claimed is:1. The herein descri@bed rqdiator Linit comI)rlsiiig oliter ii,,,tlls -l'ormecl@ from sheet metal 'I-Olded to provide ,t i:)Iurality of fins the double Ai@,alls of which are in tlgl-it contact, said sheet bent iipor, itself -",ith ,t separa'uor strip ,ind the ends of said sheet securej tocrether in a fii-i to. provide an imperviolis linil-, wall, t'iie -oortions of s,,tid sheet between @-lai.d iiiis proviclecl each ivith a I)Iural@ity of i n -Lentions airaiiged iii a row saia indentions mee'Lliii,@-@@ sftid fins to provide between each verticvl pair of indentions a lip,, and a serratect 'ilanged edo-e portion on eacli side of 9 ',d shee'u fo-.L '7Lter zn tn tn zn ti, . 1 -Littin-ly eiiua(yintlle seill.,-Ltecl edge por@Lion of a similarly fornied 2. The hereii-i described radiator unit c6mprising o Liter wal@ls f orined from sheet metal F, folOLeci to provide a plurality of fins, said sliee,c, b---iit -Lipoii itself with sliid fins inwardly disposect ii-i stao;gered relation -with a, sep.,i-a'Lor scrip bet)-veen .tiid the ends of said shc,e,t sect-Lred 'Lo(,Ye't@-her in a fiii to provide ail iiii,l)eri,,,ous un.it -%vall, the portions of said sheet betweeii said fiiis provided each -with .t plui-,ility of spherical iiiclentions arranged ii,, .i row, said iiiden-Ilioiis iii vertical ali(rnmeiit aiid irieeting saicl fins to provide between each vertic.-L'i. pair oi indeiitioiis in oiie wall a lip disposed opposite a, row of indenzoiis in the ottier Nvall -v--,The ebv i.)ositive t t ! r -LTrbulence is given to the water fl@,v@ing between s,ii(l, ivalls, a@id a serrated fltnged edge portion on eacli side of said sheet for interfittingly engagino@ tl-ie serrtted edge portion of a siniilarly formed acl-jaceiit unit, the t-wo tinits so, j,oined formiilg therebetween a -water ti--kbe comprisino, the vertical series of said indentions. 3. The here'n described ra(liator unit coi-i-i- 70 prising o-Liter wa.]:Is formed from sheet metal folded to pro-vide a plurality of fins, said sheet bent upon itself -with a separator strip bet-@veen and the ends of said sheet secured together in a fin to provide ail imperviolls 75 ur, i t @ATall, the partioiis of said sheet betweei-i s-,icl, fins p-rovided eacli with an abu'umedt aiid ct ro-", o,f spherical indentions on each si@de of said abutment, the indentions of each ro", meetiiag said fins and each otlier, t ser8( mted flano;ecl edge portioii oii each side of sfidshoetforinterfittin,(,Iyeliffaoin theser9 i-,,tted edge pcrtioii of a similarly formed adjacent unit" the two units joined aiid soldered ovili there tween a water 85 ,in er pressure tube col-til-@rising the said indentions, as well -Ls 'Lo, forii:i a celi@tilar ai@r coiidtict,iiistruell-i,li-e in each unit., said ,iir-celltil,,tr structure comi,-i@isiii(r sa;.cl separ-,ttor stril), ,tnd all of said fiis I'n L gei:-e@'t in'erfittiii@g heat conductin,n" i)o i-el ,,itio,.isl-lip therewith. --iii testiii-ioiiv whereof I affix my signature. WELLINGTON W. MUIII. 95 100 105 iio 120

Patented Dec. 29, 1931 11838 568 UNITED. STATES. PATENT OFFICE@ WF,3-,LINCL--OIT W. T@l(UI--R, CF LO--UPCRT,, NEW Yofix, ASSI@r,,-TOP. TO HARRISON RADIATOR ACORPOI,'.ATIONCF NT-.,Wyonx F.ADI.,.e.TOR cc)r%r,, r, OR @..UTO@YO:SILE COOLIIITG SYSTEMS T'@.,Lis invention r6lates t6 the cores @of racli,,t-- 'Llors for t'iie cooling systeins of iiiteri-icql Coil'ib-,istioll engines I or t-he lilce his ior i,@,s ject to provicle -,, moi.,e ob' eoiistr,,Iction v.,,hilch is le,,@s costly t6 inai-iuf acti,.te tha 'n 'Lhose oi--e propo--ed. these tDet otl)e-,! obiec-t-,@ill @,iew IL-1-le invention consis@'s in,the Dovel cleila@ils of constriiet,@oii gi-id cf pirts as w;lil be iiaore'f Lillv fter (- f,,,sciosed -i nd par0 tict,,I,@,rly -Doi@ted otit i-,, the -Ilc-,ims Referr'ing to. @,he ace(-,iiipanyil-ig -,[ra-wings foi-miiig a p,- @r-t of this sp,@cifi@,,It@ion in A-Vhi@li li-ke li'Llinerals desi ,tto lili:e 1,)arts iii all tl-ie gn views'Fig- 1 is' a front el@vatiop a', vie-,v son'lewhat cli-,igrainmatic illustrafin ti r,,tdiator for a--n 9 aiitoiilobile contai ning -,t core and bu it ,tecorcli,.-ig t,o tllis invention, @o' Fi@@@ 2 ill.-Li@-trates the tsseinbly of a porti6ii of a radi,@itor c6re and iiieliicling ci, pltirali@ly t,% . il partly in sectior. to tl-ie better illustrate the co:nsul@Liction, and said @-glire also inellid26 ing elementtl part's (Iyoip(y to make -LiP the as- :- q-embly; Figs. 3 ,tiad 4- show respec'ively,a top T)Ian vienv ancl perspective vie-w of th.@ portio-n 6f the se i)arat6r sti@ip showi-i i-n Fi-o- 2 @6 Fig. 5 is -t perspective vieiv sonieNvh,,Lt diaic illustratiiig@ an asseiiably of core gr,,tmm,t units for a radiator requiring la@-ger wat6,r cooli-ng C,,ipteity anc.1 stich for example bs foiii-id in airplanes or ar@tomobiles@'of @exti-emely high horse power; and n ri ig. 6 is a horizontal,sectional vie-w teross oiie of, the ivater tubes taken is oii the !I.-ie 6-6 of ri ig. 2 an'd 16okiiig in the direction of the arrows. io In 6rder tli.at this invention iuay be the better iincierstood@ it i stid thqt he,.,ef.Ofore radi,-,tor core constru@tions have been such that either vertical or stibstaiitially horizontal ivater tiibes have been f ori-liel Avbieli permit a passige of ivater therethrou@,h ivith insufflZ, cieiit cool;_n@@ thereof Linder some conditions. This li.Ilts been cali I sed by se-,,eral f actors siich nsions or cap, Ell."@ iiia@leqtiate dime Ieit)T, ilISUMcieiit r,,idi,,ttin',o;,surf ace f6r th.e ttanqer I of heat oil f@oiii thpcoolino- fluid to the atmosplie@e, a too direct pass,-,ge for the cooling fluid thr gh ou the raliafor whereb3f inslifficient time is --iven to the fli7iii, f or coin plete cooling thereof" and@ ivi -'@Ved tl-ler factcrs wbieli 11 be.rea@clily obse ,incl tinderstood by those sk-illed in the art. The pLiri:)os.e of tl@is inventioli is to provic e t coiistru-etioii whici-I is @@omei vl-iat si-inilar to rior constrl-i6ti6ns:in th,,it tho core Li@qits are p lia,,,,defrom extrei--qely thin inetal strips which arepreforn-iecl by criiiipin- iiito shap-_s wl-iieh -I c' Nvill fit will r@--,,tdily -'Lit one aliothe-r or WI i n @-,eparator str-'-,ps pro-,,icled therefor, all t6 the eficl tlitt the passaole 'Of cooliiig fluid tl-irougli the @rarliator core will be broken, idte I rrii tedi p 0 W -iisfer of r other ise, ,i:ffeel-ed so thot a.tra mo_re heat to the Itti-nosphere is a,econiplished because of the prolan-ation of the passa e 9 and ii-icreased tiirbulence of @the fluicl through the +@,abes of the core. e v -it A still further object of th in ei ion is@to provide a codstructioii offering less resistance of core ul@its, s-.iiel @figure be,-ng l@ll vei-'Uical de-. biit more tuirbtilep-ce to the air passing through the cori,- for absorbin the heat@given off from 9 lbh6 c6olino, Auid. This inventioii is pa.rt@@eiilarly applicable to radiat6rs having siibstantially hexaaonally, T-ornled air e cells ill its cor @ it bei.ng under-,tood that other forms may le readi elevised which will still fall I'l tll withi e limits of this inyentioii. The actiial foriiiati.on of these Go@ c s e clescribed s that the initention ell sh @Lild b 0 mav@be'the better iinclei-stood ,Lnd therefore the followino- is directed to a diselostire of such coi-istruction. Extre ely th' sheet's f soft metal, in 0 hav- 135 ing Iiigh heat coiidiietikitv ai-id such for exainple @s copp(,,r or bra.ss, are formed into na-r-, i,o@-vv strips of about 2 to 3 ineb.es width. This wliich is stibstpnti-qlly coiitinuolis is fed @i l@roi.P a r6ll th,.ough pressure rollers the sur- 90 flees oT' vvhicli constitute dies to impress in lig - I Stl,cl strip a plural Dumber of tro h I'ke indentio--Lis I ext-nding lergthw;@se of the sttip, and @10 ii-ripr,-ss in th(, surf aces of thesc, troughs it st)aced intervils traiisverse ro s of smaller i,, - w indentioils 2@ , Said rows are spaced from eaeb otl-ier so that, in its cont@ip-u'ed passage tlirougli the fori-niiig ma,chine, the core strip comes in contact with@fcldiDg,- clies which depress the portions df @the strip between tl-ie rows of @of-% i,,,

smaller indeiitions all(I tlieii Iel)i,essed portions are pinched to(yetlier it tl-,e sicles ofthe sti@ip to foriii cloi-ible thielmoss fins 3 extendiiig laterally from the plane of t'lie m,.tior portioli of the strip. The ii-identions 2,tre stibstantialll.Y of splic,@-ic,.il formation aiid the core strip i 's so fashioiied by the dies that in each ro-w, of indentions.there is a ridge, or lip, or meetliig joipt lo of metql ivblch extends oLi4.-@vard@y beyoiid the fiiis 3, ai-id the iiietal. foriiiino,, --ticli 1-@idffes has i surface an,)-ularitA, which - @:ei-iders the e_l same as sides of ,i hexagoii. That @@s to say from Figures 2 ind 6 it %iill be .zeen th,,it tic 15 -d(,es 4 of the core unit are qn(yiilarly clisposed to eacli othei-, @-,jid the eie,,Y,@e-, of rit u u I @n - l@l .1, is that bewc-en 'wo adjaceiil sdes of ,t , - hexagon. The qreas 4 exteiid ojil.), about three-six'Leenths of -,lii inch fr6m the ed(re of 20 the unit strip. or for a dist,@iiice stiffici-e-.ilu- oiilly foi@sol@lket@in-,tivoacljacentstri sto(yeth-,r. p The strip so foi-iiiecl is then cut iiito leig'tlis slil-Ilitlv more th-,n twice 'uhe dimensio,@i of the fii-iishe@l core meastireci from top 'Lo botto.-n 25 thereof. In other iyords, if the core Ps completed is to be al)oLit t-kv-,nty-fotir inches iii lieight theii 'Lhese strips .ire etit irito len(yths of al)oiit fifty inches. The piirl)ose of this is to periiii'u these pi-ef orip-ed stri-I)s to be folde(-l '30 tipon themselves as clearl -ndicateci in the y , dr,-,ivi-ngs, the surl)]-Lis inei-,-,l beino- taken up in the folcls 6 qt thc., top and botlom so tli,,Lt wheii the ends of the strip are, brought together and interlocked in the single joitit as 35 sliown at 9 i-,i Fig. 2 there -Nvill ],)e T-ormed t core iiiiit of ,t len!@th eqiial. to the 1-teiglit of thefiiiisbeO,i,acl-latoi-. Apredetei7m;-iiedniiiiiber of iiiiits are, then qssemble0t to 'Loiiii the finisbeci core indicated at 10 iii Fig. I and 40 the required heat e-ndiietiny arei,. ivision or separator strips in-,il, be placed bet-ween the fins of eqch unit -,s des;.red to "is.qist in the r-ldiation of he,,it as -wc'll as U0 stre-n(-rtheii the core. The flps fo,-m I)ortions 45 of the wall striict-Lire of the air ceils 3, the rei-nainder of the core iiiiit qnd the sel,)arator strips f@)rming the otlier ivalls of c,-Ils. -The troii(Vhs 1 constiti-ite the ma,n portions of t,i-ibes to coiidiiet the coolinfltiicl, -,u-.ch as 50 water, from si(le 'L-,o s;de of the raclialu-or diirinwliiel-i tr,-vel the heat from saici fliiicl is al-stra.cted ancl trangf-orred to the air i-)-,ssing tl-ii,ou@,rli the air cells. The formitiop- ef 'Lhe radiai-or core ii-iiit strips inay be reacl;.i.)7 i-in,55 derstood from the foreffo-,'iicr -@iid iv;tli refereiiee to i)rior issued p,,ttents sitch for example as 1,169 481 aranted Tan. 2,5, 1916, to I-Ter,)ert C ' Hirrisoii for process of atitomolDi lo r,- cli,@itor sections. 60 Referring to F]'@,r. 2 there is diselo,,zoO, t racliato,: core co-nstriietion ir. -",hich a fla'u strip of i,ei-v tliin 'meti'l is employecl -whicli hgs I)een -,r)revioiis.17 passecl tbro-Ligli- formii.-,@,y i-olls ,is , ibove described to in-ipress tl-ierein tie r! ti@oi@-ghs 1 as well as rows of subst,,intially 1,838,568 spherical inclentioli@, 1.) vvit'ii folots coiist, i'Lltiti 119 fins 3 sepaiatincy the rows of incleiitations. Fron-i Fig. 5 it -will be obserAe(.1 that ii-i tiie, formation of the troughs 1 there are create(! flaii-es 4 at each side edye of the core str' zn t, j P) so,,"d flanges haviil,)- ,)lane surfaces Tor 'L-he purpose o@ seeliriii,, one raclia@lor core Linit to its adjaceiit unit. That is to thei,e are 1,,rovided a plul-alit-y of these 4 the surf ac(,,s of all of wliieh are hexao-onall.), clis- '4'5 posed so that whcii oiie uni'u is broughl@- ul) t(rainst aii adjacent uiii'Ll the ti,,,o tiri-'Ls illay be tn secured together is Nvith solder to, foi.-i-n s'l('te,,; o'L hexagoiial air cel.Is 8 as clearly ii-i i@'ig. 2 the co;ncideiit troli-lis of tli(, adjacent 80 Li-ii1ts foi-iiii-iig t'@ie witei, tubes o,,- pass'a@-,,es o ' n tlierebetween. Radiator coiistr etions are so -well u tli@qt tie above wi-'il be reaclil.y uiiderstood l@)17 oiie sl@illed iii the ri-t 1-)art-lct,,Iarly viith ref- 85 crerce to the draivi.-i(ys, bit'L, 'It iniol-lit lie,,e be statecl tl-iit. pi@eforiiied scrips ai-c T-olde(I blek ul,)oii theiiiselves ei-eatin(Y a f-,Dld siieh ,,,s si-ioivii at C, ii Fizol-. 2 and a sei@aiator stril) -.s sliov;.iiit @'is i-iise,,-'.-ed betiveeii the 'Lol(le -d ovei- go portioiis of the strip an-,-I ify"liiist ihe i'-Iis 3 i,,,ill c(,iitac$'ingly rest so ti,at as the lictted fluicl, sucli is - water, co-ii.rse@,, dov,,n t'lie ter t!,i.,3e r), fts i-dicatel by the arroavs iii Fig. 2, the 'iie,@it froiii s,,ti(I Ni-,,tter ivi,ll b,. takeii itp 95 1)37 the IL-Iiiii metil o'l the core ,ind 'Uliis bc-,a'L-1 will be triiisferre,,l tlir(,iigh ti@e ftiis @') aiid s-2i)trator plate '@ to the atiiiosl)liere -@@,hicli @'i s p,,i,ssiii- tlirough i[lie si,@)aces 8 lznoi7n is tli-- @ii-i, cells of racli,-,tor. In othe--,- i),-ords. b @ @, the 1-00 foregoiiig desci,iptloii it be i-.Ii-i(l(,,r'stoo(I that ,i core is forir,(,d provicling closel ivatei5, ai-ici openin,)-s 8 ','oi@ tiie ttii-iospliei-c ivli-'Lcli are iaot closed at t@beir eii(is, saicl @itiiiosphei@e is free '@o 1(5 spaces aiid o-,-e@,- the stirf@ices ol' 'Llic, @ll 'Lile radiitor coi-e. it is to be observecl fioi-ii TAi(,,-s. 2, iiicl that the c@eparator stril) 7 i plaiie pi-ece of wlii-el-i 1,,.a@-, been ei-,t ai-.d exi),L-ii(]- .110 ecl in opposite cli.rect;ons as dis-,Ioso-l i 1. ]I tl-l(,@ U. S. Letters #1.220,74,,@ 27, 1917 t,) Herber'u-. C. Htrris,,,Ti @iii(i eii,L"itic-(! "-ALit'o;iiobile Pnd +114,@ -,'iiis 3 are disposecl in @-,t-,tgg,-@red v,- it'li 115 this coiistri-ictioii @Llie ii-iclei-ii iois -9 made to qssLime stfagcrecl po,@,,itions ivitli respect to elch otlier 'i-'vlicreb-,, the in -1,@-Libo 5 v@,ii.1 travc@,!- ii-i I zi@(Y-z,-," iiIF:te"l(l O'i 120 ii-i i trlily vert,@e.-,l i)atb. This is i7i(l@ic,,itod by the @,irro-v@,,s ii-i Fi,,,Y. 2 i Rd or(, n( fiirl--iie-,-, -,tescriptioll is d@e,Tielo, ce,-,t to sil-,,ite tliat by'Lli.is co-.qstruction -iot oial)- is tl-.e leiigtli of th(,, i7,ttei- colti,.-nii !25 from ill-ie to'.@ to t'l-@e I)o@toiii o,'- tlic,, co-e(, the Avl-i;le tlirolli,- i !-lie slil)je,cted t,) a, tli@iii i7l Colleretofl)re aii st@Titctions h crease(I transfei- of hei,t to thp ii-ietll o-L' j.3o

core is aecomplished without uiiduly restrieting ti-ie flo.withrot,,gh eael-i t-Libe. As a result ,t higl-iot iii-an temp r u e f the m e ai r o etal of the -,ntire core is obtained whiclii ins-Lires n-i,,tx@5@ i-mtim lier@t tm,, nsfer to the air;. Also it is to be observecl that tt-ie inde-Titioiis, as elle,, rly seen In Figs. 2, @ 5 @,tnd @6 are @slibstapt.ip,ll somisl)lierical in form aiid 6f a si,-e ,-ii,txiiiiu,iii to @th-- diiiiensioii between the fins 10@ 3 T@hereb@, ,)rte'uicalli@ all the metp,,l betwee-@i % sai-d firis is cl ilect t of the t e e . ou xial line of 'u-iie ivater tiibe 5 to create the areatest 1)o@sibl-3 deto;re(a o,-' de-@qection of the Nyater 'colu@rin i:ii tl,i". c(,,re.; @ l@T4.th P.-'Lerei-ice to Fig. 6 wi-i,@ch ;.s a ilorizciital secticiio@l@view'of the T)arts show,-i i-n Fig. 2 -@vill be seen 4-1 sh6Lild at-i-v f6reigii ri-iatter pass over ivith the coolfni flliid fron-1 the engine -.rd becoi-iie wedged in 9,iiy c.1l.e o-L' the iiidei-itions 2, ti,.-e cortinued passe@ge 20 o-11 ,vater i-s not affee@,--d si-7ice the following FIDAVTill rass @to eit@her s-tcle cf tL-Le obs@.-ruc'Fioii.- T-,i o@tli r w i,uc- - ere -Ls e , or-ds, by this const t; on til provi-,-!P-cl iiot only @t ii-ie-,Itis of @orducting tb6 he,qtecl f'ivid 'cnrougl@l Ccre c,rom @t'iie top 25 lo 1,3,-ie: I-,ottom -ILc,.erc-,-,f,-but there i s.proi-,'Lcle.cl additior,al ii-ieans oT autoi--n,,itic,@iII3, inc'reasiiig t@.e- eiiect b37 nial@:iii!g4the inden-tioiis in sta--:@-ered relption -w-Ith@each other -.nd LIU(Iliei@ there is provi-,Iecl i-nea-.is for periiiiI.-@'D tina t,ie -, P.ter II', i@ s I.Io-w froili the top to the ],-)o'cioln of the core to travel lateraII37 from one ve,,,t-c,,,,l p@ ir of '-ncleii'tions 'o Lnotl,.er ip- a I a c O@ir-3etion -@ )m @r, the f-ont to !the b,-Lek of the ii,hereby the i-p-axi@iiui-n coo7iing effect 3@5 -"shacl. - kisoitwilibeevidentfroiiitliedra-wes,,@,c-cially Figtires 5 a,-id 6 that tl-.e air t III p,,issi@ -I-)-rou-h tllle @ore will coiitact -v@,iti-i -iei,-cal ails of 'u-he ro,@i, of inel tiot-is tile s,,)! "V s eii -h e air -0 result t v@t th column will be 40 broken up, or ot',-ieriv@-se affected to cre,,i:Lue ti greater t-LirbLilenc6 thereof tha-.nif there i-, c2a no, indeiitions. Ti-i-arefore ther6 ro,sultv, a greater absorl.)tion by the air of the I-roi@-i the inetal. Fron-i @oetlial experi4," i,.i 0, --, i 'u it has bee-.q observe,-L thaf. thepe in,-Iell-- tio--@is @), s.1-@oLild be oT- a. cle-L,)th. i-iiaxiinum 'o the clas'(Iicity of the mllt,-.1. I,.i ol@her words the ei'i@ciency o-' the heat tra-usfer inc,-,eases witli t]-ie of saicl indentions and rtpidjy E,o filis ofi' Nvi-@,h a Clecre,,Ise in depti-i. In th(,, precedino- constrlictions it should be stated lihat the p7e-crim ed strips forininoP tile -",ater tubes as -well as 'Uhe se-o,,irator strips associatecl therewith are pref erably forined E'5 of e-,-Urc-,mely th-'@T-i met,,tl, ,ind in practice they are rnade of brass as well ,ts copper. Eael-i. core Linit is forr-ried as above described but ;@t @hould here be stated that tl-ie joi-nt 9 of each is soldered t6 close one wall of the water FO t,,7,b- ,igainst le,,ikaue. After the parts hdve been a@sse,.ubled to form the 4entire :@adi,,Ltor core, a clamp is placed around the 4-ssembly ai,,cl pressure applied t6 hold the parts in tight contacting enga@rement. The core with 65 the encompassing clamp. is tl-ien laid in a bath of solder so that the entire surfaces 4 see Fig. 4, will take up the -solder and thus u e core as a uni mass. The @ assee re th 'fled s@mblage is then turned over and the other side immersed go th,,tt the solder may affect the surfaces 4 Of the opp@site s-Lde of 'tlie radiator, all as will be readily rinderstood. The clamp is reiiicivod after tl-ic, solcler has coolecl and the unified radiatot@ mass placed within' iis encompassinu shell aiid'th us inaele i@eady ttac@nient 't@' ile chassis. for a o the alitomob in Fig. 5 it will be seen that between: the si@tes of the co,-e unit, at equal sp,acings, t,l-iere are forn,.ed series of raised portions 18 the --oose being to tise the' ame as abutiiients plii s to add strength to the core asseiiibly as well as to keep separated the oppcsite walls of a -kvater tube 5. TI-iis invention is not to be confused with the inventioi-is disclosed in my co-pending applicatioii,-, Ser-tal Nos. 358 f25 anct 358,@37,,each ent:,t led "R,,tdl@-Ltot 60.)@ f-or a-Liton-iobile cool'iix s3,s-l-ems" aiid ei--h filed concurrently herewith. That is to say, in applicatio_n Serial No. 358,71-)5 there is disclosed a radiator 90 core having sqlare air Celts f ormocl by ebr,strips bent arolind an,-l separafed by- an in-@ termedipte or s epara,to@.strip which is perfectly plane. In@ other -w6rds, said separator strip is il'i l@s orl_uiiial sheet formation 9,5 and is ipserted between the fins of ',he core strips and is -Linsecur-,d to said fins e,@ -cept at em e the extr e ends th reof . Further the ",ater tiibes are formed b3T a plurality of spl-lerical indentions in the stirf ac-, of the core strips io,13 and these strips with their indenti6ns are. so assemblecl tl@at ositive turbtilence is 1, P 9 ven the water co rsing throuzl-i s d tubes. N t Li 0 only this but posltive turbul6nee is gii,en to the air passing thi-o-u.. ah the I air cells cILie to 'c@ the spherical formation of said indenti-ons. On the other hand in applicatio-n Serial No. 358 73@ there is disclosed a core - h,,iving hexagonally forinecl. air cells inste,,td of sqliare Ones. @ Also the core strips of this apI_lo plication are ass,-mbled to @ form core up its which are devoid of any saparating strips the.-ebet-ween whereby t greater number of water tilb6s is made possible in a core of the same frontal area. Also the fins are so ii5 formed tl-iat there iiiav be water therein extencling in a ..Loteral 'Pl,.tne froni the main -water collimn wherebv a more direct - transfer 6f heat from the 'Water to the metal of the core is made po@sible thro-@oh said fins. 120 Accorclin -to Llie inventio-ii d;.selosed in this apT)Iic@ticn-there is provideci a core made Lip of -strips bent arolind utpon theinselves in spaced relation t6 form c6re units ,tdapted to receive an intermediate or sep,,-.rator strip in 2 such f asliion that hexagonal air cells are produced. Each strip is foriiied with rows of indentions substantially of spherical f ormation wheieby the air in 'Dasaino@ throu,(xh said cellsis--ivenahiohde!zr@eofturbLilence. In @kD

4 othc-r *crds, the air@ colurnit, is i-iot free te, slip througii the cells btit in its p,,isstge it miist coiitte'L witli the splierical ol)s'Lruction aii,-! in pissiii(y tliereai-ound tl-te niclectiles of the co'it,,,Tnn ,ir<-, d'LstLirbed a-ii(I i-,i.terelia-.tgecl 'co such ex'ueiit that the outer iiiole,-iiles o'i the coliiiiiii coine iii co,-itact -with the ii-ietti,,nd then -,re displaced tcr perinil- @Lho inner inoleci,@- !Ps to come iii co-iitact vvith s,,ti-d - Tnetal 10 ivherebv s,,ibstaii'uially tll the iiiolecules of .,@ai.d ":-klalo. s@cl,,Ii coii'b-,@iclu- Aiith (,-i-eater Iiieat as will, be reaclily iiiiderstoocl. @"@l.s@)thefins,@,@iecordi-iiutothis are prefer,,tbly closed tightly i-lirough @Lheir lergth. 1'c slioiil(l P.-,Iso@ be obsel-vo@i the sel)aratoi- ,tril)- of tliis app@liC.,.tion is so eiit alid cliftoi@ted that them @ire .,,.ttial p-,s,-,agcs tl cretlirouyh ai-icl shou'id ai-i obstrLict,oTi oceiir in oie of the -tir cells air from ,taother cell is free to reach obstri-ic"ed cell throti,,,h saicl P,,issal-cyles. It is obviotis t,'j--iat thol,@e sk@'lled iii the art ii,iay N-ar@, the clet,,@tils (-,f construction v@nd arI P@trts const'll,- r,,t ('elqe -its o' t-,ti-.ig the a.-ticl-e, is 7,,-ell as 'hc- steps ai-,c@, coii-ibinatioiis o' steps coiistiti-iting the iiiethod -witliotit dei)art,@l-i(Ir from the spi-@-it of 'uhe iiivei-itioia,,indtherefoi@e it is iiot JLeslred to be Iiinite@d io the fore(yoing excel)t,.is niay be deml@nded by the claims. li@l-iat is