at lea/ to a v great dep?4 ,h[ great a s\rce ( heat electricity is we "k n1 b t consid]able heat comes f ?is s\rce is evid5t f ! melt+ & burn+ effect :i* we (t5 see result+ f ! passage ( ! electric fluid4 ,ano!r v common s\rce ( heat is *emical action4 ,we see x cont9ually produc$ 9 *emical exp]im5ts4 ,combu/ion1 :i*1 z w be %[n to y 9 ! ,second ,"p ( ?is ,s]ies1 is no?+ b an example ( *emical action1 is ! mo/ common ( all ! *emical s\rces ( heat4 ,animal heat is also1 = ! mo/ "p1 a result ( *emical action4 ,me*anical action is a common s\rce ( heat4 ,! rubb+ ( a mat* produc+ heat en\gh to occasion flame is a famili> example4 ,! sp>k produc$ 9 :at is call$ /rik+ fire is ! burn+ ( a p>ticle ( /eel set on fire by ! bl[4 ,! ,indian 0 accu/om$ to light 8 fire by ! rubb+ toge!r ( two dry /icks till he le>n$ an easi] way f civiliz$ neighbors2 & ! blacksmi?1 previ\s to ! inv5tion ( phosphorus mat*es1 (t5 light$ 8 fire by t\*+ a sulphur mat* to a nail made r$-hot by rapid & cont9u$ hamm]+4 ,ma*9]y has sometimes be5 set on fire by friction1 & ! wat] ar\nd a mass ( metal has be5 s heat$ by bor+ z ev5 to boil4 ,if y /ret* a piece ( ,india rubb] sev]al times 9 quick succession1 & !n apply x to y\r lips1 y w p]ceive t ! motion has w>m$ x4 #bgc4 ,relations ( ,heat & ,light4--,heat is sometimes alone1 & is sometimes 9 intimate union ) light4 ,all sub/ances h "s am\nt ( heat1 & x passes f !m to o!r bodies 9 _! neighborhood t happ5 to h less heat 9 !m4 ,9 do+ ?is x may or may n h ! company ( light4 ,9 ! radiation ( heat f a /ove1 unless x be heat$ to r$ness1 !re is no light ) ! heat2 b f an op51 burn+ fire ! light & heat come toge!r4 ,b ! rays ( ! sun give u ! be/ example ( ! union ( light & heat4 ,travel+ toge!r at an equal pace !y are mo/ curi\sly m+l$1 z y w see :5 ,i come to speak p>ticul>ly ( light4 ,i w n[ proce$ to notice ! pr9cipal effects ( heat2 viz41 expansion1 liquefaction1 & vaporization4 ,illu/ration3 ,fig4 #aib4 #bgd4 ,expansion 9 ,solids4--,heat1 y h se5 9 #bc1 acts 9 opposition to ! attraction ( cohesion1 t5d+ to sep>ate ! p>ticles1 & s produces an expansion ( any sub/ance4 ,?is may be exemplifi$ 9 ! exp]im5t repres5t$ 9 ,fig4 #aib1 9 :i* ,a ,b is an iron rod1 :i* is ( su* a size t at ! ord9>y temp]ature x w fit into ! space1 ,c ,d1 9 a b> ( iron1 & easily pass ?r\gh ! hole1 ,e4 ,if ! rod be heat$ x w be enl>g$ or exp&$ 9 all directions1 s t x w nei!r fit into ,c ,d nor pass into ! hole1 ,e4 ,:5 ! :eel-wright puts a tire ^u a :eel he uses ! expansion ( heat to make x fit tightly & firmly4 ,! tire is made a little too small to h x fit ^u ! :eel z x is4 ,b by be+ heat$ x is s exp&$ t x w readily g on to ! :eel1 & !n 9 contract+ z x cools x s compresses ! fellies z to hold on v tightly4 ,wat] is p\r$ on to cool ! iron quickly1 & ?us prev5t x f burn+ ! wood4 ,iron hoops are put on b>rels 9 a simil> mann]1 ! compression caus$ by _! contraction b9d+ ! /aves toge!r v /rongly4 ,s 9 fa/5+ ! plates ( boil]s toge!r1 ! rivets are put 9 r$-hot1 s t 9 _! contraction !y may press ! plates closely toge!r4 ,if an iron gate j %uts into its place 9 cold wea!r1 its expansion w prev5t its %utt+ :5 w>m wea!r comes4 ,9 ord] to avoid ?is difficulty1 calculation mu/ be made 9 fitt+ x = its place = ! expansion to :i* x w be subject$ by heat4 ,s 9 lay+ ! rails ( a railroad 9 cold wea!r c>e mu/ be tak5 n to put ! ends too ne> toge!r4 ,9 con/ruct+ iron bridges ! expansion by heat mu/ be calculat$ = 9 ! arrangem5t4 ,nails (t5 become loose aft] ! lapse ( ye>s f ! we> ( ! wood ar\nd !m1 occasion$ by _! alt]nate expansion & contraction4 ,! leak+ ( gas-pipes 9 ! e>? is (t5 und\bt$ly caus$ by ! loos5+ ( ! jo9ts f contraction & expansion ( ! pipes by v>y+ temp]atures ( ! soil1 especially :]e !y are n laid v deep4 ,if a /opp] /ick fa/ 9 a bottle x c be loos5$ by ! application ar\nd ! neck ( a clo? dipp$ 9 hot wat]1 because ! neck becomes exp&$ at once by ! heat4 ,a simil> exp$i5t 0 once v +5i\sly made use ( 9 repair+ ! ma*9]y ( ! /eam] ,p]sia at sea1 & 0 p]haps ! means ( sav+ ! vessel & ! lives ( all on bo>d4 ,! accid5t :i* occurr$ 0 ! break+ ( ! port crank-p9 ( ! eng9e4 ,! problem to be solv$ 0 ! removal ( ?is p91 :i* weigh$ ne>ly a ton1 & ! sub/itution ( a s\nd "o :i* !y _h on h& 9 its place4 ,b x 0 f\nd impossible to />t ! brok5 p9 f its socket ) all ! =ce :i* c\ld be br\ght to be> ^u x by a sort ( batt]+-ram con/ruct$ extemporane\sly = ! purpose4 ,x 0 det]m9$ n[ to try ! expansive =ce ( heat4 ,an iron plat=m 0 built "u ! socket1 & a brisk fire made ^u x4 ,! socket soon exp&$1 & ! p9 0 n[ readily knock$ out by ! batt]+-ram1 j z ! /opp] ( ! bottle is easily remov$ :5 ! neck is heat$4 ,! walls ( a v l>ge build+ 9 ,p>is1 :i* _h bulg$ out & 7 9 dang] ( fall+1 7 re/or$ to _! upright position by ! expansion ( heat4 ,illu/ration3 ,fig4 #aic4 ,x 0 done 9 ?is way3 ,long rods ( iron 7 run ?r\gh ! walls aft] ! plan repres5t$ 9 ,fig4 #aic 7p4 #bac71 _! ends be+ made ) a screw-?read1 ) nuts fitt$ to !m4 ,! rods m>k$ a 7 fir/ heat$1 & z !y l5g!n$ ! nuts 7 screw$ up tight to ! walls4 ,on cool+1 _! contraction w\ld ( c\rse draw ! walls toge!r4 ,! o!r b>s1 b1 7 n[ heat$ & manag$ 9 ! same way4 ,! "o set1 y see1 7 made to hold on by _! nuts to :at _h already be5 ga9$1 :ile ! o!r 7 exp&+4 ,by _m repetitions ( ?is process ! walls 7 right$ & ! build+ sav$4 ,! same mode has be5 adopt$ successfully 9 o!r cases ( a simil> "*4 #bge4 ,expansion 9 ,liquids4--,liquids are exp&$ by heat m ?an solids are4 ,b !y are v unequally exp&$ by x4 ,?us wat] is exp&$ m ?an twice z mu* z m]cury1 & alcohol six times z mu*4 ,we h a frequ5t example ( ! expansion ( wat] by heat 9 our kit*5s4 ,if ! tea-kettle be put ov] ! fire fill$ to ! brim1 x w run ov] long be=e ! wat] beg9s to boil4 ,all liquids occupy m space 9 summ] ?an 9 w9t]1 & 9 ! =m] case weigh less--t is1 h less ( real sub/ance 9 !m ?an 9 ! latt]4 ,if1 !re=e1 alcohol1 or oil1 or molasses be b\ght by ! gallon 9 w9t] & sold 9 summ]1 !re w be a pr(it af=d$ by ! expansion4 ,tw5ty gallons ( alcohol 9 w9t] becomes tw5ty-"o 9 mid-summ]4 ,illu/ration3 ,fig4 #aid4 ,! influ5ce ( ! expansion ( heat ^u ! specific gravity ( liquids may be v prettily %[n by ! foll[+ exp]im5t3 ,let "s little bits ( amb]--a sub/ance :i* is ne>ly ( ! same specific gravity ) wat]--be ?r[n into wat] 9 a glass vessel1 & let ! wat] be heat$1 z repres5t$ 9 ,fig4 #aid1 by a _s-lamp4 ,t portion ( ! wat] :i* is heat$ passes upw>d because x is made specifically light]1 & cold] wat] cont9ually comes d[n to take its place4 ,! upw>d & d[nw>d curr5ts are z indicat$ by ! arr[s1 ! upw>d pass+ up 9 ! middle1 ! d[nw>d com+ d[n at ! sides4 ,?is w be made manife/ by ! little bits ( amb]4 #bgf4 ,!rmomet]s4--,x is ! expansion ( liquids by heat t 9 ! !rmomet] gives u ! measure ( temp]ature4 ,! liquid metal m]cury is commonly us$ = ?is purpose1 & answ]s well except 9 ! extreme cold ( ! arctic regions4 ,!re1 z m]cury becomes solid at #ci degrees bel[ z]o1 x is necess>y to use a !rmomet] ) alcohol 9 x1 z ?is fluid c n be froz5 by any degree ( cold4 ,! op]ation ( ! !rmomet] is simply ?is3 ,heat exp&s ! fluid 9 ! bulb1 & ! only way 9 :i* x c occupy m space z x exp&s is by ris+ 9 ! tube4 ,! ab/raction ( heat1 on ! o!r h&1 causes contraction1 & ( c\rse a proportionate fall+ ( ! fluid4 #bgg4 ,fahr5heit's ,!rmomet]4--,! !rmomet] 0 inv5t$ 9 ! beg9n+ ( ! sev5te5? c5tury1 b x is n decid$ :o 0 ! inv5tor4 ,!re may h be5 9 ?is case1 z 9 o!rs1 m inv5tors ?an "o1 ! same ideas hav+1 p]haps1 ent]$ sev]al inquir+ m9ds at ! same "t4 ,v>i\s fluids 7 us$ by diff]5t p]sons4 ,sir ,isaac ,newton us$ l9se$ oil4 ,fahr5heit1 a native ( ,hamburg1 :o fl\ri%$ 9 ! fir/ "p ( ! la/ c5tury1 0 ! fir/ to use m]cury4 ,?\gh v>i\s propositions 7 made by ,newton & o!rs 9 reg>d to ! measurem5t ( heat by !rmomet]s1 no !rmometric scale seems to h met ) g5]al reception till t ( ,fahr5heit's1 :i* 0 put =? ab\t #agbj4 ,! plan ( x is ?is3 ,8 z]o is ! po9t at :i* ! m]cury /ood 9 ! colde/ freez+ mixture t he c\ld make2 & he suppos$ t ?is 0 ! greate/ possible degree ( cold1 z x 0 ! greate/ t he knew4 ,he next f\nd ! po9t at :i* ! m]cury /ood 9 melt+ ice4 ,?is he call$ ! freez+ po9t1 because ! temp]ature is ! same 9 wat] pass+ into ! solid f ! fluid /ate z 9 wat] pass+ into ! fluid /ate f ! solid4 ,9 o!r words1 ?is po9t 9 ! scale m>ks ! transition l9e betwe5 ! two /ates4 ,f ?is po9t ,fahr5heit m>k$ (f #cb equal spaces or degrees d[n to z]o4 ,he n[ f\nd ! po9t at :i* ! m]cury /&s 9 boil+ wat]1 & call$ ?is ! boil+ po9t4 ,m>k+ (f ! space on ! scale betwe5 ?is1 & ! freez+ po9t 9 ! same mann]1 !re are #ahj degrees--t is1 ! boil+ po9t is #bab degrees above z]o4 ,! degrees above z]o are commonly designat$ by ! m>k 1 plus2 & ^? bel[ by ! m>k -1 m9us4 ,?us1 #cb signifies #cb degrees above z]o1 & -#cb signifies #cb degrees bel[4 ,illu/ration3 ,fig4 #aie4 #bgh4 ,o!r ,!rmomet]s4--,fahr5heit's !rmomet] is ! "o commonly us$ 9 ?is c\ntry4 ,b !re are sev]al o!r !rmomet]s on diff]5t scales1 z ! ,c5tigrade1 ,reaumur's1 & ,de ,lisle's4 ,9 ,fig4 #aie y see ! plans ( ! scales ( ^! !rmomet]s plac$ side by side4 ,9 ! ,c5tigrade !rmomet]1 :i* is 9 use 9 ,france1 & inde$ 9 a l>ge "p ( ,europe1 ! z]o1 y see1 is plac$ at ! freez+ po9t2 & ! space betwe5 ?is & ! boil+ po9t is divid$ into #ajj degrees1 :i* gives x ! "n ,c5tigrade4 ,reaumur's1 :i* is 9 use 9 ,russia1 has ! same z]o1 b he has only #hj degrees f ?is to ! boil+ po9t4 ,de ,lisle's1 :i* has gone entirely out ( use1 has its z]o at ! boil+ po9t4 ,! arrangem5t ( ,fahr5heit1 al?\gh its z]o is a m]e arbitr>y po9t1 is1 on ! :ole1 ! be/1 because its degrees are ( su* a size t !y m>k diff]5ces ( temp]ature ) suffici5t m9ut5ess = all practical purposes ( an ord9>y "* )\t resort+ to fractional p>ts4 ,illu/ration3 ,fig4 #aif4 #bgi4 ,expansion 9 ,a]i=m ,sub/ances4--,heat produces a va/ly great] expansive effect 9 air1 ! gases1 & vapors1 ?an x does 9 liquids4 ,! expansion ( air by heat may be %[n v prettily 9 ?is way3 ,take a glass tube t has a bulb on "o end1 &1 plac+ ! o!r op5 end 9 wat] 7z repres5t$ 9 ,fig4 #aif71 apply ! palm ( y\r h& to ! bulb4 ,! heat ( ! h& be+ communicat$ to ! bulb w exp& ! air1 & s1 z y see1 bubbles ( air w escape ?r\gh ! wat]4 ,on remov+ ! h&1 & all[+ ! bulb to cool1 ! air 9 x w be cond5s$1 & wat] w pass up 9 ! tube 9 proportion to ! am\nt ( air :i* has escap$4 ,a bladd] p>tly fill$ ) air w be made to swell out to plumpness if x be heat$ suffici5tly1 & a full "o may be s heat$ z to bur/ f ! expansion ( ! air4 ,por\s wood1 z *e/nut1 snaps v mu* :5 burn$1 because ! heat exp&s ! air conta9$ 9 ! pores4 #bhj4 ,balloons4--,! fir/ balloons t 7 us$ 7 fill$ ) heat$ air4 ,y h already se51 9 #adi1 :y x is t balloons rise4 ,n[ 9 ! hot-air balloon x is ! expansion ( ! air by heat t makes x light] ?an ! surr\nd+ air4 ,( c\rse su* a balloon is n z effective z ! gas balloon1 = ! air )9 x loses its comp>ative lightness z x becomes cool$2 :ile ! gas :i* is us$1 be+ v mu* light] ?an air at ! same temp]ature1 does n lose its lightness z ! balloon goes up4 ,y le>n$ 9 #aeb t ! atmosph]e becomes ?9n] z we g upw>d4 ,! gas balloon1 !re=e1 rises until x arrives at t po9t :]e ! air is ( ab\t ! same specific gravity ) ! gas1 & !re x /ops4 ,x is made to desc5d by lett+ out "s ( ! gas f a valve4 ,gas 0 n us$ = balloons till #aghb4 ,hydrog5 gas 0 employ$ at fir/1 be+ ov] f\rte5 times light] ?an air4 ,( late ! common burn+ gas1 c>buret$ hydrog51 has be5 g5]ally us$1 because x c be s readily obta9$ :]e !re are gas-works4 ,illu/ration3 ,fig4 #aig4 #bha4 ,curr5ts 9 ! ,air f ,heat4--,heat is ! gr& mov] ( ! atmosph]e4 ,any portion ( x t becomes w>m] ?an surr\nd+ portions rises1 or r is pu%$ up1 = ! same reason t a hot-air balloon rises1 ! only diff]5ce betwe5 ! two cases be+ t 9 ! "o ! air is conf9$1 & 9 ! o!r is left free1 & s becomes diffus$4 ,& x is ?is ris+ ( ! air f expansion t causes ne>ly all ! movem5ts t we witness 9 ! air4 ,we see ?is exemplifi$ 9 v>i\s ways :]ev] !re is a fire4 ,! air t is heat$ by ! fire is =c$ upw>d by ! cold] air1 :i*1 on ! pr9ciples ( specific gravity1 seeks to get bel[ ! w>m] & light] air4 ,! hot air t comes ?r\gh ! regi/]s ( a furnace is pu%$ up by cold] air bel[4 ,= ! same reason ! heat$ air ar\nd a /ove-pipe is con/antly go+ upw>d4 ,?is is v prettily %[n by ! toy repres5t$ 9 ,fig4 #aig 7p4 #bah71 :i* is a pap] cut spirally1 & susp5d$1 z y see1 ^u ! po9t ( a wire4 ,! upw>d curr5t makes ! pap] revolve rapidly ar\nd ! wire4 ,x is f ! ris+ ( w>m air t ! gall]ies ( a *ur* are w>m] ?an ! space bel[4 ,9 a common room ! disposition ( ! air is cont9ually to h its w>me/ portions above & ! cold] bel[4 ,x is = ?is reason t we h our arrangem5ts = produc+ or introduc+ heat at z l[ a po9t z possible4 #bhb4 ,*imneys4--,we speak ( ! draught ( a *imney1 & we say ( "o t does n smoke t x draws well1 z if ! smoke 7 9 "s way actually drawn up4 ,b ! same pr9ciples apply "h z are develop$ 9 #bha4 ,! smoke1 :i* is a comb9ation ( heat$ air & gases ) "s solid matt]s 9 a f9e /ate1 is =c$ up ! *imney4 ,:5 a *imney does n draw well we op5 a door or a w9d[ = a little :ile until ! fire gets ?or\ghly ago+4 ,:y is ?is8 ,x is t we may h d5s] air ?an !re is 9 ! room1 s t ! smoke may be pu%$ up m =cibly4 ,:5 ! *imney becomes well heat$ !re is ord9>ily no difficulty1 because !n ! smoke 9 x is n oblig$ to "p ) mu* ( its heat to ! walls ( ! *imney1 & !re=e is s mu* light] ?an ! air 9 ! room t x is v easily =c$ upw>d4 ,! pr9cipal reason t a /ove-pipe g5]ally draws bett] ?an a *imney is t !re is mu* less heat exp5d$ 9 e/abli%+ & ma9ta9+ ! upw>d curr5t4 ,especially is ?is true if ! *imney be a l>ge "o4 ,9 su* a case !re are bo? a great ext5t ( brick & a l>ge body ( air to be heat$ to e/abli% ! upw>d curr5t1 & ^! mu/ be kept w>m 9 ord] to ma9ta9 x4#c ,illu/ration3 ,fig4 #aih4 ,illu/ration3 ,fig4 #aii4 #bhc4 ,w9ds4--,if y op5 a door ( a heat$ room a c&le held ne> ! floor w h its flame bl[n inw>d1 :ile "o held ne> ! top ( ! door w h its flame bl[n t[>d ! cold entry4 ,"h y h a good illu/ration ( ! mann] 9 :i* w9ds are produc$4 ,:]ev] ! w9d bl[s x is air pu%+ out ( ! way o!r air t is w>m]1 9 ord] t x may1 9 ob$i5ce to gravitation1 get z ne> ! e>? z possible4 ,take1 = example1 ! l& & sea breezes1 z !y are call$4 ,dur+ a hot summ]'s day ! sun heats ! e>? p[]fully1 :ile ! ocean receives b little ( its heat4 ,! heat$ l& heats ! air above x2 & z ! air ov] ! ocean is cool]1 & !re=e heavi]1 x pu%es upw>d ! air ( ! l&1 = ! same reason t wat] pu%es up oil2 & z ?is goes on cont9u\sly a regul> curr5t is e/abli%$4 ,! w9d bl[s 9 ^u ! l&1 z repres5t$ 9 ,fig4 #aih1 :ile ! w>m] air passes upw>d into ! high] regions ( ! atmosph]e1 & turns t[>d ! sea4 ,! arr[s %[ ! c\rse ( ! curr5ts4 ,! resemblance ( all ?is to ! effect ^u ! c&le held ne> ! op5 door is v obvi\s1 ! cold air f ! entry bl[+ 9 bel[ repres5t+ ! breeze f ! ocean1 & ! w>m air ( ! room bl[+ out above repres5t+ ! passage ( ! w>m air ( ! l& out t[>d ! ocean4 ,at night ?is is apt to be rev]s$4 ,! e>? becomes cool$1 & ) x ! air t is ov] x4 ,! result is t ! cool$ air ( ! l& n[ pu%es upw>d ! w>m] air ( ! sea1 z se5 9 ,fig4 #aii4 ,illu/ration3 ,fig4 #bjj4 ,illu/ration3 ,fig4 #bja4 #bhd4 ,w9ds z ,affect$ by ! ,rotation ( ! ,e>?4--,! heat ( ! v]tical sun ^u ! tropics causes a rise ( heat$ air into ! upp] regions1 :ile !re is a ru% ( cold] air t[>d ! equator f bo? nor? & s\?4 ,?is effect is repres5t$ 9 ,fig4 #bjj 7p4 #bba71 ,e be+ ! sun1 ,n ! nor? pole1 & ,s ! s\? pole4 ,an effect simil> to t repres5t$ 9 ,figs4 #aih & #aii is produc$ "h1 b x is on a mu* l>g] scale4 ,b ! diagram does n pres5t ! matt] 9 its true light 9 all respects4 ,! prevail+ w9ds 9 ! equatorial regions are n nor? & s\? w9ds1 z w\ld appe> f ?is diagram2 b !y are f ! nor!a/ & s\!a/4 ,i w expla9 ?is by ,fig4 #bja4 ,z ! e>? turns on its axis x is pla9 t !re is no "p ( ! surface ( ! e>? t moves s rapidly z ! equator1 ,e ,w1 = t moves 9 a l>g] circle ?an any o!r "p4 ,& ! ne>] y g to ei!r pole1 ,n or ,s1 ! less is ! rapidity ( ! revolution4 ,n[ ! atmosph]e1 z /at$ 9 #ahh1 p>takes ( ! motion ( ! e>?4 ,! air1 !re=e1 at ! equator is mov+ f we/ to ea/ ) ! rotation ( ! e>? fa/] ?an x is any :]e else1 & ! ne>] y g to ei!r pole ! sl[] is its motion4 ,x foll[s f ?is t any portion ( air bl[+ f ! nor? or ! s\? t[>d ! equator1 z x comes f :]e x 0 mov+ ea/ sl[] ?an air at ! equator is1 w\ld f its less] mom5tum lag beh9d ! air ( ! equator1 ! w9d w\ld be curv$ t[>d ! we/w>d1 z indicat$ by ! arr[s4 ,! result w\ld be t ! nor!rn w9d w\ld be conv]t$ into a nor!a/]1 & ! s\!rn into a s\!a/]4 ,all ?is c be made m cle> ) a globe1 or1 inde$1 ) any r\nd object4 #bhe4 ,liquefaction4--,! *ange ( solids into liquids is "o ( ! mo/ obs]vable effects ( heat4 ,?is *ange requires diff]5t degrees ( heat 9 diff]5t sub/ances4 ,?us :ile iron melts at ! high heat ( #bghf1 lead melts at #fcc1 sulphur at #bci1 ice at #cb1 & m]cury at #ci bel[ z]o4 ,m]cury is nev] f\nd 9 a solid /ate1 b x sometimes becomes solid 9 ! arctic regions :5 c>ri$ !re & expos$ 9 ! op5 air4 ,we are apt to ?9k ( wat] z be+ 9 a m natural /ate :5 liquid ?an :5 x is solid1 j z we ?9k ( iron z be+ naturally solid & m]cury z naturally liquid4 ,b 9 all ^! cases ! /ate ( ! sub/ance dep5ds on its temp]ature1 & ?is is v>i$ by circum/ances4 ,wat] at ! equator is always liquid1 & ! idea ( ice !re is exce$+ly unnatural2 :ile ne> ! poles x is ! rev]se1 ice & sn[ reign+ e :]e ?r\gh\t ! :ole ye>4 #bhf4 ,evaporation4--,!re are two ways 9 :i* ! *ange ( a liquid into a vapor occurs4 ,"o is a rapid *ange :5 heat is s appli$ z to raise ! liquid to its boil+ po9t4 ,?is is commonly t]m$ vaporization4 ,! o!r mode is ! ord9>y gradual evaporation :i* goes on f ! surface ( ! liquid4 ,?is process is go+ on cont9u\sly1 n requir+ any p>ticul> degree ( heat1 b occurr+ "u all degrees ( ! temp]ature ( a liquid4 ,its rapidity1 h[ev]1 is 9 proportion to ! degree ( heat1 z may be se5 by ! rise ( vapor f wat] t is be+ heat$1 long be=e x beg9s to boil4 ,! same ?+ c also be se5 9 a bright summ]'s morn+1 :5 ! heat ( ! sun causes ! moi/ure ga!r$ f ra9 or dew to rise s abundantly f f5ces1 & bo>ds1 & ro(s z to be visible l smoke4 #bhg4 ,solution ( ,wat] 9 ,air4--,evaporation is con/antly go+ on f e wet surface1 except :5 ! air is s load$ ) moi/ure t x c take up no m4 ,! vapor is n ord9>ily visible1 ! p>ticles ( wat] pass+ quietly upw>d among ^? ( ! air1 be+ dissolv$ 9 ! air j z "s solids are dissolv$ 9 wat]4 ,x becomes visible only :5 s mu* ( x rises t ! solution ( ! wat] 9 ! air is n readily effect$4 ,! read9ess ) :i* ! solution takes place dep5ds mu* ^u ! temp]ature ( ! atmosph]e4 ,"s v common ph5om5a illu/rate ?is4 ,9 a v cold day ! brea? ( animals1 z x comes out ( ! m\?1 seems to be load$ ) moi/ure4 ,:y8 ,x is n because !re is m moi/ure 9 x ?an 9 w>m wea!r1 b because cold air c n hold 9 solution s mu* wat] z w>m air c4 ,! same explanation applies to ! smok+ ( wet f5ces & ro(s 9 ! sun ( a summ]'s morn+4 ,! moi/ure is heat$ by ! sun1 b ! air1 n hav+ become v w>m z yet1 c n readily dissolve all ! moi/ure t rises4 ,! ph5om5on is n apt to occur :5 ! hot sun %9es aft] a %[] at mid-day or 9 ! aft]noon1 because !n ! air is w>m en\gh to take up all ! moi/ure t is s5t up into x4 ,h[ wat]1 be+ heavi] ?an air1 rises 9 ! atmosph]e is a my/]y4 ,x has be5 suppos$ by "s t x 0 ow+ to a k9d ( aff9ity exi/+ betwe5 wat] & air4 ,b 9 opposition to ?is is ! fact t evaporation takes place m rapidly "u ! exhau/$ receiv] ( an air-pump1 :]e !re is almo/ no air1 ?an x does :]e x is freely expos$ to ! atmosph]e4 #bhh4 ,cl\ds4--,! wat] :i* goes up 9 ! air 9 evaporation is v>i\sly dispos$ (4 ,"s ( x is deposit$ z dew or fro/4 ,"s ( x =ms fog4 ,"s ( x also m\nts f> upw>d & =ms ! cl\ds1 :i* are really collections ( fog made high up 9 ! air4 ,9 fog & 9 cl\ds ! wat] :i* 9 its evaporation is invisible becomes visible4 ,let u see h[ ?is is4 ,!re is always m or less ( wat] 9 cle> air1 b ! p>ticles are s m9utely divid$ & s ?or\ghly m+l$ ) ! p>ticles ( ! air t !y c n be se54 ,b 9 a fog or cl\d ! p>ticles ( wat] are ga!r$ toge!r 9 little companies1 z we may express x4 ,& x is suppos$1 "s ?9k asc]ta9$1 t ea* ( ^! companies ( p>ticles is globul> & holl[4 ,if s1 !n we may reg>d e cl\d z a va/ collection ( m9ute bubbles or balloons c>e]+ ?r\gh ! air4 ,illu/ration3 ,fig4 #bjb4 ,illu/ration3 ,fig4 #bjc4 #bhi4 ,%apes ( ,cl\ds4--,cl\ds h a v great v>iety ( %ape1 ! causes ( :i* are = ! mo/ "p n und]/ood4 ,!y are g5]ally divid$ into f\r classes3 ,cirrus1 ,cumulus1 ,/ratus1 & ,nimbus4 ,! ,cirrus is repres5t$ 9 ,fig4 #bjb 7p4 #bbe74 ,x is a light1 fleecy cl\d1 hav+ graceful turns l curls1 & h5ce its "n1 :i* is ! ,lat9 ^w = curl4 ,su* cl\ds are commonly v high up 9 ! air4 ,! ,cumulus 7,lat9 = heap7 y see 9 ,fig4 #bjc 7p4 #bbe74 ,cl\ds tak+ ?is =m appe> z heaps r\nd$ upw>d1 & (t5 appe> l m\nta9s ( sn[ :5 !y are illum9at$ by ! sun4 ,we see su* cl\ds mo/ly 9 summ]4 ,! ,/ratus 7,lat9 = cov]+7 is se5 9 ! same figure "u ! ,cumulus4 ,cl\ds ( ?is =m lie l[ 9 ! horizon1 /ret*$ along l a %eet4 ,!y (t5 =m 9 ! latt] "p ( ! day1 & increase 9 ! night1 b ! ris+ sun dissipates !m4 ,! ,nimbus1 or ra9-cl\d1 is repres5t$ 9 ,fig4 #bjd 7p4 #bbf74 ,x has a uni=m gray or d>k color4 ,we (t5 h two =ms ( cl\d m+l$ toge!r4 ,?us 9 ,fig4 #bje 7p4 #bbf7 we h a mixture ( ! ,/ratus & ! ,cirrus1 t]m$ ,cirro-,/ratus4 ,?is is commonly call$ ! mack]el-sky1 & is q a sure progno/ic ( ra94 ,!n we h ! ,cirro-,cumulus1 ,fig4 #bjf 7p4 #bbg71 & ! ,cumulo-,/ratus1 ,fig4 #bjg 7p4 #bbg74 ,illu/ration3 ,fig4 #bjd4 ,illu/ration3 ,fig4 #bje4 ,wat] is ga!r$ into cl\ds und\bt$ly1 9 "p at lea/1 f ! influ5ce ( attraction4 ,b :at ! circum/ances are t give !m all ^! v>i\s %apes we "k n4 ,:atev] !y are1 !y sometimes op]ate v ext5sively1 giv+ a simil> %ape to all ! cl\ds t cov] ! :ole ar* ( ! heav5s2 & at o!r times !y op]ate v>i\sly 9 diff]5t localities1 produc+ diff]5t %apes1 sometimes ev5 9 ne> neighborhood to ea* o!r4 ,sometimes ! edge ( a cl\d is irregul>1 or curv$1 or fea!ry2 & at o!rs x is a well-def9$ l9e1 /ret*+ along ov] a l>ge portion ( ! horizon4 ,9 all ^! cases we h only div]s arrangem5ts ( ! same ?+--a collection ( vesicles ( wat] conta9+ air1 :i* is made light] ?an ! air outside ( ! cl\d by means :i* ,i %all speak ( 9 ano!r "p ( ?is *apt]4 ,illu/ration3 ,fig4 #bjf4 ,illu/ration3 ,fig4 #bjg4 #bij4 ,ra91 ,sn[1 & ,hail4--,:5 x ra9s ! vesicles or m9ute bubbles ( :i* ! cl\ds are compos$ are brok5 up1 & ea* drop ( ra9 conta9s ! wat] :i* came f a multitude ( ^! vesicles4 ,b let u see exactly h[ ?is result is produc$4 ,ra9 comes f ! contraction ( ! cl\ds by cold4 ,a cold curr5t ( air com+ 9 contact ) a cl\d w cond5se its bubbles into drops1 & ^! ( c\rse w fall4 ,! same result occurs if a cl\d passes into a cold /ratum ( air4 ,b let u look at ! process m m9utely4 ,let u see :at ! effect ( cold is ^u ! bubbles4 ,illu/ration3 ,fig4 #bjh4 ,! fir/ effect may be made cle> by ,fig4 #bjh4 ,if a bubble be contract$ by ! influ5ce ( cold1 ! wat] ( its wall be+ made ?ick]1 !re w be a ga!r+ ( x f gravitation at ! l[] "p1 z repres5t$ by ! dott$ l9e4 ,y (t5 see a simil> effect 9 ! soap-bubble4 ,x rises fill$ ) ! w>m air f y\r lungs1 & z x goes up x is contract$ by ! cold] air :i* is ar\nd x4 ,?is contraction makes ! wat] hang d[nw>d f ! bottom ( x4 ,& z ! soap-bubble at l5g? p]haps bur/s 9 ! air f ! weight ( ?is wat]1 s x is ) ! vesicles 9 ! cl\d4 ,& _m ( ^!1 unit$ toge!r by attraction1 =m a drop4 ,:5 ! cold is suffici5tly sev]e x makes ! wat] ( ! ruptur$ vesicles ( ! cl\d arrange itself 9 sn[-cry/als in/ead ( drops4 ,& :5 ! cold acts ) great rapidity ^u a cl\d x presses ! p>ticles ( ! wat] toge!r s sudd5ly t !re is n "t = ! cry/all9e arrangem5t1 & hail is =m$4 #bia4 ,vaporization4--,! production ( vapor by boil+ diff]s 9 "s respects f quiet evaporation4 ,"h ! liquid is rais$ 9 temp]ature to its boil+ po9t1 & ! =mation ( vapor is n conf9$ to ! surface4 ,9 wat] ! boil+ po9t is #bab1 b x v>ies m or less f ?is 9 o!r liquids4 ,?us ! boil+ po9t ( alcohol is #agc1 ( e!r #ie1 oil ( turp5t9e #efh1 & m]cury #feb4 ,illu/ration3 ,fig4 #bji4 #bib4 ,influ5ce ( ,pressure ^u ! ,=mation ( ,vapor4--,pressure re/ra9s ! production ( vapor1 :e!r x be =m$ by evaporation or vaporization4 ,we "k by exp]im5ts ) ! air-pump t ! less pressure ( air !re is ^u ! surface ( a liquid ! m rapidly w evaporation f x g on4 ,i h already spok5 ( ! influ5ce ( pressure ^u ! boil+ ( liquids 9 #aga4 ,i w give "h a few additional illu/rations4 ,e!r boils :5 x is heat$ to #ie1 ?ree degrees bel[ ! heat ( ! blood 9 our bodies4 ,if we place "s ( x 9 a vessel "u ! receiv] ( an air-pump1 by exhau/+ ! air we c s take (f ! pressure t ! e!r w boil at ! ord9>y temp]ature ( ! air 9 a room4 ,! re/ra9t ( pressure ^u boil+ is v /rik+ly %[n 9 ! dige/]1 ,fig4 #bji4 ,?is is a /rong boil]1 a1 p>tly fill$ ) wat]4 ,a !rmomet]1 d1 is fa/5$ into x s z to indicate ! heat ( ! wat]4 ,!re is also a tube1 c1 ext5d+ to ne> ! bottom ( ! boil] into a small quantity ( m]cury :i* is !re4 ,let1 n[1 ! boil] be heat$ till ! wat] boils1 ! air be+ left to escape by ! /op-cock1 b4 ,if ! /op-cock be %ut1 & we cont9ue to apply ! heat1 we c raise ! wat] to a v high temp]ature )\t hav+ x boil at all1 because ( ! pressure ( ! cond5s$ /eam ^u its surface4 ,an app>atus some:at aft] ?is plan1 call$ ,pap9's dige/]1 has be5 us$ sometimes 9 cook+4 ,! great heat to :i* wat] c ?us be rais$ causes x to extract ! nutriti\s matt] f bones & c>tilages1 af=d+ mat]ial = s\p f :at is commonly ?r[n away4 ,to gu>d aga9/ ! dang] ( explosion a safety-valve is provid$1 hav+ a weight ^u x :i* w keep x %ut until a c]ta9 am\nt ( pressure accumulates1 & !n x is =c$ op51 lett+ out "s ( ! /eam4 #bic4 ,/eam4--,! cl\d ( /eam1 s call$1 :i* y s (t5 see escap+ f a locomotive is n really /eam4 ,/eam is transp>5t & invisible4 ,y c see t x is s if y obs]ve x issu+ f ! sp\t ( a tea-kettle4 ,x is only aft] x gets an in* or m f ! sp\t t x becomes visible1 & !n x is really *ang$ f /eam into wat] by ! cond5s+ influ5ce ( ! cold air4 ,& ! wat] 9 ! cl\d ?us =m$ is probably 9 ! same condition ) ! wat] 9 ! cl\ds above1 z describ$ 9 #bhh4 ,illu/ration3 ,fig4 #baj4 #bid4 ,! ,/eam-,eng9e4--,z compress$ or cond5s$ air has great p[] by its ela/icity1 z se5 9 ! air-gun1 #afd1 s also has cond5s$ /eam4 ,x is /eam cond5s$1 & endeavor+1 !re=e1 9 proportion to its cond5sation1 to exp& itself1 :i* con/itutes ! mov+ =ce ( ! /eam-eng9e4 ,! /eam is g5]at$ 9 a boil]1 hav+1 l ! boil] ( ,pap9's dige/]1 a valve ) a weight atta*$ to x4 ,?is valve is call$ a safety-valve1 because :5 ! /eam has rea*$ a c]ta9 degree ( cond5sation x lifts ! valve1 &1 z "s ( ! /eam escapes1 su* an increase ( pressure z w\ld occasion an explosion is prev5t$4 ,! expansive =ce ( /eam 9 a boil] is e/imat$ 9 p\nds by ! weight on ! valve1 & h5ce ! common expression t !re are s _m p\nds ( /eam on4 ,b ! boil] is only ! g5]ator ( /eam1 & x rema9s to %[ h[ ! /eam is us$ 9 mov+ ma*9]y4 ,?is is done by all[+ ! /eam to pass f ! boil] into a cyl9d]1 & !n move a pi/on back & =? by its expansive =ce4 ,! mann] 9 :i* x does ?is may be made cle> by ! diagram1 ,fig4 #baj 7p4 #bca74 ,let e be a pi/on 9 a cyl9d]1 f1 :i* has f\r op5+s1 a1 b1 c1 & d4 ,^! all h valves4 ,! /eam is suppli$ f ! boil] to ! cyl9d] ?r\gh a & c1 & makes its escape f b & d4 ,suppose1 n[1 ! pi/on is ne> ! bottom ( ! cyl9d]1 z repres5t$4 ,! valve at a is n[ op5$ t /eam may ent] to pu% up ! pi/on1 & ! valve at b %uts t ! /eam may n escape4 ,at ! same "t1 t pressure may be tak5 (f f ! upp] surface ( ! pi/on1 d op5s t ! /eam may escape1 & c %uts t none may ent]4 ,:5 ! pi/on is to be =c$ d[nw>d all ?is is rev]s$--c op5s to admit ! /eam1 d %uts to prev5t its escap+2 & bel[1 b is op5$ to let ! /eam escape1 & a is %ut to prev5t any f ent]+4 ,?is is ! plan ( :at is call$ ! high-pressure eng9e4 ,! l[-pressure eng9e diff]s f x 9 hav+ ! /eam1 z x escapes f ! cyl9d]1 pass into wat] to be cond5s$4 ,! latt] requires less pressure ( /eam to "w x1 & !re=e is ! safe/4 ,! mann] 9 :i* ! motion ( ! pi/on is made to "w v>i\s k9ds ( ma*9]y ,i ne$ n /op to expla91 especially z exemplifications ( x may be se5 9 e qu>t]4 #bie4 ,communication ( ,heat4--,heat has a con/ant t5d5cy to an equilibrium4 ,if !re=e any w>m sub/ance be 9 ! neighborhood ( "o :i* has less heat1 a fl[ ( heat f ! =m] t[>d ! latt] takes place4 ,n[ ?is communication ( heat occurs 9 ?ree diff]5t ways1 call$ ,convection1 ,conduction1 & ,radiation4 ,i w speak ( ea* ( ^! sep>ately4 #bif4 ,convection4--,?is mode ( diffusion ( heat is 9 op]ation 9 ^? sub/ances ^: p>ticles are movable among ea* o!r--viz41 liquids & a]i=m sub/ances4 ,i h already allud$ to examples ( ?is mode 9 speak+ ( ! movem5ts :i* heat causes 9 ^! sub/ances4 ,! heat goes along ) ! p>ticles :i* are mov$1 or is convey$ along ) !m1 & h5ce ! t]m convection4 ,9 ?is movem5t ! heat$ p>ticles always asc5d1 = ! reason giv5 9 #bge4 ,( ! multitude ( examples ( convection ,i w pres5t b a few4 ,9 ! upw>d curr5t ab\t a /ove-pipe y h an example ( convection1 ! heat g5]at$ be+ c>ri$ upw>d by ! p>ticles ( ?is curr5t4 ,?is be+ s1 ! heat ( a /ove has no effect ^u ! air bel[ x by convection1 ?\gh x does h by radiation1 z y w soon see4 ,any hot fluid becomes cool *iefly by convection4 ,! air com+ 9 contact ) x tak+ "s ( its heat rises1 & o!r air comes 9 its turn to be also heat$1 & s on till ! fluid becomes ( ! same temp]ature ) ! air1 & !n ! curr5ts ( air cease4 ,! liquid cools m rapidly by /irr+ x1 because ! air is br\ght into contact ) a great] ext5t ( surface1 & s ! heat is convey$ away m rapidly4 ,! result is ! same :e!r we di/urb ! surface by /irr+ x or by bl[+ ^u x4 ,9 ! latt] case1 h[ev]1 ! effect is increas$ by mak+ ! air to come m rapidly ^u ! di/urb$ surface4 ,s 9 fann+1 x is ! br++ ( ! air fa/] ^u ! surface ( ! body t causes ! m rapid1 convection ( heat f x4 ,e "o mu/ h obs]v$ ! fact t a buck:eat cake cools mu* m quickly ?an a fl\r or rice cake4 ,x is because x has s _m pores & little projections1 & s pres5ts a mu* l>g] am\nt ( surface to ! heat-convey+ air ?an ! smoo!r & m solid cakes4 ,viscid fluids1 z molasses1 oil1 etc41 :5 heat$ d n cool z readily z wat]1 because _! p>ticles are n z movable1 & !re=e heat is n convey$ z rapidly upw>d to be giv5 (f to ! air4 ,illu/ration3 ,fig4 #baa4 #big4 ,conduction4--,9 ?is mode ( diffusion ! heat goes ?r\gh or among ! p>ticles ( sub/ances4 ,= example1 if "o end ( a b> ( iron be held 9 ! fire1 x travels ?r\gh or among ! p>ticles to ! o!r end4 ,! gradual progress ( ! heat may be se5 by ! foll[+ simple exp]im5t3 ,take a rod ( iron & atta* to x1 z se5 9 ,fig4 #baa1 "s little balls ( wood by means ( wax4 ,by heat+ "o end ) a lamp ! balls w drop "o aft] ano!r z ! heat pass+ along melts ! wax :i* holds !m4 ,illu/ration3 ,fig4 #bab4 #bih4 ,conductors & ,non-,conductors4--,heat is conduct$ m rapidly ?r\gh "s sub/ances ?an ?r\gh o!rs4 ,!re is great v>iety 9 ?is respect4 ,!re is consid]able among ^? :i* are reckon$ z good conductors1 z is %[n by ! exp]im5t repres5t$ 9 ,fig4 #bab4 ,"h are cones ( ! same size ( sev5 diff]5t sub/ances--copp]1 iron1 z9c1 t91 lead1 m>ble1 & brick--all tipp$ ) a little wax1 & plac$ on a /ove4 ,! wax w melt on ! copp] cone fir/1 %[+ t ?is is ! be/ conductor ( !m all2 & on ! brick "o la/1 %[+ t ?is is ! poore/ conductor4 ,! conduct+ p[]s ( ! re/ are accord+ to ! ord] 9 :i* ,i h m5tion$ !m4 ,^? sub/ances :i* all[ heat to pass ?r\gh !m v sl[ly are call$ non-conductors4 ,! t]m1 ?\gh conv5i5t1 is n a /rictly correct "o1 = !re are no sub/ances :i* d n conduct heat 9 "s degree4 ,wood is "o ( ^! poor conductors1 & h5ce wood5 h&les are put ^u v>i\s in/rum5ts & vessels t are us$ ab\t fires1 z ! sold]+ irons ( ! t9man1 ! metallic tea-pot1 etc4 ,z clo? is a non-conductor1 ! hold] is us$ 9 tak+ (f ! tea-kettle & 9 us+ ! flat-iron4 ,glass is s poor a conductor t if y hold a rod or tube ( x across ! flame ( a _s lamp or gas burn]1 & heat x ev5 to r$ness1 y c place y\r f+]s v ne> to ! heat$ portion ) impunity4 ,i _h occasion to-day to b5d a small glass tube 9 ?is way1 & ,i obs]v$ "s wat] 9 x q ne> to ! heat$ "p :i* rema9$ undi/urb$ ?r\gh ! process4 ,x is ! non-conduct+ quality ( glass t makes x s liable to break1 :5 x is ?ick1 if x be expos$ to any sudd5 *ange ( temp]ature4 ,= example1 if hot wat] be p\r$ into a ?ick glass vessel1 ! inn] surface is quickly exp&$2 b ! out] surface n exp&+ ) x1 because ! heat is n readily conduct$ ?r\gh1 ?is irregul>ity 9 expansion causes a fracture4 ,x is = ?is reason t ! flasks1 retorts1 etc41 us$ by ! *emi/ are made v ?91 especially :]e ! heat is to be appli$4 ,illu/ration3 ,fig4 #bac4 #bii4 ,davy's ,safety-,lamp4--,"o ( ! mo/ beautiful applications ( ! conduction ( heat we h 9 ! ,safety-,lamp ( ,sir ,humphrey ,davy1 an inv5tion :i* has be5 ! means ( sav+ ! lives ( multitudes ( m9]s4 ,x is repres5t$ 9 ,fig4 #bac4 ,) ?is lamp "o c g into ! mid/ ( ! mo/ explosive gases ) impunity4 ,n[ all t prev5ts ! flame )9 f sett+ on fire ! gases )\t is a cov]+ ( wire-gauze4 ,?is1 be+ a good conductor1 conducts (f ! heat ( ! flame )9 s rapidly t x c n g ?r\gh ! op5+s z flame1 & s does n set fire to ! gas )\t4 ,! fact ^u :i* ! con/ruction ( ?is lamp 0 bas$ 0 discov]$ by try+ _m exp]im5ts4 ,among !m 7 ! foll[+3 ,a piece ( wire-gauze 0 held ov] a c&le s t its flame /ruck aga9/ x4 ,! smoke issu$ above1 b no flame4 ,!n a /ream ( gas 0 all[$ to pass ?r\gh ! gauze1 z se5 9 ,fig4 #bad1 & 0 set on fire above4 ,x burn$ )\t inflam+ ! gas bel[4#d ,illu/ration3 ,fig4 #bad4 #cjj4 ,relation ( ,d5sity to ,conduction4--,g5]ally ! m d5se a sub/ance is ! bett] is its conduction ( heat4 ,?us ! metals are bett] conductors ?an wood1 m>ble ?an brick1 ! solids ?an liquids1 & liquids ?an a]i=m sub/ances4 ,we h frequ5tly a good illu/ration ( ! diff]5ce betwe5 /one & brick z conductors 9 ! melt+ ( sn[ on sidewalks4 ,if a light sn[ fall 9 ! spr+1 aft] ! e>? has become some:at w>m1 y w see x melt$ f ! /one walks mu* be=e x is f ! brick ones4 ,?is w be especially ! case if ! sn[ be melt$ mo/ly by ! w>m? ( ! e>? )\t ! ag5cy ( ! sun4 ,! explanation is obvi\s4 ,! /one is a bett] conductor ?an ! brick1 & !re=e ! heat ( ! e>? comes up ?r\gh ! =m] m rapidly ?an ?r\gh ! latt]4 ,illu/ration3 ,fig4 #bae4 ,illu/ration3 ,fig4 #baf4 #cja4 ,conduction 9 ,liquids4--,t liquids are poor conductors ( heat may be %[n by an exp]im5t or two4 ,if a ?9 glass tube clos$ at "o end be fill$ ) wat]1 & ! heat ( a _s lamp be appli$ to its upp] portion1 z se5 9 ,fig4 #bae1 ?\gh ! wat] at ?is portion may be made to boil1 !re w n be ! lea/ movem5t 9 ! l[] "p4 ,?is w be v obvi\s if y h "s amb]-du/ 9 ! wat]4 ,aga91 let a little wat] be froz5 9 ! l[] "p ( ! tube by plac+ x 9 a freez+ mixture1 & introduce a little oil1 & !n ov] t "s alcohol4 ,hold n[ ! tube ov] ! *imney ( a lamp1 z repres5t$ 9 ,fig4 #baf1 until ! alcohol boils4 ,! ice 9 ! bottom ( ! tube w n be 9 ! lea/ affect$1 & ! oil w be b slightly heat$4 ,if ! heat 7 to be appli$ 9 ei!r ( ! above cases at ! l[] "p ( ! tube ! result w\ld be diff]5t1 because convection w\ld !n op]ate 9 ! diffusion ( ! heat4 #cjb4 ,air z a ,non-,conductor4--,heat is rapidly diffus$ 9 air by convection2 b x is only :5 ! air is free t ?is c be done4 ,:5 ! air is conf9$ 9 spaces or pores1 or among fibres1 heat makes its way ?r\gh x v sl[ly1 = x c be diffus$ ?r\gh x !n only by conduction4 ,! v>iety ( ways 9 :i* air is ( s]vice to u z a non-conductor is almo/ endless4 ,i w notice "s ( !m4 #cjc4 ,d\ble ,w9d[s4--,! efficacy ( d\ble w9d[s dep5ds ^u ! conf9$ air betwe5 !m4 ,9 ! case ( ! s+le w9d[ a great deal ( ! heat inside is lo/ 9 ?is way3 ,! w>m air ( ! room :i* comes 9 contact ) ! w9d[ imp>ts to x "s ( its heat1 &1 be+ ?us cool$ & !re=e cond5s$1 passes d[nw>d4 ,z ?is process goes on cont9ually ?is d[nw>d curr5t by ! w9d[ is con/ant4 ,! curr5t outside is 9 ! opposite direction4 ,! heat imp>t$ to ! w9d[ is tak5 up by ! cold air1 & z x ?us becomes w>m] x passes upw>d4 ,& ?is upw>d curr5t outside is z con/ant z ! d[nw>d curr5t inside4 ,n[ ne>ly all ?is is prev5t$ by ! non-conduct+ quality ( conf9$ air 9 ! case ( d\ble w9d[s4 ,if a pane 7 tak5 out f ! upp] "p ( ! inn] w9d[1 & ano!r f its l[] "p1 ! inn] w9d[ w\ld be ( little use1 = !n ! heat ( ! air 9 ! room w\ld be cont9ually dim9i%$ by convection1 z :5 ! w9d[ is s+le4 ,! w>m air w\ld pass 9 at ! upp] op5+1 &1 be+ cool$1 pass d[n ?r\gh ! l[] "o4#e #cjd4 ,air z a ,non-,conductor 9 ! ,walls ( ,build+s4--,! spaces includ$ betwe5 ! out] wall ( a build+ & ! pla/]+ inside be+ fill$ ) conf9$ air1 prev5t ! heat ( ! air 9 ! ap>tm5ts f pass+ (f readily ?r\gh ! wall4 ,a h\se built ( brick or /one1 ) ! pla/]+ plac$ directly ^u ! inside ( ! wall1 w\ld be kept w>m ) difficulty 9 w9t]1 because ! solid wall w\ld s readily conduct (f ! heat to ! ext]nal air4 ,s1 also1 su* a h\se w\ld be v w>m 9 summ]1 because ! heat ( ! sun & ( ! ext]nal air w\ld be s rapidly communicat$ to ! air ( ! h\se4 ,9 ?is connection ,i w m5tion a contrivance to prev5t ! spread+ ( fires 9 blocks ( build+s1 :i*1 ?\gh v effectual1 is seldom made use (1 p>tly because x occasions "s tr\ble & exp5se1 & p>tly because x takes up a little room4 ,x is ?is3 ,a small space is left 9 ! division wall betwe5 ea* two h\ses f top to bottom1 conta9+1 ( c\rse1 a body ( conf9$ air1 t is1 if ! space be entirely %ut 91 :i* is z ess5tial "h z 9 ! case ( ! d\ble w9d[s4 ,) su* an arrangem5t ! int]ior ( "o h\se may be entirely consum$ )\t communicat+ suffici5t heat ?r\gh ! conf9$ air to set on fire ! o!r4 #cje4 ,fur1 ,hair1 & ,fea!rs4--,animals t live 9 cold climates are provid$ ) suitable cov]+s = _! protection4 ,quadrup$s1 = example1 are cov]$ ) fur1 & birds h an abundance ( d[ny fea!rs4 ,^! cov]+s h no w>m? 9 !mselves1 ?\gh 9 common language we speak ( !m z be+ w>m4 ,!y are simply non-conductors1 & s prev5t ! heat :i* is made 9 ! body ( ! animal f escap+ z fa/ z x o!rwise w\ld4 ,b :y are !y non-conductors8 ,x is n because ! sub/ance ( :i* !y are made is a non-conductor1 b because among _! numb]less fibres is p>tially conf9$ t great non-conductor1 air4 ,let ! fur or d[n be cond5s$ into a ?9 h>d plate ^u ! animal1 & x w\ld prove ( little s]vice z a protection aga9/ cold4 ,d[n is mu* m abundant on ! birds ( cold climates ?an on ^? 9 w>m] regions1 because m air c be conf9$ among ! fibres ( d[n ?an among ^? ( common fea!rs4 ,quadrup$s t are natives ( w>m climates g5]ally h hair in/ead ( fur4 ,:5 !re=e ! horse is tak5 to a cold climate he requires 9 w9t] ! def5se ( a blanket2 & ! ox ne$s "u ! same circum/ances to be bett] h\s$ ?an he ord9>ily is4 ,z ! elephant is a native ( a climate positively hot1 8 hairs are scanty & co>se4 ,=m]ly !re 7 elephants 9 ! cold regions ( ,sib]ia1 z has be5 asc]ta9$ by rema9s f\nd !re4 ,b ! elephant ( ,sib]ia _h "u its hair1 close to ! sk91 a f9e wool to protect x aga9/ ! cold4 ,animals t live 9 cold climates h _! cov]+s become f9] 9 fibre 9 ! cold season ( ! ye>1 to give !m ! additional protection :i* !y !n ne$4 ,& animals ) a furry cov]+1 if !y are c>ri$ into a w>m climate1 h _! fur become co>se1 & approximate ! condition ( hair4 #cjf4 ,clo?+4--,man has no cov]+ to gu>d him aga9/ cold1 because he is capable ( contriv+ clo?+ suitable to ! v>i\s degrees ( temp]ature to :i* he may be expos$4 ,! object ( clo?+ is n to make ! body w>m1 b to keep x s4 ,! heat ( ! body is g5]at$ cont9ually )9 itself1 & "u all circum/ances ?is heat is ma9ta9$ q uni=mly at #ih4 ,?is1 y see1 is a mu* high] degree ?an ! atmosph]e ord9>ily has4 ,we are all ! "t1 !n1 giv+ (f heat to ! air ar\nd u1 except :5 ! air gets up to #ih4 ,we are com=table only :5 we are giv+ (f heat to a consid]able am\nt1 = ! po9t ( temp]ature :i* is mo/ agreeable to u :5 we are at re/ is #gj or a little less1 t is ne>ly ?irty degrees bel[ ! temp]ature ( our bodies4 ,:5 ! temp]ature is bel[ ?is we ne$ extra clo?+4 ,9 mak+ *oice ( clo?+ = v>i\s degrees ( temp]ature we practically apply ! pr9ciples :i* ,i h develop$4 ,^? articles ( clo?+ :i* c conf9e or entangle1 z we may say1 ! l>ge/ quantity ( air among _! fibres are ! be/ non-conductors1 or1 9 common language1 are ! w>me/4 ,s1 too1 loose clo?+ is w>m] ?an tight1 on acc\nt ( ! am\nt ( air betwe5 ! clo?+ & ! body4 ,?us a loose glove is mu* w>m] ?an a tight "o4 ,! same g5]al fact is exemplifi$ 9 ! coat+s ( /raw :i* we put ^u t5d] trees & %rubs 9 w9t]4 ,x is ! air t is conf9$ 9 ! tubes ( ! /raw :i* makes ^! cov]+s s effective a def5se4 ,x is probably ! air 9 ! pores ( ! brick :i* makes x a poor] conductor ?an /one1 z illu/rat$ by ! fact /at$ 9 #cjj4 #cjg4 ,cocoons4--,_m insects pass ?r\gh _! pupa or transition /ate 9 cocoons4 ,:5 ?is is done dur+ w>m wea!r1 z 9 ! case ( ! silk-worm1 ! cocoon is simple4 ,b :5 ! pupa /ate la/s ?r\gh ! w9t] special provisions are made 9 ! arrangem5ts ( ! cocoon to gu>d ! insect aga9/ ! cold4 ,i w cite z an example ! cocoon ( "o ( our l>ge/ mo?s1 ! ,cecropia4 ,?is cocoon1 fa/5$ to "s %rub1 keeps its inmate secure f ! rigors ( ! w9t] by a v beautiful arrangem5t4 ,! real cocoon is simil> to t ( ! silk-worm2 b x has a v d5se air-tight out] cov]+1 & ! space betwe5 ^! two cov]+s ( ! pupa is fill$ ) a loose sub/ance1 :i* has air1 ( c\rse1 m+l$ ) its fibres1 & acts1 !re=e1 ! "p ( a blanket = ! insect4 #cjh4 ,buds ( ,plants 9 ,w9t]4--,9 ! latt] "p ( summ] buds are =m$ on trees & %rubs1 & ^! conta9 ! g]ms ( ! bran*es1 leaves1 & fl[]s :i* are to come out ! next ye>4 ,^! ( c\rse mu/ be gu>d$ aga9/ ! cold ( w9t]1 & x is done v mu* z ! pupa is gu>d$ 9 ! cocoon4 ,ea* bud y c see has a cov]+ ( scales :i* is air-tight1 & inside ( ?is !re is a s(t d[ny sub/ance1 ! blanket+ ( ! bud4 ,9 ^! cov]+s1 :i* h be5 call$ by "s "o ! w9t]-cradles ( ! buds1 ! infant vegetation ( ano!r ye> rocks back & =? 9 ! w9try w9ds secure f ! cold1 till ! w>m sun ( spr+ wakes its hidd5 life into activity4 #cji4 ,sn[ a ,protection to ,plants4--,sn[ is a good blanket to ! e>?1 keep+ its w>m? f escap+ into ! cold air4 ,?is is because x conta9s m+l$ ) its fea!ry cry/als su* a quantity ( air4 ,if sn[ come e>ly1 be=e ! gr\nd & ! plants 9 x h become froz51 x w keep !m f freez+ ?r\gh ! w9t]1 if x rema9 dur+ all t "t4 ,x is curi\s to obs]ve ! peculi> arrangem5t ( ! sn[ 9 ! arctic regions = ! pres]vation ( vegetation4 ,fir/ 9 ! autumn come s(t light sn[s cov]+ up ! grasses1 & hea?s1 & will[s4 ,!n z w9t] advances !re are laid on top ( ^! ! d5s] sn[s1 mak+ a compact1 /\t ro( ov] ! light] sn[s 9 :i* ! scanty b preci\s vegetation ( ^? regions is imb$d$4 ,on top ( ?is ro( are deposit$ ! sn[s ( spr+4 ,z ^! melt ! wat] runs (f f ! icy ro( d[n ! slopes1 leav+ unt\*$ ! plants und]nea?1 :i* lie !re alike secure f ! ru% ( wat]s & f ! nightly fro/s until ! season is suffici5tly advanc$ to br+ !m out ) safety f _! concealm5t4 ,!n ! icy ro( melts1 & ) x ! light sn[s t h s long encircl$ ! plants1 & ! sun wakes !m f _! long sleep to a new life4 #caj4 ,influ5ce ( ! ,conduction ( ,heat on ,s5sation4--,if y place y\r h& ^u fur hang+ at ! door ( a fur-/ore x does n feel z cold z ! wood f :i* x hangs1 & ! wood does n feel s cold z ! iron b> ( ! %utt] close by4 ,:y is ?is1 :5 ^! sub/ances are expos$ to ! same atmosph]e1 & really h ! same temp]ature8 ,x is because ! iron conducts ! heat f y\r h& m readily ?an ! wood1 & ! wood m readily ?an ! fur4 ,s ! iron h&le ( a wood5 pump feels cold] ?an ! pump1 & ! pump cold] ?an ! sn[ ar\nd x4 ,= ! same reason1 9 a cold room ! rug or ! c>pet w n feel z cold z ! pok] & ! he>?4 ,if wat] has /ood long en\gh 9 a room to be ( ! same temp]ature ) ! air ( ! room y\r h& w feel cold] 9 ! wat] ?an 9 ! air1 because ! wat] is ! bett] conductor4 ,s mu* = ! s5sation ( cold4 ,on ! o!r h&1 :5 sub/ances are s heat$ z to give u ! s5sation ( heat1 ! conductors d ?is m ?an ! non-conductors4 ,z !y receive heat readily !y also readily imp>t x4 ,= ?is reason1 ) a brisk fire ! he>?-/one feels v hot1 :ile ! rug be=e ! fire does n4 #caa4 ,radiation ( ,heat4--,e sub/ance s5ds heat into space con/antly 9 /raight l9es 9 e direction4 ,^! l9es are radii1 & h5ce ! t]m radiation is appli$ to heat diffus$ 9 ?is way4 ,x is v obvi\s 9 reg>d to ! sun t x radiates heat 9 all directions4 ,! same c be se5 9 ! case ( a heat$ iron ball4 ,9 :atev] direction y hold y\r h&1 above1 bel[1 or lat]ally1 y feel ! heat4 ,& x makes no diff]5ce :e!r ! ball be r$-hot or n4 ,t is1 heat is radiat$ ei!r ) or )\t light4 ,:5 a room is w>m$ by a furnace x is w>m$ altoge!r by convection2 b :5 x is w>m$ by a fire1 ei!r 9 a fire-place or a /ove1 we h bo? convection & radiation4 ,! heat :i* we receive f ! sun comes altoge!r by radiation4 #cab4 ,connection betwe5 ,heat & ,light4--,! heat & light ( ! sun pass toge!r ?r\gh transp>5t sub/ances1 z air1 glass1 wat]1 etc41 )\t heat+ !m to any ext5t4 ,?us1 :5 ! heat is transmitt$ ?r\gh a l5s1 #bgb1 ! l5s is little heat$1 t is1 x lets almo/ all ! heat pass ?r\gh x4 ,! air is heat$ by ! sun1 b n directly to any am\nt4 ,x is heat$ indirectly 9 ?is way3 ! rays ( ! sun pass+ ?r\gh ! air heat ! e>?1 & !n ! air receives a "p ( ?is heat f ! e>?1 :i* is diffus$ ?r\gh x by convection4 ,x is o!rwise ) heat t comes f a common fire4 ,x does n seem to be s ?or\ghly unit$ ) ! light1 & !re=e readily p>ts company ) x1 z we may say4 ,:ile ! heat & light ( ! sun g toge!r ?r\gh all transp>5t bodies ! heat ( a fire w n g ) its light ?r\gh all ( !m4 ,s :ile ! heat ( ! sun does n w>m ! glass ?r\gh :i* x passes ! heat ( a fire w w>m x1 & !re=e glass is an effectual scre5 aga9/ x4 ,9 "s op]ations 9 ! arts a mask ( glass is sometimes worn to w>d (f ! heat4 ,! connection ( light & heat w be f>!r notic$ :5 ,i come to treat ( light4 #cac4 ,relation betwe5 ,radiation & ,absorption4--,all surfaces t radiate w absorb also equally well ! heat t is radiat$ ^u !m4 ,all r\gh & d>k surfaces bo? absorb & radiate freely2 b all light-color$ & poli%$ surfaces d bo? sl[ly4 ,= ?is reason ! black1 r\gh tea-kettle is well fitt$ to heat wat] 92 b x is n fitt$ to reta9 ! heat 9 ! wat]4 ,on ! o!r h&1 ! bright1 poli%$ tea-pot absorbs heat poorly1 b reta9s x well4 ,illu/ration3 ,fig4 #bag4 #cad4 ,reflection ( ,heat4--,radiat$ heat is reflect$2 & "h1 z 9 ! case ( motion1 #bjf1 & ( s\nd1 #bfj1 ! angles ( incid5ce & reflection are equal4 ,"s int]e/+ exp]im5ts 9 relation to ! reflection ( heat c be tri$ ) concave metallic mirrors4 ,?us1 if we take two su* mirrors1 z repres5t$ 9 ,fig4 #bag1 & place 9 ! focus ( "o a !rmomet]1 & 9 ! focus ( ! o!r a small flask ( hot wat]1 or a heat$ iron ball1 ! m]cury 9 ! !rmomet] w rise1 al?\gh ! mirrors may be _m feet ap>t4 ,obs]ve h[ ! effect is produc$4 ,rays ( heat g f ! flask directly t[>d ! !rmomet]1 z repres5t$ by ! l9es 9 ! figure2 b t ! effect does n come f ^! c be prov$ by remov+ ! mirrors1 leav+ ! flask & !rmomet] j z !y are4 ,:5 ! exp]im5t is tri$ 9 ?is way no effect is produc$ on ! !rmomet]1 because x is too f> f ! s\rce ( heat1 ! flask1 to receive any p]ceptible influ5ce 9 ?is way4 ,! effect comes f ! rays ( heat :i* g to ! mirror ne> ! flask1 & are reflect$ to ! o!r mirror1 & !n are reflect$ ^u ! !rmomet]1 all ( :i* is repres5t$ by ! dott$ l9es4 ,!re is ano!r way1 besides t already m5tion$1 ( %[+ t x is n ! direct rays t produce ! effect4 ,aft] arrang+ ! app>atus put a scre5 betwe5 ! !rmomet] & ! mirror ne> x1 & ! effect w be prev5t$ because ! reflection is cut (f4 ,if a piece ( ice be sub/itut$ = ! flask ( hot wat] ! !rmomet] w fall--an effect opposite to t produc$ 9 ! previ\s exp]im5t4 ,?is w\ld seem to %[ t cold is radiat$1 b z !re is no su* ?+ really z cold1 #bgj1 ! effect mu/ be attribut$ to ! radiation ( heat f ! !rmomet] to ! ice4 ,if a hot ball be plac$ 9 ! focus ( "o mirror & a piece ( phosphorus 9 t ( ! o!r1 ! phosphorus w be set on fire1 ?\gh ! mirrors may be tw5ty or m feet ap>t4 ,illu/ration3 ,fig4 #bah4 ,! reflection ( heat may be exhibit$ v prettily ) ! exp]im5t repres5t$ 9 ,fig4 #bah4 ,a %eet ( bright gilt pap] is roll$ up 9 ! %ape ( a funnel1 ) ! metallic side inw>d4 ,hold+ ! l>g] end t[>d a fire1 ! rays ( heat com+ f ! fire into ! funnel are reflect$ t[>d a c5tral l9e1 & s pass out ( ! small] end ( ! funnel conc5trat$4 ,if1 n[1 a bit ( phosphorus or a lucif] mat* be held a little di/ance f ?is end ( ! funnel x w be set on fire4 #cae4 ,=mation ( ,dew4--,x is by ! radiation ( heat t dew is =m$4 ,! e>? is con/antly radiat+ heat into space z well z ! sun4 ,9 ! daytime x receives a great deal m ?an x radiates4 ,b at night ?is is rev]s$1 & ! e>? is cool$4 ,! cool$ e>? cond5ses ! moi/ure 9 ! air :i* is 9 contact ) x1 & s ! moi/ure is deposit$4 ,if ! wea!r be v cold ?is is froz51 & !n we h fro/ in/ead ( dew4 ,y obs]ve t ! dew does n fall1 ?\gh ?is is ! ord9>y expression4 ,its =mation is analog\s to ! deposit ( moi/ure :i* we s (t5 witness 9 a hot day 9 summ] on ! outside ( a tumbl] conta9+ cold wat]4 ,z ! cold tumbl] cond5ses ! moi/ure 9 ! air1 s does ! e>? at night1 x be+ cool$ by radiation1 cond5se ! moi/ure :i* has accumulat$ 9 ! air by evaporation dur+ ! heat ( ! day4 ,!re are "s circum/ances :i* h an influ5ce ^u ! deposition ( dew & fro/4 ,less is deposit$ "u a tree ?an outside ( x1 because all ! heat :i* radiates v]tically upw>d f "u ! tree is radiat$ back aga9 by ! tree4 ,h5ce ! efficacy ( a cov]+ ov] plants z a def5se aga9/ fro/4 ,cl\ds op]ate 9 ! same way1 & = ?is reason no dew or fro/ is deposit$ 9 a cl\dy night4 ,nei!r is any deposit$ 9 a v w9dy night1 because ! mov+ air promotes evaporation1 & ?us prev5ts ! accumulation ( moi/ure4 ,dew is deposit$ 9 diff]5t am\nts on diff]5t sub/ances4 ,?is is ow+ to a diff]5ce 9 radiation4 ,grass & leaves radiate heat bett] ?an e>?1 & e>? bett] ?an /one2 & !re=e :ile /ones & gravel-walks may be dry or ne>ly s1 ! loose e>? may be moi/ & ! grass & leaves ?or\ghly wet4 ,s y see t n ev5 ! dew1 pl5tiful z x is1 is wa/$ by ! ,creator1 b is deposit$ j :]e x is want$ to refre% ! p>*$ e>? & its vegetation4 #caf4 ,gideon's ,fleece4--,if y lay a fleece ( wool ^u ! gr\nd1 x is s poor a radiator ( heat t no dew w be deposit$ ^u x1 al?\gh !re may be an abundance ( x on ! grass & leaves 9 its neighborhood4 ,b ?is 0 rev]s$ 9 ! case ( ,gideon's fleece4 ,! laws ( nature 7 set aside1 & ! fleece 0 wet ) dew :ile all ar\nd 0 dry4 #cag4 ,dew-,po9t4--,:at is call$ ! dew-po9t ( ! air is t degree ( temp]ature to :i* any sub/ance mu/ be br\ght d[n 9 ord] to h dew deposit$ ^u x4 ,?is dep5ds ^u ! am\nt ( wat] !re is 9 ! atmosph]e4 ,! m !re is ! high] is ! dew-po9t4 ,:5 wat] cond5ses on a cold tumbl] 9 a hot day !re is mu* m wat] 9 ! air1 & ! dew-po9t is high]1 ?an :5 no moi/ure is cond5s$ ^u ! tumbl]4 ,s aft] a v hot cle> day ! e>? ne$s n to be mu* cool$ to produce a deposit ( dew1 because ! air has become s highly *>g$ ) moi/ure ?r\gh ! evaporation ( ! e>? "u ! hot sun4 ,we c v readily at any "t asc]ta9 ! dew-po9t4 ,take a glass ( wat]1 &1 hav+ a !rmomet] 9 x1 drop into x "s pieces ( ice1 & wat* ! outside ( ! glass4 ,z soon z x beg9s to be dimm$ ) moi/ure look at ! !rmomet]1 & y h ! dew-po9t4 #cah4 ,freez+ ,m]cury4--,m]cury c be froz5 by radiation :5 ! cold is excessively sev]e1 al?\gh ! !rmomet] may indicate a temp]ature consid]ably above -#ci1 ! degree at :i* m]cury freezes4 ,suppose t 9 a cle>1 /ill night ! temp]ature ( ! air is at -#bj4 ,9 ord] to freeze ! m]cury x mu/ be cool$ d[n #ai degrees bel[ ?is4 ,n[ ?is c be done by surr\nd+ ! m]cury ) "s good non-conductor1 z *>coal4 ,?is cuts (f ! supply ( heat to ! m]cury1 :ile x is all ! :ile giv+ (f heat into space by radiation4 ,9 l mann] c ice be =m$ 9 an atmosph]e t is above ! freez+ po9t1 & ?is is (t5 done 9 w>m climates4 #cai4 ,lat5t ,heat4--,y h se51 #bgj1 t our s5sations d n in=m u accurately ( ! am\nt ( heat 9 any sub/ance4 ,! same is also true ( ! !rmomet]4 ,?is only indicates ! s5sible or free heat4 ,!re may be a great deal ( heat lock$ up1 z we may say1 9 ! sub/ance1 :i* c be br\ght out or made free by "s *ange 9 ! sub/ance4 ,?is heat ?us lock$ up is call$ lat5t heat4 ,illu/ration3 ,fig4 #bai4 #cbj4 ,capacity = ,heat4--,! m heat a sub/ance c take 9 & r5d] lat5t ! great] is its capacity = heat1 z x is express$4 ,?us wat] has a mu* great] capacity = heat ?an m]cury4 ,?is c be prov$ by v>i\s exp]im5ts4 ,?us1 if we take two vessels j alike1 & hav+1 ! "o a c]ta9 quantity ( wat] 9 x1 & ! o!r ! same quantity ( m]cury1 & expose !m to ! same degree ( heat1 x w take mu* long] to raise ! wat] to any specifi$ temp]ature ?an ! m]cury4 ,:y is ?is1 :5 !y are bo? receiv+ ! same am\nt ( heat8 ,x is because ! wat] r5d]s a mu* l>g] portion ( ! heat lat5t ?an ! m]cury does4 ,we c rev]se ?is exp]im5t4 ,take ^! same vessels ) _! cont5ts rais$ to ! same temp]ature1 z indicat$ by ! !rmomet]1 & all[ !m to cool 9 ! air side by side4 ,! m]cury w cool mu* fa/] ?an ! wat]1 because x has mu* less ( lat5t heat to "p )4 ,! diff]5ce 9 capacity = heat betwe5 wat]1 oil1 & m]cury may be %[n by ! exp]im5t repres5t$ 9 ,fig4 #bai4 ,a p\nd ( wat] is put into "o ,flor5ce flask1 a p\nd ( oil into ano!r1 & a p\nd ( m]cury into a ?ird4 ,!y are all heat$ to #bab1 & are !n plac$ 9 funnels fill$ ) p\nd$ ice1 ! funnels re/+ 9 glass j>s ( ! same size4 ,n[ 9 cool+ ^! fluids d[n to a c]ta9 po9t1 say #cb1 diff]5t am\nts ( ! ice w be melt$1 9 ! proportions ( #ajj & #ej & #c4 ,?is %[s ! proportions ( lat5t heat 9 !m :i* become s5sible or free z _! temp]atures are l[]$4 ,illu/ration3 ,fig4 #bbj4 #cba4 ,relation ( ,lat5t ,heat to ,d5sity4--,! m d5se a sub/ance becomes ! less is its capacity = heat4 ,! heat produc$ by hamm]+ iron is ! lat5t heat r5d]$ free by cond5sation1 ?is less5+ ! capacity ( ! iron = heat4 ,! same ?+ c be bett] illu/rat$ 9 ! cond5sation ( a v compressible sub/ance1 z air4 ,9 ,fig4 #bbj y h repres5t$ a glass syr+e ) a clos$ end4 ,if !re be plac$ 9 ?is end a little bit ( cotton wool moi/5$ ) e!r1 & ! pi/on be =c$ d[nw>d v quickly1 ! e!r w be set on fire4 ,?is is because ! compression ( ! air less5s s mu* its capacity = heat t a great deal ( its lat5t heat is made s5sible or free4 ,! heat :i* is conceal$ 9 x 9 its ord9>y /ate is1 z we may say1 fairly squeez$ out1 z y w\ld squeeze out ! wat] t is conceal$ 9 ! int]/ices ( a sponge4 #cbb4 ,coldness ( ,air at ,great ,heights4--,y le>n$ 9 #aeb t ! atmosph]e is ?9n] ! f>!r y g f ! e>?4 ,x is v ?91 !re=e1 on ! summits ( high m\nta9s4 ,?is is ! *ief reason :y x is s cold !re1 = ! r>] ! air is ! great] is its capacity = heat1 & ! m ( s5sible or free heat !re=e c x r5d] lat5t4 #cbc4 ,relation ( ,lat5t ,heat to ! ,=ms ( ,sub/ances4--,:e!r a sub/ance %all be 9 ! =m ( a solid1 liquid1 or gas dep5ds ^u ! am\nt ( heat :i* is lat5t 9 x4 ,if y take a piece ( ice & melt x 9 a vessel1 ! ice & ! wat] 9 ! vessel t comes f ! melt+ ( ! ice are bo? at #cb until ! ice is all melt$4 ,b all ?is "t heat is be+ communicat$ to ! ice & wat]4 ,:at becomes ( x8 ,x is all tak5 up by ! ice z x *anges f its solid to its fluid /ate1 & becomes lat5t 9 x4 ,9 fact e p>ticle ( ice mu/ h j s mu* ( lat5t heat 9 ord] to become fluid4 ,s1 also1 if wat] be heat$ to ! boil+ po9t1 #bab1 & be kept boil+1 ! wat] w rema9 at t po9t till x is all vaporiz$4 ,all ?is "t ! wat] is receiv+ heat1 :i*1 in/ead ( rais+ its temp]ature1 is becom+ lat5t 9 ! p>ticles z !y *ange f _! liquid to _! vapor\s /ate4 ,z ,i said ( ! *ange f ! solid to ! liquid /ate1 s "h1 e p>ticle ( ! liquid mu/ h j s mu* ( lat5t heat 9 ord] to become a]i=m4 ,:5ev] !re=e any solid sub/ance becomes liquid1 or liquid becomes a]i=m1 heat is absorb$ & becomes lat5t4 ,s1 on ! o!r h&1 :5ev] any a]i=m sub/ance becomes liquid1 or liquid becomes solid1 lat5t heat is giv5 out1 & becomes free & s5sible4 ,! freez+ ( wat]1 !n1 is a s\rce ( w>m? to ! air 9 its neighborhood--a fact :i* is practically made use ( :5 tubs or pails ( wat] are plac$ 9 cons]vatories to keep plants f freez+2 & ! ?aw+ ( sn[ & ice is a s\rce ( cold1 z is exemplifi$ by ! *ill9ess ( ! air occasion$ by ?is process4 #cbd4 ,cl\ds & ,lat5t ,heat4--,! wat] ( :i* cl\ds are compos$ is heavi] ?an air4 ,:y1 !n1 does x rema9 susp5d$8 ,:y is x necess>y t x %\ld be collect$ into drops 9 ord] to h x fall8 ,?is "q c be answ]$ by look+ at ! mann] 9 :i* cl\ds are =m$4 ,a cl\d1 ,i h /at$ 9 #bhh1 is made up ( m9ute vesicles or bubbles conta9+ air4 ,n[ ! air 9 ^! bubbles is light] ?an ! air t is ar\nd ! cl\d1 because x is w>m]4 ,b h[ does x get its heat8 ,9 ord] to und]/& ?is obs]ve :at ! bubble is made f4 ,x is made f ! wat] :i* 0 9 ! air 9 a /ate ( vapor1 or 9 its a]i=m /ate1 = ?is is ! /ate ( wat] t is evaporat$ & dissolv$ 9 ! atmosph]e4 ,b :5 x =ms ! vesicle x goes out ( ?is /ate & becomes a liquid1 = ! wall ( ! vesicle is a liquid wall1 j z ! wall ( a soap-bubble is4 ,n[ 9 pass+ out ( ! a]i=m into ! liquid /ate "s lat5t heat mu/ be made s5sible4 ,:at becomes ( ?is s5sible heat8 ,x j heats ! air 9 ! vesicle1 & s makes x l a heat$ air-balloon4 ,s all cl\ds are collections ( innum]able heat$ air-balloons1 & ! reason t "s cl\ds are high] up ?an o!rs p]haps is t _! balloons h w>m] & !re=e light] air 9 !m4 #cbe4 ,freez+ ,mixtures4--,! int5se cold produc$ by ^! mixtures is ! result ( ! *ange ( free or s5sible heat into lat5t4 ,= example1 :5 salt & sn[ are m+l$ toge!r a melt+ ( ! two is quickly produc$4 ,9 ?is sudd5 *ange ( a solid into a fluid a great quantity ( heat mu/ be r5d]$ lat5t1 & !re=e !re w be a great loss ( s5sible heat by :atev] ! freez+ mixture comes 9 contact )4 ,! process "h1 y see1 is ! opposite ( solidification 9 relation to lat5t heat4 ,a portion ( ! sn[1 aft] melt+ ) ! salt1 becomes solid ice4 ,:y is ?is8 ,x is because x gives up its s5sible or free heat to portions ( ! sn[ t are 9 ! process ( melt+ & are !re=e mak+ heat lat5t4 #cbf4 ,cold f ,evaporation4--,if y p\r a little e!r into ! palm ( y\r h& x w rapidly disappe> 9 vapor1 produc+ a v cold s5sation4 ,?is s5sation occurs because1 9 ! *ange ( ! liquid into ! vapor\s or a]i=m /ate1 "s ( ! s5sible heat ( y\r h& is ab/ract$ to become lat5t 9 ! vapor4 ,! evaporation ( wat] also produces cold1 ?\gh n z decid$ly z e!r1 because its *ange into vapor is n s rapid at ord9>y temp]atures4 ,we make a practical use ( ! evaporation ( wat] 9 _m diff]5t ways4 ,?us we spr9kle wat] 9 a hot day ^u ! floors ( piazzas1 /eps1 etc41 t ! evaporation may make mu* ( ! s5sible heat ab\t our h\ses lat5t4 ,= ! same purpose1 9 hot climates1 ap>tm5ts are (t5 sep>at$ f ea* o!r by m]e curta9s1 :i* are occasionally spr9kl$ ) wat]4 ,s ! inhabitants ( su* climates (t5 cool _! bev]ages by keep+ a wet clo? = "s "t wrapp$ ar\nd ! vessels t conta9 !m4 ,evaporation is an important rem$y = _m cases ( disease4 ,= example1 if ! head be hot1 a /eady application ( a wet clo? to ! =ehead1 ?\gh a simple rem$y1 is g5]ally effectual1 & sometimes is v important4 ,mo/ p make ! application 9 a wrong mann]4 ,!y put on sev]al ?icknesses ( clo?1 :5 a s+le ?ickness is ! be/1 because x w be/ secure ! evaporation1 :i* is ! cause ( ! relief af=d$4 ,illu/ration3 ,fig4 #bba4 #cbg4 ,freez+ 9 ! ,mid/ ( ,boil+4--,x is f ! quantity ( heat r5d]$ lat5t by evaporation t wat] c be froz5 9 ! mid/ ( boil+ e!r2 &1 p>adoxical z x may seem1 ! boil+ ( ! e!r is ! cause ( ! freez+4 ,! exp]im5t is p]=m$ 9 ?is way3 ,place a te/-tube or a little ?9 vial ) wat] 9 x 9 ! mid/ ( "s e!r 9 a %all[ vessel "u ! receiv] ( an air-pump4 ,on exhau/+ ! air ! e!r w boil1 evaporation tak+ place rapidly because ! pressure ( ! air is tak5 (f f ! e!r4 ,n[ z ! e!r passes into vapor x extracts s mu* free heat f ! vial ( wat] t ! wat] is cool$ d[n to ! freez+ po9t1 & s becomes solid4 ,wat] c be froz5 ev5 by its own evaporation4 ,x is done 9 ?is way3 ,let a %all[ vessel1 b1 ,fig4 #bba1 conta9 a little wat]1 & ! vessel c oil ( vitriol or sulphuric acid4 ,:5 ! air is exhau/$1 ! pressure ( air be+ tak5 (f f ! wat]1 vapor rises f x freely4 ,z ! sulphuric acid has a great attraction = wat] x absorbs ?is vapor1 & s vapor cont9ually rises f ! wat] ! m rapidly because :at is =m$ is absorb$1 in/ead ( rema9+ to make pressure on ! wat]4 ,! result is t ?is rapid =mation ( vapor1 requir+ t a great quantity ( heat %\ld be made lat5t1 at l5g? ab/racts s mu* heat f ! wat] t rema9s t ?is becomes solid4 #cbh4 ,degree ( ,heat ,endurable by ,man4--,x 0 =m]ly believ$ t ! human body c\ld n endure ) impunity1 ev5 = a %ort "t1 a mu* high] degree ( temp]ature ?an t :i* is met ) 9 hot climates4 ,b 9 ! ye> #agfj x 0 accid5tally discov]$ t a mu* high] temp]ature ?an ?is c\ld be endur$4 ,an insect 0 de/roy+ at t "t ! gra9 ga!r$ 9 "s p>ts ( ,france1 & x 0 f\nd t if ! gra9 0 subject$ to a c]ta9 high degree ( temp]ature ! insect 0 kill$1 & yet ! gra9 0 n injur$4 ,9 try+ "s exp]im5ts 9 reg>d to ?is matt] ! exp]im5t]s wi%$ to "k ! po9t at :i* ! !rmomet] /ood 9 a l>ge ov54 ,a girl att5d+ on ! ov5 (f]$ to g 9 & m>k ! !rmomet]4 ,%e did s1 rema9+ two or ?ree m9utes1 & ! !rmomet] 0 at #bfj1 t is1 #dh above ! boil+ po9t ( wat]4 ,z %e exp]i5c$ no great inconv5i5ce f ! heat %e rema9$ t5 m9utes long]1 :5 ! !rmomet] rose to #gf above t po9t4 ,^! facts 7 publi%$1 & prompt$ sci5tific m5 to try o!r exp]im5ts4 ,9 ,engl&1 ,dr4 ,=dyce1 ,sir ,*>les ,blagd51 & o!rs1 w5t into rooms heat$ ev5 to #bdj & #bfj1 & rema9$ long en\gh to cook eggs & /eaks1 & yet !mselves suff]$ little inconv5i5ce4 ,! pulse 0 quick5$1 ! p]spiration 0 v pr(use1 b ! heat ( ! body1 z asc]ta9$ by putt+ ! !rmomet] "u ! tongue ! mom5t !y came out1 0 sc>cely rais$ at all4 ,! air 9 :i* !y 7 roa/$ eggs q h>d 9 tw5ty m9utes1 & :5 x 0 appli$ by a pair ( bell[s to a /eak x cook$ x 9 ?irte5 m9utes4 ,! "q arises1 h[ is x t ?is high degree ( heat did n produce m effect ^u ! body8 ,"o reason is t ! heat ( ! air 9 ! imm$iate neighborhood ( ! body 0 cont9ually r$uc$ by ! evaporation ( ! free p]spiration1 s5sible heat be+ ?us conv]t$ into lat5t4 ,ano!r reason is t ! air is n a good conductor1 & !re=e did n communicate its heat readily to ! body4 ,dr4 ,=dyce & 8 fri5ds f\nd t !y c\ld n t\* ) impunity any good conductor1 z ! metals1 & !y 7 oblig$ to we> ^u _! feet "s non-conduct+ sub/ance4 #cbi4 ,=mation ( ,ice4--,be=e dismiss+ ! subject ( heat ,i mu/ notice ! gr& exception :i* we h to "s ( ! op]ations ( heat 9 ! =mation ( ice4 ,heat g5]ally produces expansion4 ,b 9 ! case ( wat] ?is law ( expansion is set aside1 & ! rev]se is e/abli%$4 ,?is is done1 h[ev]1 only )9 a small range ( temp]ature1 viz41 f ! freez+ po9t up ! scale ab\t sev5 degrees4 ,9 all degrees above t ! usual expansion by heat takes place4 ,! exception occurs at ?is "p ( ! scale = a special purpose1 viz41 t wat]1 9 di/9ction f o!r sub/ances1 %all become m bulky1 & !re=e light]1 z x takes ! solid =m4 ,illu/ration3 ,fig4 #bbb4 #ccj4 ,description ( ! ,process ( ,freez+4--,9 ord] to make ! process ( freez+ cle> to y ,i w describe x z x ord9>ily occurs1 t is1 f ! action ( cold air ^u ! surface ( wat]4 ,! upp]mo/ lay] ( ! wat] imp>ts "s ( its heat to ! air 9 contact ) x4 ,?is air rises & cold] air takes its place1 :i* be+ w>m$ 9 its turn rises to make way = m ( ! cold air4 ,y h !re=e a con/ant curr5t ( w>m$ air upw>d f ! wat]4 ,9 ! mean "t !re is a curr5t ( a diff]5t "* 9 ! wat]--a d[nw>d "o4 ,z fa/ z ! wat] at ! surface p>ts ) heat to ! air x falls1 o!r w>m wat] tak+ its place1 to cool 9 its turn & g d[n4 ,?is fall+ ( ! cool$ wat] goes on regul>ly until a portion ( wat] becomes cool$ d[n to #ci1 t is1 #g above ! freez+ po9t4 ,?is lay] does n s9k1 b rema9s at ! surface1 = x is light] ?an ! w>m] wat] bel[4 ,?is is because ! law t heat exp&s matt] is n[ rev]s$4 ,beyond ?is po9t ( ! !rmomet] ! cold] ! wat] is ! light] x is4 ,z ! cool+ n[ goes on f ! air com+1 z be=e1 9 successive lay]s to ! wat]1 ! cool$ wat] at ! surface cont9ually increases4 ,at fir/ x is a m]e s+le lay] ( p>ticles1 b aft] a :ile x is q a body ( cold wat] ly+ on ! w>m] wat] bel[4 ,at l5g? "s ( x is cool$ d[n to #cb1 ! freez+ po9t1 & a ?9 film ( ice n[ =ms4 ,! /ate ( ?+s j at ?is /age ( ! process may be repres5t$ by a simple diagram1 ,fig4 #bbb4 ,let ! l9e a repres5t ! film ( ice4 ,! space betwe5 a & b is ! portion ( wat] cool$ d[n bel[ #ci4 ,! space bel[ b is occupi$ by ! wat] :i* is above ?is temp]ature4 ,9 ! space betwe5 a & b ! cool] ! wat] is ! ne>] x is to ! surface4 ,t is1 f ! l9e b1 :]e ! wat] is exactly at #ci1 z y g upw>d1 ! wat] less5s 9 temp]ature1 x be+ successively #ch1 #cg1 #cf1 etc41 till1 j 9 contact ) ! film ( ice1 a1 x is at #cb4 ,! ice goes on to ?ick5 gradually by additions bel[4 ,b x is to be rememb]$ t ice is a good non-conductor1 s t ! v fir/ lay] ( ice makes ! cool+ ( ! wat] proce$ m sl[ly ?an be=e4 ,& ! ?ick] ! ice becomes ! sl[] is ! cool+4 ,?is secures aga9/ too great a =mation ( ice4 #cca4 ,:y ! ,above ,exception to ,expansion by ,heat ,exi/s4--,t we may see ! reasons 9 "p = ! gr& exception to ! g5]al law ( expansion by heat :i* ,i h illu/rat$1 let u see :at w\ld be "s ( ! results if ! exception did n exi/4 ,9 t case ! process ( freez+ w\ld be z foll[s3 ,! wat] w\ld communicate its heat f ! surface to ! air1 z be=e describ$1 & !re w\ld be a con/ant d[nw>d curr5t ( ! cool$ wat]4 ,:5 any portion ( ! wat] became cool$ by ! air d[n to #cb1 x w\ld become ice1 & w\ld s9k to ! bottom4 ,& aft] ! process ( freez+ _h once begun1 !re w\ld be a cont9ual accumulation ( ice at ! bottom s long z ! air rema9$ cold en\gh to cool ! wat] ) :i* x comes 9 contact d[n to #cb4 ,! result may be /at$ 9 ! g5]al ?us3 ,freez+ w\ld n beg9 s quickly z x n[ does2 b :5 once begun x w\ld prove v de/ructive4 ,x w\ld n beg9 z soon1 because ! :ole ( any body ( wat] mu/ be cool$ d[n to j ?is side ( #cb be=e x c\ld beg94 ,?is w\ld n take long :]e ! wat] is %all[1 b x w\ld :]e x is deep4 ,all %all[ bodies ( wat]1 !n1 w\ld be froz5 up q e>ly 9 ! w9t]2 & z wat] is a poor conductor1 & ?aw+ mu/ g f above d[nw>d1 "s ( !m w\ld n be ?aw$ out aga9 fully till q into ! next summ]1 if ev5 !n4 ,& :]e ! wat] is q deep ice w\ld at l5g? beg9 to =m1 & :5 =m$ x w\ld be exce$+ly sl[ 9 ?aw+4 ,9 "s cases x w\ld nev] be ?aw$ ) su* a body ( non-conduct+ wat] to gu>d x aga9/ ! w>m? above4 ,x is easy to see t ! heat ( spr+ & summ] w\ld n ?aw out any ?+ l ! quantity ( ice t x n[ does4 ,! reign ( ice & sn[ on our e>? w\ld !re=e be va/ly m ext5sive ?an n[1 & :at is worse1 x w\ld be ext5d$ m & m e ye>4 ,"u su* circum/ances !re w\ld be great de/ruction ( bo? animal & vegetable life4 ,i w m5tion1 h[ev]1 b a s+le item1 z x w\ld occupy too mu* space to g into ?is subject ) any fullness4 ,9 ! wat] "u ! ice1 :i* is always above #ci1 except t :i* is close to ! ice :5 freez+ is go+ on1 !re is a va/ am\nt ( busy life :i* w\ld be de/roy$ if ice 7 =m$ at ! bottom1 *ill+ all ! wat] above4 #ccb4 ,:y ! ,freez+ ,po9t is at #cb4--;,if ! freez+ po9t ( wat] 7 high] ?an #cb1 freez+ w\ld occur s e>ly 9 ! autumn1 & ! ice & sn[ w\ld la/ s late 9 ! spr+1 t ! season w\ld be too %ort to raise our supplies ( fruits & gra9s4 ,if1 on ! o!r h&1 x 7 at a l[] po9t1 ! e>? w\ld n h ! protection ( its light coat ( sn[1 b in/ead w\ld be *ill$ by ra9s s cold t b>r5ness w\ld be ! result4 ,! multitudes ( animals1 too1 t n[ live s securely 9 ! wat]1 "s ( !m ev5 ) ! ice above !m1 w\ld all p]i% ) ! cold4 #ccc4 ,=ce ( ,expansion 9 ,ice4--,z ice occupies "o sev5? m room ?an ! wat] f :i* x is =m$1 x ex]ts 9 its =mation an expansive =ce :i* "u v>i\s circum/ances produces v>i$ & (t5 rem>kable results4 ,( ! _m exp]im5ts :i* h be5 tri$ to %[ ! =ce ( ?is expansion ,i w m5tion b "o4 ,a bomb-%ell 0 fill$ ) wat]1 at ,montreal1 & clos$ ) an iron plug :i* 0 driv5 9 ) great =ce4 ,! plug 0 ?r[n a di/ance ( #djj feet by ! expansion :5 ! wat] froze4 ,?is expansion is sometimes an inconv5i5ce to u1 z 9 bur/+ wat]-pipes2 b besides ! great s]vice :i* x does 9 ! e>?1 already notic$1 x is ( s]vice also 9 loos5+ ! soil1 & 9 supply+ x ) requisite +r$i5ts f ! rocks by break+ !m up & pulv]iz+ !m 9 small quantities f ye> to ye>4 ,,*apt] ,,xiv4 ,,light4 #ccd4 ,nature ( ,light4--,we d n "k :at light is4 ,!re are two suppositions 9 reg>d to x4 ,"o is t ( ,sir ,isaac ,newton1 call$ ! !ory ( emission4 ,accord+ to ?is light is a sub/ance1 b s e!real t x has no weight1 & is capable ( pass+ ?r\gh v>i\s sub/ances ( ev5 great d5sity4 ,! o!r supposition is :at is call$ ! undulatory !ory4 ,! advocates ( ?is1 :i* is n[ q g5]ally receiv$1 believe light to consi/ ( undulations1 waves1 or vibrations 9 an e!r :i* is suppos$ to exi/ e :]e1 p]vad+ all space & e sub/ance4 ,y p]ceive an analogy "h to s\nd1 ! vibrat+ m$ium 9 ! case ( s\nd1 h[ev]1 be+ always "s palpable sub/ance--solid1 fluid1 or a]i=m4 ,heat is suppos$1 z /at$ 9 #bga1 to be a vibration ( ! e!real sub/ance1 z light is1 ?\gh ! two vibrations mu/ ( c\rse be some:at diff]5t 9 "*4 ,any body t is capable ( communicat+ ! light-vibration to ?is e!r is said to be lum9\s4 #cce4 ,s\rces ( ,light4--,! *ief s\rce ( light to our e>? is ! sun1 :i* is a p]man5tly lum9\s body4 ,!n we h ! light ( combu/ion 9 its v>i\s =ms4 ,electricity is ano!r s\rce ( light4 ,light is sometimes emitt$ dur+ decay or putrefaction ( "s sub/ances4 ,"s animals--z fire-flies1 gl[-worms1 & phosphoresc5t animals 9 ! sea--h ! p[] ( emitt+ light4 #ccf4 ,light ,moves 9 ,/raight ,l9es4--,light1 l heat & s\nd1 radiates 9 /raight l9es 9 all directions f its s\rce4 ,we c see ?is to be true by admitt+ rays ( light into a d>k5$ room ?r\gh small op5+s 9 ! %utt]s1 ! rays mak+ /raight l9es across ! d>kness1 z may be se5 by ! motes :i* are fly+ 9 ! air4 ,! fact is recogniz$ by ! m>ksman 9 tak+ aim1 & by ! eng9e] 9 mak+ 8 levels4 ,! c>p5t] acts ^u x :5 he te/s ! smoo?ness ( any surface by lett+ ! light pass along ov] x to 8 eye4 ,illu/ration3 ,fig4 #bbc4 ,illu/ration3 ,fig4 #bbd4 #ccg4 ,diffusion ( ,light4--,z light passes 9 all directions f any body or po9t1 ! f>!r we g f its s\rce ! less w ! light be4 ,if we take any two rays ( light1 ! f>!r we trace !m f _! s\rce ! f>!r are !y sep>at$ f ea* o!r1 & :at is true ( any two rays is true ( all ! rays4 ,x foll[s t ! f>!r remov$ any surface is f a s\rce ( light ! less light w !re be ^u x4 ,?is decrease ( light 9 proportion to di/ance is a p]fectly regul> decrease1 & x is z ! squ>e ( ! di/ance2 or1 9 o!r words1 ! int5sity ( light is inv]sely z ! squ>e ( ! di/ance4 ,take a scre51 ,fig4 #bbc1 & a c&le1 plac+ a squ>e piece ( pa/ebo>d betwe5 !m at "o foot f ea*4 ,! %ad[ on ! scre51 y see1 cov]s a space f\r times z l>ge z ! pa/ebo>d4 ,t is1 ! light t %9es on ! pa/ebo>d1 if all[$ to pass on to ! scre51 w\ld be diffus$ ov] f\r times ! space1 & !re=e w\ld h only "o-qu>t] ( ! int5sity4 ,s if z %[n 9 ,fig4 #bbd1 ! scre5 be plac$ at twice ! di/ance f ! pa/ebo>d t ! light is1 ! %ad[ w cov] a space n9e times z l>ge z ! pa/ebo>d1 & !re=e ! light !re w\ld h "o-n9? ( ! int5sity :i* x has :]e ! pa/ebo>d is4 ,aga91 x is se5 by ,fig4 #bbe t if ! scre5 be plac$ at ! di/ance ( ?ree feet ! int5sity ( ! light is "o-sixte5? ( t :i* x is at ! pa/ebo>d4 ,:ile ! di/ances1 !re=e1 are z #a1 #b1 #c1 #d1 etc41 ! int5sity ( ! light is inv]sely z ! numb]s #a1 #d1 #i1 #af1 etc41 t is inv]sely z ! squ>es ( ! di/ance4 ,illu/ration3 ,fig4 #bbe4 #cch4 ,velocity ( ,light4--,! velocity ( light is s great t )9 any ord9>y di/ances x may be consid]$ z in/antane\s4 ,?us :5 we measure ! di/ance ( a cannon by ! diff]5ce betwe5 ! "t ( its fla% & ! report1 we d n reckon ! light to consume any "t 9 its passage to ! eye4 ,b :5 we come to look at objects z di/ant z ! sun & o!r heav5ly bodies1 we reckon 9 our calculations ! "t ( ! passage ( light4 ,x takes light eight m9utes to travel f ! sun to u1 a di/ance ( n9ety-five millions ( miles4 ,) ! telescope />s h be5 se5 :i* h be5 asc]ta9$ to be at su* a di/ance t x requires ov] t5 ye>s = _! light to come to ! e>?4 ,o!rs h be5 se5 :i* are mu* f>!r (f1 b _! di/ances h n be5 absolutely asc]ta9$4 ,"s h be5 se5 suppos$ to be at su* a di/ance t ! light com+ f !m to ! eye ( ! a/ronom] 0 a hundr$ ?\s& ye>s 9 its passage4 ,illu/ration3 ,fig4 #bbf4 #cci4 ,roem]'s ,obs]vations4--,! velocity ( light 0 fir/ det]m9$ by ,roem]1 a ,dani% a/ronom]1 9 #afgf4 ,x 0 done 9 8 calculations & obs]vations ( ! eclipse ( "o ( ,jupit]'s moons4 ,aft] mak+ ! calculation ( ! "t x w\ld take = ! satellite to pass ?r\gh ! %ad[ ( ! planet1 he obs]v$ its passage1 & f\nd t x did n come out f ! %ad[ z soon z 8 calculation requir$ by fifte5 seconds4 ,:at 0 ! difficulty8 ,if ! e>? _h rema9$ 9 "o spot f ! beg9n+ to ! end ( ! passage ( ! satellite1 ! obs]vation w\ld h come out exactly accord+ to ! calculation4 ,b ! e>? _h mov$ dur+ ?is "t 7ab\t =ty-two h\rs & a half7 ! imm5se di/ance ( #b1hhj1jjj miles4 ,! light ( ! em]g+ satellite !re=e _h to travel ov] ?is additional di/ance to ov]take ! e>?1 & x took fifte5 seconds to d x4 ,if we divide1 !n1 ?is di/ance by #ae we get ! di/ance :i* light travels 9 a second1 :i* is #aib1jjj miles4 ,all ?is c be made cle> by ! diagram1 ,fig4 #bbf4 ,let ,s be ! sun1 ,j ,jupit]1 & ,c "o ( its moons em]g+ f its %ad[4 ,let ,a be ! e>? z x is :5 ! eclipse ( ,jupit]'s moon beg9s4 ,:5 x em]ges ! e>? has pass$ to ,b1 & ! light f ! satellite has to travel z mu* f>!r to rea* x n[ z ,b ,c is long] ?an ,a ,c4 ,roem] made o!r obs]vations ) ! e>? at "s o!r p>ts ( h] orbit ) ! same result4 ,illu/ration3 ,fig4 #bbg4 #cdj4 ,reflection ( ,light4--,light1 l s\nd & heat1 is reflect$ 9 /raight l9es :5 x /rikes ^u any resi/+ sub/ance4 ,we c see ?is to be ! case :5 x /rikes ^u any smoo? & plane surface4 ,& x is true ( light1 z x is ( heat1 t ! angles ( incid5ce & reflection are equal4 ,?us if c1 ,fig4 #bbg1 be a reflect+ surface1 & b c a l9e p]p5dicul> to x1 !n a ray ( light1 d c1 w be reflect$ 9 ! l9e c a1 & ! angle ( incid5ce1 d c b1 w be equal to ! angle ( reflection1 b c a4 #cda4 ,h[ we ,see4--,we see ! v>i\s objects ar\nd u by ! light :i* is reflect$ f !m4 ,e po9t ( e surface t we see reflects rays or vibrations ( light to our eyes4 ,?us if we see a p]son !re are rays ( light reflect$ into our eyes f e "p ( him4 ,^! rays =m an image ( him 9 ! back "p ( ea* eye1 & x is by ?is image t we see him1 z w be expla9$ 9 full 9 ano!r "p ( ?is *apt]4 ,reflect$ light is pa9t+ ! images ( objects 9 ! eye e mom5t 9 great abundance & v>iety4 ,if a speak] h an audi5ce ( a ?\s& p]sons all look+ at him1 8 image is at ! same "t 9 two ?\s& eyes1 & 9 ea* ( ^! two ?\s& images e motion & e *ang+ expression are fai?fully depict$4 ,illu/ration3 ,fig4 #bbh4 #cdb4 ,mirrors4--,t reflect$ light does ?us =m images ( objects y see 9 ! common mirror4 ,! image =m$ 9 x ( any object comes f ! light reflect$ f t object into ! glass4 ,!n 9 see+ ! image light is reflect$ f x into ! eye1 !re to =m a simil> image1 ?\gh ( mu* less size4 ,by us+ two or m mirrors ! reflections ( ! image c be multipli$1 & by "s arrangem5ts ( !m to a v great ext5t4 ,t ! image appe>s to be at ! same di/ance beyond ! surface t ! object is be=e x1 is ow+ to ! fact t ! reflect$ rays come f ! glass at ! same angle t ! incid5t rays /rike ^u x4 ,?is may be %[n f ,fig4 #bbh 7p4 #bfc74 ,suppose m m' is a look+-glass1 & an arr[1 ,a ,b1 is be=e x4 ,rays ( light come f x at all po9ts to ! glass4 ,we w take only two ( ^! rays at ea* end ( ! arr[4 ,! ray ,a g w be reflect$ to ! eye at ! same angle 9 ! ray g o1 & ! ray ,a f w be reflect$ 9 ! ray f ,e4 ,& ! reflect$ rays w h ! same rate ( div]g5ce z ! incid5t rays4 ,! same c be %[n 9 reg>d to rays f ,b or any o!r po9t on ! arr[4 ,n[ if ! l9es o g & ,e f be ext5d$1 !y w meet at ! po9t a1 :i* is at ! same di/ance beh9d ! mirror z ,a is be=e x4 ,! same ?+ c be %[n ( ! rays f ,b or any o!r po9t4 ,!re=e ! image ( ! arr[ w appe> to ! eye to h ! same relative position beh9d ! glass t ! arr[ itself has be=e x4 ,illu/ration3 ,fig4 #bbi4 #cdc4 ,! ,kaleidoscope4--,i h already notic$ ! multiplication ( ! images ( objects by us+ two or m mirrors4 ,9 ! kaleidoscope1 by a p>ticul> arrangem5t ( mirrors1 ! images are multipli$1 & by *anges 9 ! position ( ! objects ! relative positions ( ! images are inf9itely v>i$4 ,fig4 #bbi w s]ve to expla9 ! op]ation ( ! in/rum5t4 ,let ,a ,b & ,b ,c be two plane mirrors plac$ at "r angles to ea* o!r1 & a an object be=e !m4 ,let ,i be ! position ( ! eye look+ at ! mirrors4 ,! rays a f & a g w be reflect$ to ,i z repres5t$1 & ! eye w see two images1 :i* appe> to be at b & ,e4 ,b ! ray a ,k w be reflect$ to c1 & !n to ,i1 s t a ?ird image w be se5 at d4 ,"h is b a s+le second reflection1 or reflection ( an image2 b by plac+ ! mirrors at an angle ( #fj1 #de1 & #cj ! images may be increas$ to six1 eight1 & t51 hav+ a circul> arrangem5t4 ,9 ! kaleidoscope two mirrors are plac$ 9 a tube at an angle ( #cj1 & v>i\sly-color$ pieces ( glass 9 ! f>!r end ( ! in/rum5t1 *ang+ _! relative position ) e movem5t ( x1 give an endless v>iety ( images symmetrically arrang$4 ,illu/ration3 ,fig4 #bcj4 ,illu/ration3 ,fig4 #bca4 #cdd4 ,curv$ ,mirrors4--,^! may be concave or convex4 ,! action ( a concave mirror ^u light may be illu/rat$ by ,fig4 #bcj4 ,if p>allel rays1 z repres5t$1 /rike ^u ! mirror !y w1 9 _! reflection1 be made to conv]ge1 or come toge!r1 at ! focus1 a4 ,b suppose ! light comes f ?is focus1 ! rays ( c\rse div]g+1 or go+ away f ea* o!r2 !n ! rays1 z reflect$1 w be p>allel4 ,if ! light or object be ne>] to ! mirror ?an ! focus1 & ! rays ( c\rse be m div]g+1 !n ! effect ( ! mirror w be to less5 ! div]g5ce :5 ! rays are reflect$4 ,y see t ! t5d5cy is to make ! rays conv]ge4 ,& h5ce concave reflectors are mu* us$ :5 x is desir$ to ?r[ a great am\nt ( light 9 "o direction4 ,! effect ( ! concave mirror ^u ! app>5t size & position ( objects plac$ be=e x v>ies ) ! relation ( _! position to ! focus4 ,! action ( a convex mirror ^u light is ! opposite ( t ( ! concave4 ,its t5d5cy is to make ! rays div]ge4 ,?us 7,fig1 #bca71 if p>allel rays /rike ^u a convex mirror !y div]ge1 z if !y came f a focus beh9d ! mirror1 z b1 z indicat$ by ! dott$ l9es4 ,illu/ration3 ,fig4 #bcb4 ,illu/ration3 ,fig4 #bcc4 #cde4 ,refraction ( ,light4--,:5 light passes f "o m$ium into ano!r x is b5t f its c\rse4 ,?is may be illu/rat$ by ,fig4 #bcb1 9 :i* ,a ,b ,c ,d is a box1 into :i* a c&le1 ,e1 is %9+4 ,! c&le is s plac$ t ! %ad[ ( ! side ,a ,c falls at ,d4 ,b let ! box be fill$ ) wat]1 & n[ ! %ad[ is remov$ to d1 z if ! c&le 7 at e4 ,?is is because ! rays ( light f ! c&le1 9 pass+ f ! air into ! wat]1 are b5t or refract$ s z to take a diff]5t direction4 ,"h we h light pass+ f a r>] into a d5s] m$ium4 ,let u see n[ h[ x is :5 light passes f a d5s] m$ium into a r>]4 ,?is c be illu/rat$ on ,fig4 #bcc4 ,let ! vessel1 ,a ,b ,c ,d1 be empty1 & let a co9 be plac$ at ,o4 ,let ! eye1 ,e1 be 9 su* a position t a /raight l9e1 ,o ,g ,e1 f ! co9 to ! eye w\ld /rike ! side ( ! vessel a little bel[ ! edge1 or1 9 o!r words1 t ! edge ( ! vessel w\ld prev5t ! eye f see+ x4 ,if n[1 keep+ ! eye 9 ?is position1 wat] be p\r$ 9 up to a c]ta9 level1 say ,f ,g1 ! co9 comes into view4 ,?is is because light com+ f ! co9 to ,l is b5t into ano!r direction1 ,l ,e1 & ! co9 !re=e appe>s to ! eye to be at ,k4 ,9 ?is case ! refraction is f ! p]p5dicul>1 ,p ,q1 let d[n ?r\gh ! po9t ,l1 :]e ! light em]ges f ! d5s] into ! r>] m$ium4 ,b ,:5 light passes f a r>] into a d5s] m$ium ! refraction is rev]s$--x is t[>d ! p]p5dicul>4 ,x is f ?is refraction ( light t a /ick p>tly imm]s$ 9 wat] appe>s to ! eye to be brok5 j at ! surface ( ! wat]4 ,illu/ration3 ,fig4 #bcd4 #cdf4 ,dawn & ,twilight4--,! light ( ! sun1 9 pass+ f space into our atmosph]e1 is refract$4 ,if x 7 n we %\ld h no daylight prec$+ ! rise ( ! sun1 or twilight aft] its sett+2 b light w\ld bur/ ^u ! d>kness ( night at once :5 ! sun appe>$ above ! horizon1 & d>kness w\ld sudd5ly succe$ to ! light ( day at sunset4 ,z x is1 9 ! morn+ ! light b5ds t[>d u z x /rikes across ! atmosph]e long be=e we see ! sun1 & aft] ! sun has disappe>$ f view at ev5+ its light b5ds t[>d u 9 ! same mann]4 ,& f>!r1 we really see ! sun 9 ! morn+ be=e x gets above ! horizon1 & 9 ! ev5+ aft] x has gone bel[ x4 ,?is may be made cle> by ,fig4 #bcd4 ,let ! c5tral ball repres5t ! e>?4 ,n[ z ! atmosph]e is mo/ d5se ne> ! e>?1 & is r>] z y g outw>d f ! e>?1 x is repres5t$ 9 ! figure z hav+ diff]5t lay]s 9 ord] t ! op]ation ( ! refraction may be m cle> to y4 ,! out]mo/ lay] is exce$+ly r>e1 & ea* lay] is m d5se ?an ! previ\s "o z y g 9 t[>d ! e>?4 ,! light com+ f ! sun1 ,s1 bel[ ! horizon into ! fir/ lay] ( air1 in/ead ( pass+ on /raight to a1 z indicat$ by ! dott$ l9e1 b5ds t[>d ! e>?4 ,!n 9 ent]+ ! second lay]1 in/ead ( pass+ on to b1 x w be b5t or refract$ /ill m1 z ?is lay] is d5s]2 & s on ?r\gh all ! lay]s1 be+ refract$ 9 ea* m ?an 9 ! previ\s "o4 ,! result is1 t z e object is se5 9 ! direction 9 :i* ! rays f x at l5g? rea* ! eye1 ! sun1 ?\gh really bel[ ! horizon1 appe>s to be above x1 z repres5t$4 ,! pa? ( light f ! sun1 z x passes ?r\gh ! air1 is a curv$ l9e4 ,?is is because ! air1 in/ead ( be+ ( uni=m d5sity1 less5s 9 d5sity z we g f ! e>?4 ,if x 7 ( uni=m d5sity ! light w\ld be refract$ 9 /raight l9es1 z 9 ! exp]im5ts 9 #cde4 #cdg4 ,mirages4--,sometimes inequalities occur 9 ! d5sity ( ! l[] portions ( ! atmosph]e1 caus+1 ( c\rse1 unequal refraction1 & produc+ "s /range appe>ances1 t]m$ mirages4 ,= example1 at ,ramsgate1 on ! coa/ ( ,engl&1 !re 0 se51 at "o "t1 z repres5t$ 9 ,fig4 #bce 7p4 #bfh71 a %ip at su* a di/ance t only h] topsails 7 visible2 & above 9 ! air !re 7 two complete images ( ! %ip1 ! upp]mo/ be+ erect & ! "u "o inv]t$4 ,capta9 ,scoresby1 9 a voyage to ,gre5l&1 saw an inv]t$ image ( a %ip s well def9$ t he decid$ t x 0 ! image ( 8 fa!r's %ip1 ! ,fame1 :i* 0 aft]w>d v]ifi$4 ,! %ip itself 0 at t "t at a di/ance ( #cj miles4 ,an incid5t 9 ! e>ly hi/ory ( ! au?or's place ( resid5ce may be cit$ z an example ( mirage4 ,a %ip left = ,engl& freight$ ) a valuable c>go1 & hav+ on bo>d a l>ge numb] ( ! be/ citiz5s ( ! colony4 ,"s "t aft] !re 0 imm5se excitem5t 9 ,new ,hav51 because ! inhabitants saw1 ) great di/9ctness1 :at !y suppos$ to be ?is vessel1 at only a little di/ance1 app>5tly sail+ aga9/ ! w9d4 ,b x soon disappe>$ f view1 "p aft] "p1 until ! :ole 0 gone4 ,! %ip itself 0 nev] he>d f1 & x 0 suppos$ at ! "t t ?is appe>ance 0 a manife/ation ( ,provid5ce = ! purpose ( in=m+ ! coloni/s :at _h become ( _! fri5ds4 ,b :at 0 se5 0 und\bt$ly ! reflect$ image ( ?is or "s o!r %ip4 ,x is su* appe>ances z ^! t h giv5 rise to ! /ories :i* h be5 sometimes told ( phantom %ips4 ,mirages are v common 9 ! ext5sive des]ts 9 hot climates1 exhibit+ to ! eye ( ! travel] v>i\s deceptive appe>ances1 z isl&s1 lakes1 etc4 ,9 ,bonap>te's campaign 9 ,egypt su* an appe>ance caus$ :ole battalions ( ?ir/y soldi]s to ru% =w>d1 suppos+ at ! mom5t t a pl5tiful supply ( wat] 0 at h&4 ,illu/ration3 ,fig4 #bce4 ,! mo/ a/oni%+ in/ance ( mirage ( :i* ,i h ev] he>d is ?us n>rat$3 ,! cliffs on ! ,fr5* coa/ are #ej miles di/ant f ,ha/+s1 on ! coa/ ( ,sussex1 & !y are actually hidd5 f ! eye by ! convexity ( ! e>?2 t is to say1 a /raight l9e drawn f ,ha/+s to ,calais or ,b\logne w\ld pass ?r\gh ! sea4 ,a ye> or two ago1 h[ev]1 a ,fell[ ( ! ,royal ,society1 :o 0 resid+ at ,ha/+s1 0 surpris$ to see a cr[d ( p runn+ to ! sea-side4 ,^u inquiry z to ! cause ( ?is he 0 in=m$ t ! coa/ ( ,france c\ld be se5 by ! nak$ eye4 ,he imm$iately w5t d[n to ! %ore to witness s s+ul> a sight1 & !re discov]$ di/9ctly ! ,fr5* cliffs ext5d+ = "s leagues along ! horizon1 & s vividly t !y appe>$ to be only a few miles (f4 ,! sailors & fi%]m51 ) :om ,mr4 ,la?am walk$ along ! wat]'s edge1 c\ld h>dly at fir/ be p]suad$ ( ! reality ( ! appe>ance2 b z ! cliffs gradually became m elevat$ !y 7 s conv9c$ t !y po9t$ out to ,mr4 ,la?am ! diff]5t places !y 7 accu/om$ to visit--su* z ! bay & ! w9d-mill at ,b\logne1 ,/4 ,vall]y1 & o!r places on ! coa/ ( ,pic>dy1 ev5 z f> z ,dieppe1 all ! ,fr5* %ores appe>+ to ! ,engli% sailors z if !y 7 sail+ at a %ort di/ance f !m t[>d ! h>bors4 ,) ! aid ( a telescope ! ,fr5* fi%+-boats 7 pla9ly se5 at an*or2 & ! diff]5t colors ( ! l& ^u ! heights1 toge!r ) ! build+s1 7 p]fectly disc]nible4 ,! day :5 ?is occurr$ is said to h be5 extremely hot1 )\t a brea? ( w9d /irr+1 & ! ph5om5on cont9u$ visible 9 ! highe/ spl5dor until pa/ eight o'clock 9 ! ev5+1 hav+ be5 se5 = ?ree h\rs cont9u\sly4 ,illu/ration3 ,fig4 #bcf4 ,illu/ration3 ,fig4 #bcg4 #cdh4 ,visual ,angle4--,9 ord] t y may und]/& ! op]ation ( l5ses 9 relation to vision ,i mu/ fir/ expla9 to y :at is meant by ! visual angle4 ,9 ,fig4 #bcf 7p4 #bgj7 are repres5t$ arr[s ( ! same size at diff]5t di/ances f ! eye4 ,f ! ends ( ea* ( ! arr[s are drawn l9es to ! eye4 ,! angle :i* ^! l9es make 9 ea* case z !y meet at ! eye is t]m$ ! visual angle4 ,n[ ! app>5t size ( an object dep5ds ^u ! size ( ?is angle4 ,! degrees ( ! angles are m>k$ ^u ! figure4 ,?us ! visual angle ( ! ne>e/ arr[ is #abj degrees1 & t ( ! second is #fj1 only half z l>ge4 ,! fir/ arr[ !re=e appe>s twice z l>ge z ! second4 ,= ! same reason x appe>s f\r times z l>ge z ! ?ird1 eight times z l>ge z ! f\r?1 & twelve times z l>ge z ! fif?4 ,! same ?+ is illu/rat$ 9 ano!r way 9 ,fig4 #bcg4 ,"h ! arr[s e f1 g h1 & i k appe> to ! eye z l>ge z ,a ,b1 because !y h ! same visual angle1 & = ?is reason make an image ( ! same size 9 ! eye1 z y see is indicat$ 9 ! figure4 ,x is h>dly necess>y to say t :at is true ( objects z a :ole is true also ( any "p ( !m4 ,ea* "p1 h[ev] small1 has its visual angle1 & ?is gov]ns its app>5t size4 ,illu/ration3 ,fig4 #bch4 ,illu/ration3 ,fig4 #bci4 #cdi4 ,l5ses4--,transp>5t bodies hav+ curv$ surfaces are call$ l5ses4 ,!re are six k9ds1 repres5t$ 9 ,fig4 #bch4 ,! l5ses 9 mo/ common use are ! d\ble convex & d\ble concave4 ,! explanation ( ! mode 9 :i* ^! act ^u light w suffici5tly illu/rate ! op]ation ( ! o!rs4 ,!y act by refraction1 ! convex collect+ ! rays1 or br++ !m ne>] toge!r1 & ! concave putt+ !m f>!r ap>t4 ,y c at once see1 !n1 t a convex l5s by caus+ ! rays com+ f an object to conv]ge m1 increases ! visual angle1 & !re=e makes ! object to appe> l>g] ?an x o!rwise w\ld4 ,?is effect is illu/rat$ by ,fig4 #bci4 ,! rays ( light com+ f ! arr[ are made by ! l5s s to conv]ge z to meet at a1 in/ead ( b1 :]e !y w\ld meet if !y did n pass ?r\gh ! l5s4 ,t is1 by pass+ ?r\gh ! l5s !y h a l>g] visual angle1 & !re=e ! object is magnifi$4 ,! di/ance betwe51 c & d %[s ! size :i* ! arr[ w\ld appe> to h to ! eye plac$ at a4 ,illu/ration3 ,fig4 #bdj4 #cej4 ,microscopes & ,telescopes4--,:at has be5 said ( ! action ( ! convex l5s ^u ! visual angle w s]ve to expla9 ! op]ation ( ! microscope4 ,?is in/rum5t may be s+le or comp\nd4 ,! comp\nd microscope has m ?an "o l5s1 & is us$ to magnify v m9ute objects4 ,its op]ation may be se5 by ! diagram1 ,fig4 #bdj4 ,rays f ! object1 ,e ,f1 pass+ ?r\gh ! fir/ l5s1 or object-glass1 z x is call$1 =m a magnifi$ inv]t$ image1 ,g ,h1 :i* is /ill m magnifi$ by ! eye-glass1 ,c ,d4 ,9 ! telescope we h also convex l5ses1 b !y are arrang$ diff]5tly f ^? ( ! microscope1 z ! objects to be magnifi$ are di/ant4 ,illu/ration3 ,fig4 #bda4 #cea4 ,magic ,lant]n4--,?is is an in/rum5t by :i* pictures made ^u slips ( glass ) color+ sub/ances :i* all[ ! light to pass readily are ?r[n ^u a scre5 magnifi$4 ,x is a metallic lant]n1 ,a ,a1 ,fig4 #bda1 ) a concave reflector1 p q1 & two convex l5ses1 m & n4 ,at c d is a space betwe5 ! l5ses into :i* ! pictures are introduc$4 ,l is a /rong light1 :i* is 9 ! focus bo? ( ! mirror & ! l5s m4 ,! picture is !re=e illum9at$ /rongly by ! rays reflect$ f ! mirror & pass$ ?r\gh ! l5s4 ,! l5s n :i* is movable1 is s adju/$ z to ?r[ a highly magnifi$ image ( ! picture ^u ! scre54 ,z ! image is an inv]t$ "o ! pictures mu/ be ins]t$ upside d[n1 t ! images on ! scre5 may be upright4 ,! sol> microscope is1 9 its ess5tial p>ts1 l ! magic lant]n1 ! sun be+ us$ z ! illum9ator4 ,illu/ration3 ,fig4 #bdb4 ,illu/ration3 ,fig4 #bdc4 #ceb4 ,cam]a ,obscura4--,?is in/rum5t diff]s f ! magic lant]n 9 giv+ u dim9i%$ images ( objects4 ,an in/rum5t ( ?is k9d c be arrang$ extemporane\sly any :]e4 ,?us1 if into a d>k5$ *amb] light be admitt$ ?r\gh a small op5+1 inv]t$ images ( any objects 9 front ( ! op5+ w be =m$ ^u a :ite scre5 9 ! opposite "p ( ! *amb]4 ,su* an arrangem5t is repres5t$ 9 ,fig4 #bdb 7p4 #bgc71 ,c ,d be+ ! *amb]1 ,l ! op5+1 & a b ! image ( ! object ,a ,b4 ,! images 9 su* a case1 h[ev]1 are fa9t1 because ! op5+ mu/ necess>ily be small1 & !re=e b few rays1 comp>atively1 come f ! objects4 ,by mak+ ! op5+ l>g]1 & ga!r+ ! rays t ent] x ) a d\ble convex l5s1 we c h well-def9$ & bright images ( objects4 ,?\gh ! cam]a obscura may h v>i\s =ms1 ,i h describ$ :at is ess5tially ! arrangem5t ( ! in/rum5t4 ,"o =m ( x1 = sket*+ ei!r s+le objects or gr\ps ( !m 9 l&scapes1 is repres5t$ 9 ,fig4 #bdc4 ,"h ! rays ( light com+ f objects /rike ^u a mirror1 ,a ,b1 & are reflect$ ?r\gh a convex l5s1 ,c ,d1 ^u :ite pap] on ! bottom1 ,e ,f1 ( ! box1 :]e ! outl9es ( ! images are trac$ by ! sket*]4 ,! light c ent] only at ! op5+ above1 = on ! side ( ! box :i* is op5 !re hangs d[n a curta9 on ! back ( ! arti/ z he sket*es4 ,illu/ration3 ,fig4 #bdd4 #cec4 ,! ,eye4--,! eye is ess5tially a cam]a obscura4 ,x is a d>k *amb] 9 :i* images are =m$ ^u a scre5 9 its back "p1 & ! light :i* comes f objects is admitt$ ?r\gh an op5+ 9 front1 :]e !re is a d\ble convex l5s4 ,t y may und]/& ! mann] 9 :i* ! images are =m$1 ,i give y1 9 ,fig4 #bdd1 a map ( ! eye4 ,at a is ! ?ick1 /rong :ite coat call$ ! scl]otic coat1 f a ,greek ^w mean+ h>d4 ,?is1 :i* is commonly ! :ite ( ! eye1 gives to ! eyeball its firmness4 ,into ?is is fa/5$ 9 front1 l a cry/al 9 a wat*-case1 e1 ! cornea4 ,! scl]otic & cornea1 y see !n1 make toge!r "o coat ( ! eye1 ! out] "o4 ,! cornea is ! cle>1 transp>5t w9d[ ( ! eye ?r\gh :i* ! light ent]s4 ,next to ! scl]otic coat comes ! *oroid coat1 :i* is d>k1 to prev5t too mu* reflection back & =? 9 ! eye4 ,!n y h a v ?9 membrane1 c1 ! ret9a1 ! scre5 on :i* ! images are =m$4 ,?is is compos$ *iefly ( ! f9e fibres ( ! n]ve ( sight1 d4 ,to return to ! front ( ! eye :]e ! light ent]s--beh9d ! cornea is ! iris1 g g1 :i* is imm]s$ 9 a wat]y fluid1 f1 call$ ! aque\s humor4 ,! light pass+ ?r\gh ! cornea & ! aque\s humor comes to ! cry/all9e l5s1 h1 :i*1 y see1 is a d\ble convex l5s4 ,pass+ ?r\gh ?is & ?r\gh a jelly-l sub/ance1 call$ ! vitre\s humor1 :i* fills all t l>ge space i1 x /rikes ^u ! ret9a1 c1 :]e x =ms ! images ( ! objects f :i* x came4 ,y see n[ h[ ! eye is l a cam]a obscura4 ,y h 9 x ! d>k *amb] ) its scre51 ! op5+ ?r\gh ! iris1 ! pupil1 = ! admission ( ! light1 & j beh9d ?is op5+ ! l5s = ga!r+ or conc5trat+ ! light be=e x falls ^u ! ret9a4 ,! refraction ( ! light is n1 h[ev]1 done :olly by ?is l5s4 ,! project+ cornea1 ) its conta9$ aque\s humor1 refracts x consid]ably1 = x =ms a convex l5s4 ,illu/ration3 ,fig4 #bde4 ,illu/ration3 ,fig4 #bdf4 #ced4 ,di/9ct ,vision4--,9 ord] t vision may be p]fectly di/9ct1 x is necess>y t ! rays com+ f ea* po9t ( ! object :i* is se5 %\ld1 on conv]g+1 meet toge!r1 or be br\ght to a focus on ! scre5 ( ! eye1 ! ret9a4 ,?us1 9 ,fig4 #bde1 ! rays :i* come f a1 ! end ( ! arr[1 meet on ! ret9a at b1 & ^? f c1 ! o!r end1 are br\ght to a focus at d4 ,n[ ! muscles ( ! eye h consid]able p[] 9 adju/+ ! eye to objects at diff]5t di/ances1 s z to br+ ! rays 9 mo/ cases toge!r exactly at ! ret9a4 ,!y fail to d x ) objects t are v ne>4 ,y c see t ?is is s if y br+ any object1 z y\r f+]1 ne>] & ne>] to ! eye4 ,y w at l5g? f9d t y c n see x di/9ctly4 ,! reason is1 t ! rays f x div]ge s mu* t ! cornea & l5s c n make !m conv]ge en\gh to meet at ! ret9a4 ,?is div]g5ce ( rays at diff]5t di/ances is illu/rat$ 9 ,fig4 #bdf4 ,suppose t y are look+ at "s v m9ute object4 ,! ne>] y br+ x to ! eye ! bett] y c see x1 till y come to a c]ta9 po9t4 ,!re ! rays are s div]g5t1 z y c readily see by ! figure1 t ! l5ses ( ! eye c n make !m conv]ge suffici5tly = di/9ct vision4 ,n[ j "h ! microscope comes 9 to help ! eye by caus+ ^! div]g5t rays to come ne>] toge!r be=e !y ent] ! w9d[ ( ! eye1 ! cornea4 ,illu/ration3 ,fig4 #bdg4 ,illu/ration3 ,fig4 #bdh4 #cee4 ,ne>-,sight$ & ,f>-,sight$4--,"s p]sons h _! eyes s %ap$ t !y c n fully adju/ !m to objects at diff]5t di/ances4 ,?us ! ne>-sight$ c see ) di/9ctness only objects t are ne>4 ,! reason is t ! rays conv]ge too mu*1 & are br\ght to a focus be=e !y arrive at ! ret9a1 z repres5t$ 9 ,fig4 #bdg4 ,! images !re=e ( di/ant objects are indi/9ct4 ,if ! ret9a c\ld 9 any way be br\ght =w>d a little ! difficulty w\ld be obviat$4 ,b z ?is c n be done1 concave glasses are resort$ to1 :i* c\nt]act ! effect ( ! too highly refractive p[] ( ! eye4 ,9 ! f>-sight$ ! difficulty is ( an opposite "*4 ,! refractive p[] is s feeble t :5 ne> objects are view$ ! rays are n br\ght to a focus soon en\gh1 z se5 9 ,fig4 #bdh4 ,convex glasses are us$ 9 ?is case1 mak+ ! div]g5t rays ( ne> objects less div]g5t be=e !y ent] ! cornea4 #cef4 ,images 9 ! ,eye ,inv]t$4--,! images =m$ on ! ret9a are inv]t$4 ,?is c be prov$ by tak+ ! eye ( an ox & c>efully p>+ (f ! back ( x1 leav+ little else ?an ! ret9a itself4 ,hold+ n[ a c&le be=e ! eye1 its image may be se5 inv]t$ ^u its re> "p4 ,! "q arises :y x is t we see objects erect :5 _! images on ! ret9a are inv]t$4 ,on ?is po9t ,i w quote f my ,human ,physiology3 ,x has be5 suppos$ by "s t we really see e ?+ rev]s$1 & t our exp]i5ce ) ! s5se ( t\*1 9 connection ) t ( vision1 sets u "r 9 ?is p>ticul>4 ,& ?is x is suppos$ is ! m readily done f ! fact t our own limbs & bodies are rev]s$ z pictur$ on ! ret9a1 z well z objects t are ar\nd u1 s t e ?+ is relatively "r 9 position4 ,b if ?is be ! true explanation1 ^? :o h _! sight re/or$ aft] hav+ be5 bl9d f bir? %\ld at fir/ see e ?+ wrong side up1 & %\ld be consci\s ( rectify+ ! error by look+ at _! own limbs & bodies4 ,b ?is is n s4 ,! above explanation ( erect vision1 & o!r explanations ( a simil> "*1 are bas$ ^u a wrong idea ( ! (fice :i* ! n]ve p]=ms 9 ! process ( vision4 ,x is n ! image =m$ ^u ! ret9a :i* is transmitt$ to ! bra91 b an impression produc$ by t image4 ,! m9d does n look 9 ^u ! eye & see ! image1 b x receives an impression f x ?r\gh ! n]ve2 & ?is impression is s manag$ t ! m9d gets ! "r idea ( ! relative position ( objects4 ,( ! way 9 :i* ?is is done we "k z little z we "k ( ! nature ( ! impression itself4 #ceg4 ,s+le ,vision4--,:5ev] we see any object ) bo? eyes !re is an image =m$ 9 ea* eye1 & impressions g f bo? eyes by ! optic n]ves to ! bra94 ,& yet ) ^! two impressions !re is no d\ble vision s long z ! two eyes correspond ) ea* o!r 9 situation4 ,?is is because ! image 9 "o eye occupies ! same place on ! ret9a t ! image 9 ! o!r eye does4 ,! correspond5ce is ord9>ily p]fect1 ! two eyes turn+ always toge!r 9 ! same way1 upw>d1 d[nw>d1 or lat]ally1 )\t ! lea/ v>iation4 ,y c obs]ve ! effect ( a want ( ?is correspond5ce by press+ "o ( ! eyes 9 "s direction ) ! f+] :ile ! o!r is left free to move 9 ob$i5ce to ! muscles4 ,:5 ?is is done e object appe>s d\ble1 because its image occupies 9 "o eye a diff]5t "p ( ! ret9a f :at x does 9 ! o!r1 & s two diff]5t impressions are c>ri$ to ! bra94 ,! same ?+ occurs 9 squ9t+1 9 :i* ! action ( ! muscles ( ! two eyes does n agree4 ,ord9>ily 9 squ9t+ !re is n d\ble vision1 because ! m9d has ! habit ( disreg>d+ ! impressions t come f ! defective eye4 ,b :5 squ9t+ occurs sudd5ly f disease !re is d\ble vision1 = x takes a little "t to =m ! habit ref]r$ to4 #ceh4 ,/]eoscope4--,! images ( objects 9 ! two eyes1 ?\gh always simil>1 are n g5]ally p]fectly alike4 ,!y are s only :5 ! object pres5ts a simple surface1 z 9 ! case ( pictures4 ,:5 ! object pres5ts two or m surfaces to ! sight ! images are m or less unlike4 ,?is c be illu/rat$ 9 a v simple way4 ,hold a book up /raight be=e y\r eyes ) its back t[>d y4 ,y see ! back & bo? sides4 ,n[ if y %ut y\r "r eye y w see ) ! left ! back ( ! book & ! left side4 ,t is1 ^! two p>ts ( ! book are imag$ on ! ret9a ( ! left eye4 ,by %utt+ ! left eye x w appe> t ! image 9 ! "r is diff]5t1 = y see n[ ) ! back ! "r side ( ! book4 ,"h y h ! explanation ( ! /]eoscope4 ,9 ! "r side ( ?is in/rum5t y h ! picture ( ! object z ! object itself w\ld appe> to ! "r eye1 & 9 ! left side y h ! picture ( x z x w\ld appe> to ! left eye4 ,?us1 if a book 9 ! position allud$ to above 7 ! object1 9 ! "r picture !re %\ld be repres5t$ ! back toge!r ) ! "r side ( ! cov]1 & 9 ! left ! back ) ! left side ( ! cov]4 ,! two impressions1 c>ri$ to ! bra9 by ! optic n]ves1 give toge!r ! impression ( a solid book4 ,! same pr9ciples apply to ! repres5tation ( all solids 9 ! /]eoscope4 ,illu/ration3 ,fig4 #bdi4 #cei4 ,?aumatrope4--,ea* impression made ^u ! optic n]ve by light la/s ab\t ! eigh? "p ( a second4 ,no di/9ct impressions c be made1 !re=e1 ^u ! ret9a unless !y succe$ ea* o!r ) less rapidity ?an ?is4 ,if1 = example1 9 ! revolution ( a :eel1 eight or m spokes pass by "o po9t 9 a second1 !y c n be se5 z di/9ct spokes1 b w be m+l$ toge!r1 produc+ "o cont9u\s impression4 ,s1 too1 if a light revolve s z to describe a circle 9 an eigh? "p ( a second x w appe> to ! eye z "o unbrok5 circle ( light4 ,x is ?is cont9u\s impression on ! ret9a t makes small objects1 z ! c>s pass swiftly along1 appe> to run 9 long l9es along ) u4 ,! fact ?us develop$ is made use ( 9 ! contrivance ( a toy call$ ! ?aumatrope4 ,a picture is made on ea* side ( a circul> c>d1 & :irl+ ! c>d ar\nd v rapidly by means ( two /r+s fa/5$ to x1 ! two pictures are made to m+le toge!r z "o4 ,?us 9 ,fig4 #bdi are repres5t$ ! two sides ( su* a c>d1 on ! "o side !re be+ ! picture ( a dog1 & on ! o!r t ( a monkey4 ,:5 made to revolve rapidly ! monkey w be se5 sitt+ on ! back ( ! dog4 ,illu/ration3 ,fig4 #bej4 #cfj4 ,light ,comp\nd4--,i h ?us f> spok5 ( light z if x 7 a simple ?+4 ,b x is comp\nd4 ,e ray ( :ite light has 9 x sev5 diff]5t colors4 ,t ?is is s we c prove by tak+ a beam ( light by itself & dissect+ x1 z we may say1 or sep>at+ x into its sev5 p>ts4 ,i w %[ y h[ ?is c be done4 ,let ,d ,e1 ,fig4 #bej1 a beam ( ! sun's light1 pass ?r\gh a small op5+ 9 a %utt] into a d>k room4 ,! rays w pursue a /raight c\rse1 & if a scre5 be plac$ at ,f !y w make a spot ( :ite light4 ,b if a glass prism1 ,a ,b ,c1 be held 9 ! position repres5t$ ! rays w be refract$1 & :5 receiv$ ^u ! scre5 ,m ,n ! light w be sep>at$ into sev5 colors 9 ! ord] :i* is giv54 ,! figure ?us produc$ is call$ ! sol> spectrum4 ,obs]ve :y x is t ! colors are sep>at$4 ,x is because !y are refract$ unequally4 ,if !y 7 equally refract$ ! light ^u ! scre5 w\ld be :ite1 z be=e x 0 refract$4 ,! violet rays are mo/ refract$1 ! indigo next1 ! blue next1 etc41 & ! r$ are ! lea/ refract$ ( all4 #cfa4 ,proportion ( ! ,colors 9 ,light4--,! colors 9 light are n equal 9 am\nt4 ,if we divide ! spectrum into #cfj equal p>ts ! proportion 9 ! colors w be z foll[s3 r$1 #de2 orange1 #bg2 yell[1 #dj2 gre51 #fj2 blue1 #fj2 indigo1 #dh2 violet1 #hj4 ,"s suppose t !re are really b ?ree simple colors1 r$1 yell[1 & blue1 ! o!r colors be+ produc$ by a comb9ation ( ^!4 ,?us r$ & yell[ w toge!r =m orange1 & yell[ & blue w =m gre54 ,illu/ration3 ,fig4 #bea4 #cfb4 ,recomposition ( ,light4--,aft] decompos+ light by pass+ x ?r\gh a prism we c br+ ! sep>at$ colors toge!r aga9 & =m f !m :ite light4 ,! mann] 9 :i* ?is is done is repres5t$ 9 ,fig4 #bea4 ,! beam ( light1 aft] pass+ ?r\gh ! prism ,s ,a ,a'1 in/ead ( proce$+ 9 ! direction indicat$ by ! dott$ l9es to =m ! spectrum1 is made to pass ?r\gh ! prism ,s' ,b ,b'1 plac$ 9 a rev]s$ position1 & its rays are refract$ s z to assume _! orig9al relation1 mak+ a :ite beam1 ,m4 ,"h ! second prism c\nt]acts ! effect ( ! fir/1 because its position is exactly ! rev]se4 ,illu/ration3 ,fig4 #beb4 ,newton v ju/ly consid]$ ! decomposition & ! recomposition ( light z af=d+ ! mo/ positive pro( t :ite light conta9s all ! sev5 colors4 ,he tri$ v>i\s exp]im5ts to prove ! same ?+4 ,?us he m+l$ toge!r intimately sev5 p[d]s hav+ ! sev5 prismatic colors1 & f\nd t ! mixture _h a grayi%-:ite aspect4 ,he also pa9t$ a circul> bo>d ) ^! colors1 & f\nd t on :irl+ x s rapidly t ! colors c\ld n be di/+ui%$ ! :ole bo>d appe>$ to be :ite4 ,9 ord] to h ?is succe$ p]fectly ! proportion betwe5 ! colors mu/ be obs]v$1 z 9 ,fig4 #beb4 ,a v pretty way ( illu/rat+ ! composition ( light is to h a top pa9t$ 9 ?is way4 ,:5 ! top is :irl+ rapidly x is :ite1 b z x slack5s its motion ! sev5 colors appe>4 #cfc4 ,colors ( ,objects4--,! color ( any object dep5ds ^u ! mann] 9 :i* x reflects light4 ,?us1 if x be r$1 x reflects ! r$ rays ( ! spectrum1 absorb+ ! o!r rays2 & if x be gre51 x reflects ! gre5 rays1 etc4 ,if x reflect all ! colors toge!r1 x is :ite2 & if x reflect none1 or almo/ none1 ( ! light1 x is black4 ,y c readily see :y ! color ( an object v>ies ) ! k9d ( light t %9es ^u x4 ,if an object :i* is r$ 9 sunlight be expos$ to a yell[ light1 z a yell[ flame1 or sunlight t has pass$ ?r\gh a yell[-color$ glass or curta91 x loses its r$ color1 = !re are no r$ rays 9 ! light to be reflect$ by x into our eyes4 ,a p]son expos$ to su* a light has a dea?like pal5ess1 ! lips & sk9 los+ entirely _! r$ color4 ,?is effect c be witness$ at any "t by mix+ alcohol ) a little salt on a plate & sett+ fire to x4 ,y see 9 :at has be5 said ! reason t1 9 exam9+ goods 9 ! ev5+1 especially by c&le-light1 we f9d ! colors (t5 diff] some:at f ^? :i* !y h 9 ! day4 ,9 "s sub/ances ! colors are *angeable ) v>y+ positions1 ?\gh ! light be ! same4 ,we see ?is (t5 9 %ells & m9]als4 ,we see x also 9 "s fabrics1 z *angeable silk4 ,?is is ow+ to ! arrangem5t ( ! p>ticles1 x be+ su* z to occasion v>iety 9 reflection ) *anges ( position4 #cfd4 ,colors ( ! ,cl\ds4--,!re is no m gorge\s display ( colors ?an we sometimes see 9 ! cl\ds at morn+ or ev5+1 especially ! latt]4 ,^! colors are occasion$ simply by refractions & reflections 9 ! m9ute vesicles 7 #bhh7 ( :i* ! cl\ds are compos$4 ,h[ simple are ! mat]ials1 light1 wat]1 & air1 & yet h[ gr& & div]sifi$ are ! results6 ,illu/ration3 ,fig4 #bec4 ,illu/ration3 ,fig4 #bed4 #cfe4 ,! ,ra9b[4--,9 produc+ ! colors ( ! ra9b[ ! mat]ials are less ev5 ?an 9 produc+ ^? ( ! cl\ds4 ,!y are only light & wat]4 ,! colors come f ! reflection & refraction ( light 9 ! drops ( ! fall+ ra94 ,i w illu/rate ! mann] 9 :i* ^! reflections & refractions take place4 ,take a s+le drop1 repres5t$ 9 ,fig4 #bec4 ,let ,s be a beam f ! sun4 ,?is ent]+ ! drop at ,a1 is refract$1 & passes to ,b1 at ! f>!r side ( ! drop4 ,"h a portion ( x is lo/ by its proce$+ on 9 ! l9e ,b ,c4 ,! rema9d] is reflect$ to ,d1 & passes to ,e1 be+ refract$ z x ?us passes out into a r>] m$ium1 ! air4 ,"h y h a s+le reflection & two refractions4 ,b 9 ! second b[1 :i* is sometimes =m$1 !re are two reflections z well z two refractions1 z repres5t$ 9 ,fig4 #bed4 ,! beam ( light1 ,s1 f ! sun ent]s ! drop at ,a1 is refract$1 & passes to ,b4 ,"h a portion proce$s on 9 ! direction ,b ,c4 ,! o!r portion is reflect$ to ,d4 ,!n ?is is less5$ by a "p ( x proce$+ on 9 ! l9e ,d ,e4 ,:at rema9s is reflect$ to ,e4 ,y see "h ! reason t ! second b[ is n s bright z ! prim>y "o4 ,9 ! latt] !re is b "o reflection 9 ea* drop1 & !re=e !re is b "o po9t :]e !re is loss ( light by its pass+ on out ( ! drop2 :ile 9 ! =m] !re are two reflections1 & !re=e loss at two po9ts4 ,illu/ration3 ,fig4 #bee4 #cff4 ,circum/ances "u :i* ,ra9b[s are ,se54--,a ra9b[ is se5 :5 ! spectator /&s betwe5 ! sun & fall+ ra94 ,?is commonly c n be ! case1 except 9 ! latt] "p ( ! day4 ,x sometimes1 ?\gh v r>ely1 happ5s t a %[] passes f ! ea/ to ! we/ 9 ! morn+1 & !n a ra9b[ c be se5 9 ! we/4 ,fig4 #bee is int5d$ to %[ "u :at circum/ances a ra9b[ is se54 ,let a horizontal l9e be drawn f ,o1 ! obs]v]1 to ,p1 a po9t directly "u ! middle po9t ( ! ar*4 ,if ?is l9e 7 ext5d$ backw>d f ! obs]v] x w\ld be precisely 9 ! direction ( ! sun f him4 ,t is1 ! sun is directly opposite ! middle ( ! b[4 ,n[ if ! drop at ,a reflect a r$ ray to ! eye ( ! spectator all o!r drops simil>ly situat$ 9 ! ar* w reflect r$ rays4 ,s if ,b reflect a gre5 ray all o!r drops simil>ly situat$ w d ! same4 ,& s ( ,c1 reflect+ ! violet ray4 ,= ! sake ( cle>ness !re are only ?ree reflections repres5t$1 b ! same is true ( all ! sev5 colors4 ,9 ! second>y b[ ! arrangem5t ( ! colors is rev]s$1 ! r$ be+ at ! inn] "p ( ! b[ & ! violet at ! out] "p4 ,! d\ble reflections are manife/ 9 ! drops ,d1 ,e1 & ,f4 ,:at ,i h describ$ z tak+ place 9 a few drops takes place 9 c\ntless multitudes ( !m 9 =m+ ! b[4 ,z ! exact place ( ! ra9b[ dep5ds n only ^u ! direction ( ! rays ( ! sun b also ! position ( ! spectator1 x is cle> t no two spectators see precisely ! same b[1 = ! drops t =m x = ! "o are n ! same drops t =m x = ! o!r4 ,?is is v obvi\s if ! two be q di/ant f ea* o!r2 b x is equally true if !y are v ne> toge!r1 al?\gh 9 ?is case ! b[ = ! "o w\ld be v ne>ly co9cid5t ) ! b[ = ! o!r4 ,x is also true t ! ra9b[ ( "o mom5t is n ! ra9b[ ( ! next1 = z ! drops t reflect x are fall+ drops !re mu/ be a con/ant succession ( !m 9 any "p ( ! b[4 #cfg4 ,colors 9 ,dew-,drops & ,ice-,cry/als4--,we (t5 see some?+ v analog\s to ! ra9b[ 9 ! dew4 ,z ! sun rises1 if1 ) our backs to x1 we look at ! dew-drops1 we see all ! colors ( ! ra9b[ gli/5+ e :]e be=e u1 z if ! grass 7 fill$ ) gems ( e hue4 ,"h we h ! same refraction & reflection 9 drops ( wat]1 & ! resemblance fails only 9 ! regul>ity ( arrangem5t :i* ! ra9b[ pres5ts4 ,we see ! same ?+ also if ! gr\nd is /rew$ ) bits ( ice :i* h fall5 f ! bran*es ( ! trees1 & ! sun %9es aslant ^u !m4 #cfh4 ,heat & ,light4--,we h n yet f9i%$ our dissection ( ! beam ( light1 begun 9 #cfj4 ,9 ! beam ( light :i* is sep>at$ into ! sev5 colors !re is heat also2 & 9 ! sep>ation x is f\nd1 z repres5t$ 9 ,fig4 #bef1 t ! rays ( heat are mo/ abundant j beyond ! r$ rays1 :ile !y are v sp>+ inde$ at ! o!r end ( ! spectrum4 ,! greate/ degree ( light is at ! b\nd>y betwe5 ! orange & ! yell[ rays4 ,illu/ration3 ,fig4 #bef4 #cfi4 ,*emi/ry ( ,light & ! ,dagu]reotype4--,!re is a *emical p[] also 9 light1 produc+ e :]e1 quietly b ?or\ghly1 important effects4 ,! *emical rays are mo/ abundant at ! end ( ! spectrum opposite to t :]e ! heat-rays ab\nd4 ,x is ^! :i* d ! "w 9 ,dagu]reotyp+4 ,9 ?is art light has be5 said to be ! pa9t]2 b ?is is n /rictly true4 ,light makes ! image ( ! object1 j z x does 9 ! cam]a obscura & 9 ! eye1 b x has no p[] to fa/5 t image ^u ! metallic plate4 ,?is is done by ! *emical rays1 :i*1 l ! rays ( heat1 g along ) ! light4 ,)\t go+ into p>ticul>s1 :i* w be giv5 9 ,"p ,second1 ! process ( ,dagu]reotyp+ is simply ?is3 ,a metallic plate is s prep>$ t ! *emical rays ( light %all act ^u x s5sibly4 ,!n ! object to be tak5--a p]son or any ?+ else--be+ be=e ! in/rum5t1 a slip ( gr\nd glass is ins]t$1 & :5 ! op]ator gets ! l5s s adju/$ t a good image ( ! object is se5 on ! glass he takes ?is out & puts 9 its place ! metallic plate4 ,rays ( light com+ f ! object make ! image1 & ! *emical rays b\nd up ) ! light act ^u ! plate s z to fix ! image !re4 ,,*apt] ,,xv4 ,,electricity4 #cgj4 ,orig9 ( ! ,t]m4--,! anci5ts obs]v$ t :5 c]ta9 sub/ances 7 rubb$ toge!r s+ul> ph5om5a 7 produc$4 ,"o ( ^! sub/ances 0 amb]1 & z ! ,greek "n = ?is is 1 ! p[] :i* is ?us excit$ into action has be5 call$ electricity4 ,illu/ration3 ,fig4 #beg4 #cga4 ,attraction & ,repulsion 9 ,electricity4--,"o ( ! mo/ common effects ( electricity is attraction4 ,if we rub a tube or rod ( glass ) wool5 or silk x w attract light articles1 su* z cotton1 fea!rs1 l9t1 etc41 s t !y w adh]e to x4 ,b repulsion is also an effect ( electricity "u c]ta9 circum/ances4 ,9 ord] t ! explanation ( ^! two opposite effects may be cle> to y1 ,i w detail "s ( ! exp]im5ts :i* exhibit bo?4 ,suppose t we h a pi? ball1 ,a1 ,fig4 #beg1 susp5d$ by a silk ?read1 ,b1 f a /&1 ,c4 ,i mu/ premise t silk does n readily let electricity pass ov] x1 or is a non-conductor1 & !re=e any electricity communicat$ to ! pi? ball w rema9 !re unless some?+ be br\ght 9 contact ) x or v ne> x4 ,if n[ y rub a glass tube1 ?us excit+ electricity ^u x1 & !n br+ x ne> ! ball1 x w attract ! ball to x1 & !n 9 a mom5t repel x1 s t x w /& (f f ! tube & retreat f x if y foll[ ! ball ) ! tube4 ,:y is ?is8 ,x is suppos$ t !re is a subtile fluid on ! electrifi$ glass1 "s ( :i* passes to ! ball z x t\*es ! glass1 s t ! ball & ! glass are 9 a simil> condition4 ,b ! p>ticles ( ! fluid repel ea* o!r2 & ?is is ! reason t ! ball is repell$ f ! glass z soon z x becomes *>g$ ) a "p ( ! electricity ( ! glass4 ,= ! same reason if two pi? balls hang+ f a /&>d become electrifi$ f a glass tube or rod !y w repel ea* o!r1 = !y are 9 ! same electrical condition4 #cgb4 ,vitre\s & ,res9\s ,electricity4--,suppose n[ t y rub a rod ( seal+-wax ) wool5 or silk & hold x ne> a pi? ball :i* has be5 electrifi$ f glass4 ,x w attract ! ball4 ,! reason is t an electricity is excit$ on ! seal+-wax ( a diff]5t k9d f t :i* is excit$ on ! glass4 ,! =m] is call$ res9\s1 & ! latt] vitre\s electricity4 ,!y are suppos$ to be two fluids1 :i* h a /rong attraction = ea* o!r1 :ile1 on ! o!r h&1 ! p>ticles ( ei!r fluid are repell5t to ea* o!r4 ,x is ?is attraction betwe5 ! two fluids :i* causes 9 ! case j /at$ ! seal+-wax to attract ! ball to itself4 ,we c illu/rate ?is attraction 9 ano!r way4 ,take two pi? balls & electrify !m1 ! "o f glass & ! o!r f seal+-wax4 ,br\ght ne> toge!r !y w attract ea* o!r1 because !y h two unlike electricities4 ,?is1 y see1 is j ! rev]se ( ! effect produc$ 9 an exp]im5t cit$ at ! conclusion ( #cga1 9 :i* ! electricities 7 alike 9 ! two pi? balls4 ,aga91 if y br+ ! rubb$ seal+-wax ne> to ! ball electrifi$ f glass1 ! ball w be attract$1 & ! same effect w foll[ if y br+ ! rubb$ glass ne> to ! ball electrifi$ f seal+-wax4 #cgc4 ,frankl9's ,!ory4--,9 #cgb is develop$ ! !ory n[ commonly receiv$ 9 reg>d to electricity4 ,! !ory ( ,frankl9 0 diff]5t4 ,he suppos$ t !re is b "o electric fluid1 & t all bodies are 9 _! usual /ate *>g$ ) a c]ta9 portion ( x1 "s hav+ m ?an o!rs1 accord+ to _! capacity = electricity4 ,:ile a body is 9 its usual /ate !re is no manife/ation ( electricity4 ,! fluid is 9 a quiesc5t condition1 because its p>ticles are prev5t$ f repell+ ea* o!r by ! attraction :i* exi/s betwe5 !m & ! p>ticles ( ! sub/ance4 ,b ?is quiesc5ce c be di/urb$ by friction & o!r causes4 ,?us if a glass rod be rubb$ ) a piece ( silk1 ! natural equilibrium is di/urb$1 ! glass hav+ an excess & ! clo? a defici5cy ( electricity4 ,! glass is !re=e said to be positively & ! clo? negatively electrifi$4 ,! equilibrium c be re/or$ 9 ! case ( a positively electrifi$ body by hav+ its excess drawn (f1 & 9 ! case ( a negatively electrifi$ body by hav+ its defici5cy made up by receiv+ electricity f o!r bodies4 ,?\gh ?is !ory is disc>d$1 ! t]ms positive & negative d]iv$ f x are reta9$1 be+ appli$ to ! two fluids#f or electricities1 & !y are (t5 designat$ by ! two signs & -4 #cgd4 ,^u ,:at ! ,k9d ( ,electricity ,excit$ ,dep5ds4--,x dep5ds on :at a sub/ance is rubb$ ) :e!r vitre\s or res9\s electricity is excit$ 9 x4 ,?us smoo? glass rubb$ ) wool5 clo? or silk w be positively electrifi$2 :ile if x be rubb$ ^u ! back ( a cat x w exhibit negative or res9\s electricity4 ,s1 also1 if a res91 z gumlac or seal+-wax1 be rubb$ ) silk or wool5 clo?1 x w be *>g$ ) res9\s electricity1 b x w be *>g$ ) vitre\s or positive if x be rubb$ ) sulphur4 ,! t]ms vitre\s & res9\s are !re=e incorrect1 = !y are bas$ ^u ! idea t "o k9d ( electricity is always excit$ on glass1 :atev] ! friction may be made )1 & t ! o!r k9d is always excit$ on res9s4 ,! mo/ decid$ illu/ration ( ! incorrectness ( ^! t]ms we h 9 ! fact1 t :ile smoo? glass rubb$ ) silk or wool5 clo? becomes *>g$ ) positive 7vitre\s7 electricity1 r\gh5$ glass rubb$ ) ! same gives u negative 7res9\s7 electricity4 ,bel[ ,i give a table ( sub/ances1 any "o ( :i* has positive electricity develop$ on x :5 x is rubb$ ) any sub/ance bel[ x on ! li/1 & negative :5 rubb$ ) any sub/ance above x3 #a4 ,cat-sk94 #b4 ,poli%$ glass4 #c4 ,wool5 clo?4 #d4 ,fea!rs4 #e4 ,wood4 #f4 ,pap]4 #g4 ,silk4 #h4 ,seal+-wax4 #i4 ,amb]4 #aj4 ,r\gh5$ glass4 #aa4 ,sulphur4 #cge4 ,conductors & ,non-,conductors4--,electricity passes ov] ! surface ( "s sub/ances v readily2 :ile ov] o!rs x moves ) v great difficulty1 & !re=e v sl[ly & sp>+ly4 ,! =m] are t]m$ conductors1 & ! latt] non-conductors4 ,z 9 ! case ( heat1 s ) electricity !re are no sub/ances :i* are :olly non-conduct+4 ,! be/ ( all ! conductors are ! metals1 ^? lea/ liable to oxydation be+ ! mo/ p]fect4 ,next come *>coal1 wat]1 liv+ sub/ances1 flame1 smoke1 /eam4 ,! be/ non-conductors are gumlac & gutta-p]*a4 ,!n come amb]1 res9s1 sulphur1 glass1 silk1 wool1 hair1 fea!rs1 cotton1 pap]4 ,non-conductors are sometimes call$ insulators1 f ! ,lat9 ^w insula1 z !y s]ve to conf9e electricity )9 c]ta9 b\nds1 & prev5t its escap+4 ,?us 9 ! exp]im5ts ) pi? balls1 already cit$1 ! silk ?reads by :i* !y are susp5d$ prev5t ! electricity f escap+ f !m4 ,s ! glass knobs on :i* ! wires ( ! telegraph re/ are insulators1 prev5t+ ! electric fluid f escap+ d[n ! poles into ! gr\nd4 ,illu/ration3 ,fig4 #beh4 #cgf4 ,electricity ,always on ! ,surface4--,!re is a m>k$ diff]5ce betwe5 heat & electricity 9 ! mann] 9 :i* !y are dispos$ (4 ,heat p]vades all ! p>ticles ( sub/ances1 & 9 its conduction spreads ?r\gh !m1 :ile electricity 9 its ord9>y movem5ts op]ates altoge!r on ! surface4 ,a holl[ ball1 !re=e1 c conta9 z mu* electricity z a solid1 & a holl[ conductor ( electricity is j z effectual z a solid "o4 ,! foll[+ exp]im5t exhibits 9 a v /rik+ mann] ?is disposition ( electricity to occupy ! surface alone3 ,let a1 ,fig4 #beh1 be a metallic ball support$ by a glass /&1 b2 & let c c be metallic caps :i* w j cov] ! ball1 hav+ non-conduct+ h&les1 ei!r glass or gumlac4 ,n[1 aft] hav+ *>g$ ! ball ) electricity1 let ! caps held by ! insulat+ h&les be c>efully plac$ ov] ! ball4 ,on )draw+ !m x w be f\nd t ! electricity ( ! ball has all pass$ to ! out] surface ( ^! caps4 #cgg4 ,electrics & ,non-,electrics4--,x w be obs]v$1 on look+ ov] ! li/ ( conductors & non-conductors1 t among ! non-conductors are ^? sub/ances 9 :i* electricity is easily excit$ by friction1 su* z glass1 amb]1 silk1 etc4 ,^! 7 !re=e call$ electrics4 ,! conductors1 on ! o!r h&1 7 call$ non-electrics1 x be+ suppos$ t electricity c\ld n be excit$ ) !m4 ,b ?is has be5 f\nd n to be true4 ,= example1 if a metal be insulat$ by be+ plac$ on a pill> ( glass or ( gumlac1 s t ! electricity1 :5 excit$1 c n pass (f readily1 its g5]ation c be made manife/4 ,x is probably true t e sub/ance is m or less an electric1 x be+ difficult to make ?is manife/ 9 ! case ( conductors1 because ! electricity passes (f z fa/ z x is g5]at$4 #cgh4 ,electricity ,e ,:]e ,active4--,i h said t !re is electricity 9 all sub/ances1 ea* hav+ its own capacity = x1 b t 9 ! usual condition ( sub/ances ! electricity is 9 a /ate ( equilibrium1 & !re=e ( quiet4 ,we see ?is quiet di/urb$ :5ev] !re is a ?und]-/orm1 :5 we rub glass or silk1 or a cat's back1 or :5 we "w an electrical ma*9e4 ,b ! active /ate ( electricity is n limit$ to su* palpable demon/rations z ^!4 ,electricity is und\bt$ly 9 action e :]e & always1 al?\gh we c seldom appreciate & measure its action4 ,:]ev] !re is motion !re is a di/urbance ( ! equilibrium ( electricity1 & a consequ5t return to ?is equilibrium4 ,& ?is *ange f ! "o /ate to ! o!r mu/ be ! con/ant cause ( important *anges & op]ations 9 ! _w ar\nd u1 & 9 our own bodies4 ,let u look at "s ( ! indications ( ?is univ]sality electrical action4 ,! friction ( any electric ^u ano!r awak5s x4 ,! friction ( ! belts ^u ! drums 9 cotton factories does x q freely4 ,e /roke ( ,india rubb] ^u pap] z y erase a p5cil m>k excites electricity4 ,! bl[+ ( air ^u glass does ! same4 ,s1 also1 does ! bl[+ (f ( /eam f an eng9e4 ,electricity has be5 excit$ ev5 ^u ice by rubb+ x :5 cool$ d[n to #ac bel[ z]o4 ,exp]im5ts ^u ! air h %[n t !re is usually "s free electricity 9 x1 ! atmosph]e be+ g5]ally 9 a positive /ate1 especially :5 ! air is dry & cle>4 ,x is con/antly g5]at$ f "o s\rce & ano!r4 ,x is g5]at$ e :]e by evaporation4 ,e gu/ ( w9d1 caus+ friction ( ! p>ticles ( ! air ^u v>i\s sub/ances1 g5]ates x4 ,motion ( e k9d probably g5]ates x4 ,*emical action1 z y w see 9 ano!r "p ( ?is *apt]1 g5]ates x e :]e4 ,x is g5]at$ also 9 ! op]ations ( life1 & 9 "s animals !re are special organs--electrical batt]ies--= ! g5]ation ( ?is ag5t4 ,illu/ration3 ,fig4 #bei4 #cgi4 ,induction4--,a rem>kable influ5ce is ex]t$ by an electrifi$ body ^u ano!r body 9 its usual /ate :5 br\ght ne> x1 & ?is influ5ce is call$ induction4 ,i w illu/rate ?is by ,fig4 #bei4 ,let ,a be a metallic ball /&+ on a glass pill>1 & *>g$ ) positive electricity4 ,let ,b be a metallic cyl9d] support$ ^u two glass pill>s4 ,n[ if ,a be plac$ ne> ,b1 b n ne> en\gh = ! electric sp>k to pass f x to ,b1 x w de/roy ! equilibrium ( ! two electricties 9 ,b1 ! negative electricity be+ accumulat$ at ! end ne> ,a1 & ! positive at ! remote end4 ,?is is because ! positive electricity 9 ,a repels its l 9 ,b & attracts ! unlike fluid4 ,y obs]ve t !re is a pair ( pi? balls susp5d$ at ea* end ( ,b1 & also at ! middle4 ,! two balls at ! positive end repel ea* o!r because !y are *>g$ ) ! same electricity1 & s ) ! balls at ! negative end4 ,b ! balls hang+ f ! middle are n affect$1 because !y are on middle gr\nd betwe5 ! two electricities4 ,"h is no communication ( electricity f ,a to ,b1 b only an influ5ce ^u ! quiesc5t balanc$ electricities ( ,b4 ,accord+ly1 if ! surplus electricity ( ,a be dis*>g$ by putt+ ! h& or any good conductor ^u x ! influ5ce w cease1 ! equilibrium 9 ,b w be re/or$1 & ! pi? balls w all hang /raight d[n4 ,! same effect w be produc$ if ,a be )drawn to a di/ance f ,b1 & ! influ5ce w be r5ew$ if ,a be br\ght ne> aga94 ,illu/ration3 ,fig4 #bfj4 ,if in/ead ( "o conductor we use two1 ,b & ,c1 ,fig4 #bfj1 & h !m 9 contact1 we %all h ! negative electricity on ,b & ! positive on ,c4 ,n[ if we )draw ,c f ,b we may h ! two electricities sep>ate1 ,b be+ *>g$ ) ! negative & ,c ) ! positive4 ,illu/ration3 ,fig4 #bfa4 #chj4 ,electrical ,ma*9e4--,y are n[ prep>$ to see h[ ! common electrical ma*9e op]ates4 ,!re are two k9ds--! plate & ! cyl9drical4 ,! plate ma*9e1 ,fig4 #bfa1 has at p a l>ge plate ( glass1 & at r a rubb] :i* consi/s ( two brass plates l9$ ) lea!r :i* is /uff$1 ! pressure ( :i* ^u ! glass is regulat$ by a screw4 ,above ?is rubb] is a brass ball1 d1 & a brass *a9 connects ! rubb] & ! ball ) ! floor1 or1 9 o!r words1 ) ! e>?4 ,at c is :at is call$ ! prime conductor--a holl[ brass cyl9d] ) r\nd$ ends1 hav+ atta*$ to x a rod ) po9ts1 z se5 at a4 ,!re is a simil> rod atta*$ to x on ! o!r side ( ! glass plate4 ,! diff]5t p>ts ( ! in/rum5t are support$ on glass pill>s1 g g g1 /&+ on a wood5 plat=m4 ,! l[] "p ( ! plate is cov]$ ) a case ( silk1 :i*1 be+ a non-conductor1 prev5ts ! electricity on ! glass f be+ lo/ 9 ! air1 & also s]ves to keep ! plate free f du/4 ,! rubb] is cov]$ ) an amalgam ( t91 z9c1 & m]cury1 ?is be+ f\nd v effectual 9 excit+ electricity4 ,! op]ation ( ! ma*9e is ?is3 ,z ! plate revolves positive electricity is collect$ ^u ! glass1 & negative electricity ^u ! rubb]4 ,! =m]1 z x comes to ! po9ts at a1 goes to !m & passes on by ! rods to ! prime conductor1 :ile ! latt] passes f ! rubb] by ! *a9 to ! e>?4 ,! po9ts at a are ( great s]vice 9 collect+ ! electricity1 because ! fluid is always mu* m ready to g to po9ts ?an to conductors ( a blunt %ape4 ,illu/ration3 ,fig4 #bfb4 ,! cyl9d] ma*9e is repres5t$ 9 ,fig4 #bfb1 a a be+ a glass cyl9d]1 :i* c be turn$ rapidly by ! multiply+ :eel1 b b4 ,at c is a piece ( silk1 & on ! re> "p ( ! cyl9d] is ! rubb]4 ,at d is ! prime conductor4 #cha4 ,exp]im5ts4--,_m exp]im5ts may be tri$ ) ! electrical ma*9e4 ,i w cite a few ( !m3 ,if pi? balls be atta*$ to ! prime conductor1 z se5 9 ,fig4 #bfa1 !y w /& out f ea* o!r z soon z ! ma*9e is work$1 because !y are bo? *>g$ ) ! same k9d ( electric fluid4 ,let a small figure ) its head cov]$ ) hair be plac$ ^u ! prime conductor4 ,z soon z ! conductor becomes *>g$ ) electricity ! hair /&s out1 z repres5t$ 9 ,fig4 #bfc1 = ! same reason t ! pi? balls div]g$ 9 ! previ\s exp]im5t4 ,illu/ration3 ,fig4 #bfc4 ,fig4 #bfd4 ,s1 also1 if y place on ! conductor a figure hav+ atta*$ to x /rips ( tissue-pap]1 !y w div]ge 9 ! mann] %[n 9 ,fig1 #bfd4 ,illu/ration3 ,fig4 #bfe4 ,let a metallic plate1 a1 ,fig4 #bfe1 be susp5d$ by a *a9 to ! prime conductor1 & ano!r plate1 b1 be support$ ^u a conduct+ /&4 ,if figures ( pap] or pi? be plac$ betwe5 ^! plates z ! ma*9e is work$ !y w move ab\t briskly betwe5 ! plates1 be+ alt]nately attract$ & repell$ by ! communication ( ! electricity4 ,illu/ration3 ,fig4 #bff4 ,! exp]im5t repres5t$ 9 ,fig4 #bff is a v beautiful "o4 ,let a b be a brass rod ) an ar*1 g1 by :i* x c be susp5d$ f ! end ( ! prime conductor4 ,to ?is rod are susp5d$ ?ree bells1 ! two out] ones by *a9s1 & ! middle "o by a silk ?read2 also two clapp]s1 d & e1 by silk ?reads4 ,! middle bell has a *a91 f1 connect+ x ) ! table--t is1 ) ! e>?4 ,! op]ation ( ! app>atus is ?is3 ,z soon z ! out] bells become electrifi$ !y attract ! clapp]s4 ,^!1 on t\*+ ! bells1 receive a portion ( _! electricity1 & are repell$4 ,!y !re=e /rike aga9/ ! middle bell1 to :i* !y imp>t ! electricity :i* !y receiv$ f ! out] bells4 ,!y sw+ back aga9 !n 9 ! same /ate t !y 7 9 at fir/1 & n[ are attract$ aga9 by ! out] bells4 ,?is goes on s long z ! electricity is communicat$4 ,illu/ration3 ,fig4 #bfg4 ,let !re be pa/$ ^u a slip ( glass a cont9u\s l9e ( t9-foil1 go+ back & =?1 z repres5t$ 9 ,fig4 #bfg1 & let !re be a ball1 ,g1 connect$ ) "o end (1 ! foil4 ,! ^w light is made ^u x by cutt+ out ) a %>p knife little portions ( ! foil4 ,if n[ ) y\r f+] on "o end ( ! l9e ( foil at a1 y pres5t ! ball ,g to ! prime conductor1 ! electric fluid w run along ! :ole l5g? ( ! l9e f ,g to a4 ,9 do+ ?is ! lett]s are beautifully illum9at$1 a sp>k be+ produc$ at ea* int]ruption ( ! l9e4 ,s rapid is ! passage ( ! electricity t ! :ole appe>s to ! eye simultane\sly illum9at$4 ,illu/ration3 ,fig4 #bfh4 #chb4 ,! ,insulat+ ,/ool4--,?is consi/s ( a wood5 top1 a1 ,fig4 #bfh1 support$ by glass legs1 c c4 ,x c be made simply by bor+ holes 9 ! f\r corn]s ( a piece ( bo>d suffici5tly l>ge to admit ! necks ( bottles4 ,_m amus+ exp]im5ts c be tri$ ) ?is4 ,a p]son /&+ ^u x c be highly *>g$ ) electricity by hold+ a *a9 connect$ ) ! prime conductor4 ,! hair w rise up z repres5t$ 9 ,fig4 #bfc1 & he c give electric %ocks to o!r p]sons f any "p ( 8 body4 ,illu/ration3 ,fig4 #bfi4 #chc4 ,electricity ,dis*>g$ f ,po9ts4--,i h already1 9 giv+ an acc\nt ( ! electrical ma*9e1 spok5 ( ! read9ess ) :i* electricity is receiv$ by po9ts4 ,x is dis*>g$ f !m ) equal read9ess2 s t1 if a metallic po9t be atta*$ to ! prime conductor1 ! electricity w be c>ri$ (f into ! air ne>ly z fa/ z x is receiv$ ^u ! conductor4 ,& z x passes (f x creates a curr5t 9 ! air z x /rikes ^u x4 ,! reaction ( ! air ^u ! electrical curr5ts c be v prettily exhibit$ ) ! app>atus repres5t$ 9 ,fig4 #bfi1 :i* consi/s ( a cap1 ,a1 re/+ ^u ! po9t ( a rod1 & hav+ po9t$ wires bran*+ out f x 9 a :eel-l arrangem5t4 ,y obs]ve t ! po9ts are all b5t "o way4 ,if ?is app>atus be set upright ^u ! prime conductor1 ! :eel c be made to revolve rapidly by work+ ! ma*9e4 ,z ! reaction ( ! air aga9/ ! gases issu+ f ! rocket makes x rise1 s ! same reaction aga9/ ! electricity issu+ f ^! po9ts causes ! circul> motion4 ,if electricity be dis*>g$ f a po9t 9 a d>k5$ room x appe>s l a bru% ( light1 z repres5t$ 9 ,fig4 #bgj4 ,illu/ration3 ,fig4 #bgj4 ,illu/ration3 ,fig4 #bga4 #chd4 ,leyd5 ,j>4--,! ,leyd5 j>1 ,fig4 #bga1 is s call$ because x 0 contriv$ at ,leyd54 ,x 0 sugge/$ by an accid5tal result ( an exp]im5t tri$ !re ) ! electrical ma*9e4 ,x consi/s ( a glass j> coat$ ^u ! inside & ! outside to ne> ! top ) t9-foil1 & hav+ a metallic rod pass+ ?r\gh ! cork1 ) "o end t\*+ ! inn] coat+1 & ! o!r surm\nt$ by a brass ball or knob4 ,! j> is *>g$ by hold+ ! knob ne> to ! prime conductor :ile ! ma*9e is work$4 ,! electricity passes by ! metallic rod to ! inside coat+ ( ! j>1 & accumulates !re4 ,?is is positive electricity4 ,9 ! mean "t !re is an accumulation ( negative electricity on ! outside coat+4 ,b h[ is ?is8 ,x is by ! repulsion ( positive electricity = itself1 & its attraction = its opposite1 negative electricity4 ,z y hold ! j> 9 y\r h& positive electricity is repuls$ f its outside ?r\gh y\r arm e>?w>d1 :ile negative electricity is attract$ to x by ! positive :i* is )94 ,! two fluids get z ne> to ea* o!r z possible4 ,!y are prev5t$ f com+ actually toge!r by ! non-conduct+ quality ( ! glass4 ,if a slip ( t9-foil 7 made to connect ! inside foil ) ! out]1 !re w\ld be no accumulation ( electricity on ! inside1 = z fa/ z x pass$ f ! prime conductor to ! inside x w\ld pass out ov] ! bridge ( foil to ! outside1 & d[n y\r arm & body to ! e>?4 ,illu/ration3 ,fig4 #bgb4 ,if !re 7 no communication ( ! outside ) ! e>? ! j> w\ld n be *>g$4 ,no electricity w\ld pass to x1 because ! positive electricity :i* is on ! outside c n be driv5 (f1 & no negative electricity c be receiv$4 ,to make ?is pla91 suppose t ! j>1 a1 ,fig4 #bgb1 hav+ a b5t rod1 is susp5d$ to ! prime conductor1 b4 ,"h y h ! inside t9-foil connect$ ) ! s\rce ( positive electricity4 ,b ! outside is insulat$4 ,no electricity c pass f x or to x4 ,x has bo? positive & negative electricity1 b !y are 9 equilibrium4 ,if !re 7 a prepond]ance ( negative electricity !re1 x w\ld attract positive electricity to x z ne> z possible1 & s ! latt] w\ld ent] ! j> f ! conductor4 ,b !re is no su* prepond]ance1 & s1 ?\gh a little may ent]--a sp>k or two--!re w n be en\gh to *>ge ! j> s5sibly1 because !re is no attraction 9 t direction4 ,b br+ n[ ano!r j>1 c1 ne> to ! outside coat+ ( a1 & !re is a movem5t at once 9 ! electricities4 ,! positive electricity has a *ance n[ to pass (f f ! outside ( a to ! inside ( c1 leav+ !re=e a prepond]ance ( negative electricity on ! outside ( a1 :i* ex]ts an attractive influ5ce on ! positive electricity ( ! conductor draw+ x to ! inside ( ! j>4 ,illu/ration3 ,fig4 #bgc4 #che4 ,dis*>ge ( ! ,leyd5 ,j>4--,! j> may be dis*>g$ by mak+ a communication betwe5 ! inside & outside by means ( any conductor4 ,x may be done ) ! dis*>g+-rod 7,fig4 #bgc74 ,?is has two sl5d] metallic rods1 ) brass knobs at _! ends1 & jo9t$ at a1 s t ! knobs c be sep>at$ to diff]5t di/ances4 ,! h&le is glass1 s t z ! electricity passes ?r\gh ! rods none ( x may be communicat$ to ! h&4 ,9 dis*>g+ ! j> "o knob is plac$ ^u ! outside foil1 & ! o!r is br\ght ne> to ! knob ( ! j>4 ,! two fluids n[ ru% toge!r f _! attraction1 & 9 do+ s a bright fla% is produc$1 go+ f ! knob ( ! j> to t ( ! dis*>g+-rod1 & ) ?is a report4 ,y c y\rself be ! conductor to dis*>ge ! j>4 ,if1 hav+ "o h& ^u ! outside ( ! j>1 y br+ ! o!r ne> its knob1 ! fluids meet 9 y z !y d 9 ! dis*>g+-rod1 & a %ock w be exp]i5c$ 9 proportion to ! am\nt ( *>ge 9 ! j>4 ,any numb] ( p]sons c toge!r receive ! same %ock4 ,to d ?is !y mu/ jo9 h&s1 & ! p]son at "o end ( ! r[ mu/ t\* ! knob ( ! j> :ile ! p]son at ! o!r end has 8 h& ^u ! outside4 ,y may t\* ei!r ! knob ( ! j> or ! outside coat+ sep>ately1 & ! p[] t is 9 x rema9s quiet2 b ! mom5t t y t\* bo? x bur/s =?1 because a bridge is made ^u :i* ! two fluids c meet4 ,9 a dry air ! *>ge 9 ! j> c be reta9$ = "s "t1 ! communication betwe5 ! two electric fluids be+ v sl[ ?r\gh ! m$ium ( air4 ,x is o!rwise :5 !re is mu* moi/ure 9 ! air1 = wat] is a good conductor4 ,= ?is reason1 if y let ! moi/ure f y\r brea? come ^u ! j> betwe5 ! outside coat+ & ! rod1 ! j> w be dis*>g$ soon1 ?\gh imp]ceptibly1 ! moi/ure mak+ a m$ium ( communication betwe5 ! inn] & out] electricities4 ,illu/ration3 ,fig4 #bgd4 #chf4 ,! ,electrical ,sportsman4--,9 ?is contrivance1 ,fig4 #bgd1 ! dis*>ge ( ! ,leyd5 j> is v prettily exhibit$4 ,! j>1 c1 has a rod ) two bran*es4 ,on ! end ( "o ( ^!1 ,b1 are susp5d$ pi? balls cut 9 ! %ape ( birds4 ,on ! o!r is a knob by :i* ! j> c receive its *>ge f ! prime conductor4 ,aft] x is *>g$ x is plac$ on ! /& ) its knob1 b1 ne> ! gun1 a1 ( a metallic figure4 ,! susp5d$ birds1 y obs]ve1 /& out f ea* o!r1 because !y are *>g$ ) ! same fluid1 positive electricity1 & !re=e are repell5t4 ,n[ :5 ! *a91 e1 :i* is connect$ ) ! outside ( ! j>1 is made to t\* ! foot ( ! metallic image1 ! connection betwe5 ! inside & outside ( ! j> is e/abli%$4 ,( c\rse !re is an in/antane\s fla% betwe5 a & b1 & ! birds1 los+ _! electricity1 fall1 & hang z !y did be=e ! j> 0 *>g$4 ,illu/ration3 ,fig4 #bge4 #chg4 ,electrical ,batt]y4--,by comb9+ toge!r a numb] ( j>s1 hav+ ! insides all connect$ toge!r1 z se5 9 ,fig4 #bge1 ) metallic rods1 & ! outsides connect$ toge!r 9 a simil> mann]1 we h :at is t]m$ an electrical batt]y4 ,by su* an arrangem5t we c accumulate a l>ge am\nt ( electricity1 :i* c be dis*>g$ 9 ! same way ess5tially z 9 ! case ( ! s+le j>4 #chh4 ,light ( ,electricity4--,! light produc$ by electricity is n occasion$ by any ?+ l combu/ion4 ,x dep5ds obvi\sly ^u ! resi/ance :i* is (f]$ to its passage4 ,?us :5 ! electric fluid passes ?r\gh air f ! prime conductor to ! knob ( ! ,leyd5 j> x causes a fla% ( light1 b :5 x arrives at ! knob ! fla% ceases4 ,:at is ! reason ( ! diff]5ce8 ,9 bo? cases x has ! resi/ance ( ! air1 = :5 x comes to ! knob x passes ov] ! surface ( ! knob & rod2 b 9 ! latt] case x is s diffus$ 9 its conduction ov] ! metallic surface t x meets ) mu* less resi/ance f ! air4 ,by exp]im5ts ) ! air-pump x is f\nd t ! d5s] ! air is ! m vivid is ! sp>k2 & if electricity be pass$ ?r\gh a glass vessel f :i* ! air has be5 mo/ly exhau/$ we h ! /reams ( light se5 9 ! aurora borealis1 :i* are s /rik+ly 9 contra/ ) ! vivid fla%es ( ! lightn+4 ,9 ! exp]im5t1 #cha1 9 :i* ! ^w light is made by ! pass+ electricity1 we h a /rik+ illu/ration ( ! production ( ! sp>k by ! resi/ance ( ! air4 ,if ! foil 7 "o cont9u\s surface ! electricity w\ld be diffus$ ov] x )\t giv+ any light4 ,x is only :]e ! electric fluid has to leap ?r\gh ! air f "o portion ( foil to ano!r t ! light is se54 #chi4 ,s\nd ( ,electricity4--,! report ( electricity is a sort ( crack or snap f ! sudd5 cond5sation ( ! air by ! rapid passage ( ! fluid4 ,! roll+ ( ?und] is occasion$ by ! rev]b]ation ( ! fir/ s\nd among ! cl\ds4 ,! ne>] ! fla% is to u ! m l a crack is its fir/ s\nd z x comes to our e>s4 #cij4 ,me*anical ,injuries f ,electricity4--,:5 any great am\nt ( electricity meets 9 its passage ) any imp]fect conductor x does mu* viol5ce to x4 ,?us x r5ds wood1 scatt]s wat]1 breaks glass1 etc4 ,v>i\s exp]im5ts h be5 tri$ illu/rat+ ! mann] 9 :i* me*anical injuries result f electricity4 ,?us if x be made to pass ?r\gh a c>d or sev]al leaves closely press$ toge!r1 !re is a burr on ea* side ( su* a "* z to %[ t two =ces mov+ 9 opposite directions h made _! passage4 #cia4 ,heat ,produc$ by ,electricity4--,electricity always produces 9 its passage "s am\nt ( heat1 probably by its me*anical effect4 ,:5 x is diffus$ ov] a l>ge conduct+ surface ! heat is n suffici5t to be obs]vable2 b if x be conf9$ to ! surface ( a small wire ! heat may be suffici5t to melt or ev5 burn x4 ,v>i\s effects c be produc$ by ! heat ?us caus$ by ! passage ( electricity4 ,gunp[d] may be explod$ by x4 ,alcohol & e!r may be readily ignit$ by x1 especially ! latt]4 ,gas c sometimes be light$ by po9t+ ! f+] to an op5$ burn] aft] walk+ across ! room two or ?ree times briskly1 rubb+ ! feet ^u a ?ick c>pet4 ,illu/ration3 ,fig4 #bgf4 #cib4 ,frankl9's ,discov]y4--,x _h v e>ly be5 conjectur$ t ! electricity produc$ by ! electrical ma*9e is id5tical ) lightn+2 b x 0 res]v$ = our c\ntryman ,frankl9 to prove ! fact4 ,a tall spire :i* 0 be+ erect$ 9 ,philadelphia 9 #ageb he conceiv$ might be us$ 9 8 inve/igations1 b be=e x 0 complet$ ! sight ( a boy's kite 9 ! air sugge/$ to him ano!r plan4 ,he made a kite by /ret*+ a silk h&k]*ief ov] a frame1 & s5t x up z he saw a ?und]-%[] ris+1 8 only companion be+ 8 son4 ,hav+ rais$ ! kite1 he atta*$ to ! end ( ! hemp5 /r+ a key1 & also a silk ribbon1 by :i* he insulat$ 8 app>atus1 z se5 9 ,fig4 #bgf4 ,he n[ wat*$ ) mu* anxiety ! result4 ,a cl\d arose1 :i* he suppos$1 f its appe>ance1 0 well *>g$ ) electricity1 & yet no effect 0 se54 ,frankl9 began to despair2 b he soon saw "s loose fibres ( ! hemp5 /r+ bri/l+ up1 &1 apply+ 8 knuckle to ! key1 receiv$ j su* a sp>k z he _h (t5 receiv$ f ! conductor ( an electrical ma*9e4 ,! discov]y 0 made1 & ,frankl9 0 at once ov]come ) emotion at ! ?\ght ( ! immortality :i* x w\ld give 8 "n4 ,he felt v mu* z ,ar*im$es did :51 aft] mak+ "o ( 8 gr& discov]ies z he lay 9 a ba?1 he w5t home say+ all ! way1 6 6 ,! fame ( ! discov]y1 made 9 a mann] s simple & yet s orig9al1 spread e :]e1 & prompt$ to _m exp]im5ts by o!r philosoph]s4 ,"o1 ,pr(essor ,ri*man ( ,/4 ,pet]sburg1 fell a victim to 8 inve/igations4 ,:ile he 0 att5d+ a meet+ ( ! ,academy ( ,sci5ces he he>d ! s\nd ( di/ant ?und]1 & ha/5$ home to make "s obs]vations ) an app>atus :i* he _h erect$4 ,:ile do+ ?is a *>ge ( electricity fla%$ f ! conduct+ rod1 & pi]c+ 8 head kill$ him in/antly4 ,8 assi/ant1 :o /ood ne>1 0 /ruck d[n1 & rema9$ s5seless = "s "t1 & ! door ( ! room 0 torn f its h+es4 #cic4 ,lightn+-,rods4--,x 0 ! discov]y ( ,frankl9 :i* l$ to ! cu/om ( atta*+ lightn+-rods to build+s4 ,! object ( a lightn+-rod is to conduct any electricity 9 a cl\d t may come ov] ! build+ d[n into ! gr\nd4 ,= ?is purpose ! rod %\ld t]m9ate 9 ! air 9 po9ts1 z ^!1 z y saw 9 #chj1 s readily receive ! electric fluid4 ,! rod %\ld be sep>at$ f ! h\se by wood5 supports1 & x %\ld pass s f> into ! gr\nd z to h its end 9 ! mid/ ( cont9ual moi/ure4 ,! po9ts %\ld be gilt1 9 ord] to pres]ve f corrosion1 or !y may be made ( silv] or plat9a4 ,lightn+ is v apt to g d[n 9 *imneys1 z smoke is a v good conductor2 & !re=e x is well to h ! rods g up by *imneys1 especially if !y are to h fire 9 !m dur+ ! summ]4 ,lightn+-rods (t5 und\bt$ly are ( s]vice :5 !re is no obvi\s passage ( ! lightn+ d[n !m1 by quietly & cont9u\sly receiv+ electricity ^u _! po9ts1 & pass+ x d[n into ! e>?4 ,illu/ration3 ,fig4 #bgg4 #cid4 ,galvanic or ,voltaic ,electricity4--,?is =m or mode ( electricity ,i w b>ely notice "h1 res]v+ its full consid]ation = ,"p ,second1 :]e x appropriately belongs4 ,! hi/ory ( its discov]y is int]e/+4 ,! fir/ dawn+ ( ,galvanism is to be f\nd 9 an exp]im5t notic$ by ,sulz]1 a citiz5 ( ,b]l91 9 #agfg4 ,he /ates t if a piece ( z9c be plac$ "u ! tongue1 & a piece ( silv] ^u x1 on be+ br\ght 9 contact a metallic ta/e is p]ceiv$1 & a %ock is felt by ! tongue4 ,sulz] attribut$ ! effect to "s vibratory motion occasion$ by ! contact ( ! metals1 &1 satisfi$ ) ?is fanciful explanation1 pursu$ ! inquiry no f>!r4 ,! /atem5t excit$ b little notice until o!r facts ( a simil> "* 7 br\ght out 9 #agij by ,galvani1 pr(essor ( ,anatomy at ,bologna4 ,he obs]v$ t ! legs ( "s frogs1 :i* _h be5 obta9$ = 8 invalid wife1 7 convuls$1 :5 ne> an excit$ electrical ma*9e1 on t\*+ ! n]ves ) a knife4 ,9 contra/ ) ! example ( ,sulz]1 he 0 l$ to exam9e ! matt] fur!r4 ,he f\nd t ! effect 0 produc$ :5 no electricity 0 communicat$ f ! ma*9e1 by e/abli%+ a connection betwe5 ! n]ves & ! muscles by "s conductors4 ,= example1 :5 a /rip ( z9c 0 plac$ 9 contact ) ! n]ve :i* goes to ! l[] extremities1 & a /rip ( copp] 9 contact ) ! legs1 on br++ ! two toge!r at ! o!r end ! legs w\ld be convuls$1 be+ drawn up1 z repres5t$ 9 ,fig4 #bgg 7p4 #cjf74 ,b ,galvani did n get at ! true explanation4 ,he suppos$ ?is to be an exhibition ( animal electricity1 reg>d+ ! muscles z be+ a sort ( ,leyd5 j>1 ! n]ve be+ ! m$ium ( communication ) ! inside4 ,illu/ration3 ,fig4 #bgh4 #cie4 ,volta's ,pile4--,! obs]vations ( ,galvani awak5$ mu* int]e/ 9 all sci5tific m9ds1 & ( c\rse !re 0 mu* ( inquiry1 obs]vation1 & exp]im5t4 ,pr(essor ,volta1 ( ,pavia1 w5t a /ep f>!r ?an ,galvani t[>d ! true explanation1 9 ref]r+ ! effects to ! contact ( dissimil> metals1 & he 0 l$ by ?is view ( ! subject to con/ruct 8 pile or batt]y--call$ aft] him ! voltaic pile--! object ( :i* 0 to produce a mu* great] am\nt ( electricity ?an c\ld be obta9$ by ! contact ( only two pieces ( metal4 ,! pile is made ( circul> pieces ( copp]1 z9c1 & clo?1 ! clo? be+ moi/5$ ) salt-wat]4 ,!y are arrang$ z repres5t$ 9 ,fig4 #bgh4 ,fir/ a disk ( copp] is laid d[n1 !n ^u ?is "o ( z9c1 !n "o ( clo?1 & s on 9 ! same ord]1 ! top ( ! pile end+ 9 a plate ( z9c4 ,if y t\* "o end ( ! pile ) a moi/5$ f+] & ! o!r end ) a f+] ( ! o!r h&1 y w feel a %ock l t f a ,leyd5 j>4 ,! communication betwe5 ! two ends ( ! pile may be made by wires1 z se5 9 ! figure4 ,volta aft]w>d *ang$ ?is to ! =m ( a cup batt]y1 ! plates ( metal be+ imm]s$ 9 a s]ies ( cups 9 a mixture ( sulphuric acid & wat]4 ,!re h be5 v>i\s improvem5ts f "t to "t1 b ! arrangem5t is 9 all ! diff]5t batt]ies ess5tially ! same4 ,al?\gh ,volta accompli%$ s mu* he did n arrive at ! tru? 9 full4 ,8 contact !ory1 z x is call$1 s long receiv$ z ! true !ory1 gradually gave way to ! true explanation1 viz41 t ! electricity produc$ is ow+ to *emical action4 #cif4 ,diff]5ce ,betwe5 ,frictional & ,voltaic ,electricity4--,! electricity produc$ by ! friction ( ! electrical ma*9e is m int5se ?an t ( ! voltaic batt]y4 ,voltaic electricity1 on ! o!r h&1 is mu* m abundant1 & is m cont9u\s & la/+4 ,z x is !re=e m /eady & m easily controll$ ?an frictional electricity1 x is us$ 9 ! work+ ( ! ,telegraph4 ,,*apt] ,,xvi4 ,,magnetism4 #cig4 ,load/ones4--,x 0 discov]$ _m c5turies ago t a c]ta9 ore ( iron has ! prop]ty ( attract+ pieces ( common iron or ( /eel4 ,! fact 0 probably consid]$ at fir/ z a m]e curiosity1 & ! _w 7 sl[ to f9d out its value4 ,x is n till q rec5tly t x has be5 discov]$ t 9 magnetism we h "o ( ! great =ces ( ! e>?2 & ev5 n[ we "k b little probably ( ! real ext5t & v>iety ( its action4 ,new & important discov]ies are yet und\bt$ly to be made 9 reg>d to ! ag5cy & ! laws ( ?is my/]i\s p[]1 & its connections ) ! o!r gr& =ces ( nature4 ,! t]ms magnet & magnetism come f ! fact t ! load/one 0 fir/ f\nd ne> ,magnesia1 an anci5t city 9 ,asia ,m9or4 ,?is ore appe>s 9 consid]able masses 9 ! iron m9es ( ,sw$5 & ,norway1 & also 9 diff]5t p>ts ( ,arabia1 ,*9a1 & ,siam4 ,x has occasionally be5 f\nd 9 small quantities 9 ,engl& & 9 ?is c\ntry4 #cih4 ,attraction ( ,magnetism4--,! attraction ( ! magnet & iron = ea* o!r is exhibit$ 9 _m diff]5t ways4 ,if a magnet be br\ght ne> to a heap ( iron-fil+s or ne$les1 x w h a quantity ( !m adh]+ to x z y raise x up4 ,9 ! toy fi%es ( *ildr5 !re is fa/5$ 9 ! head a bit ( iron1 :i* occasions ! foll[+ ( ! fi%es aft] ! magnet4 ,9 ?is case y c see v pla9ly t ! ne>] ! magnet & ! iron are to ea* o!r ! /rong] is ! attraction4 ,inde$1 ! attractive influ5ce is gov]n$ by ! same law 9 reg>d to di/ance z ! common attraction ( matt] is1 viz41 x is inv]sely z ! squ>e ( ! di/ance4 ,! attraction also is mutual "h1 ! iron attract+ ! magnet z mu* z ! magnet does ! iron4 ,illu/ration3 ,fig4 #bgi4 ,illu/ration3 ,fig4 #bhj4 #cii4 ,poles ( ! ,magnet4--,e magnet has two poles4 ,x is ab\t ^! poles :]e ! *ief p[] resides4 ,= ?is reason1 if a magnet be roll$ 9 iron-fil+s1 ^! are collect$ ab\t ! ends1 z repres5t$ 9 ,fig4 #bgi4 ,!re is a dim9ution ( attraction f ! ends to ! middle l9e1 :i* is call$ ! neutral l9e4 ,^! poles are call$ nor? & s\? poles1 because if a magnet be susp5d$1 or be support$ ^u a pivot1 s t x c revolve1 x w take a nor? & s\? direction1 "o ( its ends inv>iably po9t+ t[>d ! nor?4 ,9 ,fig4 #bhj is repres5t$ a magnet support$ ^u a pivot1 ,c4 ,illu/ration3 ,fig4 #bha4 #djj4 ,magnetism by ,induction4--,! magnet 9 ex]t+ its attraction really tempor>ily makes a magnet ( :at x attracts4 ,actual contact is n necess>y to ?is result4 ,?us if a l>ge key be only br\ght v ne> to a p[]ful magnet x w support small keys1 z repres5t$ 9 ,fig4 #bha4 ,:5 ! key is remov$ away f ! magnet ! keys atta*$ to x fall4 ,y see ! analogy to ! induction ( electricity notic$ 9 #cgi4 ,z 9 ! induction ( electricity1 s "h ! two ends ( ! body 9 :i* ! influ5ce is induc$ are 9 opposite /ates4 ,if ! end ( ! magnet1 to :i* ! fir/ key is ne> or atta*$1 be ! nor? pole1 ! end ( ! key next to ! magnet is ! s\? pole1 & its f>!r end is ! nor? pole4 ,! same is ! case ) ! small key atta*$ to ! end ( ! l>ge "o4 ,& s if a nail %\ld hang f ! small key1 & a ne$le f t1 bo? ( ^! w\ld h ! same pol>ities4 ,b all ?is w\ld be rev]s$ if ! l>ge key 7 atta*$ to ! s\? pole ( ! magnet4 ,9 ?is case ! upp] end ( ea* ( ^! articles w\ld be ! nor? pole1 & its l[] end ! s\? pole4 #dja4 ,attraction & ,repulsion 9 ,magnets4--,y h se5 9 induction t 9 magnets l poles repel :ile unlike attract4 ,b ?is law c be m /rik+ly illu/rat$4 ,if a magnet be plac$ on a pivot1 z 9 ,fig4 #bhj1 & ano!r magnet be br\ght ne> x1 attraction or repulsion w be manife/$ accord+ to ! mode ( pres5tation4 ,if a nor? pole be pres5t$ to a nor? pole1 or a s\? to a s\?1 repulsion w be ! result4 ,b if a nor? pole be pres5t$ to a s\?1 or a s\? to a nor?1 !n attraction w be manife/$4 ,illu/ration3 ,fig4 #bhb4 #djb4 ,magnetic ,curves4--,! pol>ity ( magnetism causes a v s+ul> arrangem5t ( iron fil+s :5 g5tly agitat$ ^u a %eet ( pap] ov] a magnet1 z repres5t$ 9 ,figure #bhb4 ,! curves :i* y see h be5 suppos$ by "s to be occasion$ by ! escape ( "s fluid or influ5ce f ! magnet 9 ^! p>ticul> directions4 ,b !y are ow+ entirely to ! fact t ea* bit ( fil+ is pol>iz$ by ! bit next prec$+ x 9 ! r[ reckon+ f ! magnet outw>d1 ! ne>e/ "o 9 ea* r[ d]iv+ its magnetic /ate f ! magnet itself4 ,?is be+ s1 z ! *ief p[] resides 9 ! ends ( ! magnet1 x is easy to see h[ su* a disposition ( ! l9es ( magnetic fil+s is effect$4 ,^! curves may be beautifully & curi\sly v>i$ by hav+ sev]al magnets v>i\sly arrang$ "u ! pap]4 #djc4 ,artificial ,magnets4--,! p[] resid+ 9 ! load/one c be communicat$ readily1 z y h se51 to iron & /eel4 ,?\gh s(t iron takes ! magnetic influ5ce m readily ?an /eel1 x does n reta9 x z /eel does1 & ! latt] is !re=e us$ 9 mak+ artificial magnets4 ,:5 a magnet imp>ts its magnetic influ5ce x loses none ( its own p[]1 :e!r x be an orig9al load/one or an artificial magnet4 ,!re1 are _m ways ( imp>t+ magnetism p]man5tly to /eel1 b ,i w notice only two ( !m4 ,if y wi% to magnetize a b> or ne$le pass "o pole ( a magnet f "o end ( x to ! o!r a consid]able numb] ( times1 always 9 ! same direction4 ,a m effectual way is to take two magnets1 &1 plac+ ! s\? pole ( "o & ! nor? pole ( ! o!r 9 contact ov] ! middle ( ! b> or ne$le1 draw !m sl[ly & /eadily ap>t t[>d ! opposite ends4 ,?is process mu/ be repeat$ sev]al times4 ,illu/ration3 ,fig4 #bhc4 ,illu/ration3 ,fig4 #bhd4 #djd4 ,horse%oe ,magnets4--,"o ( ! mo/ common =ms ( ! magnet is ! horse%oe magnet1 ,fig4 #bhc4 ,!re is a piece ( s(t iron atta*$ to ! end ( ?is1 held !re by attraction4 ,?is is call$ ! armature4 ,s long z x is suff]$ to rema9 !re x is a magnet hav+ its two poles1 ! nor? pole be+ atta*$ to ! s\? pole - ( ! magnet :i* holds x1 :ile ! rev]se is ! case ) its s\? pole4 ,! object ( ! armature is to pres]ve ! p[] ( ! in/rum5t4 ,inde$ x is f\nd t ! ex]tion ( ! magnet's p[] n only pres]ves b actually increases x4 ,if y atta*1 !re=e1 to a magnet an armature hav+ a hook1 z se5 9 ,fig4 #bhd1 y c add to ! weight gradually f day to day1 & s consid]ably augm5t ! p[] ( ! magnet4 #dje4 ,magnetic ,ne$le4--,! magnetic ne$le is a v small magnet fix$ ^u a pivot4 ,z x po9ts nor? & s\? x is ( great use to ! m>9]4 ,! m>9]'s compass is a r\nd box ) su* a ne$le balanc$ 9 x1 & hav+ a c>d on :i* is drawn a circle divid$ into ?irty-two p>ts1 z se5 9 ,fig4 #bhe4 ,! orig9al compass 0 a rude affair1 consi/+ ( a slip ( load/one laid ^u a piece ( cork float+ 9 wat]4 ,! date & place ( its fir/ use are unkn[n4 ,illu/ration3 ,fig4 #bhe4 #djf4 ,decl9ation ( ! ,ne$le4--,! decl9ation ( ! ne$le is its deviation f a nor? & s\? l9e4 ,x is 9 comp>atively few p>ts ( ! e>?'s surface t !re is no deviation f ?is l9e to ! ea/ or ! we/4 ,true z ne$le to ! pole has become a prov]b1 & :5 x 0 fir/ utt]$ x 0 suppos$ to be f\nd$ 9 /rict tru?2 b mod]n inve/igation has %[n n only t ! ne$le v>ies 9 its po9t+ 9 diff]5t localities1 b t x v>ies to "s little degree 9 its v>iations4 ,! decl9ation ( ! ne$le 0 fir/ obs]v$ by ,columbus 9 8 fir/ voyage ( discov]y1 & x occasion$ great al>m among ! sailors1 :o1 z ,irv+ /ates1 ?\ght ! laws ( nature 7 *ang+1 & t ! compass 0 ab\t to lose its my/]i\s p[]4 ,not)/&+ ^! & o!r obs]vations ( a simil> "*1 no great acc\nt 0 made ( ! decl9ation ( ! ne$le till ! middle ( ! sev5te5? c5tury4 ,b s9ce t "t ext5sive records ( its decl9ations at diff]5t localities h be5 made1 & tables & *>ts h be5 con/ruct$ exhibit+ !m4 ,^! decl9ations are n con/ant1 b v>y some:at e day1 f ! influ5ce1 x is suppos$1 ( ! sun ^u ! e>?4 #djg4 ,dip ( ! ,ne$le4--,x is f\nd t 9 mo/ p>ts ( ! e>?1 if a ne$le be balanc$ be=e x is magnetiz$1 & !n be susp5d$ f ! same po9t1 x w n be balanc$1 b "o end w dip d[nw>d4 ,?is fact 0 discov]$ by ,norman1 a ,london optician1 9 #aegf4 ,he f\nd t ! dip at ,london 0 t[>d ! nor? at an angle ( #gb4 ,9 pursu+ ! inve/igation ( ?is ph5om5on x 0 f\nd t go+ f ! nor? t[>d ! equator ! dip con/antly less5$1 until a po9t 0 rea*$ :]e ! ne$le 0 horizontal4 ,!n1 on go+ s\? ( ?is1 a rev]se dip occurr$1 t ( ! s\? pole1 & ! f>!r s\? ! ne$le 0 c>ri$ ! great] 0 ! dip4 ,9 ! nor?1 ,capta9 ,ross 9 #ahcb came to a locality nor? ( ,hudson's ,bay1 9 lat4 #gj #e ,n41 long4 #if #de ,w41 :]e ! magnetic ne$le1 freely susp5d$1 0 9 a v]tical l9e4 ,no su* locality has yet be5 discov]$ t[>d ! s\? pole4 #djh4 ,! ,e>? a ,magnet4--,y c readily see1 f all t has be5 /at$ 9 reg>d to ! magnetic ne$le1 t ! e>? is a magnet1 or has t cov]$ up 9 x :i* 9 "s way acts z su*4 ,! dip ( ! ne$le %[s t ! two poles ( ?is magnet are some:]e ne> ! nor? & s\? poles ( ! e>?4 ,! locality :i* ,capta9 ,ross f\nd mu/ be ne> ! nor? pole ( ! magnet 9 t qu>t] ( ! _w4 ,! v]tical position ( ! ne$le !re is analog\s to ! /raight l9es ( iron fil+s :i* y see 9 ,fig4 #bhb1 ne> ! poles ( ! magnet2 & x is easy also to trace ! analogy betwe5 ! dip ( ! ne$le at diff]5t di/ances f :at is call$ ! magnetic equator ( ! e>?1 :]e ! ne$le is horizontal1 & ! curves :i* y see ext5d+ f pole to pole4 ,! diff]5t decl9ations ( ! ne$le & ! diff]5t int5sities ( ! magnetic =ce 9 diff]5t localities correspond+ 9 latitude %[ t ! magnet 9 ! e>?1 if !re be "o1 is irregul> 9 %ape1 or 9 "s way has its p[] v>i$ mu* 9 diff]$ p>ts ( ! e>?'s cru/4 #dji4 ,! ,e>? z a ,magnetiz]4--,z ! e>? is really a magnet1 x might be expect$ to imp>t magnetism by induction z o!r magnets d4 ,& ?is is f\nd to be ! fact4 ,if y hold a b> ( s(t iron 9 ! direction ( ! dip ( ! ne$le x becomes a magnet1 its l[] end be+ ! nor? pole1 & its upp] ! s\?4 ,t ?is is s c be asc]ta9$ by br++ a small magnetic ne$le ne> ea* end4 ,no effect ( ?is k9d is produc$ :5 ! b> is held horizontally ea/ & we/4 ,lightn+-rods1 pok]s1 upright iron b>s 9 f5ces1 etc41 are (t5 f\nd to be magnetiz$ because !y h cont9u$ s long ne>ly 9 ! requir$ position = magnetization4 ,:5 a b> ( iron has be5 magnetiz$ 9 ! mann] indicat$1 its magnetism may sometimes be fix$ by giv+ x a /roke ) a hamm]4 ,x is a curi\s b inexplicable fact t ?is vibration ( ! p>ticles ( ! iron %\ld h ?is effect4 ,b ?\gh su* vibration helps to imp>t magnetism1 x is n at all favorable to its ret5tion1 = magnets are always injur$ by bl[s or falls1 or inde$ any rude treatm5t4 ,= ?is reason c>e is requisite 9 remov+ an armature f a magnet4 ,if pull$ (f abruptly ! p[] ( ! magnet is less5$4 #daj4 ,magnetism 9 ,o!r ,sub/ances besides ,iron4--,x 0 =m]ly suppos$ t magnetism 0 conf9$ to f]rug9\s sub/ances1 b ?is has be5 f\nd n to be true4 ,v>i\s m9]als are magnetic1 especially :5 !y h be5 heat$1 also "s ( ! preci\s /ones1 & ev5 silica1 :i* ent]s s l>gely into "s ( ! rocks ( ! e>?4 ,& x is suppos$ by "s t future inve/igations w %[ t ! influ5ce ( magnetism is z ext5sive 9 ! e>? z t ( electricity4 #daa4 ,9 :at ,magnetism is ,l ,electricity4--,magnetism is l electricity 9 sev]al p>ticul>s3 #a4 ,its p[] is on ! surface ( bodies4 #b4 ,x is ( two k9ds1 nor? & s\?1 or boreal & au/ral1 comp>+ ) ! positive & negative electricities4 #c4 ,! same rule ( attraction & repulsion applies to bo?2 viz41 l repel & unlike attract4 #d4 ,z electricity c be communicat$ by induction1 s c magnetism4 #dab4 ,9 :at ,magnetism is ,unlike ,electricity4--,! circum/ances 9 :i* magnetism is unlike electricity are *iefly ^!3 #a4 ,! obvi\s manife/ations ( magnetism are to a great ext5t conf9$ to "o class ( sub/ances1 ! f]rug9\s1 & to b a portion ( !m2 :ile electricity makes its manife/ations 9 connection ) all k9ds ( sub/ances4 #b4 ,magnetism is nev] transf]r$ z electricity is f "o body to ano!r1 b a body ga9s r ?an loses 9 imp>t+ magnetic p[] to o!r bodies4 #c4 ,! two magnetisms1 ! boreal & au/ral1 c n be obta9$ sep>ately z ! two electricities c4 ,if a magnet be brok5 9 two1 ea* piece w h 9 x ! two magnetisms & ! two poles z ! :ole did4 ,?is is 9 entire contra/ ) ! electrical exp]im5t notic$ 9 ! la/ ( #cgi4 #d4 ,!re are no non-conductors to int]rupt magnetic influ5ce4 ,if 9 ! exp]im5ts 9 #cgi a plate ( glass or res9 7 int]pos$ betwe5 ,a & ,b1 ! influ5ce w\ld cease1 b x w\ld h no effect on ! induction ( magnetism if int]pos$ betwe5 a magnet & a bit ( /eel or iron4 #dac4 ,electro-,magnetism4--,?\gh electricity & magnetism diff] s mu* f ea* o!r1 yet !y h intimate relations1 & x is n[ ! g5]al op9ion among sci5tific m5 t !y are m]ely diff]5t modes ( ! same p[]4 ,magnetism c produce electricity1 & electricity c produce magnetism4 ,! fir/ discov]y ( facts reveal+ ?is connection 0 made by ,pr(essor ,o]/$ ( ,cop5hag5 9 #ahai4 ,s9ce t "t electro-magnetism1 or ! production ( magnetism by electricity1 has be5 a prom95t subject ( obs]vation & exp]im5t4 ,o]/$'s fir/ obs]vation 0 t a curr5t ( electricity pass+ ov] a wire ne> a magnetic ne$le affect$ ! position ( ! ne$le4 ,he f\nd also t iron fil+s w\ld adh]e to a wire ov] :i* a curr5t ( electricity is pass+1 j z !y d to a magnet1 dropp+ (f1 h[ev]1 z soon z ! curr5t ceases to pass4 ,su* facts l$ to a great v>iety ( inve/igations & arrangem5ts ( app>atus by ,o]/$ & o!rs4 ,illu/ration3 ,fig4 #bhf4 #dad4 ,electro-,magnets4--,! mo/ p[]ful electro-magnets are made by b5d+ a ?ick cyl9drical b> ( s(t iron into ! =m ( a horse%oe1 ,a ,b1 ,fig4 #bhf1 & coil+ ar\nd x a copp] wire4 ,! wire mu/ be insulat$ by be+ w\nd ) "s non-conduct+ mat]ial1 z silk1 s t ! electric curr5t may pass ?r\gh ! :ole l5g? ( ! wire4 ,) ! in/rum5t ?us prep>$1 if ! two ends ( ! wire be connect$ ) ! poles ( a voltaic batt]y :i* is 9 action1 ! b> w be magnetiz$1 & w hold up a heavy weight s long z ! electric curr5t is pass+ ?r\gh ! wire4 ,:5ev] ! curr5t is cut (f by disconnect+ ! wires ! weight w fall4 ,illu/ration3 ,fig4 #bhg4 ,electro-magnets h be5 made 9 ?is way hav+ su* p[] z to su/a9 a weight ( f\r ?\s& p\nds4 ,9 ,fig4 #bhg we h repres5t$ an app>atus :i* exhibits electro-magnetism v prettily4 ,! s(t iron1 y see1 is 9 two pieces :i* :5 put toge!r =m a r+1 d1 & ea* piece has a h&le4 ,if ! pieces be put toge!r ) ! coil1 c1 9 ! position repres5t$1 on connect+ ! wires ,p & ,n ) a batt]y 9 action1 ! adhesion is s /rong z to resi/ a great =ce2 b z soon z ! connection is brok5 ! pieces come ap>t at once4 ,illu/ration3 ,fig4 #bhh4 #dae4 ,electric ,telegraph4--,! mo/ rem>kable & useful application ( electro-magnetism we h 9 ! electric telegraph4 ,z be=e /at$1 voltaic electricity is us$4 ,?is is g5]at$ at ! place f :i* ! message is s5t1 & passes ov] ! wire to ! place :]e ! message is receiv$4 ,!re x acts ^u s(t iron by pass+ ?r\gh coil$ wire1 produc+ ! modifi$ p[] call$ electro-magnetism4 ,i w make all ?is pla9 to y by describ+ ! ma*9e us$ 9 ,morse's ,telegraph1 ,fig4 #bhh4 ,w ,w are ! wires :i* connect ) ! /ation f :i* ! message is to be receiv$1 & ^! connect ) ! copp] wire coil$ r\nd ! horse%oe ( s(t iron1 m m4 ,above ! magnet is a lev]1 a l1 :i* works on a fulcrum at d4 ,"o end ( ?is lev] has a /eel po9t1 s1 atta*$ to x4 ,at c is an arrangem5t ( :eel-"w1 ! object ( :i* is to pass along regul>ly a slip ( pap]1 p1 9 ! direction ( ! arr[s4 ,obs]ve n[ h[ ! app>atus works4 ,:5 ! electric curr5t passes ?r\gh ! coil$ copp] wire x makes a magnet ( ! iron1 m m4 ,! lev]1 a l1 is !re=e attract$ at ! end1 a1 d[nw>d4 ,( c\rse ! end1 l1 moves upw>d1 br++ ! /eel po9t1 s1 aga9/ ! pap]1 :]e x makes a m>k4 ,! l5g? ( ?is m>k dep5ds ^u ! l5g? ( "t ! electricity is all[$ to pass along ! coil$ wire1 = ! mom5t t x is %ut (f m m ceases to be magnetic1 ! keep]1 a1 be+ no long] attract$1 moves upw>d1 & ! o!r end1 l1 ( ! lev] moves d[nw>d1 tak+ ! po9t1 s1 f ! pap]4 ,illu/ration3 ,fig4 #bhi4 ,9 ord] to make ! m>ks on ! pap] ( diff]5t l5g?s1 !re is a contrivance = regulat+ ! l5g? ( "t t ! curr5t %all pass ?r\gh ! coil$ wire4 ,?is contrivance1 call$ ! signal key is repres5t$ 9 ,fig4 #bhi4 ,n & ,p are two /rips ( brass connect$ ) ! two wires ,r & ,m1 ( :i* ,m comes f ! batt]y4 ,! end ( ! /rip ,n is rais$ a little above ! end ( ,p4 ,s long z !y d n t\* ! circuit is n complete1 & no electricity passes4 ,b if ! op]ator press ,n d[n ^u ,p1 ! circuit is e/abli%$1 & ! electricity passes to ! /ation ) :i* he is 9 communication1 & !re acts ^u ! app>atus se5 9 ,fig4 #bhg4 ,n[ ! long] ! f+] presses d[n ,n ^u ,p ! long] w be ! m>k on ! pap] at ! di/ant /ation4 ,an op]ator !n at ,new ,york1 = example1 controls by ?is key ! l5g? ( ! m>ks made on ! pap] 9 ,new ,hav5 or any o!r place ) :i* he is communicat+4 ,y c see !n v readily h[ a telegraphic alphabet c be con/ruct$ by comb9ations ( m>ks ( diff]5t l5g?s agre$ ^u to repres5t diff]5t lett]s & num]als4 ,i give ! alphabet us$ 9 connection ) ,morse's ,telegraph3 ,a -- ---- ,b ---- -- -- -- ,c -- -- -- ,d ---- -- -- ,e -- ,f -- ---- -- ,g ---- ---- -- ,h -- -- -- -- ,i -- -- ,j ---- -- ---- -- ,k ---- -- ---- ,l -------- ,m ---- ---- ,n ---- -- ,o -- -- ,p -- -- -- -- -- ,q -- -- ---- -- ,r -- -- -- ,s -- -- -- ,t ---- ,u -- -- ---- ,v -- -- -- ---- ,w -- ---- ---- ,x -- ---- -- -- ,y -- -- -- -- ,z -- -- -- -- ,num]als4 #a -- ---- ---- -- #b -- -- ---- -- -- #c -- -- -- ---- -- #d -- -- -- -- ---- #e ---- ---- ---- #f -- -- -- -- -- -- #g ---- ---- -- -- #h ---- -- -- -- -- #i ---- -- -- ---- #j --------------- ,"o ( ! mo/ s+ul> & int]e/+ ?+s 9 ! op]ation ( ! telegraph rema9s to be notic$4 ,9 ord] to h ! electricity "w x is necess>y to h ! connection betwe5 ! poles ( ! batt]y at ! po9t :]e ! effect is to be produc$4 ,y see ?is 9 ! exp]im5ts repres5t$ 9 ,figs4 #bhf & #bhg4 ,! same is true ( ! electro-magnet ( ! telegraph4 ,?is be+ s1 x 0 ?\ght at fir/ t x 0 necess>y to h two wires connect+ two communicat+ /ations2 b x 0 f\nd t only "o wire 0 ne$$1 ! e>? itself answ]+ ! same purpose z ano!r wire4 ,to make ! communication ?r\gh ! e>? effectual1 !re is at ea* /ation a plate ( metal1 hav+ a surface ( sev]al squ>e feet1 buri$ 9 ! gr\nd1 ) a wire runn+ up to ! ma*9e4 ,,que/ions4 ,tea*]s diff] mu* 9 _! plans ( conduct+ recitations4 ,"s are v m9ute 9 _! que/ions2 :ile o!rs g to ! o!r extreme1 & m]ely "n ! topics1 ! pupils be+ expect$ to give 9 full :at is said ^u !m4 ,nei!r ( ^! plans %\ld be adopt$ exclusively1 b ! mode ( recitation %\ld be mu* v>i$ f "t to "t4 ,?is v>iety is some:at aim$ at 9 ! que/ions :i* ,i h prep>$1 ?\gh 9 no case are ! que/ions z m9ute z !y %\ld occasionally be made by ! tea*]4 ,! numb]s ref] to ! pages4 ,x w\ld be well to h ! pupils draw _m ( ! figures ^u ! blackbo>d1 & !n recite f !m4 ,by draw+ ! simple/ figures fir/ suffici5t skill may be acquir$ to enable ! pupil to draw ^? :i* are q difficult4 ,,*apt] ,i4 #ac4 ,:at is said ( ! di/9ction betwe5 matt] & _s8 ,:at ( ,bi%op ,b]keley's ideas8 ,:at ( ,hume's8 #ad4 ,:at is ! orig9 ( ! ^w _s8 ,:at is ! relation ( ! s5ses to ! _s8 ,:at is said ( ! effects ( matt] on ! s5ses8 ,:at are ! =ms ( matt]8 #ae4 ,illu/rate ! diff]5ce betwe5 ela/ic & non-ela/ic fluids4 ,:at is said ( ! union ( ! p>ticles ( a solid8 ,give ! diff]5ce not$ betwe5 diff]5t solids4 ,h[ does a liquid diff] f a solid8 ,give p>ticul>ly :at is said ( wat]4 #af4 ,:at is said ( ! p>ticles ( gase\s sub/ances8 ,:at ( ! atmosph]e8 ,:at ( ! vapor 9 x8 ,:at is said ( ! ent]+ ( liquids & gases into int]/ices8 ,:at ( ! m+l+ ( gases ) liquids8 ,give ! illu/ration 9 reg>d to fi%es4 #ag4 ,:at is said ( ! solution ( solids 9 liquids8 ,:at ( ! evaporation ( wat] 9 ! air8 ,illu/rate ! influ5ce ( heat on ! =ms ( matt]4 ,:at is said ( ! !rmomet]8 ,:at ( m]cury1 wat]1 & iron 9 relation to ! liquid /ate8 ,:at is said ( our k ( matt]8 #ah4 ,:at 0 ! supposition ( ,newton ab\t ! composition ( matt]8 ,:at is said ( ! *anges ( matt]8 ,:at are ! impond]able ag5ts1 & :y are !y s call$8 ,,*apt] ,,ii4 #ai4 ,:at is said ( v>iety 9 ! prop]ties ( matt]8 ,:at ( ! divisibility ( matt]8 #bj4 ,:at is said ( gold-leaf1 & ( ! wire ( gold-lace8 ,:at ( ! soap-bubble8 ,:at ( ! ?read ( ! silk-worm1 & ( ! web ( ! spid]8 ,:at ( solution ( blue vitriol8 ,:at ( odors8 #ba4 ,:at is said ( ! du/ ( ! puff-ball8 ,:at ( poll58 ,:at ( ! du/ rubb$ f a mo?'s w+8 ,:at ( guano8 ,:at ( ! glaz+ ( visit+-c>ds8 ,:at ( ! m9ut5ess ( "s animals8 #bb4 ,:at is said ( ! ,deity 9 relation to m9ute animals8 ,:at is said ( sub/ances call$ por\s8 ,:at ( ^? 9 :i* !re are no pores app>5t8 ,:at pro( is !re t all sub/ances h spaces 9 !m8 #bc4 ,:at is said ( ! am\nt ( space 9 gases & vapors8 ,give ! /atem5t 9 reg>d to /eam4 ,:at is said ( solutions ( solids 9 fluids8 ,:at ( evaporation8 ,:at ( ! diffusion ( odors 9 ! air8 #bd4 ,:at is ! relation ( heat to space 9 matt]8 ,^u :at d d5sity & r>ity dep5d8 ,expla9 t5acity4 ,:at is said ( ?is prop]ty 9 gases & liquids8 #be4 ,h[ is ! comp>ative t5acity ( sub/ances asc]ta9$8 ,give ! comp>ative t5acity ( v>i\s sub/ances4 ,:at animal sub/ances h great t5acity8 ,:at is said ( ! value ( t5aci\s sub/ances8 #bf4 ,:at is said ( h>dness8 ,:at ( flexibility & brittl5ess8 #bg4 ,give examples ( flexible & brittle /eel4 ,expla9 ! actual diff]5ce betwe5 !m4 ,expla9 ! temp]+ ( /eel4 #bh4 ,:at is said ( ! anneal+ ( glass8 ,:at ( ,pr9ce ,rup]t's drops8 ,:at metals are ! mo/ malleable8 ,:at ! mo/ ductile8 #bi4 ,:at is said ( ! ductility ( melt$ glass8 ,:at ( ! *ange ( position ( p>ticles 9 mak+ plates & wires ( metals8 ,:at ( weld+8 ,:at is said ( compressibility8 ,:at ( ! incompressiblity ( liquids8 #cj4 ,:at influ5ce has heat on ! bulk ( liquids8 ,illu/rate by ! !rmomet]4 ,:at is said ( ! compressibility ( gases8 ,h[ does ela/icity op]ate 9 ! case ( ! ,india-rubb] ball8 #ca4 ,give ! illu/ration 9 reg>d to jump+4 ,/ate ! exp]im5t ) ! ivory ball4 ,:at is said ( ! movem5ts ( p>ticles on ea* o!r 9 ela/ic sub/ances8 ,:at ( ! degrees ( ela/icity 9 diff]5t sub/ances8 #cb4 ,:at is ! def9ition ( ela/icity8 ,:at is said ( ! usefulness ( ! v>iety ( prop]ties 9 matt]8 ,,*apt] ,,iii4 #cc4 ,:at is meant by ext5sion z a prop]ty ( matt]8 ,illu/rate ! fact t x is an ess5tial quality4 ,:at is said ( x 9 ref]5ce to air8 #cd4 ,does matt] ev] p5etrate matt]8 ,give ! illu/ration repres5t$ 9 ,fig4 #f4 ,give t repres5t$ 9 ,fig4 #g4 #ce4 ,/ate ! arrangem5t ( ! div+-bell4 ,give ! comp>ison betwe5 bullets & ne$les 9 relation to p5etration4 ,:at is said ( solution8 ,:at ( odors8 #cf4 ,:at is ! prop]ty ( matt] call$ in]tia8 ,give illu/rations ( x4 ,illu/rate ! fact t matt] has no p[] to /op its own motion4 ,:at is ! reason t ! popul> notion is t matt] is m incl9$ to re/ ?an to motion8 #cg4 ,:at is said ( p]petual motion8 ,:y is x n true ( divisibility t x is an ess5tial prop]ty ( matt]8 ,:at is said ( weight8 ,,*apt] ,,iv4 #ch4 ,:at is said ( ! nature ( attraction8 ,:at 0 ,newton's idea ( x8 #ci4 ,:at is said ( attraction 9 solids8 ,:at ( its diff]5t modes ( action8 ,:at is ! diff]5ce 9 attraction 9 ! case ( /eel & ( wat]8 ,:at is said ( ! fre5ess ) :i* p>ticles ( a fluid move among ea* o!r8 #dj4 ,expla9 ,fig4 #i4 ,expla9 ,fig4 #aj4 #da4 ,give ! diff]5ce betwe5 m]cury & wat] 9 reg>d to ! globul> =m4 ,:at if said ( drops ( wat] on leaves8 #db4 ,:at is said ( oil 9 ref]5ce to attraction8 ,describe & expla9 ! manufacture ( %ot4 ,:at is said ( ! globul> =m ( ! e>? & ! heav5ly bodies8 #dc4 ,:at is said ( cry/allization8 ,/ate ! examples cit$4 ,:at is said ( ! cry/allization ( wat]8 ,give & expla9 ! example ( sudd5 cry/allization4 #dd4 ,:at is said ( fro/-"w8 ,:at ( sn[8 #de4 ,:at is /at$ 9 reg>d to ! sn[-cry/als ( ! arctic regions8 ,:at is said ( ord] 9 nature8 ,:y c y n make ! surfaces ( brok5 glass adh]e8 #df4 ,expla9 ! cem5t+ ( glass4 ,:at is said ( ! adhesion ( pieces ( ,india-rubb]8 ,describe & expla9 ! exp]im5t ) bullets & ) balls ( lead4 ,h[ may silv] & gold be made to adh]e to iron8 ,:at is said ( ! adhesion ( t9 & lead8 ,:at ( ! adhesion ( panes ( glass8 #dg4 ,^u :at does ! /r5g? ( adhesion dep5d8 ,illu/rate ! ag5cy ( heat 9 promot+ adhesion4 ,give famili> examples ( attraction betwe5 solids & liquids4 ,expla9 ! exp]im5t repres5t$ 9 ,fig4 #ae4 #dh4 ,:at is said ( /ems 9 /agnant wat]8 ,expla9 ,figs4 #af1 #ag1 & #ah4 #di4 ,expla9 ,fig4 #ai4 ,expla9 ! rise ( fluids 9 tubes by ,fig4 #bj4 #ej4 ,:at is meant by capill>y attraction8 ,give famili> examples ( ! ris+ ( liquids 9 int]/ices4 #ea4 ,describe & expla9 ! process ( gett+ out mill/ones4 ,h[ does a blott] diff] f writ+-pap]8 ,,*apt] ,v4 #ea4 ,:at is ! attraction ( cohesion8 ,give examples ( attraction betwe5 masses or portions ( matt]4 #eb4 ,expla9 ! fall+ ( a /one to ! gr\nd4 ,illu/rate ! fact t attraction is mutual4 ,give ! illu/ration ( ! %ip & boat 9 full4 #ec4 ,illu/rate ! proportion betwe5 ! mutual motions ( ! attract+ bodies4 ,give ! calculation 9 reg>d to ! motion ( ! e>? 9 attract+ small] bodies4 #ed4 ,:at is said ( ! univ]sality ( attraction8 ,expla9 ! tides4 ,:at is said ( ! attraction ( ! moon = ! l&8 ,:at is ! diff]5ce betwe5 ! attraction ( cohesion & ! attraction ( gravitation8 ,:y is ! ^w gravitation ?us us$8 ,:at is t]re/rial gravitation8 #ee4 ,expla9 ,fig4 #bb4 ,expla9 ,fig4 #bc4 ,:at is said ( sub/ances susp5d$ 9 diff]5t p>ts ( ! e>?8 #ef4 ,expla9 ,fig4 #bd4 ,:at is said ( plumb-l9es8 #eg4 ,:at is weight8 ,give ! comp>ison 9 reg>d to muscul> =ce4 ,:at is said ( scales & weights8 ,:at ( us+ spr+s 9 weigh+8 #eh4 ,:at w\ld be ! effect on weight if ! d5sity ( ! e>? 7 increas$8 ,9 :at ways w\ld ?is be p]ceiv$8 ,:at is said ( ! v>iation ( weight ) di/ance8 #ei4 ,:at is said ( ! diff]5ce ( weight on m\nta9s & 9 valleys8 ,:at ( weight 9 ! moon8 ,:at ( x 9 ! sun8 ,:at is said ( ! diff]5t modes ( attraction8 #fj4 ,%[ :y attraction ( cohesion seems to be diff]5t f gravitation4 ,%[ n[ t x is really n diff]5t4 ,:at is said ( ! exp]im5t ) ! two bullets m5tion$ 9 #ff8 ,:at ( ! adhesion ( liquids to solid sub/ances8 #fa4 ,:at is said ( ! v>i\s results ( attraction8 ,expla9 fully :y y c p\r wat] f a pit*] easi] ?an f a tumbl]4 #fb4 ,expla9 ! op]ation ( ! quick movem5t by :i* y prev5t wat] f runn+ d[n ! side ( a tumbl] 9 p\r+ x out4 ,:at is said ( dropp+ f a vial8 ,h[ is ! size ( drops limit$8 ,:at is said ( ! movem5ts ( drops on w9d[ panes8 #fc4 ,:y are ! drops ( diff]5t liquids diff]5t 9 size8 ,give ! illu/ration ab\t *alk4 ,give t ab\t du/4 ,expla9 ,figs4 #bg & #bh4 #fd4 ,expla9 ,fig4 #bi4 ,:at is said ( ! diff]5ce 9 size betwe5 wat] & l& animals8 #fe4 ,give ! illu/ration 9 reg>d to trees4 ,give t 9 reg>d to m\nta9s4 ,:at is said ( ! m\nta9s ( ! moon8 ,:at ( ^? ( ,jupit]8 ,give ! illu/rations 9 #ic ( transgression ( ! pr9ciples :i* h be5 elucidat$4 #ff4 ,:at is ! diff]5ce betwe5 ! attraction treat$ ( 9 natural philosophy & *emical attraction8 ,,*apt] ,,vi4 #fg4 ,%[ :at we mean by ! c5tre ( gravity by ,figs4 #cj1 #ca1 & #cb4 #fh4 ,give ! def9ition ( c5tre ( gravity1 & expla9 x4 ,:at is %[n by ,fig4 #cc8 #fi4 ,h[ c we f9d ! c5tre ( gravity ( a body8 ,:at is said ( scales & /eely>ds8 #gj4 ,/ate :at is repres5t$ by ,fig4 #ch4 ,illu/rate ! fact t ! c5tre ( gravity seeks always ! l[e/ po9t4 #ga4 ,give ! illu/rations ( ! rock+-horse1 ! sw+1 etc4 ,:at is said ( ! ,laggan /ones8 ,:y does an egg lie on its side8 #gb4 ,give ! illu/rations f toys 9 #aja4 ,give ! illu/rations 9 #ajb4 #gc4 ,^u :at two ?+s does ! /ability ( a body dep5d8 #gd4 ,:at is said ( ! /ability ( bodies ^: %apes are repres5t$ 9 ,figs4 #dh1 #di1 & #ej8 ,:at ( t ( a r\nd ball8 ,:y is ! pyramid ! firme/ ( all /ructures8 #ge4 ,:at is ! relation ( upright position to /ability8 ,:at is /at$ ( ! t[] ( ,pisa8 #gf4 ,give ! famili> illu/rations 9 #aje4 ,:at is said ( ! support ( ! c5tre ( gravity 9 animals8 #gg4 ,:at is said ( ! skill ex]cis$ 9 walk+8 ,:at ( ! mode ( walk+ 9 a *ild8 ,:at ( ! motions ( ! c5tre ( gravity 9 walk+8 #gh4 ,:at is said ( ! walk+ ( a man ) wood5 legs8 ,illu/rate ! managem5t ( ! c5tre ( gravity 9 diff]5t attitudes4 ,describe & expla9 ! way 9 :i* "o rises f a *air4 #gi4 ,/ate & expla9 ! wag] case4 ,:at is said ( un/able equilibrium8 ,give illu/rations4 ,,*apt] ,,vii4 #hj4 ,:at is said ( ! ph5om5a treat$ ( 9 ,hydro/atics8 ,:at are ! two *>act]i/ics ( liquids8 ,:at makes a liquid h a level surface8 ,give ! explanation4 ,give ! comp>ison ( ! %ot4 #ha4 ,:at is said ( wat] z a mirror8 ,%[ t ! surface ( a liquid is n /rictly level4 ,if ! e>? _h no elevations ( l& :y w\ld x h a p]fectly globul> cov]+ ( wat]8 #hb4 ,:at is a s-call$ p]fectly level surface8 ,:at is ! v>iation p] mile f a real level8 ,describe ! _s-level4 ,give ! comp>ison betwe5 a tr\gh & a riv]4 #hc4 ,:at is said ( ! declivity ( riv]s8 ,h[ h "s riv]s be5 made8 ,:at is /at$ 9 reg>d to ! ,riv] ,danube8 #hd4 ,:at is /at$ ab\t ! ,lake ( ,g5eva8 ,describe ! arrangem5t ( canal locks4 #he4 ,h[ are canals us$ = work+ ma*9]y8 ,give v>i\s illu/rations ( ! t5d5cy ( wat] to be on a level4 #hf4 ,describe ! arrangem5t repres5t$ 9 ,fig4 #ga1 & give ! explanation4 #hg4 ,describe a fooli% man's plan = p]petual motion1 & give ! reason ( its failure4 ,:at is said ( anci5t & mod]n aqu$ucts8 #hh4 ,expla9 ! op]ation ( spr+s & ,artesian wells4 #hi4 ,:5ce comes ! "n ,artesian8 ,:at is /at$ ( a well 9 ,p>is8 ,:at ( ! situation ( ,london8 ,:y is ! pressure ( a liquid 9 proportion to its dep?8 ,give ! illu/rations ( ?is m5tion$ 9 #abb4 #ij4 ,expla9 ,fig4 #ge4 #ia4 ,:at is said ab\t ! con/ruction ( dams & brew]s' vats8 ,expla9 ! lat]al pressure ( liquids4 ,%[ ! diff]5ce betwe5 a liquid & a solid 9 ?is respect4 #ib4 ,%[ h[ ! e>?'s attraction causes ! lat]al pressure by ,figs4 #gg & #gh4 ,give ! view pres5t$ 9 #abd4 #ic4 ,:at is said ( ! propos$ %ip canal betwe5 ! ,m$it]ranean & ! ,r$ ,sea8 ,%[ t pressure 9 liquids is equal 9 all directions4 #id4 ,give ! illu/rations 9 #abf4 ,%[ t ! upw>d pressure 9 a liquid is z ! dep?1 & t ?is is produc$ by gravitation4 #ie4 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #hb4 ,give ! exp]im5t ) ! tube & ,india-rubb]4 #if4 ,/ate ! examples giv5 ( great effects produc$ by small quantities ( a fluid4 ,expla9 ^! effects by ,fig4 #hc4 #ig4 ,expla9 ,fig4 #hd4 #ih4 ,:at is ! ,hydro/atic ,p>adox1 & :y is x s call$8 ,describe & expla9 ! ,hydro/atic ,bell[s4 #ii4 ,describe & expla9 ,bramah's ,hydro/atic ,press4 ,,*apt] ,,viii4 #ajj4 ,def9e specific gravity4 #aja4 ,:at is ! mo/ obvi\s way ( asc]ta9+ ! specific gravities ( diff]5t liquids8 ,expla9 ! s9k+ ( heavy sub/ances 9 wat]4 ,expla9 ! ris+ ( light sub/ances 9 wat]4 ,expla9 :at is illu/rat$ 9 ,fig4 #hg4 #ajb4 ,expla9 ,fig4 #hh4 ,expla9 ,fig4 #hi4 #ajc4 ,give ! illu/rations 9 #ach3 lift+ a /one2 rais+ a bucket2 & rais+ ! arm 9 a ba?4 ,relate ! anecdote ( ,ar*im$es4 ,:at is said ( boats & life-boats8 ,:at ( e/imat+ ! weight ( ! load 9 a canal-boat8 #ajd4 ,:at is said ( ! specific gravity ( birds8 ,( insects8 ,( fi%es8 ,:at ( ! specific gravity ( ! human body1 & ( ! prev5tion ( dr[n+8 #aje4 ,give ! reasons :y s _m are dr[n$ t might easily be sav$8 #ajf4 ,:at is /at$ ab\t *ildr5 9 ,*9a8 ,:y does ! body ( a dr[n$ p]son s9k8 ,:y does x aft] a :ile rise8 ,:at is said ab\t wad+ 9 riv]s8 #ajg4 ,expla9 ! mann] 9 :i* ! specific gravity ( a solid may be asc]ta9$8 ,give ! exp]im5t ( weigh+ wat]4 ,:at is /at$ ( ,ar*im$es & ! cr[n8 #ajh4 ,describe & expla9 ! hydromet]4 ,relate ! anecdote ( ! ,*9ese4 ,:at is said ( ! sell+ ( milk 9 ,switz]l&8 #aji4 ,:at is said ( ! c5tre ( gravity 9 float+ bodies8 ,give ! illu/rations4 ,,*apt] ,,ix4 #aaj4 ,:at does pneumatics tea*8 ,h[ c y %[ t air is mat]ial8 ,h[ t x has weight8 ,:at is its weight comp>$ ) t ( wat]8 #aaa4 ,:at is said ( ! air's be+ attract$ by ! e>?8 ,expla9 :y "s ?+s rise & o!rs fall 9 air4 ,h[ ?ick is ! e>?'s air-cov]+8 #aab4 ,h[ is ! height ( ! atmosph]e asc]ta9$8 ,at :at rate does ! e>? move r\nd ! sun8 ,h[ does x c>ry along ! air ) x8 ,/ate ! influ5ce :i* gravitation has ^u ! d5sity ( ! air at diff]5t heights4 #aac4 ,give ! comp>ison ( air to wool4 ,:at is said ( hydrog5 & balloons8 ,9 :at are gases & liquids alike1 & :at are ! results ( ! simil>ity8 ,:at is ! am\nt ( pressure ( ! atmosph]e on ea* squ>e in* ( surface8 ,give ! calculations 9 reg>d to ?is pressure4 #aad4 ,%[ :y ! great pressure ( ! air does n produce de/ructive effects4 ,describe ! air-pump4 #aae4 ,expla9 by ,fig4 #ie ! plan & work+ ( ! air-pump4 #aaf4 ,/ate "s ( ! exp]im5ts ) ! air-pump4 ,h[ c y prove t air1 l wat]1 presses equally 9 all directions8 ,/ate ! comp>ison ab\t ! fi%4 #aag4 ,:at is said ( ! ,magdeburg hemisph]es8 ,give ! exp]im5t ) m]cury4 ,expla9 ! op]ation ( ! boy's suck]4 #aah4 ,give ! /atem5ts ab\t suck]-l arrangem5ts 9 animals4 ,/ate ! exp]im5t ( ! bladd] & weight4 ,give ! exp]im5t ) ! ,india-rubb] bag4 #aai4 ,/ate ! exp]im5t ) ! egg4 ,expla9 ! op]ation ( ! hydro/atic balloon4 #abj4 ,expla9 ! op]ation ( ! ,c>tesian image4 ,:at is said ( ! pres5ce ( air 9 v>i\s sub/ances8 #aba4 ,:at is said ( ! ela/icity ( air8 ,describe & expla9 ! cond5s]4 #abb4 ,describe & expla9 ! gasomet]4 ,%[ h[ ! air-gun op]ates4 ,expla9 ! pop-gun4 #abc4 ,expla9 ! op]ation ( gunp[d]4 ,expla9 t ( /eam4 ,:at is said ( ret>dation by cond5s$ air 9 gunn]y8 #abd4 ,describe & expla9 :at is repres5t$ 9 ,fig4 #aac4 ,expla9 ! collection ( gases 9 ! pneumatic tr\gh4 #abe4 ,expla9 ! exp]im5t repres5t$ 9 ,fig4 #aae4 ,:at is said ( tapp+ a b>rel8 ,:at causes ! gurgl+ s\nd :5 a liquid is p\r$ f a bottle8 ,h[ high a column ( wat] w ! pressure ( ! atmosph]e su/a98 ,h[ d y f9d f ?is ! pressure ( ! air on e squ>e in* ( surface8 ,h[ high a column ( m]cury w ! atmosph]e su/a98 #abf4 ,expla9 ! b>omet]4 ,relate ! incid5t giv5 by ,dr4 ,arnot4 #abg4 ,:y w\ld n a wat]-b>omet] answ]8 ,:at is said ( ! b>omet] z a measur] ( heights8 ,h[ is ! boil+ po9t influ5c$ by ! am\nt ( ! air's pressure8 ,give ! exp]im5t ) e!r4 #abh4 ,/ate ! exp]im5t ) ! flask4 ,:at w\ld happ5 to liquids if ! atmosph]e 7 remov$ f ! e>?8 ,expla9 ! op]ation ( ! syphon by ,fig4 #aag4 #abi4 ,expla9 :at is repres5t$ by ,fig4 #aah4 #acj4 ,expla9 ! uses ( ! syphon4 ,expla9 ! op]ation ( ! ,cup ( ,tantalus4 #aca4 ,h[ are int]mitt+ spr+s acc\nt$ =8 ,expla9 ! op]ation ( ! common pump4 #acb4 ,:y does ! wat] rise 9 ! pump8 ,h[ is suck+ done8 ,expla9 ! =c+ pump4 #acc4 ,expla9 ! fire-eng9e4 ,,*apt] ,x4 #acd4 ,:at is said ( ! univ]sality ( motion8 ,:at ( attraction z a cause ( motion8 ,:at ( heat8 ,:at ( *emical ag5cies8 ,:at ( life8 #ace4 ,:at is meant by say+ t action & reaction are equal8 ,/ate ! illu/rations ( ?is tru? :i* are giv54 ,describe ,b>k]'s mill4 #acf4 ,give ! comp>isons to ! op]ation ( a spr+1 ( fir+ ( a cannon1 & ! ?r[+ ( /ones f ! crat] ( a volcano4 ,:at is said ( ! jump+ ( a man f ! gr\nd8 #acg4 ,:at is said ( ! reaction 9 ! case ( a hopp+ bird8 ,illu/rate ! in]tia ( matt] z %[n 9 ! communication ( motion4 ,give ! illu/rations ( ! fact t "t is requir$ to communicate motion to bodies4 #ach4 ,give illu/rations ( in]tia z %[n 9 ! disposition ( motion to cont9ue4 #aci4 ,describe & expla9 ! eque/rian feat repres5t$ 9 ,fig4 #abg4 ,:at is said ( skill 9 jump+ f a mov+ c>riage8 ,relate ! case 9 c\rt :i* is /at$4 #adj4 ,:at is said ( ! c\rse ( bodies ?r[n into ! air8 ,:at ( a man fall+ f a ma/-head8 #ada4 ,:at is said ( ! atmosph]e z revolv+ ) ! e>?8 ,:at rapid motions are we subject$ to :5 we speak ( ourselves z at re/8 ,:y are we ins5sible to ^! motions8 #adb4 ,foll[ out 9 full ! comp>ison ( ! /eamboat4 ,:at is ! diff]5ce betwe5 absolute & relative motion8 ,:at is said ( absolute re/8 #adc4 ,illu/rate ! tru? t all ! motions :i* are app>5t to ! eye are slight diff]5ces 9 ! common absolute motions4 ,:at are ! ob/acles to motion8 ,h[ is ! motion ( a /one ?r[n upw>d de/roy$8 ,:at causes & :at opposes its desc5t8 #add4 ,/ate & expla9 ! exp]im5t ) ! lead & fea!r4 ,expla9 ! op]ation ( ! wat]-hamm]4 ,%[ ! relation ( bulk to ! resi/ance ( liquids & gases4 #ade4 ,illu/rate ! relation ( bulk to ! motion ( solids1 produc$ by mov+ gases & liquids4 #adf4 ,:at is said ( ! opposition ( gravitation to wat] & air 9 mov+ solids8 ,:at diff]5ce does ! pres5ce ( ob/acles make 9 ! relation ( =ce to velocity8 #adg4 ,/ate ! law ( ! relation ( =ce to velocity1 & illu/rate by ,fig4 #acf4 ,:at are "s ( ! practical applications ( ?is law8 ,:at is said ( ! relation ( %ape to velocity8 ,:at is said ( ! %ape ( fi%es8 #adh4 ,:at is said ( ! %apes ( boats8 ,:at ( ! managem5t ( ! webb$ feet ( wat]-f[ls8 ,:at ( ! w+s ( birds8 ,:at is said ( friction z an ob/acle to motion8 ,:at ( x z a cause to motion8 ,illu/rate fully 9 ! case ( ! :eel4 #adi4 ,:at is said ( ! friction ( liquids 9 tubes8 ,:at is ! effect ( sudd5 turns 9 pipes8 ,:at is ! arrangem5t ( art]ies 9 ! heads ( graz+ animals8 ,illu/rate ! diff]5ce ( friction 9 small & l>ge pipes by ,fig4 #aca4 #aej4 ,:at is said ( ! effect ( friction 9 brooks & riv]s8 ,9 :at "p ( a /ream does ! wat] move mo/ rapidly8 ,expla9 ! =mation & break+ ( ! cre/ ( waves roll+ ov] a bea*4 ,:at is said ( ! velocity ( riv]s z affect$ by friction8 ,expla9 ! =mation ( waves4 #aea4 ,:at is x t really advances 9 ! =w>d movem5t ( a wave8 ,give ! comp>ison m5tion$4 ,:at is said ( ! height ( waves8 #aeb4 ,:at is mom5tum8 ,^u :at two ?+s does x dep5d8 ,illu/rate ?is dep5d5ce4 ,expla9 ,fig4 #acc4 #aec4 ,give ! illu/ration ( ! musket-ball & cannon-ball4 ,give t ( ! plank4 ,t ( ! c&le4 ,t ( ! air4 #aed4 ,:at is said ( ! expression1 quantity ( motion8 ,"u :at circum/ances may a s+le impulse produce a great velocity8 ,:at examples h we ( ?is8 ,h[ is x ) ! motions t we see ar\nd u8 ,:at is said ( ! fall ( bodies to ! e>?8 #aee4 ,give examples f muscul> action4 ,give t ( ! arr[4 ,give t ( gunp[d]4 ,:at is said ( ! arre/ ( great velocities8 ,give ! illu/rations 9 reg>d to cannon-balls4 #aef4 ,/ate & expla9 ! feat ( ! anvil4 ,give examples f common ef=ts & labors4 #aeg4 ,expla9 ! communication ( motion 9 ! case ( ela/ic bodies by ,figs4 #acc & #acd4 ,:at is said ( ! reflection ( motion8 #aeh4 ,:at is said ( ! uni=mity ( motion8 ,:at ( its uni=mity 9 velocity8 ,/ate by :at means we calculate z to "t4 #aei4 ,:at is said ( ! sun-dial8 ,:at ( ! h\r-glass8 ,:at ( ,galileo & ! p5dulums8 ,expla9 ! op]ation ( ! p5dulum4 #afj4 ,expla9 ,fig4 #acg4 ,expla9 ! op]ation ( ! gridiron p5dulum by ,fig4 #ach4 #afa4 ,:at is said ( ! disposition ( motion to be /raight8 ,:y is motion nev] /raight1 s f> z we "k8 ,h[ c we make motion v ne>ly /raight8 ,give ! illu/ration ( ! bullet 9 full4 #afb4 ,give ! illu/ration repres5t$ 9 ,fig4 #ada4 ,:at is comp\nd motion8 ,illu/rate /raight comp\nd motion4 #afc4 ,expla9 ,fig4 #adc4 #afd4 ,expla9 :at is repres5t$ ,figs4 #add1 #ade1 & #adf4 #afe4 ,expla9 ,fig4 #adg4 ,h[ is curv$ motion produc$8 ,give ! illu/ration ( ! ball & /r+4 ,:at are c5trifugal & c5tripetal =ces8 #aff4 ,:at are ^! two =ces 9 ! revolution ( ! e>? ar\nd ! sun8 ,give v>i\s illu/rations ( ! op]ation ( c5trifugal =ce4 #afg4 ,:at is said ( ! =mation ( b5ds 9 riv]s8 #afh4 ,%[ h[ eddies & :irlpools are =m$4 ,h[ is ! c5trifugal =ce us$ 9 ! art ( pott]y4 ,h[ 9 mak+ w9d[-glass8 #afi4 ,describe & expla9 ! op]ation ( ! /eam-gov]nor4 #agj4 ,:at is said ( ! ag5cy ( ! c5trifugal =ce 9 %ap+ ! e>?8 #aga4 ,expla9 ! op]ation ( ! app>atus repres5t$ 9 ,fig4 #aed4 ,:at are ! =ces :i* act on a projectile8 ,:at is said ( balls ?r[n horizontally f cannon ) diff]5t velocities8 #agb4 ,%[ by ,fig4 #aee :y a ball dropp$ f ! m\? ( a cannon w fall to ! gr\nd 9 ! same "t t "o fir$ f x w4 ,by ,:at two =ces is a fall+ body act$ ^u8 #agc4 ,expla9 ,fig4 #aef4 ,:at is ! c\rse ( a ball dropp$ f a railway c> or f a ma/-head8 ,give ! comp>ison betwe5 ! cannon-ball & ! moon4 #agd4 ,:at is said ( ! velocities ( ! heav5ly bodies8 ,,*apt] ,,xi4 #agd4 ,:at are ! ,me*anical ,p[]s8 ,:y is ! t]m p[] n /rictly prop]8 #age4 ,expla9 ! t]ms p[]1 weight1 & fulcrum4 ,:at is said ( ! use ( ! lev]8 ,:at is ! lev] ( ! fir/ k9d8 ,:at is said ( its =ce8 #agf4 ,:at is said ( scales8 ,:at ( /eely>ds8 #agg4 ,give examples ( ! fir/ k9d ( lev]4 ,%[ by ,fig4 #aei t !re is no ga9 ( p[] 9 ?is lev]4 #agh4 ,give ! illu/ration ( ! see-saw4 ,:at is said ( ,ar*im$es's lev]8 #agi4 ,/ate ! analogy betwe5 ?is lev] & ! ,hydro/atic ,bell[s1 ,bramah's ,press1 etc4 ,:at is ! lev] ( ! second k9d8 ,apply ! rule ( equilibrium to x4 ,%[ h[ ! common :eel-b>r[ is a lev] ( ?is k9d4 #ahj4 ,give o!r examples ( ! second k9d ( lev]4 ,:at is lev] ( ! ?ird k9d8 ,h[ does ?is diff] f ! o!r two k9ds8 ,apply ! rule ( equilibrium to x4 #aha4 ,give examples ( ! ?ird k9d ( lev]4 ,%[ h[ x acts at a me*anical disadvantage 9 ! diff]5t examples m5tion$4 ,/ate 9 full :at is said ( muscul> action4 #ahb4 ,expla9 by ! figures ! op]ation ( comp\nd lev]s4 #ahc4 ,/ate ! comp>ison betwe5 ! lev] & ! :eel & axle4 ,:at is said ( ! common w9dlass8 #ahd4 ,describe & expla9 ! cap/an4 ,:at are its *ief uses8 ,:at is said ( ! fusee ( a wat*8 #ahe4 ,describe ! arrangem5t ( ! fix$ pulley4 ,:at are its uses8 #ahf4 ,describe ! arrangem5t ( ! movable pulley4 ,%[ h[ ! relation ( ! p[] to ! weight is e/imat$ 9 ! case ( comp\nd pulleys4 #ahg4 ,expla9 ! me*anical advantage ( ! incl9$ plane4 ,give examples ( x4 #ahh4 ,:at is said ( roads8 ,give ! comp>ison ( ! w$ge to ! incl9$ plane4 ,h[ is ! p[] ( ! w$ge e/imat$8 ,give examples ( ! w$ge4 #ahi4 ,:at is said ( ! screw8 ,%[ by ,fig4 #ahj h[ ! =ce ( ! screw is e/imat$4 ,:at are "s ( ! uses ( ! screw8 #aij4 ,give ! e/imate ( ! p[] ( ! screw & lev] z us$ toge!r4 ,h[ c y %[ t !re are really b ?ree me*anical p[]s8 ,:at is said ( ^! z compos+ tools & ma*9]y8 ,:at is said ( friction 9 ma*9]y8 #aia4 ,:at is ! fir/ advantage ( ! me*anical p[]s :i* is m5tion$8 ,give ! illu/rations4 ,:at is ! second advantage8 ,give ! illu/rations4 #aib4 ,:at is ! ?ird advantage8 ,give examples4 ,h[ is ! velocity ( motion 9 ma*9]y usually v>i$8 ,:at is ! f\r? advantage8 ,m5tion examples4 ,describe ! in/rum5t call$ a ,lewis4 #aic4 ,:at is said ( ! title by :i* ,ari/otle di/+ui%$ man f o!r animals8 ,,*apt] ,,xii4 #aid4 ,:at is s\nd8 ,:at relation has s\nd to rapidity ( vibration8 ,m5tion cases 9 :i* ! vibration ( s\nd+ bodies is manife/ to ! sight & t\*4 ,:at is said ( w9d in/rum5ts8 #aie4 ,/ate ! analogy ( a s\nd+ body to a p5dulum4 ,describe ! process by :i* ! s5sation ( s\nd is produc$4 ,:]e does ! vibration caus$ by ! s\nd+ body /op 9 ! e>8 ,:at is transmitt$ f !nce to ! bra98 #aif4 ,give examples ( ! transmission ( s\nd ?r\gh v>i\s sub/ances8 ,/ate ! exp]im5t by :i* x is %[n t s\nd is n transmitt$ ?r\gh a vacuum4 ,:at is said ( s\nd at great heights8 #aig4 ,h[ f> has ! s\nd ( a volcano be5 he>d8 ,if ! same s\nd 7 made 9 space at t di/ance f ! e>? :y c\ld n ! inhabitants he> x8 ,:at is ! cause ( ! noise ( bodies pass+ ?r\gh ! air8 ,:y d ! heav5ly bodies1 mov+ s rapidly1 produce no s\nd8 ,cite examples %[+ ! diff]5t velocities ( s\nd 9 diff]5t m$ia4 #aih4 ,:at is said ( ! uni=mity ( ! velocity ( s\nd8 ,%[ h[ we c measure di/ances by s\nd z comp>$ ) light 9 velocity4 ,^u :at does ! l\dness ( s\nd dep5d8 ,illu/rate ?is po9t4 #aii4 ,:at is said ( ! diffusion ( s\nd8 ,:at ( its reflection8 ,:at ( e*oes8 #bjj4 ,:at is said ( multipli$ & m+l$ reflections ( s\nd8 ,expla9 ! op]ation ( :isp]+ gall]ies by ,fig4 #ahg4 #bja4 ,expla9 ! op]ation ( ! speak+-trumpet4 ,give o!r examples ( ! conc5tration ( sonor\s vibrations4 #bjb4 ,:at is ! diff]5ce betwe5 a musical s\nd & a noise8 ,:at is said ( ! exact regul>ity ( musical vibrations8 ,h[ are diff]5t notes produc$ 9 /r+$ in/rum5ts8 ,^u :at does ! note dep5d 9 w9d-in/rum5ts8 #bjc4 ,expla9 ! op]ation ( ! organ-pipe repres5t$ 9 ,fig4 #aij4 ,:at is said ( ! notes ( bells & ( musical glasses8 ,expla9 ! me*anism ( ! human voice4 #bjd4 ,:at is h>mony8 ,^u :at does x dep5d8 ,betwe5 :at two notes ( ! scale is !re ! greate/ h>mony8 ,:at note next to ! octave h>monizes be/ ) ! fundam5tal note8 ,& :at note next8 ,%[ :y ! second note1 9 contra/ ) ! octave1 is s discordant ) ! fundam5tal note4 #bje4 ,/ate ! proportions betwe5 ! numb]s ( ! vibrations 9 ! diff]5t notes4 ,if y "k ! numb] ( vibrations ( ! fundam5tal note 9 a second1 h[ may y det]m9e ! numb] ( vibrations 9 ! o!r notes8 ,:at is said ( ! numb] ( notes 9 ! diatonic scale8 ,:at ( ! proportionate l5g?s ( /r+s = diff]5t notes8 ,:at is said ( tun+ in/rum5ts8 #bjf4 ,:at is meant by say+ t a note is too %>p or too flat8 ,/ate 9 full :at is said ab\t ! my/]ies ( s\nd & he>+4 ,,*apt] ,,xii4 #bjg4 ,/ate ! exp]im5t ( ! ?ree vessels1 & ! inf]5ce f x4 #bjh4 ,:at o!r facts su/a9 ?is inf]5ce8 ,h[ did ,sir ,humphrey ,davy prove t !re is heat 9 ice8 ,:at are ! two !ories ( heat8 ,:at is ! *ief s\rce ( heat = ! e>?8 ,:at is said ( ! heat ( ! sun itself8 #bji4 ,:at is said ( ! univ]sal influ5ce ( ! heat ( ! sun 9 ! e>?8 ,:at ( ! heat suppli$ f )9 ! e>? itself8 ,:at ( electricity z a s\rce ( heat8 #baj4 ,:at is said ( *emical action z a s\rce ( heat8 ,give examples ( ! production ( heat by me*anical action4 ,:at is said ( ! relations ( heat & light8 #baa4 ,%[ ! expansive influ5ce ( heat by describ+ ! exp]im5t repres5t$ 9 ,fig4 #aib4 ,give famili> examples ( ?is expansion4 #bab4 ,h[ c y loos5 a /opp] /uck fa/ 9 a bottle8 ,give ! anecdote ab\t ! ,p]sia4 ,give ! /atem5t ab\t ! build+ 9 ,p>is4 #bac4 ,:at is said ( ! expansion ( liquids by heat8 ,h[ may ! influ5ce ( ?is expansion ^u specific gravity be %[n8 #bad4 ,:at is said ( !rmomet]s8 ,:at ( ! inv5tion ( ! !rmomet]8 #bae4 ,/ate ! plan ( ,fahr5heit's !rmomet]4 ,give ! plans ( o!r !rmomet]s4 #baf4 ,:y is ,fahr5heit's !rmomet]1 on ! :ole1 ! be/8 ,:at is said ( ! expansion ( gases by heat8 ,/ate exp]im5ts 9 illu/ration4 #bag4 ,:at is said ( balloons8 ,:at ( ! influ5ce ( heat on ! atmosph]e8 ,give examples ( ?is influ5ce4 #bah4 ,:y1 9 heat+ ap>tm5ts1 d we h ! heat creat$ or introduc$ at z l[ a place z possible8 ,expla9 ! draught ( a *imney4 ,:y does a /ove-pipe g5]ally draw bett] ?an a *imney8 #bai4 ,/ate ! exp]im5t ) ! c&le & ! door4 ,:at is ! explanation ( ! occurr5ce ( w9d8 ,expla9 ! l&-breeze4 #bbj4 ,expla9 ! sea-breeze4 ,h[ are w9ds affect$ by ! rotation ( ! e>?8 #bba4 ,%[ by ,fig4 #bja :y ! prevail+ w9ds at ! equator are nor!a/ & s\!a/4 #bbb4 ,m5tion ! melt+ po9ts ( v>i\s sub/ances4 ,:at is said ab\t ! natural /ate ( wat] & o!r sub/ances8 ,:at are ! two modes ( *ang+ a liquid into vapor8 #bbc4 ,:at is said ( ! rapidity ( evaporation8 ,:at ( ! solution ( wat] 9 air8 ,:at influ5ce has heat ^u ! capability ( air to dissolve wat]8 ,:at ph5om5a illu/rate ?is8 ,h[ is x suppos$ t wat] rises 9 air8 ,:at fact is 9 opposition to ?is supposition8 #bbd4 ,:at becomes ( ! wat] t rises 9 ! air8 ,:at is said ( ! =mation ( fog & ( cl\ds8 ,m5tion ! diff]5t %apes ( cl\ds & _! names4 #bbf4 ,:at is said ( ! influ5ces t give %ape to cl\ds8 #bbh4 ,/ate h[ ra9 is produc$1 & expla9 ,fig4 #bjh4 ,h[ are sn[ & hail =m$8 ,:at is said ( vaporization8 #bbi4 ,:at influ5ce has pressure ^u ! =mation ( vapor8 ,give ! exp]im5t ) e!r 9 illu/ration4 ,describe ! exp]im5t repres5t$ 9 ,fig4 #bji4 ,:at is said ( ,pap9's dige/]8 #bcj4 ,:at is said ( /eam8 ,9 :at consi/s ! p[] ( ! /eam-eng9e8 ,h[ is ! expansive =ce ( ! /eam 9 ! boil] e/imat$8 ,describe ! work+ ( ! eng9e by ,fig4 #baj4 #bca4 ,:at is ! diff]5ce betwe5 high & l[ pressure eng9es8 ,:at is said ( ! communication ( heat8 ,h[ _m modes ( communication are !re1 & :at are !y8 ,:at is ! mode call$ convection8 #bcb4 ,give examples ( convection4 ,:at is ! conduction ( heat8 #bcc4 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #baa4 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #bab4 ,:at is said ( non-conductors ( heat8 ,give ! examples cit$4 #bcd4 ,expla9 ,davy's safety-lamp4 #bce4 ,give :at is /at$ 9 ! note ab\t ,/eph5son & ,davy4 ,:at is said ( ! influ5ce ( d5sity on ! conduction ( heat8 ,give ! illu/ration ab\t melt+ sn[4 #bcf4 ,/ate ! exp]im5ts :i* %[ t liquids are poor conductors ( heat4 ,:at is said ( air z a non-conductor ( heat8 ,:at is said ( d\ble w9d[s8 #bcg4 ,:at is said ( arrangem5ts ( ! walls ( build+s8 ,:at ( an arrangem5ts = prev5t+ ! spread+ ( fires 9 blocks8 #bch4 ,h[ are animals 9 v cold regions protect$ f ! cold8 ,:at is x 9 _! cov]+s t af=ds ! protection8 ,:at is said ( ! cov]+s ( quadrup$s t are natives ( w>m climates8 ,:at ( ! elephants ^: rema9s are f\nd 9 ,sib]ia8 #bci4 ,:at *anges take place 9 ! cov]+s ( animals c>ri$ f a cold to a w>m climate1 & ! rev]se8 ,:y has man no cov]+ aga9/ ! cold8 ,expla9 ! object ( clo?+4 ,:at is said ( articles ( clo?+8 ,:at ( loose clo?+8 ,:at ( coat+s ( /raw put on trees8 ,:at ( bricks comp>$ ) /ones8 #bdj4 ,:at is said ( cocoons8 ,:at ( buds ( plants 9 w9t]8 ,:at ( sn[ z a protection ( plants8 #bda4 ,/ate ! arrangem5t ( sn[ obs]v$ 9 ! arctic regions4 ,/ate 9 full :at is said ( ! influ5ce ( ! conduction ( heat ^u s5sation4 #bdb4 ,:at is meant by ! radiation ( heat8 ,give examples ( x4 ,:at is said ( ! connection ( heat & light 9 ! rays ( ! sun8 ,:at is said ( heat f a common fire8 #bdc4 ,:at is said ( ! relation betwe5 absorption & radiation8 ,:at ( ! reflection ( heat8 ,/ate ! exp]im5t ) ! mirrors & ! !rmomet] & flask4 #bdd4 ,expla9 ! exp]im5t ) ! ice4 ,give ! exp]im5t ) phosphorus4 ,give ! exp]im5t repres5t$ 9 ,fig4 #bah4 #bde4 ,expla9 ! =mation ( dew4 ,/ate ! analogy ( ! tumbl]4 ,:at is said ( ! circum/ances t influ5ce ! deposition ( dew & fro/8 #bdf4 ,:at is said ( diff]5t sub/ances 9 reg>d to ! deposition ( dew8 ,:at ab\t ,gideon's fleece8 ,:at is ! dew-po9t8 ,h[ c y asc]ta9 9 x8 #bdg4 ,:at is said ( ! freez+ ( m]cury8 ,expla9 ! diff]5ce betwe5 s5sible & lat5t heat4 ,:at is said ( capacity = heat8 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #bai4 #bdh4 ,:at is ! relation ( heat to d5sity8 ,give ! illu/rations4 #bdi4 ,:at is ! reason t ! air is s cold on great heights8 ,:at is ! relation ( heat to ! =ms ( sub/ances8 ,:at is said ( ! melt+ ( ice8 ,:at ( ! vaporization ( wat]8 ,/ate ! g5]al conclusion 9 reg>d to lat5t & s5sible heat4 #bej4 ,/ate 9 full :at is said ( lat5t heat 9 ref]5ce to cl\ds4 ,expla9 ! op]ation ( freez+ mixtures4 #bea4 ,/ate ! examples ( ! production ( cold by evaporation4 #beb4 ,/ate & expla9 ! exp]im5t repres5t$ 9 ,fig4 #bba4 #bec4 ,give ! facts /at$ 9 reg>d to ! degree ( heat :i* man c endure4 ,give ! reasons :y ! heat did n produce a great] effect 9 ^! cases4 #bed4 ,:at effect does heat produce ^u ! bulk ( sub/ances8 ,:at is said ( wat] z an exception8 ,describe ! process ( freez+ z illu/rat$ by ! diagram4 #bef4 ,:at w\ld be ! process if ! exception did n exi/8 ,/ate :at w\ld be ! results4 #beg4 ,:at w\ld be ! consequ5ce if ! freez+ po9t 7 above #cb8 ,:at if x 7 bel[8 ,:at is said ( ! =ce ( expansion 9 ice8 ,:at are "s ( ! b5efits :i* come f ?is expansion8 ,,*apt] ,,xiv4 #beh4 ,:at is ,newton's !ory ( light8 ,:at is ! undulatory !ory8 ,/ate ! analogies to s\nd & heat4 ,:5 is a body lum9\s8 ,:at are ! s\rces ( light8 #bei4 ,h[ may y see t light moves 9 /raight l9es8 ,/ate v>i\s famili> recognitions ( ?is fact4 ,illu/rate ! fact t ! int5sity ( light is inv]sely z ! squ>e ( ! di/ance4 #bfj4 ,:at is said ( ! velocity ( light 9 reg>d to ord9>y di/ances8 ,h[ long is light com+ f ! sun to ! e>?8 ,:at is said ( ! light com+ to u f c]ta9 />s8 #bfa4 ,give ! obs]vation ( ,roem] repres5t$ 9 ,fig4 #bbf4 #bfb4 ,:at is said ( ! reflection ( light8 ,:at ( its reflection 9 relation to see+8 ,:at ( ! images =m$ 9 mirrors8 #bfc4 ,%[ by ,fig4 #bbh :y ! image 9 a mirror seems to be z ! same di/ance beh9d x t ! object is be=e x4 ,expla9 by ,fig4 #bbi ! op]ation ( ! kaleidoscope4 #bfd4 ,expla9 ! op]ation ( a concave mirror by ,fig4 #bcj4 ,expla9 t ( a convex mirror by ,fig4 #bca4 #bfe4 ,:at is meant by ! refraction ( light8 ,illu/rate its reflection 9 pass+ f a d5s] into a r>] m$ium4 ,!n f a r>] into a d5s]4 #bff4 ,h[ is ! refraction 9 reg>d to a p]p5dicul> 9 ! two cases8 ,expla9 dawn & twilight4 ,expla9 :at is repres5t$ 9 ,fig4 #bcd4 #bfg4 ,:at are mirages8 ,describe ! mirage :i* occurr$ at ,ramsgate4 ,describe t se5 by ,capta9 ,scoresby4 ,relate ! incid5t :i* occurr$ at ,new ,hav54 #bfh4 ,:at is said ( mirages 9 des]ts8 #bfi4 ,describe ! mirage ( ! ,fr5* coa/4 ,expla9 :at is meant by ! visual angle z illu/rat$ by ,fig4 #bcf4 #bgj4 ,expla9 ,fig4 #bcg4 ,:at are l5ses8 ,:at are ! diff]5t k9ds8 #bga4 ,:at is ! diff]5ce ( effect 9 convex & concave l5ses8 ,expla9 ! effect ( a convex l5s on ! visual angle4 ,:at is said ( microscopes & telescopes8 #bgb4 ,describe & expla9 ! magic lant]n4 ,describe & expla9 ! cam]a obscura4 #bgc4 ,describe ! arrangem5t ( a cam]a = sket*+4 ,h[ is ! eye l a cam]a8 #bgd4 ,describe ! arrangem5t ( ! p>ts ( ! eye z mapp$ 9 ,fig4 #bdd4 #bge4 ,%[ n[ p>ticul>ly h[ ! eye is l a cam]a4 ,:at is said ( ! influ5ce ( ! cornea on ! light8 ,%[ :at is requir$ = di/9ct vision1 z illu/rat$ 9 ,fig4 #bde4 ,%[ :y x is t objects br\ght v ne> ! eye are n se5 di/9ctly4 #bgf4 ,:at is said ( ! microscope8 ,expla9 ! difficulty 9 ! ne>-sight$4 ,9 ! f>-sight$4 #bgg4 ,h[ c y %[ t ! images ( objects 9 ! ret9a are inv]t$8 ,give 9 full :at is said ( explanations ( ! fact t we see objects erect not)/&+ ?is inv]sion4 ,expla9 s+le vision4 #bgh4 ,by :at simple exp]im5t c y %[ ! explanation ( s+le vision to be correct8 ,:at is said ( squ9t+8 ,expla9 ! /]eoscope4 #bgi4 ,:at is said ( di/9ct impressions on ! ret9a8 ,expla9 ! ?aumatrope4 #bhj4 ,/ate 9 full :at is said ( ! comp\nd nature ( light4 ,give ! proportions ( ! colors 9 x4 ,:at is said ab\t !re be+ only ?ree colors8 #bha4 ,:at is said ( ! recomposition ( decompos$ light8 ,give ! illu/ration ( ! p[d]--! circul> bo>d--! top4 #bhb4 ,:at is said ( ! colors ( sub/ances8 ,:at ( ! v>iations ( ^! colors 9 diff]5t lights8 ,:at ( v>iations ) v>y+ positions8 ,:at ( ! colors ( cl\ds8 #bhc4 ,expla9 ! =mation ( ! fir/ ra9b[ by ,fig4 #bec4 ,expla9 ! =mation ( ! second b[ by ,fig4 #bed4 #bhd4 ,:at is said ( ! circum/ances "u :i* ra9b[s are se58 #bhe4 ,expla9 9 full ! =mation ( ! two b[s z illu/rat$ by ,fig4 #bee4 ,:at is said ( ! b[ z se5 by diff]5t p]sons1 & at diff]5t mom5ts by ! same p]son8 ,:at ( ra9b[ hues 9 dew-drops & ice-cry/als8 #bhf4 ,give ! dissection ( light z repres5t$ 9 ,fig4 #bef4 ,:at is said ( ,dagu]reotyp+8 ,,*apt] ,,xv4 #bhg4 ,:at is ! orig9 ( ! t]m electricity8 ,:at is said ( attraction & repulsion 9 electricity8 #bhh4 ,:at is ! suppos$ explanation ( electrical repulsion8 ,expla9 ! diff]5ce betwe5 res9\s & vitre\s electricity4 ,:at is said ( ! two suppos$ electrical fluids8 ,detail ! illu/rations ( attraction :i* are /at$4 #bhi4 ,/ate ! !ory ( ,frankl94 ,expla9 ! use ( ! t]ms positive & negative4 ,illu/rate ! fact t ! k9d ( electricity excit$ dep5ds on :at a sub/ance is rubb$ )4 #bij4 ,:at is said ( ! incorrectness ( ! t]ms vitre\s & res9\s8 ,:at is said ( conductors & non-conductors8 ,:y are non-conductors call$ insulators8 #bia4 ,:at m>k$ diff]5ce is !re betwe5 heat & electricity8 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #beh4 ,:at is said ( electrics & non-electrics8 #bib4 ,:at is said ( equilibrium 9 electricity1 & ( its di/urbance8 ,give 9 full :at is said ( ! univ]sality ( electricity4 #bic4 ,/ate :at is said ( induction1 z illu/rat$ by ! exp]im5t repres5t$ 9 ,fig4 #bei4 #bid4 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #bfj4 ,describe ! arrangem5t & op]ation ( ! electrical ma*9e repres5t$ 9 ,fig4 #bfa4 #bie4 ,describe ! cyl9d] ma*9e4 ,/ate ! exp]im5t ) ! pi? balls4 ,/ate t ) ! head ( hair4 #bif4 ,/ate ! exp]im5t ) ! tissue-pap]4 ,/ate t ) ! danc+ figures4 ,/ate t ) ! bells4 #big4 ,describe ! exp]im5t ) ! t9-foil4 ,describe ! insulat+ /ool & ! op]ation ( x4 #bih4 ,:at is said ( ! escape ( electricity f po9ts8 ,describe ! app>atus repres5t$ 9 ,fig4 #bfi1 & ! op]ation ( x4 ,:at is said ( ! dis*>ge ( electricity f a po9t 9 a d>k room8 ,describe ! ,leyd5 j>4 #bii4 ,expla9 ! op]ation ( ! ,leyd5 j>4 ,:at w\ld be ! effect ( connect+ ! inside foil ) ! out] by a /rip ( foil8 ,give 9 full ! exp]im5t repres5t$ 9 ,fig4 #bgb1 & ! explanation4 #cjj4 ,:at is said ( ! dis*>ge ( ! j>8 ,h[ c a l>ge numb] ( p]sons take a %ock f x toge!r8 #cja4 ,expla9 ! effect ( moi/ure ^u ! *>g$ j>4 ,/ate ! exp]im5t repres5t$ 9 ,fig4 #bgd4 #cjb4 ,:at is ! electrical batt]y8 ,:at is said ( ! light produc$ by electricity8 #cjc4 ,to :at is ! report ( electricity ow+8 ,:at is said ( me*anical injuries caus$ by electricity8 ,:at ( ! heat caus$ by x8 ,:at effects may be produc$ by ?is heat8 #cjd4 ,:at 0 ! discov]y ( ,frankl91 & h[ did he make x8 #cje4 ,relate ! accid5t :i* occurr$ at ,/4 ,pet]sburg4 ,:at is said ( lightn+-rods8 #cjf4 ,:at 0 ,sulz]'s exp]im5t8 ,:at 7 ,galvani's obs]vations8 #cjg4 ,:at is said ( ! pile ( ,volta8 ,:at ( 8 cup batt]y & ( o!r batt]ies8 #cjh4 ,:at diff]5ce is !re betwe5 frictional & voltaic electricity8 ,,*apt] ,,xvi4 #cjh4 ,:at are load/ones8 ,:]e d !y ab\nd8 ,:at is said ( discov]ies 9 magnetism8 ,:5ce come ! t]ms magnetism & magnet8 #cji4 ,:at is said ( ! attraction ( magnetism8 ,:at law is !re 9 reg>d to x8 ,:at is said ( ! poles ( a magnet8 ,:at ( magnetism by induction8 #caj4 ,:at is said ( attraction & repulsion 9 magnets8 ,expla9 ! =mation ( ! curves ( iron fil+s 9 ! exp]im5t repres5t$ 9 ,fig4 #bhb4 #caa4 ,h[ may artificial magnets be made8 ,:at is said ( ! horse%oe magnet & its armature8 #cab4 ,:at is said ( ! magnetic ne$le & ! m>9]'s compass8 #cac4 ,:at is ! decl9ation ( ! ne$le8 ,:5 0 x fir/ obs]v$8 ,:at is said ( obs]vations aft] ?is8 ,:at is said ( ! dip ( ! ne$le8 #cad4 ,:at is said ( ! e>? z a magnet8 ,:at ( x z a magnetiz]8 #cae4 ,:at is said ( fix+ magnetism8 ,:at ( impair+ x8 ,9 :at o!r sub/ances besides iron does magnetism exi/8 ,9 :at is magnetism l electricity8 ,9 :at is x unlike x8 #caf4 ,:at relation has magnetism to electricity8 ,:at 7 ! orig9al obs]vations ( ,o]/$ 9 reg>d to x8 #cag4 ,describe ! mann] ( mak+ ! mo/ p[]ful electro-magnets4 ,describe ! exp]im5t repres5t$ 9 ,fig4 #bhg4 #cah4 ,%[ ! application ( electro-magnetism 9 ! electric telegraph4 #cai4 ,:at is ! contrivance call$ ! signal key8 ,h[ is ! alphabet ( ,morse's ,telegraph con/ruct$8 #cbj4 ,:at is said ( ! communication ?r\gh ! e>? 9 telegraph+8 ,,index4 ,! numb]s ref] to ! p>agraphs ,action & reaction equal1 #ahb ,air1 compressibility (1 #aeb ,air1 ela/icity (1 #afa ,air1 d5sity (1 dep5d5t on pressure1 #aeh ,air1 pressure (1 z affect+ ! boil+ po9t1 #aga1 #cbg ,air1 curr5ts 91 f heat1 #bha ,air1 solution ( wat] 91 #bhg ,air attract$ by ! e>?1 #adh ,air 9 int]/ices ( sub/ances1 #afj ,air a non-conductor ( heat1 #cjb1 #cjd ,air-pump1 #aee ,air-guns1 #afd ,animals1 cov]+s suit$ to climate1 #cje ,ar*im$es1 8 lev]1 #bbi ,ar*im$es1 8 discov]y 9 ! ba?1 #ach ,ar*im$es & ! cr[n1 #adc ,artesian wells1 #abj ,aqu$ucts1 #aai ,atmosph]e1 pressure (1 #aed1 #afh ,atmosph]e1 h[ x moves ) ! e>?1 #ahh ,atomic !ory1 #ae ,attraction1 nature (1 #ec ,attraction1 capill>y1 #gb ,attraction betwe5 masses1 #gc ,attraction betwe5 solids & liquids1 #fi ,attraction1 ,newton's idea (1 #ed ,attraction1 univ]sality (1 #gg ,attraction1 v>iety 9 results (1 #hg ,attraction1 opposition betwe5 modes (1 #hh ,attraction1 proportion ( ! mutual motions (1 #gf ,balloons1 #adi1 #bhj ,balloon1 hydro/atic1 #aei ,b>omet]1 #afi ,b>k]'s mill1 #ahb ,batt]y1 electrical1 #chg ,b]keley1 8 ideas ( matt]1 #b ,boats1 :y !y float1 #aci ,boil+ po9t z affect$ by ! pressure ( ! air1 #aga ,brittl5ess1 #bi ,buds 9 w9t]1 #cjh ,bulk1 relation (1 to resi/ance ( liquids & gases1 #aic ,cam]a obscura1 #ceb ,canals1 #aag ,capill>y attraction1 #gb1 #hf ,c>tesian image1 #aei ,c5tre ( gravity def9$1 #if ,c5tre ( gravity1 support (1 9 animals1 #ajf ,c5tre ( gravity1 movem5ts (1 9 walk+1 #ajg ,c5tre ( gravity 9 relation to attitudes1 #ajh ,c5tre ( gravity 9 float+ bodies1 #ade ,c5trifugal =ce1 #bac ,c5tripetal =ce1 #bac ,*imneys1 draught (1 #bhb ,clo?+1 object (1 #cjf ,cl\ds1 h[ =m$1 #bhh ,cl\ds1 colors (1 #cfd ,cl\ds1 %apes (1 #bhi ,cl\ds1 lat5t heat 91 #cbd ,cocoons1 con/ruct$ = w9t]1 #cjg ,colors ( objects1 #cfc ,colors ( ! cl\ds1 #cfd ,cohesion1 /r5g? (1 #fh ,cohesion1 :at is ess5tial to x1 #ff ,cold1 abs5ce ( heat1 #bgj ,cold at great heights1 cause (1 #cbb ,cold f evaporation1 #cbf ,compressibility ( sub/ances1 #ce ,compressibility ( air1 #aeb ,cond5s]1 #afb ,conductors ( heat1 #bih ,conductors ( electricity1 #cge ,conduction ( heat1 #big ,conduction1 relation ( d5sity to1 #cjj ,conduction 9 liquids1 #cja ,conduction1 influ5ce (1 on s5sation1 #caj ,convection ( heat1 #bif ,cov]+s ( animals suit$ to climate1 #cje ,cry/allization1 #fb ,dagu]reotype1 #cfi ,dams1 #abb ,davy's safety-lamp1 #bii ,dawn expla9$1 #cdf ,d5sity1 #bd ,dew1 =mation (1 #cae ,dew-drops1 colors 91 #cfg ,dew-po9t1 #cag ,diatonic scale1 #bfg ,draught ( *imneys1 #bhb ,dr[n+1 h[ x c (t5 be prev5t$1 #ada ,e>?1 globul> =m (1 #fa ,e>?1 r\ndness (1 %[n1 #aac ,e>?1 attraction t[>d c5tre (1 #hj ,e>?1 ?ickness ( its air-cov]+1 #aej ,e>?1 %ape (1 influ5c$ by c5trifugal =ce1 #bah ,e>?1 rotation (1 affect+ w9ds1 #bhd ,ela/icity1 #ci ,ela/icity1 def9ition (1 #db ,electricity1 orig9 ( ! t]m1 #cgj ,electricity1 attraction & repulsion 91 #cga ,electricity1 vitre\s & res9\s1 #cgb ,electricity1 galvanic1 #cid ,electricity1 univ]sality (1 #cgh ,electricity1 dis*>ge (1 f po9ts1 #chc ,electricity1 s\nd (1 #chi ,electricity1 heat produc$ by1 #cia ,electricity1 me*anical injuries by1 #cij ,electrics & non-electrics1 #cgg ,electrical batt]y1 #chg ,electro-magnetism1 #dac ,electro-magnets1 #dad ,electric telegraph1 #dae ,eque/rian feat1 #ahe ,equilibrium1 /able & un/able1 #aji ,evaporation1 #bhf ,evaporation1 cold produc$ by1 #cbf ,expansion by heat1 #bgd ,expansion1 exception to x1 #ccj1 #cca ,ext5sion1 a prop]ty ( matt]1 #dd ,eye1 description (1 #cec ,eye1 images 91 inv]t$1 #cef ,fea!rs1 h[ a non-conductor ( heat1 #cje ,fire-eng9e1 #agi ,flexibility1 #bi ,flies1 feet (1 #aeg ,=ce1 relation (1 to velocity1 #aid ,=c+-pumps1 #agh ,frankl91 8 !ory ( electricity1 #cgc ,frankl91 8 discov]y1 #cib ,freez+1 process (1 describ$1 #ccj ,freez+ po9t1 :y at #cb1 #ccb ,freez+ 9 ! mid/ ( boil+1 #cbg ,freez+ m]cury1 #cah ,freez+ mixtures1 #cbe ,friction1 #aif-aih ,friction 9 ma*9]y1 #bde ,fro/1 #dd ,fur1 h[ a non-conductor ( heat1 #cje ,fur1 h[ alt]$ by climate1 #cje ,fusee ( a wat*1 #bch ,galvanism1 #cid ,gases1 movem5ts ( ! p>ticles 91 #aj ,gases1 space 91 #ba ,gases1 compressibility (1 #ch ,gasomet]1 #afc ,glass1 anneal+ (1 #cb ,glass-mak+1 c5trifugal =ce us$ 91 #baf ,gov]nor1 /eam1 #bag ,gravitation1 #gi1 #hf ,gravitation1 limit+ size1 #ij ,gravitation1 action (1 on solids 9 a liquid1 #acf ,gravity1 specific1 def9$1 #ace ,gridiron p5dulum1 #baj ,gunn]y1 ret>dation by cond5s$ air 91 #aff ,hail1 h[ produc$1 #bij ,h>dness1 #bh ,h>mony1 #bff ,he>+1 my/]ies (1 #bfi ,he>+1 trumpet1 #bfb ,heat1 nature (1 #bga ,heat1 s\rces (1 #bgb ,heat1 relations (1 to =ms ( matt]1 #ac ,heat1 relation (1 to bulk ( liquids1 #cg ,heat1 relation (1 to light1 #bgc ,heat produc+ expansion1 #bgd1 #bge1 #bgi ,heat1 communication (1 #bie ,heat1 convection (1 #bif ,heat1 conduction (1 #big ,heat1 radiation (1 #caa ,heat1 reflection (1 #cad ,heat1 connection (1 ) light1 #cab ,heat1 production (1 by electricity1 #cia ,heat1 degree (1 endurable by man1 #cbh ,heat1 lat5t1 #cai ,heat1 capacity ( diff]5t sub/ances =1 #cbj ,heat1 relation (1 to d5sity1 #cba ,heat1 relation (1 to =ms ( sub/ances1 #cbc ,heat & cold1 #bgj ,heights measur$ by b>omet]1 #agj ,hume1 8 ideas ( matt]1 #c ,hydromet]1 #add ,hydro/atics1 :at x tea*es1 #aaj ,hydro/atic balloon1 #aei ,hydro/atic bell[s1 #acb ,hydro/atic p>adox1 #aca ,hydro/atic press1 #acc ,ice1 =mation (1 #cbi ,ice1 =ce ( its expansion1 #ccc ,ice-cry/als1 colors 91 #cfg ,iceb]gs1 c5tre ( gravity 91 #ade ,imp5etrability1 #de ,impond]able ag5ts1 #af ,incl9$ plane1 #bda ,induction 9 electricity1 #cgi ,induction 9 magnetism1 #djj ,in]tia1 #dh ,in]tia %[n 9 ! communication ( motion1 #ahc ,in]tia %[n 9 disposition ( motion to cont9ue1 #ahd ,insulat+ /ool1 #chb ,jupit]1 m\nta9s 91 #ib ,kaleidoscope1 #cdc ,laggan /ones1 #ajj ,l&-breeze1 #bhc ,l5ses1 #cdi ,lev] ( fir/ k9d1 #bbd ,lev]1 no ga9 ( p[] 9 x1 #bbg ,lev] ( second k9d1 #bca ,lev] ( ?ird k9d1 #bcb ,leyd5 j>1 #chd1 #che ,life-boats1 #aci ,light1 nature (1 #ccd ,light1 s\rces (1 #cce ,light1 diffusion (1 #ccg ,light1 velocity (1 #cch ,light1 reflection (1 #cdj ,light1 refraction (1 #cde ,light moves 9 /raight l9es1 #ccf ,light %[n to be comp\nd1 #cfj ,light1 colors 91 #cfj ,light1 recomposition (1 #cfb ,light1 *emi/ry (1 #cfi ,lightn+-rods1 #cic ,liquids1 movability ( _! p>ticles1 #i1 #eg ,liquids1 incompressibility (1 #cf ,liquids1 attraction 91 #ef ,liquids1 globul> %ape ( drops (1 #eh ,liquids1 cause ( level surface (1 #aaa ,liquids1 pressure (1 9 proportion to dep?1 #aba ,liquids1 lat]al pressure (1 #abc ,liquids1 pressure (1 equal 9 all directions1 #abe ,liquids1 upw>d pressure z dep?1 #abg ,liquids1 9 :at l gases1 #aec ,liquids1 friction (1 9 tubes1 #aig ,liquids1 friction (1 9 /reams1 #aih ,liquids1 expansion (1 by heat1 #bge ,load/ones1 #cig ,ma*9es n s\rces ( p[]1 #bbb ,ma*9]y1 friction 91 #bde ,magic lant]n1 #cea ,magdeburg hemisph]es1 #aef ,magnetism1 orig9 ( t]m1 #cig ,magnetism1 attraction (1 #cih ,magnetism1 repulsion (1 #dja ,magnet1 poles (1 #cii ,magnets1 artificial1 #djc ,magnets1 horse%oe1 #djd ,magnetic ne$le1 #dje ,malleability1 #bh ,man a tool-mak+ animal1 #bdg ,m>9]'s compass1 #dje ,matt] di/+ui%$ f _s1 #a ,matt]1 effects (1 on s5ses1 #f ,matt]1 =ms (1 #g ,matt]1 nature (1 #ad ,matt]1 con/itution (1 #ad ,matt]1 v>iety 9 prop]ties (1 #ag ,matt]1 divisibility (1 #ah1 #ea ,matt]1 m9ute division (1 #ai ,matt]1 pores & spaces 91 #bb ,matt]1 relation ( heat to spaces (1 #bc ,matt]1 in]tia (1 #dh ,matt]1 imp5etrability (1 #de ,matt] equally incl9$ to re/ & motion1 #ej ,me*anical p[]s1 real advantages (1 #bdf ,m]cury1 freez+ (1 #cah ,microscopes1 #cej ,microscopical animals1 #ai ,mirages1 #cdg ,mirrors1 #cdb ,mirrors1 curv$1 #cdd ,mo?'s w+1 #ai ,motion1 causes (1 #aha ,motion1 univ]sality (1 #ahj ,motion1 absolute & relative1 #aia ,motion1 ob/acles to1 #aib ,motion1 reflection (1 #bjf ,motion1 comp\nd1 #bab ,motion1 curv$1 #bac ,motion 9 orbits1 #bba ,motion dispos$ to be /raight1 #baa ,motion1 t ( fall+ bodies projectile1 #bbj ,motion & re/1 #ahi ,mom5tum1 #bja ,m\nta9s1 size limit$1 #ib ,nature1 ord] 91 #fe ,ne>-sight$ness1 #cee ,ne$le1 magnetic1 #cii ,ne$le1 decl9ation (1 #djf ,ne$le1 dip (1 #djg ,noise1 h[ x diff]s f musical s\nd1 #bfc ,non-conductors ( heat1 #bih ,non-conductors ( electricity1 #cge ,notes1 musical1 h[ produc$1 #bfd ,odors1 m9ut5ess ( _! p>ticles1 #ai ,ord] 9 nature1 #fe ,pap9's dige/]1 #bib ,p5dulum1 #bjh-baj ,p]petual motion attempt$1 #aah ,p]sia1 accid5t to1 #bgd ,pisa1 t[] (1 #ajd ,pit*]s1 :y !y h lips1 #hi ,pneumatics1 :at x tea*es1 #adf ,pneumatic tr\gh1 #afg ,pop-guns1 #afd ,pott]y1 c5trifugal =ce us$ 91 #baf ,p[d]1 explosive =ce (1 #afe ,pr9ce ,rup]t's drops1 #cc ,projectiles1 #bai1 #bbj1 #bba ,pulleys1 #bci ,pumps1 #agf ,pumps1 =c+1 #agh ,radiation ( heat1 #caa ,radiation1 its relation to absorption1 #cac ,ra91 h[ x is caus$1 #bij ,ra9b[1 #cfe1 #cff ,r>ity1 #bd ,reaction equal to action1 #ahb ,reflection ( heat1 #cad ,reflection ( light1 #cdj ,reflection ( motion1 #bjf ,reflection ( s\nd1 #bfj ,remora1 #aeg ,re/1 m]ely relative1 #ahi ,riv]s1 #aae1 #aaf ,riv]s1 b5ds 91 #bae ,roem]1 obs]vations (1 9 reg>d to ! velocity ( light1 #cci ,rope-danc]s1 skill (1 9 manag+ c5tre ( gravity1 #aji ,safety-lamp1 #bii ,scales1 #ih1 #bbe ,screw1 #bdc ,sea-breeze1 #bhc ,see-saw1 a lev]1 #bbh ,s5sation1 influ5ce ( ! conduction ( heat on1 #caj ,%ape1 relation (1 to velocity1 #aie ,%ot1 manufacture (1 #fj ,signal key1 #dae ,silk-worm1 ?read (1 #ai ,size limit$ by gravity1 #ij ,sluice-gates1 #abb ,sn[1 h[ produc$1 #bij ,sn[1 cry/als (1 #fd ,sn[ a protection to plants1 #cji ,solids1 con/itution (1 #h ,solids1 attraction 91 #ci ,solution1 #ab1 #bb ,s\nd1 :at x is1 #bdh ,s\nd1 s5sation (1 h[ produc$1 #beb ,s\nd1 velocity (1 #bef ,s\nd1 transmission (1 #bec ,s\nd1 l\dness (1 #beh ,s\nd1 diffusion (1 #bei ,s\nd1 reflection (1 #bfj ,s\nd1 conc5tration (1 #bfb ,s\nd1 none produc$ by ! heav5ly bodies1 #bee ,speak+-trumpet1 #bfb ,specific gravity def9$1 #ace ,specific gravity ( animals1 #adj ,specific gravity ( ! human body1 #ada ,specific gravity ( solids1 h[ asc]ta9$1 #adb ,specific gravity ( liquids1 h[ asc]ta9$1 #add ,spectrum1 #cfj ,spid]1 web (1 #ai ,_s di/+ui%$ f matt]1 #a ,_s1 orig9 ( ^w1 #d ,_s-level1 #aad ,spr+s1 #abj ,/ability ( bodies1 #ajc-aje ,/eam transp>5t & invisible1 #bic ,/eam1 expansive =ce (1 #afe ,/eam-eng9e1 #bid ,/eel1 flexible & brittle1 #cj ,/eel1 temp]+ (1 #ca ,/eely>ds1 #ih1 #bbe ,/]eoscope1 #ceh ,suck]s1 #aeg ,suck+1 explanation (1 #afg ,suction1 #agg ,sulz]'s exp]im5t1 #cid ,sun z a s\rce ( heat1 #bgb ,surface1 relation (1 to movability1 #aic ,syphon1 #agb ,tantalus1 cup (1 #agd ,telegraph1 #dae ,telescopes1 #cej ,t5acity1 #be ,t5acity1 comp>ative1 ( sub/ances1 #bf ,t5aci\s sub/ances1 value (1 #bg ,!rmomet]1 #cg1 #bgf ,!rmomet]1 ,fahr5heit's1 #bgg ,tides1 #gh ,tubes1 friction ( liquids 91 #aig ,twilight expla9$1 #cdf ,unison1 #bfh ,up & d[n1 explanation (1 #ha ,vapor1 influ5ce ( pressure ^u ! =mation (1 #bib ,vaporization1 #bia ,velocity1 relation (1 to =ce1 #aid ,velocity1 relation (1 to %ape1 #aie ,velocities1 great1 h[ produc$1 #bjc ,velocities1 great1 h[ arre/$1 #bjd ,vibration ( s\nd+ bodies1 #bdi ,vision1 di/9ct1 :at necess>y to1 #ced ,vision1 :y s+le1 #ceg ,vision1 :y erect1 #cef ,visual angle1 #cdh ,voice1 h[ produc$1 #bfe ,voltaic electricity1 #cid ,volta's pile1 #cie ,walrus1 feet (1 #aeg ,wat]1 cry/allization (1 #fc ,wat] man's fir/ mirror1 #aab ,waves1 h[ =m$1 #aii ,waves1 height (1 #bjj ,w$ge1 #bdb ,weight1 #eb1 #hb-he ,:eel & ,axle1 #bce ,:eel-b>r[ a lev]1 #bca ,:isp]+ gall]ies1 #bfa ,w9dlass1 #bcf ,w9d[s1 d\ble1 #cjc ,w9ds1 #bhc ,w9ds z affect$ by ! rotation ( ! e>?1 #bhd ,,! ,,end4 ,,footnotes3 #a ,i take ! foll[+ f ,dr4 ,arnot3 ,! reasons t s _m p are dr[n$ 9 ord9>y cases1 :o might easily he sav$1 are ! foll[+3 #a4 ,_! believ+ t cont9u$ ex]tion is necess>y to keep ! body f s9k+1 & h5ce _! g5]ally assum+ ! position ( a swimm]1 9 :i* ! face is d[nw>d1 & ! :ole head mu/ be kept out ( ! wat] to all[ ( brea?+4 ,n[ z a man c n reta9 ?is position )\t cont9u$ ex]tion1 he is soon exhau/$1 ev5 if a swimm]1 & if n1 ! unskillful attempt w sc>cely secure = him ev5 a few respirations4 ,! body rais$ = a mom5t by ex]tion above ! natural level1 s9ks z f> bel[ :5 ! ex]tion ceases2 & ! plunge1 by appe>+ ! comm5cem5t ( a p]man5t s9k+1 t]rifies ! unpractic$ individual1 & r5d]s him an easi] victim to 8 fate4 #b4 ,f a fe> t wat] ent]+ by ! e>s may dr[n z if x ent]$ by ! nose or m\?1 a wa/eful ex]tion is made to prev5t x2 ! tru? be+1 h[ev]1 t x c only fill ! out] e>1 or z f> z ! membrane ( ! drum1 & is !re=e ( no consequ5ce4 #c4 ,p]sons unaccu/om$ to ! wat]1 & 9 dang] ( be+ dr[n$1 g5]ally attempt 9 _! /ruggle to keep _! h&s above ! surface1 f feel+ z if _! h&s 7 ti$ :ile held bel[2 b ?is act is mo/ hurtful1 because any "p ( ! body kept out ( ! wat]1 9 addition to ! face1 :i* mu/ be s1 requires an ef=t to support x :i* ! individual is suppos$ at ! "t incompet5t to af=d4 #d4 ,n hav+ reflect$ t :5 a log ( wood or a human body is float+ upright1 ) only a small portion above ! surface1 9 r\gh wat]1 z at sea1 e wave 9 pass+ mu/ cov] ! head = a little "t1 b w aga9 leave x project+ 9 ! int]val4 ,! practic$ swimm] *ooses ?is int]val = brea?+4 #e4 ,n kn[+ ! importance ( keep+ ! *e/ z full ( air z possible2 ! do+ :i* has ne>ly ! same effect z ty+ a bladd] ( air to ! neck1 & )\t o!r ef=t w cause ne>ly ! :ole head to rema9 above ! wat]4 ,if ! *e/ be once empti$1 & if f ! face be+ "u wat] ! p]son c n inhale aga91 ! body is !n specifically heavi] ?an wat]1 & w s9k4 #b ,?is is true except :5 ! tube is s small t capill>y attraction ex]ts consid]able influ5ce4 #c ,i 0 once consult$ 9 reg>d to a smok+ /ove4 ,x 0 an op5 ,frankl9 /ove1 ! pipe ( :i* w5t ?r\gh a fire-bo>d into a mon/r\s *imney4 ,i recomm5d$ t a pipe ) a knee %\ld ext5d f ! pipe ( ! /ove a little way up ! *imney4 ,! exp$i5t 0 successful1 because b a small body ( air1 t 9 ! pipe1 ne$$ to be heat$ to e/abli% an upw>d curr5t4 #d ,z 9 ! case ( _m o!r inv5tions1 s "h ! same idea 0 orig9at$ & put to practical use by m m9ds ?an "o4 ,george ,/eph5son1 :o f be+ a common eng9e-wright 9 a colli]y rose /ep by /ep till he inv5t$ ! locomotive1 con/ruct$ a lamp :i* illu/rat$ 9 ano!r way ! same pr9ciple z ! lamp ( ,davy does--9 o!r words1 he inv5t$ ano!r safety-lamp4 ,b ?is does n 9 ! lea/ detract f ! glory :i* ! inv5tion has giv5 to ! "n ( ,davy1 = ea* act$ indep5d5tly ( ! o!r4 ,9 ,davy's case1 x is to be rem>k$1 !re 0 a long c\rse ( sci5tific reason+ & inve/igation :i* l$ him at l5g? to ! inv5tion1 ! record ( :i* is exce$+ly int]e/+4 ,no inv5tion or discov]y is made )\t ?\ght1 ?\gh accid5t may sugge/ ! ?\ght2 b "h is an inv5tion :i*1 )\t any sugge/ion by accid5t1 0 evolv$ by labori\s & long-cont9u$ ?\ght1 proce$+ /ep by /ep to its conclusion4 #e ,i w m5tion "h a contrivance t ,i once adopt$ = a small cons]vatory1 :i* ,i wi%$ to keep w>m f ! heat ( a room to :i* x 0 adjo9+4 ,9 ea* space ( ! w9d[-frames 7 put two panes ( glass1 !re be+ ne>ly half an in* ( space betwe5 !m4 ,9 ?is way ,i secur$ all ! b5efit ( d\ble w9d[s ) less exp5se & a less cumbr\s arrangem5t4 ,9 m5tion+ ?is contrivance n[ & !n1 casually1 ,i h f\nd t a few o!rs h ?\ght ( x1 & adopt$ x ) ! same success t ,i did4 #f ,we are 9 entire ignorance ( ! nature ( electricity1 & we use ! t]m fluid m]ely z a matt] ( conv5i5ce4 ,,transcrib]',s ,,note ,italic text is d5ot$ by und]scores4 ,bold text is d5ot$ by equal signs4 ,obvi\s typographical errors & punctuation errors h be5 correct$ aft] c>eful comp>ison ) o!r occurr5ces )9 ! text & consultation ( ext]nal s\rces4 ,except = ^? *anges not$ bel[1 all misspell+s 9 ! text1 & inconsi/5t or ar*aic usage1 h be5 reta9$4 ,= example3 f>!r1 fur!r2 ,india rubb]1 ,india-rubb]2 e :]e2 cate*etical2 incloses2 tricksy2 p]vi\s2 motal2 enrobes2 subtile4 ,pg #gi1 'gravity made made him' replac$ by 'gravity made him'4 ,pg #aeg1 'if non ela/ic' replac$ by 'if non-ela/ic'4 ,pg #bfd1 '! div]g5cy :5' replac$ by '! div]g5ce :5'4 ,pg #big1 '#bhc4 ,electricity' replac$ by '#chc4 ,electricity'4 ,pg #cba1 ! ,que/ions beg9 ) numb] '#ac' & has n be5 *ang$4 ,pg #cca1 ! numb] '#agd' is us$ twice & has n be5 *ang$4 ,pg #cce1 ') phosporus' replac$ by ') phosphorus'4