• REF ID:A70438 • 

Patented Oct 23, 1923 1,471,437 

UNITED ST A TES PA TENT OFFICE. 

HELEN WOOD, or CLEVIJLAND, OHIO 

PRIMARY EDUCATIONAL APPLIANCE 

Apphcat on filed Novembe1 16 1921 Serial N'o 515,688 

Jo all wh01n it nun1 r nnrcrn 

Be 1t known th·n I, Hr:LE:r. '\Yoon, a c1h7en 

of the Umted States, ie<::1ding 'lt Cle,ehnd, 

m the county of Cuyahoga 'Uhl Eitate of 

6 01110 h l \ e un ented cert,11n new and useful 

ImpIO\ eill(BLS rn P1 lill'lq rJuL ,110nal \_p 

ph'lnces, of wh1ch the :follo\\ mg is a speuficat.1011 

Tlus 111\ ent10n ielates io a prmrnr) edu10 cat10nal appb.ince tnll his for 1is OUJCcl lhe 

proVJs10n of a de\ Ile of tlu::. ch n 'l.ctcr 

where\\ ith the IunJ lmrntul lnlh1netical opeiailons may be obJecinel3 clemonstL1ted to 

clnlchen, oi pnmai ") pupils 

16 It is an aulheubc f id th tl the m1malm e, 

or nnde' elope(l mirnl h mo1e suscephble to 

mateual obJecto: \d11ch p1e~u1t qu'l.nt1ly, 

than 1t is to <.h ll 'l.Ctei "'such 1c:.. figmco:, wlnrh 

have me1eh quanht1 si~.nnhc mce thrrefo1e 

20 the fund'l.mental inmriples of quantit) calculahons are read1h grns)'Cll "hen rlemonsti ated to a dnlrl b) obJer1 lv-~OP"' 

The pi esenl 1m en hon pt''' irk<: for ihe de 

'elopment of quantit\ ilrn11'mg b1 e'.eI r1s 

25 mg the senses of sight 'l.ncl toue,h Jt en 

ables the clnld to H'aclih concenc ihe 1elat10n of qnanlltes l>1 pr0\1cl111g 'l. m'l.tPJ 1'11 

obJectn e umt of 'l. O'l\ en s1zp 'l.S a h'lsis 01 

clementa1 v umt 'l.nif 'l <=<'ri<''l of u.mh13 ob10 Jects of d1:ffe1ent sizes proporl10nah to the 

elemeniary umt B1 p1ope1 'l.rr'l.ngement of 

tlw Pmhry obJects the pupil will 'l.pprc>Piate 

each member _as 'l. mnt h'l' mg its irnhv1rh1'l.l 

relatne sm~ It m(lkes poo:sihlc the rnmhm 

35 mg of sm'l.ller nmt<: mto 'l. large' nml whole m snch a manner that the pupil roncen es 

1hc constr11ct10n of the h1gc1 umt It en 

ables the p11p1l to analyze e'l.rh umt, ilom 

one to an mrlefimte gre'l.te1 m1mhe1 mto its 

40 component umts 01 pa1 ts The use of the 

'l.pplrnnce 'l.lso en'l.bles the pr1m'l.ry or child 

pnp11 to nnderstand what component umt 

rem'l.ms when another component nmt IS remowd fiom the hrge1 umt whole aml to 

46 read1l3 see how 'l g1>en l a1 ge1 umt whole 

ma) be resolved mto its equal component 

umts and to re'lchlv obscne what part the 

sm'l.ller umt is of the larger nmt whole of 

which it is one or more of the equal compo50 nrnt p'l.rts The appli'l.nPe fnrther p1ov1cles 

for the ehmm'l.bon of hap-h'l.zard guessmg, 

or hnger countmg on the part of a child 

pupil 

I have devised an appliance of simple con61l strnrhon fo1 con,emenll} clemonsti 'l.hng or 

accomphshmg these obJects An embod1-

ment 0£ the s::ud appliance is illuslrnted m 

the accompanJrng dra,,mg wlnch is m'lde 

part of the specification, and to facilitate the 

unde1st.aiidmg of the appliance I h,n e cm •10 

plo)ed snmla1 iefe1ence cha1.icte1s to cks1g 

nale coirespondmg pa11.c; lluoughoni ihe de 

sc11pt10n and m s'l.id dr'l.wmg 

Fig 1 rs a perspectne uew of 'l. rnck uc:e.J 

as a support :for nume1ons block holcle1s an<1 fi5 

the blocks earned the1 em 

Fig 2 illustrates 'l. munbe1 of the block 

holders, and Fig 3 sho" s a 'auet3 of Llocl,.., 

"h1ch are ~mployed 

In the embodiment of the 111\ cnt10n as 70 

illustr'l.ted 1 represents a support h l \mg 'l 

flat base element J" on "111ch 1s monnte<.l 'l.n 

npup:ht 1 'l.ck wlnch, for com emence is pref 

erably mclrned b'lckwanl from the b lsc up 

W'l.I cl This l 'l.Ck pr oucles a serH'S of Pom 76 

p'l.rtments, or parallel Hrhcal cli'l.1mel" P 

cqu'l.lly spaced b) ch vision membeu:, 1 c 

These channels 'l.re cles1gned for the 'l.ccom 

modahon of a series of holder element<: 2 or 

v'l.r10us lengths which may be m'l.de of light 80 

sheet metal of channel founahon open at thr 

top and closed 'l.t 01c bottom 'l.S o:hown 'l.1. 2n 

The holrlers 2. p1 o\ icle C'l.rne1s or returners 

for blocl,c; 3 of d1:ITuent s17e<:, as more full3 

set forth herema ft er 85 

Tlic blocks 3 a1e of umi'orm h rn<:H'1se rh 

men<:JQ!lS p1efe1'l.bh o:quare but 'l.lf' Qf d1f 

fcrent lengths An elemeni'l.1 \ umt hlnd>: o F 

'l. precletermmerl swe hemg adopt< rl th1 

length of each anrl 'l.11 the bloc],s C'mplo1 r1l >O 

h l ce1hm prop01t10n to the lendh of the 

ehmcnta11 umt lor the pmpo<:e of ch11 

f3 mg the e\:planat1on 'l.srnme one mch 

<:quarc 'lS the elemenl a1' umt Tlw prc>o:cnt 

emhocbment pro\ ides 'l. rap'l.cit, of 1wcnl1 !J5 

fonr r 'l.ck comp'l.rtmPnt<., of 'l.n eljn'l.l lw1ght 

of sa\ twenty fonr mches In th1<: mst rnre 

a total of e1ght3 seven blocks and h' entvfonr holders are used The holrl.ers range 111 

height from one mch to md mclndmg twen 100 

tv four mehe" "Jule the blocks 'lre m se 

ries as follows -Twenty four 1 mch lugh, 

tweh e 2 mches erp:ht 3 mches SJ\: 4 rnches, 

five 5 mches four 6 'l.nd fom 7 mches high, 

three 8 and th1ee 9 mches, two each 10 11 105 

'l.nrl 12 mches, and one each of 13, 14, 15, 16, 

17 18 19, 20, 21, 22 23 and 24 mches m 

height 

Referrmg to Fig 3 the dotted lmec:i denote 

that block 3b is three hmei; ac; long 'lS block 110 

~" and that block 3° is e1ght times as long as 

block 3a The holders are hkew1se propor-
• REF ID:A70438 • 

1,471,437 

bom:_cJ. 'lS $o}vn m Fig 2, m seqnenc.e nml 

tiples of the elementa1J unit 

The blocks 3 'l:rP 'In lptl rl lo fit 1ll the 

holders 2, anrl 'lle t11~pl tjc.J L'r u1 mgrng 

IS the holders ln the rack 1, le:; shO\\n m Ji 1g l 

The primal) stage of lllSh Ul ti on bv 

means of the impro\ ed appllan<'e mdmles 

the p1e\ailmg upon t.he dulil to au mg<:> 

the blocks m the holdeJ.s, 01 to bmlcl up t 11 ... e 

10 down, ancl comp'l.10 \a11ous combm'l110ns 

This JS easily broup:ht. 'lhout 'lS lt 1c, moH. 01 

less amusmg to the chihl Tlns amn .... l nwnt 

mte1ests hun so th tt 1t 1mp1 .... c;,es on Ins 

mmd the results of 1bc udfe1er1t ('Olllhlllcl 

llS hons anJ. these rec..ult s ,u e oli]ed demon-.! I cl 

hons of tl e fundament'll anthmPI H''ll op 

er'lhons 

The £o1lo\\ mg are e"'lmpl<:>c: of ,11011s 

oper'lhon"' 

20 (a) The pup1l 'lrran!!'es 'l '3 mch blork be 

side 'l 3 mch hol•lP1 'lnrl tlu 11 phces 'l 2 111d1 

and 'l i mch Llo<'k m th" }1olrlf' tlus c:;}rn~-, 

lnm that the combmC'd qnanhh 01 lhP 2 

rnch umt '\,1c1 tlle 1 mch unit is equ'll to thP 

26 3 mch umt, or th lt g rntl 1 E'CJU'll '3 

(b) T n 'ln 8 m<'h holrlel' the pupil pl l<'<'c:; 1 

5 mch block 'lnrl '1 '3 m hlo<'lr hC' 1 then t.111.l 

to remo\ e the '3 IIl<'h block and he oliH 1 'es 

that the 5 mch block iemuns "l11ch •lC'notl ... 

30 that '1 1 mch umt tal..,ln f1om "n R inrh nmt 

lc'1T"C$ 'l 5 inch umt, anfl. th'lt 5 'ncl 3 equ'll ~ 

(,.) A t"o mch unit ic:; pl'lcerl m 'l 111 tn• h 

ho1cle1 and the pup1l fills 1he holcll r "it h 

othe1 2 m<'h umt .. , he thPn -.eei;; lh'lt 5 of the 

J5 2 mch umts complet<>h fill the 10 mch 

holcle1, 'tnd the1efo1c 1s m'l•le rn '!Ie that 5 

hmes 2 eqn'l1& 10 

( d) RemO\ mg tht• 2 m<'h umt"' "Im h h l' e 

been phcerl m the 10 mch holrlei 'lnd c:e1no1.o i 'ltmg them, the pup1l 1s m'lclC' to undei t'ln1l 

th ll the 10 mrh~ is m'lc1e up of "i eqn'll 

umts or g mch blo<'k$, 'lml th 1t 10 Ul'l) he 

cln iflefl mto "i twoc:; 

(e) Besule c1. '3 mrh hlo<'l .. thP pnpil ph1i>s 

46 tlnee 1 mch blod .. c; m a 1 mch ho]cle1 'lnrl 

obc.er' es 1 'l c. l umt whole, nm°' mp: one of 

th<> three LlOl l~ he <.eec: th 1t he 11 ts t 11 .. n ' 

of ihe whole umt, .Jnrl h\ remoT"m.!! ho of 

the Llock:,, he h'lc:; t'lken ~ of the \\hnle umt 

50 The aho\ e 'lrl but a fe" oI the mnnmer 

'lble c:;imple problemt- or p11n1111 'lr1thmlt1 

cal operahons th'lt ml"\ be obJertn elv 

demonstJ 'lte1l b' the n r'lngement of the 

b1ocl...s 'lncl holc1:e1s Vnionc:; rombm'lt10ns 

55 ma1 be e-,:lnb1tec1 m the l 'lCk whue com 

pailsons may be m'lde, 'lnd the difFuent op 

enhons e'i:phmed b, te'l<'hers to c.l 1sse-., 01 

mcln ich1'1l pupilc; 

While thP present emboclnnent of the 'lp60 ph'ln<'e p10T"1des for 24: holder!, 87 blotks, 

anfl. '1 suppoi tmg rack 24 um ts lug-h 'lnd 

h ivmg 24 comp'lrtmentci it "111 hP under 

stood th'l.t these quanhhe= ne arhlh uy that 

the car.ac1ty o1 the c1.ppl1ance may be m 

creasec, or decreaseu1 that the ele111cnta1J 85 

umt block ma1 be 01 different dimension~ 

than th 1t opec1fied, with the multiple umt 

hlocl ... s d1111ens10necl accordingly, and that 

the1e m'ly be other c.hanges, oi dnersions 

:Ciom the £oregomg specific.i.hon without J.e '10 

p'11lrng £1om the i.:.pir1t of the imenhon or 

th<.. scope ot the cl ums 

Haung de&c11bed hlJ ime-nl10n, \\bat I 

cl'!.JJD. and 1lec:;1re 1o be<..Ure bj I ettei., P neut 

w " 1 In UI tdulat10n 11 'lpph'lnle 'l -.eul'"' ol 

bloc.kl: of um form gn en du11enc.10ns "lud, 

are u&ed as elemental) umts and l &elll"- of 

blocl ... s haung b.i.n&H1sc rhmem.1ons cqu'll 

to tho::it of the element 'll \ umtc; and ha\ mg 80 

1h:lfe1 ent length 1hme1h10n'1 of mc1c'lc:m~ .. e 

queme multiple.& of the len/!th d1m<>nc:10n or 

n elunenl'llJ nmt L1ocl ... , t.hl secon 1 se11Ls 

tompusmor g1oupi;; of d1ffetLnt. length::i l 

cletunune~ numl1u of ]Jlotlc& bPm~ t\\ Jle the 85 

lengtl1 of '111 elen.ent,uj urut bloc!\: 'l deter 

mmed numhe1 hemg three hme::i the len~th 

of an e1ement'l1 '\ Llock, 'lnJ so on mckh 

mteh m sLqneme the1e liem~ 'l dete1mm1..1l 

llUIDbe1 of hl .. C' lJlolk& In l lCh g"lOUp mil 1 ltt 90 

length d1mc>nc:;10nc: of the blocks m e'lch 

g1oup hemg .i multiple of the length c11mrn 

::i10n of m ekn.ent'l1~ block-i and :i. seues of 

11ol1lc.>rs for the hlo• J..q, S'lld holders bemg of 

ddferent lengths coirespondmμ- to the 95 

lengt h::i of the block"' m both the fh c:;t, and 

::icconrl series 

2 111 ln e1l11c1t10n'll i,iph'ln1 e i .... er1es 

of bJocl..s of uruf ou .. 1 gn en • hn1c ns1ons 

wln<'h 'lH. used 'lS eJem<.nt 11 '\ urnt.... md 1 lOO 

c.ent::i of Llod .. .., h'l\rng transH t~e 1lim<:>n 

'-IOnc:; e'lu'll to tho e of 1he c e111Lnt U 'r untie; 

.irnl h'l' mg 1hffJ'll nt length d1mc.>n .... 1o1h of 

muPa'Hng sequc>n<'e mnlt1ple.... of tht> 

luL1.Jh 1hm n~10n of m <>llmc.>nt 1n i.m1l lO'S 

blo<'lr the 'u on1l ~lll"' • omp11-.mL g"lollp' 

of chffe1 em IPn1-rth.. ,1 clt ft.>1 mmf'• l m1111l1e1 

of hloC'kc; bung t" l<'<' the Ii 11gth of m f'lP 

ment 'll \ nmt lilorl.. i clC'tUl'1.111Ul 11111 tlil t 

hemg threl bmes the lrng1h of rn "It. 110 

ment'lIJ blodr, 'lml "0 on mrlefilllh h m <-c 

11neme thu C' b0m,g- i ckte mm1.1 l numlJl l" 

of hl .. c blocI~., m e'lch g1oup mil th1 1eu<;!,"lh 

d1me1'sionc; of tlw hl0<'kc:; me •th g1 oup h<:>lll,!! 115 

l mulhph of 11H lenirth dm1e1Lc.10n of an ele 

ment ll"\ uml blol k 'l se11ec;, 01 holc1C'1.., for 

t.he hlocI .. ., "''llrl holdei::i be•nJ! of tl1ffuent 

len~ths r01respornlmg; to the lcn.gths of the 

bloc.kc;, m both the fiJ c:;t 'lnd bernn1l ser1ec., 120 mtl 1 c.uppm tmq i 1ck pro\ 1cled \\ ith a se,.Jes 

of opPn romp'l1tmentc, m which the holclf'rc:; 

'lie a1hpted 1o is1ule f.o1 cl1c:pJnmg- c:airl 

holrle1s unil the lJloc I .. s 1 'lrpul thc>1em 

In testlmon"\ whe1eof I 'lffi~ 1m i:;1gnature 

HFLENWOOD 
• 

Oct 23, 1923 

3 

REF ID:A70438 

H WOOD 

PRIMARY EDUCATIONAL APPLIANCE 

Filed Nov 16 1921 

1,471,437 

( 

\ 

.,. 

J!Y-2 

t 
• REF ID:A70438 

UNITED STATES PATENT OFFICE. 

Ne 832,871 

ROY DAVlD ~tl I f'III~LL, OT! SANDUbKY, OIIIO 

EDUCATIONAL DEVICE 

Spec:Ui.ca.t1on of Letters Patent 

Appho'lhon filed Deoember 21 1906 Sert'\! No 289,964 

Pa.tented Oct 9, l~Ob 

1o all 11Tlmn zt mm1cmia1n column l41s produced c11v1clccl mto 'cxhcal 

Be it l'"no\\ nth it I Ro1 DA\ ID l\hTCirCLI, columns conespomhng tu tl1( boch-rnlumns 

'l. citizen ot the Umtcd St ite:o, 'ln<l a ieSident on tht dnrt and irnchng thue\nth In e'lch 

of S'lnclusl'"), m the counh of Eiu 'ln<l St i.tL sp'l<'C thu<s made m the tlefmmg-column J.1 a 

S of Olno, hau imcnted 'l. DL\\ and Improved figure is produced, and thu;,c.. figuics re1d 60 

Educ'lhonal De' ic.c, of "lnC'h thl iuUO\ung consecutivc.h from 1" to an1 gn en figure, 

1s a full, clc tr, 'l.Dcl C'\. 1Ct desC'11pt um 'lnd the S'lid tl<'funng-column 1-1 is tluphcatetl 

The purpoc::e oi thL 1ment10n is to p1m.1dc at thl hottom of tht c.h nt, t.hL kl\\ er column 

a s1mpl<' de' 1ee to a&s1st 1 tNrhtr m mstl uct- bung clts1gn ite1l 'l.t 11" At tht l<'ft-harnl 10 mg 'l chs& m m'lthu111tico;, p'lrhcululy m sllle c.dge of the c.hnrt 1verhC'1l1lC':o10'n'lhng- 65 

'idchtwn, "lnch de' xc e "Ill ..., n r lla hme of column 15 1s p1 oduced md at the r1g~1t-h rnd 

a te'lch<.'l m chctntmg problems 'lnd thl tune edge of the rluut a rnrn•<;ponchng dc.b1gnatof tht stuclenib m \\ utmg thun, it bong mg-column 15" lb locatul 'I hL:oc columns 

possible for thL tl ichtr tu qmcl'"h u11l dC<'U- are cln ukd mto spac(s hn,~mg fi~urC's reacl15 r'ltth deb1gn,1tL tln bound ir1t<1 of fibures on mg from tht top 1lu\\ll\\ u<I con.,ecuhvC'l) 70 

'l rlnrt ID columns, thL figm es \\lthm "luch from 1 ' to any dl s1recl numher 

column:. are to bC' addc.<l, and f01 tht :otudent-. P:nallcl un<lC't<'Ut giom c:o l 6 and 17 'lre 

to loC'att tnd lUlc ofl thl hountlanes \Ht}wut produced In tlu> f1ont i 1cc of thC' uppC'rfI'lme 

InJUIY to the c.h 11 t member l 1, e\..tu1dm<r 1rom end to c.n<l of :oa1cl 20 .A fmthex purpoo;e of thl m'ent.1011 1q to member, ,mil p'lrallel longitmlmal unclC'rcut 75 

provide 't. de,1ce of tht clrnnctl.'r described gioovesl611 and 1;amcp1oclme<lmtheoutc1 

\d11ch \\lll be voy snnplC', c.a&Il) under-;;too<l, f'lce of thL 11ght-lumd sICIC' member of the ~ 1 ancl IC'lchl1 h'ln<llcd, and "luch can be wn- frame, 'lncl tlwo;e lat to grooves e\..tcnd f1om 

vcmcntl) held m tht lap 01 phC'ed flat upon a thC' uppC'r member 11 out tlnough the bottom 

25 desk end of tltl :owl sule membu, l"I 1s illustr1te<l 80 

The mvent10n LOill>lbt:o m thL no' cl um- m Fig 1 'I hL ...,l gi oo' es Hi mcl 17 1611 and 

strnchon and comb11u.t10n of the bner'll 17~'lreofhh.ecross-sccttonalishapE' ln<lthC') 

pc1rt:o 'ls "111 bt h<'l<'lll'lftt l full) .,l.'t fo1 th m'l) be. T - .,}i 1pE'd m cro<ss-scction, but 

and pomtcd out m tht chuns usu'llh tht \ 'l.1<' gn en a eH '3<'cnt sh,ipt 

30 RefetC'nce is to be lt,1d to thl 1rcomp1n-r- (Sho\\U m !'lg 1) In C'onn<>ctwn \\1th thL 85 

mg t.h<rn mgs, foumng a put of tlu:o bJll l Ifil 1- b ml f1 um t\\ o dt'fmmg umo; 01 rulers(' md 

hon,m\\lnc.hbmHhrdrn1actubofrefeunre (' e'\.tLrnl from tht uppC'r portion of the 

rnchc'l.tt roneqpondmgp'lrh malltht hgme::. frtm<' tu fht lo\Hrporhon tlurcof, md thl,.,e 

Figure 1 ts a pl'ln 'ie\\ of the 11np11n eel clC'- clefinmg-'ltm.., 'l.re p1efer'lbh maclE> of thm 

1 35 v1ce Fig .2 1:0 'l longi.trnlmal seet1on hkt n Iht mtt 11-fcn c. '\.'lmple o;tLd-anil the sule 90 

pra<.t1clll) ontht hne22ofF1a 1 F1g 31s edges of the um., 'llC' punlld nnd btiught 

'l. J:>erspcctive v1c" of one of ft1L adp1st 1hle I Tlit hodv pmtwn:o of thC'bl 'lrtns are hrought 

definmg-arms emplo1 eel, and Fig 4 l'S 'l Ion- 'lS clo:oc 'lS com tment to thl 11ute1 f'lc.e or the 

gitudmal scct10n through one of tht slides I chart 1nd th1:. upper ends of s.ud 'lrms arl.' 

-1-0 A represent:. cl irmlC' compnsmg a bottom cun tel up\\ 'lHlh and tlwn earned o\ er the 9S 

memlJtr 10, 'l top member 11 ancl s1Cle mem- outu fac.C' of thL upp<'r frame mcmbu 11, a:o 

hers 12 'lncl 13, 'lncl withm tlnb frame 'l ch.ut bhown 'lt 11;: m t11E tha" mgs F'lch of the 

B IS loc't.ted, hehl m pl l<'e b\ 'l bllll 1hle b'lck smd 'lrmq 01 i ule1:0 C and C' iq prov1ded "1th 

B', &ecur<'d h) clo.mpo; B2 or their £qmva- 'l shde lQ, secured to 11.b uncl<.'l f.i.ce at 1t:o 

45 lents, as sho\\D m Fig 2 Tlu:o chart B IS uppe1 encl, th<. bald shde:o h·nmg tht same xoo 

ruled ma series of columns, arnl e'lch column cross-sectional sh'lpe 'l'> tl1<. gioo'\ cci 16 me\ 17 

contam'9 'l. series oi smglc figmc.., nn mged 'ln<l 16~ nn1l l 7J., 'lnd s'l1cl qhdcs fur the rulers 

one below the.. othu, thL figures on the rlnrt (' anll ('' 'lle m'lde to C'nter 'lllll arc adjustable 

hemg m almement. both' erhc'lll) and trans- I one m tht g;:oove 16 and the othu m the 

50 ve1:oel) gioo\ c 17 1•·or convemcnct m movmg smd io5 

ThL figures m the columns of th1:. hod\ I RI ms C'lch nun 1s prm ide<l "1th a but to l 20 

portion of the ch'l.rt 'lre p1on11sruously a1- or ib:. equn 'llent 'lt ltb upper entl In eonr'lnged, Lut 'lt the uppe1 edge of the r h n t 

1 

nC'rhon \\1th tht umc;, (.. nncl C' ancl <'lossmg 

R<]J'lC'C'Dt to the lTIDll edge' of the urpC'l mem- the said arms t \\ 0 t llll1SVC'rse dC'fimng-anns 

5 , bu 11 of the.. frn.mC' a hor1.tonta dcfuung- D and D' 'l.t <' emplo) eel of thC' <;•une constrlll- 11 o 
REF ID:A70438 • 

882 071 

t10n 'l& tlu .. Ulllb C' nnd f', but the shtlcb of tannng tolunms of figures 'lnd defirung-arms 

the .i.nns D and D' hau lllO"\enllnt m the mounted t.o bhde over the thn1t, trane.,ersel) 

untle1<. ut groo' cs ma. nncl 17a of tht frnmc and longitutlm'tlly rehhvel~ to the columns 

The f1ce ends of the longitutl1111l e.hdcs C of fw;me'3, S'lld 'trm'3 bemg m pairs but each 

5 and C' C'\..tcnd ncarl)' to the mncr m ugm of arm bemg cap'tble of m<lependent movement, 70 

the I°'' er membe1 IO of the frame, 'lnu the the 1rms of one p'lu crossmg the 1nnb of the 

mner ends of t.l e transve1se auns D md D' I other p't1r 

e-\.tend pr'tt tlc'tll) to the mne1 edge of the 3 In m educ'lt10n'tl de' ice, a frame, a 

left-hmd side member 11 of tht Ira.me.. J chut \\Ilhm the bUd hame, contammg col- 10 These 'trms C and C', D a.ncl D' 11111)' hL pl tm umnb of figures, and longitudm tl tnd ti anb- 7 5 

but. p1efo :i.bh the. urns C and C' havt u 'er- vc'fbe defmmg-ums adJustably mounted m 

t1rnll)-1eaclmg scale of figmeb m the 'e1tlt 1l th<' sud ft une, the said arms e'\..tendmg o'er 

defmmg-columns 15 and 15.i, "Jule the tr<.1.Hb- the bald ch ut, t.he longit.udmal a1mb f1om 

ve1se <urns D <tnd D' h He trnnsversely-1e td- tup to buttom .i.nd the trnnsve1se •urns from 1 5 mg sc tles of .figm es tho eon ie'lding the bllme side tu Side 80 

'ts the figmes m the upp<>r 1 ud lo" e1 defmmg- -1: In 111 educ'ltlon tl de' ICe, i framP the 

colunme. 14 tnd ua. upp<'r member \\he1eof lb pun1ded \\Ith unEach shde IC), 1s is dlustntecl 111 Fig 4, lb c'lercut grooves m ib outer f<tte J.nd the sule 

p10vided "1th 1 do" m\ udlJ-bo\\ ed spung mernbm "1th c01 responchnfO' grooves, ancl 20 19" at 1t1:> under e.mface, ue.u<tlh held 111 poe.1- tra.nsve1be tnd long1tudma definmg-arme., 85 

t10n by dip& 1q~ c,au.ed do\\n from the ends elch arm bemg prnuded with a sprmg-conof the shdee. .tS) me'lns of the said &prmgb hulled e.hde at one encl ind 1 h.nob it the 

19a the irms c nued bv the shdes •ne kept clt s1111e end, the shcleq of the long1tuclina.l urns 

right angles to the frmne m \\luth the) \\urh. bemg id tpted to ente1 the unde1rnt grooves 2 'i 'lnd are not. ea.&1ly mo' ed 01 Janed from m the top member of the f-r uue and the shcleb 90 

phce "hen c1.dJusted m tlie transvetbe arm to enter the undercut 

In tht. ope11hon of tlus dev1c.e, el<'h pupil gruu' ec; m the blde member of the ft tme 

being prm ided \\1th on<' of bald devices and 5 In an educatwnal device, <1 fr<tme havt.he te 1d1e1 'llbo "1th 011e, the te td1u \Hll mg un<le1cut grooves m one of it.,, trmb"e11:.e 

30 set tho longitu<lmal armb 'lt p1erletc1mmed memberb tnd conesponchngg100,ei:.moneof 95 

figm es m the upper <tncl m the hm er defimug- its blde members, a chnrt held m the said 

columns 'lnd the tnnsverbe 'lrms to tert un JH>me, h tvmg upper md lo\\ er defimng-col-

.figureb m the lungitudmal defuung-columns muns 1e irlmg m consetutne figures com15 o.ncl 15 .. , c1lhug uut these figurCb lo the mencmg with "1," and long1tudmal mn1-

35 dass 'Ihe studcntb of the thss \\Ill then gmal defming-colurnns hl..e\use ie'tclmg 111 

m'lh.e t rnrrespundmg adJushnent ut thL i:. wl c.onbec.ut1Yl hgureb commencing with ' I, 

anus upon then ch.11tb, tnd the figureb t.o be the hu<l) p111 hon of the c.h i.rt bemg provided 

'ldd<'cl tie thus con ta.med "1tl11n tht fidcl "1t.h colunmb 111 "lmh figmeb ire p101111sruhounded b) the s t1d trlllb 'Ihub tn unlmt- oush p111duced, lung1tudm ti and h tns' erbe 

40 1ted numl er of e"'\.'tmples can be given out defmmg- nms, each clefuung-trm being proand md1c'tte<l un the chart '.it.huut mutil tt- '1ded \Hth L slide tt one end and J. luiob 1t 

mg the... sanu. anrl sa.' mg t.he tunt of dic- t.lle so.me encl, thL slides correbponclmg m 

t ltmg the figures and the tune of "utmg crobs-sect1011 tu the CIO">s-sec,hon of the bll.Id 

do\\n the figmec; In 01der th<tt the hce g1.>ons, t11t bhdes of tlu. longitudinal ttrms 

45 ends of tht defuung orme. or rnles shull 11ut. Le hemg <LdJU&tnble m the h<lilbVe11:>e g100' eb 

m the W'l) of the use1 of the device, t gmde- and the. bhdes of the tiuns~ <'rbe 'tl ms m the 

rod 21 is seemed to the h<nne 'lnd is a1ched lung1tudm tl g100' es, the ti m•n e1se 'lrms e"'\.- o,~e1 t.he endb oft.he long1tudmal urns C 'ln<l tendmg nom side to @de of the c.h i.rt and 

C', and 't smulJ.1 rod 21 IS aiched O\er the, the longitudm'tl 111ms from top to bottom 

50 flee ends of the trmsve1se arms D and D' the1eof, the hall.b\ erse 'tlills h t"mg n sc'tle 

I desne it to be unde1stoud th<tt I do not of fi.gme::. J)roduted thereon coucspondmg 

confine lll)self to the. Iota.hon of the g1ooves to the ret mg of figmeb in the uppe1 and 

lil the n tme, as the) may be d1fh,1entl) I lmH?I ma1gin t1 rnlumns a.nd the long1tud11utl 

placed "1thuut dep'lrtmg from the bpllll of armslnVIIlg a scale of figureb produced the1e5 ~ the in' ent10n on c,orrespondmg to the figm es m the said 

Havmg thus descl'lbed 111) mvent1011, I m'trgm,i.l columns of the ch irt, a.nd guards fo1 

ch1m as new 'lnd deSI1e to bee.me by Letters U1L f1ee ends of the s.i.1d anus 

Pitent- In tebtm1ony "he1eof I have Signed my 

I In .i.n educ'lhon 11 device, 'l chi.rt wn- J n une to tlus spec,1fi.catio11 m tile presenre of 

'ir tJ.llllllg columns of figmes, and defmmg-a1ms I two subscubmg \\Itnebl.eb 

wluch e"'\.t.end o' ei the c11urt md 11 e mountc,d ROY D.A VID l\IITCIIELL for mdepeudent bhdmg 1110' ement, sund1 y of 

them longitudmally mu othe1s ti tnsversely 

iel it1vely to the sud c,olumns of .figmes 

2 In a.n educat10n 1l de' ICe, c1. chai t conWitnesses 

l VV Boo11..M'l 1m, 

Fu \Nh. F LANG"\\ :cu 

100 

105 

l IO 

120 

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No 832,871 

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• REF ID:A70438 • 

PATENTED OCT 9, 1906 

R D MITCHELL 

EDUCATIONAL DEVICE 

APPLIOATION FILED DEO 2 1905 

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ATTORNEYS 

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