The Journal of Industrial and Engineering Chemistry, Vol. 5, No. 11

The J o u r n a l of In d u strial and Engineering Ghemistry

Pub l i s he d b y T H E A M E R I C A N G H E A I G A L S O C I E T Y

Volume Y N O V E M B E R , 1913 No. 11

B O A R D O r E D I T O R S

E ditor: M. C. W h i t a k e r

Associate Editors: G . P . A d a m so n , E . G . B a ile y , H. E . B arn a rd , G . E . B arto n , A . V . B lein in ger, W m . B ra d y , C. A. Brow ne, F . K . C am e ro n , F . B . C arp e n te r, C . E . C asp a ri, V . C o b le n tz , W . C . G eer, W . F . H illeb ran d , W . D- Horne, T . K a m o i, A . D . L ittle , C . E . L u ck e , P. C . M c llh in e y , J. M . M a tth e w s, T . J. P ark e r, J. D . P enn ock, W. D. R ich ard son , G . C . S to n e, E . T w itc h e ll, R . W ah l, W . H. W a lk e r, W . R . W h itn e y , A . M . W righ t.

P u b lish ed m o n th ly . S u b sc rip tio n price to non-m em bers of th e A m erican C hem ical Society, $6.00 y early . F o reig n p o stag e, seventy-five cents, C an a d a , C u b a a n d M exico excepted.

E n te re d as S econd-class M a tt e r D ecem b er 19, 1908, a t the Post-O ffice a t E a sto n , P a ., u n d e r th e A c t of M a r c h 3, 1879.

C o n t r i b u t i o n s s h o u l d be a d d r e s s e d to M. C. W h it ak e r, C ol um bi a U n i v e r s i t y , N e w Y o rk City

Communications c o n c e r n i n g a d v e r t i s e m e n t s s h o u l d b e s e n t to T h e A m e r i c a n C h e m i c a l S o c i e t y , 42 W e st 3 9 t h St ., N e w York City S u b s c r i p t i o n s a n d c l a i m s for l o s t c o p i e s s h o u l d b e r el er r ed to C ha r le s L. P a r s o n s , B o x 5 0 5 , W a s h i n g t o n , D. C.

Es c h k n b a c h Pr i n t i n g Co m p a n y, Ea s t o n, Pa.

T A B L E OF CONTENTS Editorials :

The M ining C on gress... 882

Ozone... 882

Bureau of M in es C o a l A n a ly s e s... 883

Original Pa p e r s: Copper C overed or C op p er C la d S teel. B y Jam es O tis H a n d y... The Condensation of G asolin e from N a tu ra l G as. B y George A . B u rrell and F ra n k M . S e ib e rt...■. Some T ests of P a in ts for S teel, S u b jected to A ltern ate Exposure to A ir and F resh W ater. B y P e rc y H . W alker and S. S. V o o rh e es... he Corrosion of M eta ls b y W ater. B y A . T . S t u a r t . . Some Experim ents on th e C on version of L o n g-L eaf Pine to Paper P u lp b y th e S od a and S u lfate Processes. B y Sidney D . W e lls ... Investigations w ith th e U . S . B ureau of M in es M o d i­ fication of th e A b e l-P e n sk y and P en sk y-M arten s Flash-Point T esters. B y Irv in g C . A llen and A . S. _ Crossfield... The T itration o f C alciu m and M ag nesium in the Sam e Solution. B y P a u l J. F o x ... Comparison of the K jeld a h l-G u n n in g -A rn old M eth o d with the O fficial K jc ld a h l and O fficial G unning M ethods of D eterm in in g N itro gen . B y T . C . T res- c o t... Ortho-Tolidine as a R e ag en t for th e Colorim etric Estim ation of S m all Q u an tities of Free Chlorine. B y J. W . Ellm s and S. j . H a u s e r... The Q u an titative E stim atio n of G liad in in F lo u r and Gluten. B y G eo. A . O lso n ... Duality of th e M assach u setts M ilk S u p p ly as Show n oy the Inspection of the S ta te B oard of H ealth. B y Herman C . L y t h g o e ... I he D etection of G ela tin in Sou r C ream . B y A rin in Seidenberg... A Study of the C om position of C id er V in egars M ad e b y the G enerator Process. B y L . M . T olm an and E . H. G oodnow ... On the D ecrease of A v a ila b le P hosphoric A cid in M ixed Fertilizers C on ta in in g A c id P h osp hate and C alcium Cyanamid. B y R . N . B r a c k e t t ... Laboratoryan d Pl a n t: ^ es'£n ° f an E x p erim en tal W ood D istillation Want. B y H . K . B enson and M a rc D a r rin ... « A p p a r a t u s , for D eterm in in g the M eltin g Points of substances of Indefinite M eltin g Po in t. B y A . P. “ jerregaard... Modified B a n k o f A m m on ia Stills. B y F red B erry and L. H. V a n B u s k ir k ... 884 895 899 905 906 908 910 914 915 917 922 927 928 933 935 938 941 Ad d r e s s e s: O ur R ad iu m Resources. B y C harles L . P a rso n s 943 T h e R ela tion of B ig Business to Ind ustrial Prosp erity w ith Special R eference to M in ing. B y C harles R . V a n H ise ... 946

F ertilizer C h em istry— A R ep ort of Progress. B y P aul R u d n ic k ... 948

Food Stan d ard s and th eir E ffe c t upon F ood L a w E n - 1*3 forcem ent. B y F lo y d W . R o b iso n ... 949

Cu r r e n t In d u s t r ia l Ne w s: A n A u to m atic C hem ical F e e d e r... 950

M ica rta and B ak elite M ic a rta ... 950

N e w C en trifu gal P u m p ... 951

T estin g the L iq u o r in Sulfite C o o k s... 951

T h e P resent S ta tu s of the G lass B o ttle and H ollow W are Industries in the U n ited S ta t e s ... 951

A S a n ita ry D rin k in g F o u n ta in ... 954

T h e S co ria B riq u ettin g P ro cess... 954

E xposu re T ests of C opper, C om m ercial A lum inum and D u ra lu m in ... 955

E lec tro ly tic C oa tin g of Iron and S teel w ith L e a d 955 T an n ic A cid from S p en t Sulfite L iq u o r... 955

A N e w D esu lfu rizin g M e t h o d ... 955

Sc ie n t if ic So c i e t i e s: A m erican C hem ical S o c iety — F o rty -eig h th M eeting , R och ester, Septem ber 8 -12 , 1 9 1 3 ... 956

A m erican C hem ical Journal to be C om bined w ith the Journal of the A m erican C hem ical S o c ie t y ... .. . 958

A m erican Petroleum S o c ie ty ... 958

O b itu a ry : Julius L e w k o w its c h ... 959

No t e s a n d Co r r e s p o n d e n c e: On the Influence of the R a tio of Lim e to M agnesia on P la n ts ... 95,

N o te on D eterm in ation of F a t in Ice C re a m ... 960

D esign of Surface C om b u stion A p p liances— C orrection 960 N o te on Q u an titative D eterm in ation of R osin in P ap er 960 P latin u m Prod uction Increases... 960

Bo o k Re v i e w s: E lectro -P latin g and A n a ly s is of Solutions; G eneral Index to the C hem ical N ew s; C alciu m C y an a m id ; T he A m erican F ertilizer H a n d b o o k ... 961

N e w P u b l i c a t i o n s... 962

R e c e n t I n v e n t i o n s... 963

M a r k e t R e p o r t... 964

EDITORIALS

8S2 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 5, No. n

T H E M IN IN G C O N G R E S S

T w o n o ta b le addresses p resented a t th e recen t m eeting of th e A m e rican M in in g C on gress a t P h ila ­ d elph ia arc p u b lish ed in th is issue of T in s Jo u r n a l.

A n address on “ O ur R a d iu m R e so u rce s,” b y C h arles L . P arson s, of th e B u re au o f M in es, brin gs o u t m an y v a lu a b le fa c ts in conn ection w ith th is m ost in terestin g d evelo p m e n t. H e again calls a tte n tio n to th e A m e rican carn o tite dep osits as a new source of rad iu m an d th e p o ssib ility of th e p ro d u ctio n of th is m aterial in A m e rica.

H is address in clu d es a discussion of th e m eth od s for th e e x tra ctio n of rad iu m , its p rese n t m a rk et va lu e , and a w arn in g to th e m edical profession and th e p u b lic a ga in st th e a c t iv it y of im postors. H e calls a tte n tio n to th e fa c t th a t th e U n ited S ta te s B u re au of S ta n d a rd s is p rep arin g rad iu m sta n d a rd s b y m eans of w h ich it w ill be possible for p h ysician s to p ro te ct th e m selve s a gain st frau d s.

D r. P arson s ann oun ces a new p o lic y in th e ad m in is­

tra tio n of th e B u re au of M ines w h ich is of far-rea ch in g im p o rta n ce in in d u stria l d evelo p m e n ts of g re a t p u b lic in te re st in th e fo llo w in g sta te m e n t: “ I am a u th o rized b y th e D ire cto r of th e B u re au of M in es to ann ou n ce th a t a c o o p e ra tiv e a greem en t has b een en tered in to w ith th e n e w ly o rgan ized N atio n a l R a d iu m In stitu te w h ereb y th e B u reau o b ta in s th e o p p o rtu n ity of scien ­ tific and te ch n o lo g ica l s tu d y of th e m inin g and co n ­ c e n tra tin g of carn o tite ores and of th e m ost efficient m eth o d s of o b ta in in g rad iu m , uran iu m and va n ad iu m th erefro m w ith a vie w to increased efficien cy of p ro ­ d u ctio n and th e p reven tio n of w a ste .” T h e c o o p era ­ tion of th e g o ve rn m e n t in th e so lu tio n of th e radium p rob lem w ill m eet th e h e a rty a p p ro v al of th e m edical profession and th e general p u b lic w ho are so in tim a te ly concern ed in th e e ra d ica tio n of cancer.

I t is also proposed to carry on in v e stig a tio n s re­

gard in g th e p h ysica l ch a ra cte ristics of th e rad iu m ra y s in th e hop e th a t som e or all of th e resu lts m a y be d u ­ p lic a te d b y p h ysica l m eans.

R eferen ce is m ade to th e fo rth co m in g a n n o u n ce­

m en t of rem ark ab le cures effected b y th e use of rad iu m and m eso-thorium , and in v ie w of th e sen satio n al an n ou n cem en ts in th e p u b lic press, a u th o r ita tiv e s ta te m e n ts in th is field w ill be a w a ite d w ith breath less in terest.

T h e address b y P resid e n t V a n H ise, a full a b s tra c t of w h ich is p u b lish ed in th is issue, w ill be read w ith keen in terest b y th o se concern ed in th e p rob lem of scien tific co n servatio n . A carefu l a n a lysis of these prob lem s h as led P resid e n t V a n H ise to p o in t o u t in th e m ost fo rcib le lan gu a g e th e o b liga tio n s o f th e g o v e rn m e n t and th e p u b lic in fu rth e rin g th e in terests of le g itim a te c o n se rv a tio n , and th e ad dress w ill be e x ceed in g ly su g g e stive read in g n o t o n ly to th e people im m e d ia te ly co n n ected w ith in d u stria l d evelo p m e n t, b u t also to th o se respo nsible for our le g is la tiv e and a d m in istra tiv e policies.

I t is our b elief th a t th is address w ill serve to e m p h a ­

size th e need of a c o o p e ra tiv e p o lic y and legislation c a lc u la te d to d evelo p co n s e rv a tio n instead of the o b s tru ctiv e p o licy now in general fa v o r.

O Z O N E

A strik in g exam ple of th e d anger of commercial­

izin g a p o p u la r n otion w ith o u t first subjecting it to proper te sts is b ro u g h t o u t in tw o articles in the Journal of the A m erican M cdical Association' for Sept.

27, on th e P u rificatio n o f A ir w ith Ozone. We were ta u g h t in our “ P re p ” school ch e m istry th a t it was the

“ ozone of th e co u n try a ir ” w hich w as responsible for th e h ea lth and lo n g e v ity of th e ru ral p o p u latio n ; and of course th e h e a lth fu l effe ct of ozone we inferred w as due to its v a lu e as a d isin fe ctan t. Furthermore, ozone is an en erge tic o x id izin g a g e n t; so is hydrogen p e ro xid e; h yd ro gen p ero xid e is a va lu a b le germicide;

so, w e th o u g h t, w as ozone.

O h lm u ller’s exp erim en ts, tw e n ty y e a rs ago, together w ith th o se of several in v e stig a to rs since, discrediting its ge rm icid al a ctio n , did n ot sh a k e th e popular faith in ozone. P u b lic officials h a v e rea d ily accepted claim s such as th e fo llo w in g : (1) O zone is a necessity fo r th e d estru ctio n o f in fe ctio u s germ s, for the steril­

iza tio n o f air in o p e ratin g room s, for th e purification of air in hom es o f persons su fferin g from contagious diseases, and fo r g iv in g to offices and homes the in­

vig o ra tin g air o f co u n try , seashore and mountain.

(2) O zone can n o t ex ist ex ce p t m o m en tarily in air con­

ta in in g organ ic m a tter, and th erefo re th e presence of ozone is an in d icatio n th a t th e air is sterile and devoid of organ ic m a tter. (3) O zone is u n iqu e as a germicide b y reason o f th e fa c t th a t it h as no deleterious effect on th e high er form s of anim al life, ow ing to the low p e rcen ta ge of carb o n in th e ir stru ctu re .

In th e first o f th e tw o a rticles m entioned, “ Ozone:

Its B a c te ric id a l, P h ys io lo g ic and D eod o rizing Action, b y E . 0. Jo rd an , M .D ., and A . J. C arlson, M.D., of C h ica g o , th e a u th o rs describe an extensive series of exp erim en ts u n d e rtak en b y th em a t th e suggestion of, and u nder a g ra n t from The Journal of the American M edical A ssociation. T h e ir in v e stig a tio n was c o m p l e t e an d e x h a u stiv e and th e ir d a ta fu lly ju stify their conclusion s and su m m a ry w h ich w e q u o te:

" S o fa r as the destruction of bacteria is concerned, ozone has little or no valu e. Som e bacteria are undoubtedly killed b y ozone, esp ecially if th ey are in a m oist condition and are in co n ta ct for several hours w ith a curren t of ozone coming direct from the generator. In practice, how ever, th e fact is of slight im portance. H um an beings are in ju riou sly affected by amounts of ozone far less th an are necessary to produce even this slight b actericid al effect, and there is no evidence for supposing that a q u a n tity of ozone th a t can be tolerated b y m an has the leas germ icidal action . I f disinfection of a d o sed room without inm ates is desired, this can be m uch m ore effectively carried ou t b y the use of form ald eh yde or som e other familiar gaseous disin fectan t th an b y ozone. O zone has no place in practica room disinfection.

‘ ‘O zone is n ot an actu a l ‘ deodorizer’ in concentrations that can obtain in p ractical ven tilation . In v er y great concent»

Nov., 1 9 1 3 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y S83 tions ozone seems cap able of oxid izing some odorous substances

so that the odors are dim inished or changed, b u t the change may be in the direction of increasing the disagreeableness of the odor. In v ery great con cen trations ozone 'm asks' m ost odors by its ow n in ten sive odor, and possibly b y fatig ue or anaesthesia of the o lfa cto ry epithelium . C ertain odors are masked b y ozone even in w eak concentrations. Is such m asking of odors desirable and g en erally ad van tageou s? W e think not.

It is probable th a t the in ju ry to th e resp iratory tra c t b y ozone in sufficient concentration to a c t as an effective m ask is of greater moment than the deleterious actio n of m ost odors. E x cep t in special industrial processes, th e unpleasant odor of the inspired air in shops, offices or liv in g room s is u su ally a sign th a t the air needs to be renew ed or changed . W h y should w e p u t ou t of commission the sense organ w h ich aids us in determ ining w hether or not the air is fit to breathe? I t seem s to us th a t this is w rong in principle, and th a t ozone is being used and w ill be used as a crutch to bolster up poor v en tila tin g system s. O zone does not make ‘ pure a ir’ a n y m ore th an strong spices m ake pure food.

"In concentrations th a t a p p reciably affect m an and anim als, ozone appears to h a v e uniform ly an injurious action. T h is in­

jurious action is p rim arily on the resp iratory passages— irrita­

tion of the sensory n erve endings, and irritation, corrosion and depression of the epithelial cells. T h e depression of the alveolar epithelium leads to changes in th e gaseous exchange in the lungs, and secondarily to changes in the blood, and ozone head­

ache, depression and drow siness are produced.

“ Hill and F la ck [Proc. Roy. Soc., 82, 404 (1 9 1 1 ); Jour. Roy.

Soc. Arts., 6o, 344 (1912) ] p oin t o u t th a t ozone gives a certain

‘tang’ to the air, and th us relieves the im p u rity (tem perature and moisture) w h ich is a p t to ob tain in offices and assem bly rooms. This tan g is a com bined effect of ozone odor and the ozone irritation of th e sensory nerves in the resp iratory tract.

We have seen th a t this a cts (reflexly) on the vascu lar m echanism and it m ay tem porarily ‘w hip u p ’ a fagged brain. B u t is this ozone tang an y more beneficial or a n y m ore physiologic than a whiff of sm elling-salts or a puff of the cigarette? W e recognize that a certain am ou n t of v aria tio n in the rate of m ovem ent and in the tem perature of the air a b o u t us aids in m aintaining the tonus of the brain, b u t our ven tila tio n engineers m ust reproduce the variability of outdoors b y actu a l v ariatio n s in the air and in the rate of m ovem en t of th e air in the v en tila tin g system s, and not b y adding a poisonous gas to the air. N o r can we accept the suggestion of H ill and F la c k th a t sm all am ounts

ozone m ay be of th erap eu tic v alu e in certain diseases of the respiratory tra c t b y reason of the hyperem ia follow ing the ozone irritation. T h e cells injured b y ozone are p ro bably more readily invaded b y b acteria, and h ave less than norm al power of growth and healing despite the hyperem ia. A n d all bacteria so far studied are-m u ch m ore resistan t to ozone th an are the cells of the respiratory tra c t of m an and experim ental anim als.

The physiology of ozone points to the conclusion th a t the use of this poisonous gas as a th erap eu tic a g e n t is either valueless or injurious.”

The second a rticle, “ T h e A lle g e d P u rificatio n of Air by the O zone M a c h in e ,” b y W . A . S a w y e r, M .D ., Director of th e H y g ie n ic L a b o ra to ry of th e C alifo rn ia State Board of H e alth , and his co-w orkers, B eck w ith and Skolfield, th o u gh n o t as exten sive, is no less con ­ vincing th an th e first. T h e conclusions of these authors are q u o ted also:

The gaseous products of the tw o w ell-know n ozone machines examined are irrita tin g to th e resp iratory tra c t and, in con- S1derable concentration, th e y w ill produce edem a of th e lungs and death in guinea pigs.

A concentration of th e gaseous products su fficien d y high to typhoid bacilli, stap h ylococci and streptococci, dried on

glass rods, in the course of several hours, w ill k ill guinea pigs in a shorter tim e. Therefore these products h ave 110 valu e as bactericides in breathable air.

“ B ecause the products of th e ozone m achines are irritatin g to the m ucous m em branes and are p ro bab ly injurious in other w ays, the m achines should n ot be allow ed in schools, offices or other places in w hich people rem ain for considerable periods of tim e.

“ T h e ozone m achines produce gases w hich m ask disagreeable odors of m oderate strength. In this w a y the m achines can con ­ ceal fau lts in v en tilatio n w h ile n ot correctin g them . B ecause the ozone m achine covers unh ygienic conditions in the air and a t the sam e tim e produces new injurious substances, it can n ot properly be classed as a hygien ic d e v ice .’ ’

I t is to be h oped th a t th e results of these in v e s ti­

ga to rs w ill receive sufficient p u b lic ity to co rrect p o pu lar ideas on th e germ icid al actio n of ozone and th a t th e w ork w ill n o t h a v e to be rep e ated as it has been so m a n y tim es w ith in th e la s t tw e n ty years.

_________ • A . M . B u s W E L L B U R E A U O F M IN E S C O A L A N A L Y S E S

G o v ern m en t p u rch asin g agen ts, d esignin g and op er­

a tin g engineers, an d th e fu el d ep artm en ts of in d u strial concerns, dealers in large q u an tities of coal, and per­

sons in terested in th e d istrib u tio n and ch ara cte r of th e differen t coals in th e U n ited S ta te s w ill find v a l­

u able in fo rm atio n in a rep o rt ju s t issued b y th e U n ited S ta te s B u re au of M ines as B ulletin 22, e n titled “ A n a ly ­ ses of C o als in th e U n ited S ta te s, w ith D escrip tio n s of M in e an d F ield Sam p les C o lle cte d b etw een J u ly 1, 1904, and June 30, 19 10 .” T h is rep o rt co n tain s the a n alyses of 5,000 sam ples of coal taken from 1,500 coal m ines and p rosp ects situ a te d in th e vario u s coal fields of th e U n ited S ta te s. N o t o n ly all of th e im ­ p o rta n t fields are represented , b u t p ra c tic a lly all of th e m ore im p o rta n t m ining d istricts.

T h e purpose of th e B u re au in co m p ilin g and p u b ­ lish ing th is info rm atio n is to present reliab le in fo rm a ­ tio n regardin g th e chem ical com p o sition and h eatin g valu e o f th e coals. T h e sam ples of coals were co llected b y exp erienced men acco rd in g to a definite and u n i­

form sy ste m , and were a n a ly ze d under c a re fu lly co n ­ tro lled cond itio ns, so th a t th ere m igh t be no qu estion as to th e relativ e m erits of th e d ifferent coals so far as th is can be d eterm in ed b y ch em ical a n a lyse s and d eterm in atio n s of h ea tin g valu es.

A n increasing p rop ortion o f th e coal consum ed in th e pow er sta tio n s and th e larger m a n u fa ctu rin g p lan ts of th e c o u n try is now being pu rch ased u n der sp ecifi­

catio n s based on ch em ical a n alyses and calo rim etric d eterm in atio n s of h eat units. In th e purch ase of fu els m a n y m atters fo rm erly le ft to ch an ce are now ca re fu lly in v e stig a te d . I t is th e aim of m ech anical engineers to co n stru ct fu rnaces and to arran ge th e heat- abso rb in g su rface in a fu rn ace w ith referen ce to th e p ecu liar ch ara cte r of th e fuel w hich is to be burned.

N o tin g th e com position o f th e fu el and co n stru ctin g th e fu rn ace w ith reference to it, he can assure efficient and sm okeless com bu stion . M o reo ver, in a n y p a r­

tic u la r m a rk et, th e choice of coal is lim ited ge n e ra lly b y its q u a lity and b y fre ig h t rate s to one or tw o fields in w hich th e ch a ra cte r o f th e coal beds is c o m p a ra tiv e ly u niform . H a vin g on h and a rep rese n ta tiv e a n a lysis

884 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 5, No. 11 of th e coal fro m a g iv e n bed in a n y p a rticu la r d istrict,

th e engineer can d eterm in e w h eth er th e coal he re ­ ceive s com es fro m th e b ed and th e d istrict sta te d , and w h eth er it is b ein g p rep ared for m a rk e t as c a re ­ fu lly as it sh ould be. W id e v a ria tio n s in th e co m p o si­

tio n s and h ea tin g valu es of th e coals from d ifferen t d istricts and from d ifferen t beds m ake co m p arab le a n a lyse s alm o st ind isp en sab le to engineers h a v in g to in stall boiler or gas-p ro d u cer p la n ts in d ifferen t cities, as w ell as to railro ad s and s te a m b o a t com panies, and to th e engineers and p u rch asin g agen ts of th e v a rio u s d ep artm en ts of th e U n ited S ta te s G o vern m en t.

T h e B u re au of M in es rep o rt is in tw o p a rts: one giv es tfre m eth od s used in co lle ctin g and a n a lyzin g th e sam p les and th e resu lts of th e a n a lyse s; th e oth er

giv e s th e e x a c t lo catio n fro m w h ich each sample of coal w as ta k e n , to g e th e r w ith a description of the ch a ra cte ristic fe a tu re s of th e coal bed a t the point of sam p lin g, th e n om inal c a p a c ity of th e m ine and such n otes on th e p re p ara tio n of th e coal as m ight be use­

fu l to consum ers. T h e d a ta co n tain ed in thèse two vo lu m e s are n o t eq u a lled in scope and detail and in v a lu e fo r c o m p a ra tiv e purpo ses b y th e figures that h a v e been p u b lish ed b y a n y oth er coal-producing c o u n try in th e w orld. T h e G o v ern m en ts of some of th e se co u n tries h a v e p u b lish ed analyses of coals from d ifferen t m ines and from d ifferen t districts but, w ith fe w excep tio n s, th e sam ples of coal were not co lle cted and a n a ly z e d u n d er a u n ifo rm system that w ou ld m ake th e resu lts co m p a ra b le in all respects.

ORIGINAL PAPERS

C O P P E R C O V E R E D O R C O P P E R C L A D S T E E L 1 T H E M A N U F A C T U R E , P R O P E R T IE S A N D U S E S O F C O M P O S IT E

M E T A L M A D E B Y A L L O Y IN G O R W E L D IN G C O P P E R A N D S T E E L

B y Ja m e s Ot i s Ha n d y

Of th e m etals in com m on use, co p p er is th e o n ly one w hich occurs n a tu r a lly in large q u a n titie s in th e m e­

ta llic sta te . T h e g re a t n a tiv e co p p er d ep osits of M ich iga n are th e best illu stra tio n w h ich cou ld be fo u n d of th e e x tra o rd in a ry resistance of co p p er to corrosion.

T h e m etals zinc, tin , and lead , w hich are co m m o n ly used as p ro te ctiv e co a tin g s fo r iron an d steel, do n ot o ccu r in th e n a tiv e s ta te and do n o t ap pro ach cop p er in d u ra b ility under atm o sp h eric cond itio ns. T h e ir use is c o m p a ra tiv e ly m odern and in th e case of tin (now selling a t 41 cen ts per pound) is co m m ercia lly possible o n ly b ecau se of th e e x ce e d in g ly th in co a t w h ich m a y be p u t on (2 lbs. per box m eans a 0.00012 in ch tin co a tin g ).

T h e n e ce ssity of p ro te ctin g iron fro m corrosion and th e d e sira b ility o f stren gth en in g cop p er a llo y s used for p rim itiv e too ls and w eap o n s led, a t a v e r y e a rly period, to th e use of a co m b in atio n of an iron core and a b ronze co ve rin g. Such a rticles h a v e been fo u n d in th e ruins of N im rou d , an an cien t A ssyrian c ity , and am ong th e rem ain s of th e Sw iss L a k e D w ellers

(F rien d : “ C orrosion of Iron and S te e l,” page 8).

F o r sim ilar reasons, th e union of iron or steel w ith copp er in such a m anner as to ob tain a com p o site m etal retain in g u n im p aired th e good q u alities of b o th m etals has lon g been a d esid eratu m .

M a n y in v e n to rs h a ve g iv en th e ir a tte n tio n to th e d ifficu lt p rob lem o f se cu re ly u n itin g iron or steel w ith cop p er, and th e p a te n t lite ra tu re of th e U n ited S ta te s and of E u ro p ea n cou n tries con tain s m an y illu s tra ­ tion s, ch iefly of u n w o rk ab le or im p e rfect processes.

T h e earliest p a te n t w e h a ve fo u n d w as one issued to P oole, o f E n g la n d , in th e y e a r 1821. C o p p er or brass w as m elted in a sh allo w cast iron pan (B ritish P a te n t 459S o f 1S21).

1 P a p e r p re sen te d a t th e 4 8 th m eeting of th e A m erican C hem ical S o ciety , R o ch ester, S e p te m b e r 8 -1 2 , 1913.

T h e com m ercial electro -d ep o sitio n or electroplating o f co p p er on iron or steel seem s to h a v e started before 1840, in E n g la n d . T h is process h as been used chiefly for th e p ro d u ctio n of th in co atin g s, b u t processes have been d evelo p e d b y E lm o re and oth ers for making, b y electro -d ep o sitio n , copp er tu b e s of considerable th ick n ess.

Such a process w as u n d o u b te d ly used commercially b y th e m a n u fa ctu re rs w ho, in th e y e a r 1883, supplied to th e P o s ta l T e le g ra p h C a b le C o m p a n y bimetallic w ire con sistin g of a h ard steel core wire 0.120 inch in d iam e ter su rro u n d ed b y a seam less, electro-plated, clo se ly -fittin g copp er tu b e h a v in g app roxim ately 0.042 inch w alls. T h e ra tio of steel to copper by weight w as a b o u t 1 : 3 (F igs. 1 an d 2).

T h e sam e co m p a n y used also a com pound wire con­

sistin g of a steel core w ire su rro u nd ed first b y a thin e lectro -d ep o sited copp er sh eath 0.008 inch thick and th en b y a w rap p in g of h e a v ie r copper with walls 0 .0 44 inch th ic k (F igs. 3 and 4).

In n eith er ty p e of w ire w as th ere a bond between copp er and steel o th er th a n a close conformation.

T h e w o rkm an sh ip w as so excellen t, however, that sam p les ta k e n dow n a fte r 28 y e a rs ’ exposure in the line fro m N ew Y o r k to C h ica g o showed absolutely no corrosion of th e steel core. T h e copper sheaths reta in e d th e dim ensions g iv en ab o ve.

D esire to so lv e th e p rob lem of u n itin g copper with iron or steel w ou ld n a tu r a lly le a d to attem p ts to make a w eld b y processes an alo go u s to th e one successful with iron or m ild steel. W h en, h o w e ver, h eatin g and ham­

m ering iron and cop p er to g e th e r failed , even with the use of va rio u s fluxes, to p ro d u ce a w eld, it became ap­

p a ren t th a t th e p ro b lem w as a d ifficu lt one.

In v e n to rs trie d to fo llo w estab lish ed methods for c o a tin g one m etal w ith a m ore fu sib le one, e. g• > the co a tin g of iron or steel w ith zin c, tin , or tin-lead alloy b y p assin g th e fo rm er m etals, p ro p erly cleaned, t h r o u g h

b a th s of th e m elted , fu sib le m etals. T h e high melt­

in g p o in t of co p p er and its stro n g ten d en cy to oxidize w hen m elted, offered g re a t ob stacles. Coatings ma e b y d ip p in g steel in to m elted copp er are always thin if th e steel is h o t, and are u su a lly im p e rfectly a d h e r e n t .

T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y

The id e a s o f c a s t i n g m e l t e d c o p p e r in c o n s id e r a b le amount a g a i n s t a n ir o n o r s t e e l b a s e o r a r o u n d a s t e e l core, o r o f c a s t i n g ir o n o r s t e e l i n s id e a c o p p e r t u b e , were c o n c e iv e d a n d t r i e d b y t h e f o l l o w i n g i n v e n t o r s :

"Rollers for P rin tin g F a b ric s,” B ritish P a t. 1924 of 1856;

Tytherleigh. Method.— D ip p in g iron in m elted copper; then heating and castin g m ore copper around it.

“ Im p rovem en t in C oa tin g M e ta ls ,” U . S. P a t. 21,797 of 1858;

Hiler. Method,— C astin g iron or steel in a copper m old and com pleting the union b y rolling.

Specification.— “ I h ave discovered th a t th e best union of the iron or steel w ith its coatin g m etal can be m ade b y heating the iron or steel u n til it is fused and bringing it w hile in th a t con d i­

tion in co n ta ct w ith th e coatin g m etal, and keeping it so in con-

Fig. 1 X 1 1 Fig. 2 X 44 Fig. 3 X 1 1

Postal T e le g ra p h ” W ire w ith S teel C ore ‘P o stal T eleg rap h ” W ire w ith Steel Core “ P o sta l T e le g ra p h ” W ire w ith Steel C ore, a n d E n tire ly E lectro d ep o sited an d E n tire ly E lectrodeposited E lectro d ep o sited T u b e , and Fo ld ed — on

C o p p er C overing C opper C overing C o p p er C over

Specification.— " I n c arry in g m y in ven tion into effect, I ta k e ta c t until b o th m etals h ave becom e cooled to a proper tem pera- a hollow iron cylinder, of som ew h at less diam eter th an the roller tu re.” ... “ On the melted iron being poured into the or cylinder to be m an ufactu red. I prefer to p erforate th e said mold in contact with the coating metal the latter becomes fused by cylinder w ith holes. I clean th e said iron cylin d er b y acids or the heat o f the former; bu t before it is so fused th e iron has parted otherwise. I afterw ard s co v er the said iron cylin d er w ith borax w ith so m uch of its h eat as to be sufficien tly chilled to preven t or other suitable flux, and h e a t it sufficien tly to fuse the flux th e coatin g m etai from m ixing w ith the iron, and also to pre- thcreon. In another furn ace I h e a t a pan or vessel (made of v e n t th e said coatin g m etal from sinkin g dow n and occu p yin g a material capable of bearin g the requ isite h eat), the said pan the bottom of the m old .”

or vessel containing copper, brass, or other a llo y of copper. Claim.— " W h a t I claim as m y invention, and desire to secure When the copper or a llo y is fused, I p u t th e iron 'cylin d er therein b y L etters P aten t, is: T h e coatin g iron or steel w ith copper, and turn it, so as to coat it w ith th e m etal. I ta k e th e cylind er silver, or brass, or alloys where silver or copper is used, b y bring- from the said pan or vessel, and w h ile h o t I p u t it in a hollow ing the iron or steel, w hile in a m elted state, in to c o n ta ct w ith cylinder or mould, closed a t b o tto m w ith c la y or other suitable the coatin g m etal, and allow ing them to so rem ain until th e tw o

Fi g. 4 X 44

Postal T e le g ra p h ” W ire w ith Steel Core, Electrodeposited T u b e , a n d F o ld ed — on

C o p p er C over

Fig. 5 X 50

C om m ercial Alloy U nion of C opper an d Iron.

L o n g itu d in al Section of “ M o nnot-D u- plex” W ire

F ig . 6 X 44

C om m ercial A lloy U nion of C o p p er a n d Iro n . Cross Section of “ D uplex C opper-

C la d ” W ire oatenal. I place a core or axis in th e iron cylinder, and adjust

ll> by screws or otherw ise, in th e axis of the m ould. I put

&e whole into a furnace, and w h en the coatin g on the iron c> Under begins to m elt I pour fu sed copper or copper alloy into

^e mould, and I m ain tain the h e a t u n til the copper or a lloy is thoroughly incorporated w ith the coatin g on the iron cylind er;

e fee is then slackened, and th e w h ole allow ed to cool. T he roller or cylinder is afterw ard s finished b y the process of tu rn in g.”

m etals h a v e becom e hard b y cooling, su bstan tially as specified.”

Suggested Uses o f H iler Product.— S tair rods, trun k nails and bands, button s, etc.

"Im p ro v em en t in Line-W ires for T eleg rap h ,” U . S. P a t.

47,940 of 1865; F arm er and M illiken. Method.— C astin g copper around an iron bar; then rolling and draw ing in to w ire. T h is seem s to be the pioneer p aten t on telegraph w ire com posed of copper w ith a steel core.

886 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 5, No. 11 Specification.— “ In the con struction of aerial telegraph lines

the general practice, as is w ell know n, is to use iron w ire for transm ission of th e electric current, this w ire bein g galvan ized o r covered w ith a th in coatin g of zin c to p reven t oxidation.

In th e earlier constructions of lines it w as som etim es a ttem p ted to use copper w ire, b u t for w a n t of tensile stren gth in such w ire its use had to be abandoned. Y e t the em p loym en t of copper w ire is a desideratum on accou n t of its great su p eriority o ver iron as a conductor, and could its tensile stren gth be m ade equ al to th a t of iron it w ould, to a great exten t, supersede the iron w ire.”

“ O ur invention, therefore, consists in a copper telegraph w ire cored or covered, for the purpose of strength, w ith iron or steel.”

“ In carryin g o u t th e in ven tion or con structin g this com pound w ire w e prefer to core the copper w ith iron, first castin g the copper around an iron b ar and then b y the processes of rolling and d raw ­ ing a tten u a tin g th e sam e in to w ire b y th e w ell-know n m ethod s of w ire-draw ing. I t w ill be obvious, how ever, th a t the iron can be placed around th e copper and th e resu ltan t b ar draw n o u t in to a wire, leavin g the copper in the cen ter; b u t th e first-nam ed con struction w e consider preferable, as th e iron is p rotected from oxidation, and the m an ufactu re of this w ire is the more p rac­

tica b le .”

Claim .— “ A s a new article of m an ufactu re, a telegraph w ire reenforced, for th e purpose of stren gth , w ith a core or cover of iron or steel, the w ire being m ade b y draw ing a com pound b a r of the tw o m etals.”

“ Im p ro vem en t in C om bin in g C op p er w ith C a s t S te el,”

U . S. P a t. 73,375 of 1868; P a rk . Method.— C astin g steel in a hollow copper ingot, p reviou sly heated.

Specification.— “ A com bin ation or union of copper w ith some harder, and stronger m etal has been long needed for m an y purposes in th e arts and m anufactures, such as locom otive fire-box sheets, w ire for ships’ rigging, rods, bolts, spikes, and various other articles for w h ich copper alone can n ot be em ployed, ow ing to its softness and w a n t of stren g th .”

" M y in ven tion consists of com bining copper w ith cast steel, b y castin g the m olten steel 011 or around th e copper, w hich is p reviou sly heated, th us form ing an in got w h ich m a y be ham m ered, rolled, or otherw ise w orked in to a n y desired shape, th e steel being tem pered or hardened as m a y be desired a fter it is w o rk ed .”

" I f it is desired to h a v e steel in th e cen ter and copper all around it, as is required for m akin g copper-coated steel w ire, or copper-coated spikes or rods, I prepare a hollow in g ot of copper, into the cen ter or c a v ity of w hich, a fter it has been heated to a good red heat, I teem or pour th e m olten cast steel. In th is case no m ould w ould be necessary, b u t m a y be used if pre­

ferred. S u ch in got m a y be draw n o u t in to wire, or w orked into other articles, such as bolts, spikes, e tc .”

C laim .— “ C om bining copper and cast steel b y h eatin g the copper to a good red heat, and teem ing or pouring thereupon liquid m olten cast steel, su b sta n tially as and for th e purposes hereinbefore described.”

"P ro ce ss of M an u fa ctu rin g C om pou nd T elegrap h W ire ,”

U . S. P a t. 310,995 of 1885; Farm er. Method.— C op p er plated iron w ire draw n through m elted copper.

Claim .— “ 1. T h e m ethod herein described, of m an ufactu rin g com pound telegraph wire, w hich consists in electrop latin g a steel or iron w ire w ith a th in film of copper, then draw ing the sam e through m olten copper and shaping the coatin g in su b ­ sta n tia lly the m anner set fo rth .”

“ Im p rovem en ts in the M an u fa ctu re of W ires, F ren ch P a t.

168,133 of 1885; M artin . Method.— (a) C astin g copper in iron tube. (b) C astin g copper around m edial p a rt of iron b ar and then reheating and rolling, e tc .”

In an 1888 su p p lem en t to the a b o v e p a te n t he de­

scrib ed castin g copp er aroun d th e m edial p a rt of a

steel bar. He th en rolled and d rew it. M artin seems to h a v e in tro d u ce d b im e ta llic w ire v e r y extensively in F ra n ce and elsew here in E u ro p e. His work appears to be th e co m m ercial d e v e lo p m e n t of the ideas of F arm e r and M illike n .

C laim .— “ I claim in this sup p lem ent to m y principal patent m y perfected m ethod of m akin g b im etallic w ires in which the m etal w h ich form s the exterior envelope is more ductile than th a t w hich form s the interior core, this m ethod consisting es­

sen tia lly in castin g the m etal intended to form the envelope around th e m edial portion of th e rod w hich m ust form the heart o f th e w ire, and in exten din g the rod so p artially covered by the m etal of the envelope b y altern ate passes first ¡11 one direc­

tion and then in th e other betw een the rolls of a rolling mill."

“ Process of P rod ucing C om p ou nd M e ta l B odies,” U. S. Pat.

853,716 of 1907; and “ C op p er C la d Iron and Steel,” 893,932 o f 1908; M on n ot.

M o n n o t d evelo p s fu rth e r th e plan suggested by T y th e rle ig h , F arm e r and M illik e n , and Martin. He uses su p erm o lten , i. e., v e r y h o t m elted copper to give a th in in itia l co a tin g and th e n casts copper around th e c o a ted steel b illet. H e fin a lly reh eats and rolls.

Specification.— (U. S. P at. 853,716.) “ W hen a t the super- m olten tem peratu re m a n y m etals are v e r y sensitive to flame, gases and other bodies, read ily becom ing im pure; and there is reason to believe th a t a t such tem peratures such metals hare a solvent action on other solid m etals placed in them.

“ B y a p p lyin g on ly a th in film coatin g b y the action of super- m olten m etal, and then a p p lyin g the m ain coating by means of m etal nearer its point of solidification, there is less probability o f reduction o f quality of the coating metal. However, the main coating may be and frequently is formed entirely from supermolten metal, this method having the important advantages of requiring less m anipulation and fewer baths o f molten metal.''

Claim s.— (U. S. P a t. 893,932.) “1st. A s a new article of m an ufactu re, a ferrous m etal base, h a v in g a welded-011, contin­

uous, poreless, dense coatin g of copper united thereto by a union resisting tem p eratu re changes, c u ttin g tools, and mechanical stresses, said co a tin g having the properties o f metal set from a liquid state.

“ 2nd. A s a new article of m an ufacture, an extended metal article com prising a ferrous m etal base and a continuous, pore- less, dense coatin g of copper w eld-un ited thereto, by a union resisting tem perature changes, c u ttin g tools, and mechanical stresses; said ferrous base and copper coatin g having been ex­

ten ded to g eth er.”

In all of th e a b o v e processes ex ce p t those o f T y t h e r ­ leigh an d M o n n o t, h e a tin g and rollin g are essen tial to co m p lete th e union b etw e en th e tw o metals. The unions are m ore or less p e rfe ct accord in g to w h e th e r th e op erato r reads into th e p a te n ts effective m e a n s 0! k eep in g th e a b u ttin g su rfaces clean a t the critical in s ta n t. T h e p ro d u cts of m ost of these p r o c e s s e s con­

ta in copp er and iron a llo y s becau se steel dissolve5 re a d ily in m elte d cop p er an d m elted steel dissolves cop p er w ith g re a t speed. C o p p er in steel or iron in cop p er are d isa d v a n ta g e o u s electrica lly because th e y h ard en th e p rin cip al m etal and dim inish the con d u c tiv ity of com po site w ire. C o p p er in steel r e t a r s i t s corrosion (B u ck , T h i s J o u r n a l , 5> 4 4 7)-

I t is possible b y sk ilfu l reg u la tio n of temperatu*1-- of castin g and b y p ro p o rtio n in g c o rre ctly the amount of m elted m etal and of th e solid m etal core or tu e, to a vo id a llo y fo rm atio n , e x c e p t in th e Tytherleig ? P a rk , and M o n n o t p rocedures. In the latter,

alloy is in te n tio n a lly m ade, and th e fa c t is considered an im portant m ech an ical a d v a n ta g e , co u n terbalan cin g, in the in v en to r’s op inion, th e high er electrica l resist­

ance.

There h ave been a n u m ber of a tte m p ts to u tilize hydraulic pressure and m eans o th er th a n rolling pres­

sure to w eld cast copp er w h ile still h o t to steel. A s examples of th e se are th e fo llo w in g :

"New Process of M a n u fa ctu rin g B im e tallic P la te s and W ires,”

Belgian Pat. 171,442 of 1903, M artin.

Claim.— " A process of m akin g b im etallic plates and wire, which consists in ap p lyin g on the inside w alls of a conical ingot mold, widened a t the bo ttom , a lining or sheet of copper, of silver, of brass, etc., covering all or a p a rt of th e surface of the ingot mold, then running th e steel into th e mold, and (finally) forcing out the ingot through th e sm all end of th e m old b y the use of a hydraulic press w hose piston presses a gain st the large end of the ingot, in such a w a y as to w eld th e tw o m etals and to suppress all flaws betw een th em .”

“ Process of M ak in g B im e tallic P ro d u cts,” U . S. P a t. 853,932 of 1907, Monnot and M artin.

The chief fe a tu re of th e se p a te n ts , w hich both cover the same processes, is th e fo rcin g of a cast, com posite Nov., 1913 T H E J O U R N A L O F I N D U S T R I A L

of th e plates from scale, oxid, or other im purities, th en coatin g or covering one or more faces of this p late w ith a m etal or an alloy thereof h avin g a low er fusing point, then ap p lyin g to this coated surface a plate of m etal or an a lloy of the sam e character as the coating, b u t free from an y coating, then ap p lyin g h eat to the tw o plates, and finally uniting b y pressure, su b sta n tially as de­

scribed.”

T h e n e w m e t h o d s i n t r o d u c e d b y G r i f f i t h w e r e t h e p l a t i n g o f t h e ir o n w i t h c o p p e r , e i t h e r b y c h e m i c a l o r e le c t r ic a l d e p o s it io n , a n d t h e n p l a c i n g c o p p e r a n d c o p p e r - c o a t e d ir o n in c lo s e c o n t a c t , h e a t i n g t h e m u p a n d r o l l i n g t h e m t o g e t h e r a t t h e p r o p e r t e m p e r a t u r e . T h e c o p p e r - p l a t i n g o f t h e ir o n p r e v e n t s i t s o x i d a t i o n a n d k e e p s i t s s u r f a c e in c o n d i t i o n t o u n i t e f i r m l y w i t h t h e c o p p e r w h e n t h e t w o m e t a ls r e c e i v e a p r o p e r r o l l i n g p r e s s u r e a t t h e r i g h t t e m p e r a t u r e . T h e t e m p e r a t u r e r e c o m ­ m e n d e d b y G r iff it h w a s a b o u t 1 7 0 0 ° F . T h e w r i t e r h a s o b s e r v e d t h a t a t 9 5 0 ° C . ( 1 7 4 2 0 F .) w e l d i n g o f c o p p e r t o c o p p e r - p l a t e d i r o n , r o lle d a s c o m p o s it e c y l i n d r i c a l b i ll e t s , w a s c o m p l e t e a f t e r t h e f i r s t f e w p a s s e s . W e l d i n g b y r o l l i n g p r e s s u r e is t h e m o s t e f ­ f e c t i v e m e t h o d . F o r c i n g t h r o u g h a d ie o r o t h e r w i s e A N D E N G I N E E R I N G C H E M I S T R Y 887

F ig . 7 X 44 F ig . 8 X 44 F ic . 1 1 X 1 1

C om m ercial A lloy U nion. C om m ercial W eld U nion of C opper an d Iro n . A lloy U nion of C opper

D efective S teel Cross Section of S ta n d a rd and Iron a t

C ore C. C. C .” W ire 1130° C.

ingot t h r o u g h a d ie , o r t h e u s e o f h y d r a u l i c p r e s s u r e on p r o p e r ly h e a t e d , f l a t s l a b s , in o r d e r in b o t h c a s e s t o

1

In th e p r o c e s s o f G riffith ( U . S . P a t . 5 8 0 ,3 4 4 o f 18 9 7 ) for “ U n it in g o r W e l d i n g M e t a l , ” t h e r e w a s a r e t u r n to th e o r ig in a l i d e a o f w e l d i n g w i t h o u t f ir s t m e lt in g either c o p p e r o r ir o n .

Specification.— “ T o this end the in ven tion consists in the pro­

cess hereinafter described, in w h ich th e plate, bar or other article

°f iron or steel is first cleansed from scale or oxid; its surface or surfaces then covered w ith a coatin g or deposit of copper or an alloy of copper or a n y other su itable m etal or a llo y thereof eapable of being deposited b y chem ical or electrical deposition or otherwise, in this instance b y the actio n of a bath of a solution

°f the salts of copper; is th en placed face to face w ith a sheet or Plate of copper or an a lloy thereof; is then heated to the proper degree, and, finally, is passed through rolls or is subjected to Pressure requisite to effect the perfect and in tim ate w elding of the metals.”

Claim.— “ T he herein described process of u niting or w elding Plates of metal of different kinds, w h ich consists in cleansing one

u s in g h y d r a u l i c p r e s s u r e a r e v e r y c u m b e r s o m e m e t h ­ o d s .

G erm an P a t. 152,042 of 1903, W ach w itz.

T h i s i n v e n t o r u s e s a l u m i n u m a s i n t e r m e d i a r y in e f ­ f e c t i n g a u n io n o f c o p p e r a n d i r o n . H e r o lls c le a n a lu m i n u m a n d c o p p e r s h e e t s t o g e t h e r a t a b o u t 8 0 0 0 F . H e r u b s m e t a l l i c a l u m i n u m i n t o t h e s u r f a c e o f c le a n ir o n . H is fir s t o p e r a t i o n in s h e e t m a n u f a c t u r e is t o b i n d t h e c o p p e r - a l u m i n u m s h e e t t o t h e ir o n - a l u m i n u m s l a b a n d h e a t a n d r o ll. T h e s e c o m p l i c a t e d o p e r a t i o n s a r e s a i d t o p r o d u c e a s e c u r e w e ld .

U . S. P a t. 1,065,727 of 1913, R o ck e y and E ldridge.

T h i s is a n a t t e m p t t o m a k e c o p p e r - c l a d , s t e e l b y d i p p i n g i n t o s u c c e s s i v e b a t h s o f m e lt e d c o p p e r c o v ­ e r e d w i t h m e lt e d b o r i c a n h y d r i d e . I t is m e n t i o n e d o n l y t o s h o w t h a t e f f o r t s a r e s t i ll b e i n g m a d e a lo n g t h e lin e s i n d i c a t e d .

I t h a s b e e n n o t e d t h a t w e ld e d c o m p o s it e m e t a l m a d e b y t h e G r if f it h p r o c e s s c o n t a i n s l i t t l e o r n o c o p ­ p e r - ir o n a l l o y . S p r i n g , in 1 8 7 8 , b y p r e s s u r e a lo n e ( w i t h o u t h e a t ) , p r o d u c e d a l l o y s o f c e r t a i n m ix e d m e t a l