THE KENT RS/C METER
Being of the shunt type, the Kent RS/C steam meter is simple in itself, and simple to install.
It can be put in the run of the main, or in a shunt by-pass across an orifice in a large main. A particular feature is its suitability for checking steam consumption of individual
departments o r machines. Slow pulsa
tions amounting to as much as 90 per cent, of the range, do not affect the
accuracy of integration.
/
The meter is suitable also for air.
/ ,
6d. Pe e Copy Post Fr e e 8d. VOL. LIV
No. 1406 SA TU RDAY, JU N E 8, 1946
REGISTERED AS A NEWSPAPER
W I I t e f o r f u l l y d e s c r ip t iv e lite ra tu re
AUDLEY ENGINEERING COMPANY L "
NEWPORT. SHROPSHIRE
K E L V I N
THE CHEMICAL AGE Ju n e 8 , 19 4 6
Ju n e 8 , 1 9 4 6 THE CHEMI CAL AGE
C L A R K ’ S M I X E R S
C AST IR O N OR MILD STEEL
G L A S S E N A M E L L I N E D H IG H L Y A C I D R E S IS T IN G C A P A C IT IE S up to 1,000 Galls.
M O T O R IS E D o r B E L T D R IV E N .
Established over a Century and a Half.
T .& C .C LA R K & C o. Ltd
W O L V E R H A M P T O N
Telegram s : Telephone :
C la rk , W o lv e rh a m p to n 20204/5
H U N SL E T , L E E D S, 1 0
Tel: LEEDS 32521 'C ra m s: OXBROS, LEEDS
London Office :
W in c h e s t e r H o u s e , O ld B ro a d S t r e e t , L o n d o n , E.C.Z.
T el.: London W a ll 3731 ’G ram s.: " Asbengpro, Stock. London
W46a
SPECIAL PURPOSE VESSELS b y OXLEY
for the Chemical Industries
O x le y u n d erta k e th e m a n u fa c tu r e o f p la n t for s p e c ia l p u r p o s e s , w h e th e r in w e ld e d or r iv e te d co n str u c tio n , in m ild or s t a in le s s s t e e ls , to c u s t o m e r s ’ r e q u ir e m e n ts.
A
ii THE CHEMI CAL AGE Ju n e, 8 , 1 9 4 6
C A N A D A P resc o tt & C o ., Regd.
774. St, Paul S t. W e st, M ontreal S C O T L A N D
K irk p atrick & Lauder Ltd., 180, H ope S tr e e t, G lasgow , C.2 I N D I A
K hatau V alabhdas & Co.
Vadgadl Bombay.
I N T E R M E D I A T E P R O D U C T S A N I L I N E D Y E S
F A S T B A S E S F O R IC E C O L O U R S
Benzol, N itro b e n zo l, B ln itro b en zo l, N ltro n a p h th alen e , B in ltro n ap h th alen e, X ylol, N ltro x y lo l, Blnltroxylol X ylldlne, T o lu o l, O r th o & Para N ltro to lu o l, B ln ltro to lu o l (All G rad es)
Para N ltro O r th o T o lu ld ln e, M eta N ltr o Para T oluldlne
O R T H O TOLU ID INE PARA TOLUIDINE
E xtensive Range of O il C o lo u rs, Acid C o lo u rs, Basic C o lo u rs, D ire ct C o lo u rs, P igm ent C o lo u rs, Azoic C o lo u rs for. W o o l, also C o lo u rs su itab le fo r all Trades
META TOLUYLENE DIAMINE META PHENYLENE DIAMINE
P O S I T I V E A I R B L O W E R S
J O H N W . L E I T C H & C O . , L T D .
MILNSBRIDGE CH EM ICA L W O R K S
HOLMES - CONNERSVILLE
d e liv e r a p o sitiv e , re lia b le an d o il-fre e su p p ly of A ir eco n o m ically a n d efficiently.
A b se n c e of in te rn a l contact e n s u r e s lo n g life, low m ain
ten a n c e a n d continuous o p e r a tion o v e r lo n g p e rio d s .
M any of th e s e m ac h in e s a r e in su ccessfu l o p e ra tio n fo r the h a n d lin g of G a se s. O v e r 1,400 h a v e b e e n su p p lie d “ a lr e a d y fo r su c h p u rp o s e s .
# One o f th e m any H olmes-ConnersvUlc Blowers supplied to C hem ical W orks, Capacity o f m achine illustrated, 120.000 cu, ft , p er hour ag a in st a pressure o f 3 lbs, per sq. inch. Speed 40 0 r.p.m .
T elep h o n e:^
189-190 MILNSBRIDGE
H U D D E R S F I E L D
T eleg ram s:LEITCH. MILNSBRIDGE
H E A D O F F I C E - T U R-'N B R I D G E • H U D D E R S F I E L B
LO IO O H O F FI C F • 119 VICTORIA ST.SWI • H ID L AR 0 S 0 F F I C E -2 I B ENKETT'5 HULL' BIR MI NG H A M. 2 Telephones: Huddersfield. 5280 : L O N D O N . V i c t o r i a , 9971 : B I R M I N G H A M . Midland, 6830
T H E C H E M I C A L A G E
Making a good entry
.. ...
Rotary Filter Drum Casting, size 8' o" diameter by 6' 3" long, weighing six tons, about to start a life of long service— manufactured by Widnes Foundry, where experience and up-to-the-minute methods were employed in its casting. Whether your casting problem is large or small, we can offer you our help.
A N D E N G IN E E R IN G C O M P A N Y L IM IT E D
M a k e r s o f S p e c ia l D u t y C astings for m o re t h a n a C e n tu ryB r e t t e n h a m H o u s e W .C.2 Te m ple B a r 9 6 3 1
W ORKS : W IDN ES,
L a n c s Londoni v THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
D I M E T H Y L G L Y O X I M E
in a w a te r solu b le form
T H E S O D I U M S A L T of dimethylglyoxime is a stable crystalline product of definite and uniform composition.
CH3.C(:N0Na).C(:N0Na).CH3.8H20 and can be employed in water solution for the detection and determination of nickel.
W I L L I A M S , LIMITED
1 6 - 1 7 S T . C R O S S S T R E E T , L O N D O N , E . C . I
T o w e r s E l e c t r ic O v e n s
Double W all type with thermostatic control for temperatures up to 120° C. Asbestos cement outer case, copper interior, enclosed heating elements, vacuum relay preventing sparking, glass o r asbestos door.
M 46I 12
x
10x
10 in. inside £18 0 0 M 462 14x
12x
12 in. inside £20 10 0 M463 16x
14x
14 in. inside £23 0 0 M464 18x
15x
15 in. inside £25 0 0all above prices are subject to 1 0 % advance Full details on application
J. W . T O W E R S & C O ., LTD.
H ead O ffice & W o r k i : W I D N E S
M A N C H E S T E R : 44, Chapel St., Salford 3.
L IV E R P O O L : 134, Brow nlow Hill.
/
Now available from
H O P K IN &
Ju n e S , 1 9 4 6 THE CHEMI CAL AGE V
ATHOLE G. ALLEN (Stockton) LTD.
S T O C K TO N -O N -TE E S
Telephones :
S T O C K T O N 6375 (3 lines)
C O DURHAM
N O N M E M B E R S O F T R A D E A S S O C I A T I O N S
A R E PRO D U CERS OF
B A R IU M COM POUNDS
B A R IU M C H L O R ID E
Fully Sold f o r E x p o rt
B A R Y T E S
L im ited S upplies O n ly
IRO N COMPOUNDS
F E R R IC C H L O R ID E (P E R C H L O R ID E O F IR O N )
P ro m p t D eliv ery H o m e an d E x p o rt
F E R R O U S C H L O R ID E
P ro m p t D eliv ery H o m e and E x p o rt
TO LU EN E N IT R A T IO N PRO D U CTS
M O N O N IT R O T O L U E N E D I-N IT R O T O L U E N E P A R A N IT R O T O L U E N E
E n q u iries Invited fo r H o m e and E x p o rt
O R T H O N IT R O T O L U E N E
v i THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
K E W
FA C T O R Y
-
but will its bo iler plant be
efficient ?
TH E ERA O F R E C O N S T R U C T IO N is approaching Factory sites are chosen ; plans discussed.
Efficient boiler plant is one of the first essen
tials of an efficient factory. T h e present high cost of fuel makes econom y essential ; an efficient boiler plant is in Itself an economy.
W h e n plans are being made, call in J. B. Jackson
& Partners. O u r engineers, w ith their wide experience of steam raising problems, are at y o u r service.
167-168, MILLBANK, L O N D O N , S.W .I Telephone; V ictoria 7864-5
A ip fia r - -
W e carry out complete boiler house installa
tions, central heating, air conditioning and ventilating.
J.6. JACKSON s PARTNERS
Combustion, Heating and Ventilating Engineering Contractors
and 13, LEWES R O A D , E A ST B O U R N E Telephone .• 544
B
r it a in’
s cheapest po r t’¿dence to - THE TOWN CLERK • HULL in .
Ju n e 8, 1946 THE CHEMICAL AGE
c i
1896 1946
50
YEARS OF PROGRESSIVE SERVICE TO THE
ELECTRICAL IN D U ST R Y
_ y - <
TH E BRITISH THOMSON-HOUSTON COMPANY LIM ITED.
RUGBY. ENGLAND.
v i i i THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
N o r th e r n O ff ic e a n d F u e l E n g in e e r : 'P h o n e : H o r s h a m 9 6 5
T. C. FEGAN, CANNONFIELD, HATHERSAGE, n r. SHEFFIELD
’G r a m s .■ E v a p o r a to rM A I N T A I N
S T E A M
W ITH
L O W G R A D E F U E L S
INSTAL
F O R C E D D R A U G H T F U R N A C E S
THE CHEMICAL ENGINEERING & WILTON’S
PATENT FURNACE CO., LTD., HORSHAM, SUSSEX
Imperial
Made in Great Britain
Imperial Typew riter Company L td . Leicester
/
Ju n e 8 , 1 9 4 6 THE CHEMICAL A G E i x '
O ur M aster
o f a l l T r a d e s
J u n k e r explains . . ,
My first appearance in these columns caused quite a number of enquiries so perhaps I may be allowed to tell YOU about ION exchange.
During the last six years ION EXCHANGE materials have played an ever increasing part in new pro
cesses. These include the purification of solutions by removal of metallic ions, acids or dissolved salts and re
covery of valuable materials from dilute solutions and from industrial wastes.
These materials are already known
to Industrial Chemists through the Permutit “ DEMINR0L1T PROCESS”
for producing water equivalent in quality to distilled water from crude water without distilling.
A L L Permutit Processes are now available to industry in general and we shall be glad to help solve your own particular problems.
If you are interested in . . .
(1) Recovery o f valuable materials from dilute solutions.
(2) Removal o f undesirable materials from valuable solutions or any similar problems, we will be glad to assist you. Write fo r fu ll particulars.
P e r m u t it Co. Ltd.
M A N U F A C T U R E R S O F I O N E X C H A N G E M A T E R I A L S
D e p t. V .A . P e r m u t it H o u s e , G u n n e rs b u r y A v e n u e , C h isw ic k , L o n d o n , W . i . T e l. C h isw ick 6131
X THE CHEMI CAL AGE J U N E 8 , 1 9 4 6
Important tests that control production.
"THE m aintenance of th e high unvarying standard of quality in PYREX Brand Scientific Glassware Is so vital to efficiency in th e finished p roduct, th a t freq u en t routine vests are m ade to en su re th e closest relation to th e established form ula. H ere two tests are seen in progress.
(A) On th e left is th e Boric Oxide test, o r th e estim ation , of Boric Oxide (B2O3) In PYREX Brand Glass, B2O3 being o n e of th e m o st Im portant constituents In this famous Boro-silicate glass.
(B) On th e right, one of o u r research chem ists is estimating th e am o u n t of Sodium Oxide (N a20) by Zinc-uranyl-acetate, a rapid and extrem ely accurate m eth o d of controlling th e Sodium Oxide in PYREX Brand Glass, th e N a20 co n ten t being extrem ely Im portant to th e physical property of the glass, especially th e co-efficient of expansion.
CH EM IC A L AND GAS E N G I N E E R I N G CON TRACTO RS
SPECIALISTS IN DESIGN MANUFACTURE OF COMPLETE PROCESS PLANT t EQUIPM ENT
. INDUSIWM- G W »
& I 5T
4 t t U U W W O « » 6 *
4 R W N I H G O H S & F M S
Of
IDlBLf
HïDROGtHMIOH
f M S p r o d u c in g — W D U S U U M - o i i s
VEOtUBlt
4 DUSI REMOVAL & RECOVERY
T h a t ’s w h y y o u c a n a l wa y s r el y o n
PYREX
•It* OKU MMHC
S C I E N T I F I C G L A S S W A R E
J A M E S A. J O B L IN G & C O . LTD.
W e a r Glass W o rk s , S U N D E R L A N D . T.0LC
Ju n e 8 , 1 9 4 6 THE CHEMI CAL AGE x i
I M P E R I A L C H E M I C A L I N D U S T R I E S L T D .
N O B E L H O U S E - - L O N D O N , S . W . X
CRICKET FESTIVALS
w e d o NOT l i k e
C R IC K ETS breed prolifically in th e early sum m er on refuse tips and w aste ground, and m ay spread rapidly to neighbouring p roperty.
U SE ‘G A M M E X A N E ’ D U S T D.034 NOW , AND E N S U R E FR E E D O M FRO M CRICK ETS F O R T H E W H O L E SEASON.
The breeding of F L IE S will also
SA FE TO U SE • EFFEC TIV E
be Prev cn ted -
INDOORS A N D IN T H E OPEN
• PER SIST E N T IN ACTION • U NA FFEC TE D B V SUNLIGHT OR M OISTURE.
‘G A M M E X A N E ’ D U S T D .0 3 4 is a v a ila b le in lim ite d q u a n titie s , in 56 lb . a n d I c w t. p a c k a g e s . S m a lle r q u a n titie s a r e r e p a c k e d a n d so ld b y r e ta ile r s .
T HE
‘Gamm exane' is the nam e given to the gam m a isomer o f benzene hexachloride.
KESTNER
K E S T N E R ’ S
THE CHEMI CAL A GE Ju n e 8 , 1 9 4 6
PROFLAVINE SULPHATE NEUTRAL - B O O T S - —
(Proflavine H em isulphate )
A n e u tr a l sa lt o f p ro f la v in e w h ic h is less lik e ly to c a u se d a m a g e to d e lic a te tissu e s th a n th e a c id sa lt, P ro f la v in e S u lp h a te B .P .
S u p p lie d in B o ttle s o f 5, 2 5, 1 0 0 a n d 5 0 0 g m .
Available on trade terms through jour usual wholesaler or direct from the
W holesale a n d E x p o rt D ep artm en t
B O O T S P U R E D R U G C O M P A N Y L I M I T E D
N O T T I N G H A M E N G L A N D
Chemical Engineers 5, G R O S V E N O R G A R D E N S , L O N D O N , S .W . I.
• Plants supplied from I to 3,500 c.f.m. and larger, If required.
C on tin u ou s operation achieved by—
use
Illustration le ft: Drying Unit.
Illustration below : Close-up o f the Autom atic 1 Regenerator and Change
over Valves.
Dual A b so rb e r unit with fully automatic r e g e n e r a t i o n and change-over valves.
D ryn ess dow n to dew J f & B point— of minus 60°C.
W R IT E F O R L E A FL E T 24S,
Ju n e S , 1 9 4 6 THE CHEMICAL AGE x i i i
there.
Photography, Te xtile s, Paints, Paper and Food
stuffs, to name but a few i n d u s t r i e s to w h i c h Staveley brings a range of important Acids, Alkalis and Chemicals.
THE S TAVEL EY COAL £ I R O N CO. LTD C H E S T E R F I E L D
x i v THE CHEMI CAL AGE Ju n e S , 1 9 4 6
“POSTLIP”
( N o , 6 3 3 ' M i U )
ENGLISH
FILTER
.P A P E R S
White and
Grey, Plain,
A n t i q u e ,
C r i n k l e d, and Embossed.
Pure Filterings fo r Lab o rato ry W o r k , and In quantities for all Industrial
purposes.
See rep o rt of TESTS m ade by the National Physical Laboratory* a copy of which will ^ be sent on application together ^ with free sam ples if required.
Posilip Filterings are stocked by all the leading Wholesale ______ Laboratory Dealers______________ _
EVANS ADLABD & Co., Ltd.
P O S T U P M IL L S
W IN C H C O M B E , C H E L T E N H A M , EN G L A N D
A C I D - R E S I S T I N G
= C E M E N T S =
P A T E N T A C I D - P R O O F N O N - S L I P F L O O R S
T A N K L I N I N G S E T C . E T C .
—Consult.
F. HAWORTH (
A C I C E m I n T I N G ) L T D .R A M S B O T T O M • L A N C A S H IR E
P h o n e : G ram s :
R a m sb o tto m 3254. “ C e m e n ts .” R am sb o tto m .
TYPHOX
A N D
T IT A N IU M P O T A S S IU M O X A L A T E
IDEAL M O R D A N T S FOR LEATHER DYEING
W R IT E FOR P A R T IC U LA R S
PETER SPENCE & SONS LTD.
••Nr.7 < 0 .'C'i i);,VGS •. jT. «V *n t V ‘
M A N C H E S T E R , 3
LONDON OFFICE: 7 7 8 /7 8 0 SAU'EL'Rlr HOUSE SC2
TA TE
S EM I-BA LAN CED SOLENOID OPER ATED VALVES
SUITABLE FOR STEAM. W A TE R , AIR, SPIRITS, OIL, and CHEMICALS
JAMES TA TE & CO.
VICTORY WORKS . EAST P A R A D E
B R A D F O R D
Ju n e 8 , 1 9 4 6 THE CHEMI CAL AGE
THERMAL LINKAGE
SAVES LAUNDRY 23°/oOF
c o a l b i l lL A U N D R Y ’ S B I G E C O N O M Y B E F O R E
Therm al L in ka g e—
A laundry, in two sections ( with separate boiler plants), one each side o f a road, used 5,550 lb. o f steam per hour and consum ed 41 tons o f coal w eekly.
A F T E R T herm al L in ka g e—
The laundry m aintained the sam e output on a reduced coal consum ption o f only 31 i tons p er w eek. Replace
m ent o f a condem ned boiler was also rendered unnecess
ary, saving £6 ,0 0 0 o f new plant.
W o r e p l a n t s , o f a / / t y p e s , a d o p t p r o v e d p r o d u c t i o n -
e c o n o m y t e c h n i q u e
T h erm a l L in k ag e saves fuel. T h erm a l L in k ag e cuts p ro d u c tio n costs. T h erm a l L in k ag e increases o u tp u t.
T h o se are the three p ro v ed reasons w hy progressive factories everyw here a re a d o p tin g T h erm a l Linkage.
T h e rm a l linkage m eans in teg a tin g y o u r v ario u s h eat-u sin g processes a n d , as far as possible, o p e ra tin g them as a single c o -o rd in a te d h eat-u sin g u nit. In stead o f being in d ep en d e n tly su p p lied to several se p a ra te p o in ts o f c o n su m p tio n a n d th e su rp lu s going to w aste, h e a t is c ircu lated a n d re-circu- lated fro m p o in t to p o in t so long as th ere is w ork fo r it to do.
U R G E N T A C T I O N N E E D E D F uel efficiency a n d im p ro v ed p ro d u c tio n will rem ain a p ressin g need. H o w m u ch c o u ld y o u r existing p la n t benefit fro m the a p p lic a tio n o f these p rin cip les ? N o schem e o f re c o n stru c tion o r p la n t c o n v ersio n sh o u ld com m ence w ith o u t T h e rm a l L in k ag e being co n sid ered .
F O R G E N E R A L I N F O R M A T I O N Se e Fuel Efficiency B ulletin N o . 21 (T he C o n stru c tio n o f a F a c to ry H e a t B alance).
f o r s p e c i f i c a d v i c e a n d guid an ce c o n ta c t y o u r R eg io n al Office o f th e M inistry o f F u el a n d Pow er.
F O R C O M P L E T E D E T A IL S S E E •‘F U E L E F F IC IE N C Y N E W S "
D E C E M B E R , 1945.
Good timber is scarce, but for essential work
CARTY’S can still supply VATS
IN TIMBER UP TO
PRE-WAR STANDARD OF QUALITY AND SEASONING
— CARTY—
A N D S O N , L I M I T E D
H arders R d ., P e c k h a m , L O N D O N , S.E.15
P h o n e s N e w C r o s s 1826
pH 2 Deep Red pH 8 Green
pH 4 Light Brown pH 9 Bluish Green
pH 6 Yellow Orange pH 10 Deep Blue pH 7 Yellow Green pH 10.5 Violet
These new test papers are convenient both for process control in the works and for rough tests in the laboratory. Standard colours are printed on the cover o f each book for comparison.
Boxes containing 12 books of 20 leaves each 4/- per box^; per dozen boxes 45/-
T H E B R I T I S H D R U G H O U S E S L I M I T E D
G R A H A M S T R E E T L O N D O N N. l
B .D .H . ‘ W ID E R A N G E 9 IN D IC A T O R P A P E R S
B.D .H . “ Wide-Range " Indicator Papers are prepared from a mixture of indicators to show a range of distinct colours from pH2 to pH io.5
THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
The Chemical Age
A Weekly Journal Devoted to Industrial and Engineering Chemistry
B O U V E R IE H O U S E , 154 F L E E T S T R E E T , L O N D O N , E .C .4 T e le g ra m a : A LL A N C A S F L E E T LO N D O N
G LA SG O W : 1 1 6 H ope S tre e t (C entral 39 7 0)
T e le p h o n e : C E N T R A L 3 2 1 2 (1 2 lines) D 1R M 1N G H A M : D aim ler H o u se, P a ra d ise S tr e e t (M idland 078 4-5) T H E C H E M IC A L A G E offices a re closed on S a tu rd a y s in acco rd an ce w ith th e a d o p tio n of th e fiv e-d ay w eek b y
B enn B ro th e rs L im ited
VOL. LIV
No. 14 0 6.
June 8, 1946
A n n u al S u b sc rip tio n 2 1 s .O verseas 26s.
Speed T
l] E E n g lish m a n a n d th e C hin am anran h e lte r-sk e lte r dow n th e escalator, crashed th e ir w ay th ro u g h a m ass of people leaving an un d erg ro u n d tr a in and d ashed, h o t and dishevelled, th ro u g h th e closing door. As th ey flung them selves into a seat, th e E n g lish m an said : “ T here.
W e ’ve saved tw o m in u te s by t h a t . ”
" G ood,” said th e C h in am an , “ W hat shall we do w ith th e m ? ”
T his a n c ie n t sto ry of th e different view s on h u rr y of ea ste rn and w estern m e n ta litie s cam e in ev itab ly and u n b id d en to our m in d w hen, th e o th e r d ay , w e took a b u sm a n ’s holiday to h ear M ajor H alfo rd , ch airm an and m anaging d irecto r of D e H av illan d , speak upon th e su b ject of “ J e t P ro p u l
s io n .” T h e c h a ir w as tak en by no less a person th an A ir Com m odore W h ittle . T he -kings of speed w ere assem bled, an d seem ed
n o t a w h it su rp rised by w h at th ey h eard . I t is n o t so very long ago since an y form of h u m an trav el a t speeds over 100 m iles an h o u r seem ed e n o rm o u s;
150 m iles an h our w as o u tsid e th e bounds of im ag in atio n . Y et a y ear ago, w hen A ir Com m odore W h ittle flew into, his - hom e aerodrom e and w as asked by h is son a t w hat speed he w as flying, th e figure of 400 m .p .h . w as r e ceived w ith o u t e n th u siasm , and th e son w as la te r h eard ex-
On Other Pages
Sa les anil Comments E lectroplating in the W ar S o u th African Chemical Notes ...
Plant M anufacturers’ Association Non-Ferrous Metals
A nalysis o f Tall Oil
.1 C hem ist’s liookshelf ...
Alleged N ickel Monopoly L etter to the E ditor ...
Personal N otes ...
Insecticide M anufacturers Control of A tom ic Energy German Technical Reports In stitu te of Physics ...
Parliam entary Topics ...
Industrial Spectroscopy
Prevention of Silicosis ...
G eneral News fro m W eek to W eek 649 Commercial Intelligence ... 651 Stocks and Shares ... 652 British Chemical P r i c e s ... 653
p lain in g to a friend th a t “ D addy w a s n 't really tr y in g .”
M ajor H alfo rd already h as designs for a tran s-o cean ic passenger m ach in e holding 50 people to cross th e A tlan tic a t 600 m .p .h . It- will tak e less tim e to trav el from London to N ew Y ork th a n it did 40 y ears ago from L ondon to P a ris. Six of th ese p assen g er m ach in es, costing to g eth er a b o u t 4-3,000,000, could ta k e each y ear, w ith o u t h u rry in g them selves to change ro u n d quickly, as m an y passengers as th e Queen M a ry , costing p erh ap s four tim es as m u ch to-day. . M oreover, because th e plane w ould fly sufficiently high to be out of th e w eath er and in rarefied a ir, and because of its quick change-round, th e passenger fares w ould be less for th is high speed th a n a t p r e s e n t1 for air tra v e l a t to -d ay 's speeds. J e t propulsion, there, can
be no d o u b t, h as brought upon us a com plete revolution in trav el. I t h as brought c o u n tries n e a re r to each o th er. I t has in creased th e ir risks in w ar. I t has increased th e ir co n tac ts in peace.
W e shall h av e to a d ju s t ourselves to a w orld in w hich speeds are n o rm al th a t w ere undream ed of in o u r y o u th . W h e th e r th a t is a good th in g or a bad w e fo rbear to a rg u e : it is a fa c t th a t we h av e to face. T he human, b eing w ill a d a p t h im self to th e changed 631
633 639 640 642 643 644 645 645 646 646 647 647 647 646 649 649
629
630 THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
conditions. T h a t in itself is ra th e r a w onderful th in g . F o r teons, N a tu re has been a d ap tin g h er child ren slowly through th e w ays of evolution to changed environ, m e n ts. Now, w ith in th e sh o rt space of less th a n a lifetim e, th e h u m an race cau a d a p t itself to a tem po of life w hich would h ave seem ed im possible a c e n tu ry ago.
N or, stran g ely enough, has our span of life been sho rten ed by th e speed, a t w hich we live. W e crowd far m ore into the day th an o u r ancestors could possibly have done.
V erily, we liv e! Y et th e h u m an fram e does n o t w ear o u t m ore q u ic k ly ; on th e c o n tra ry , o u r expectation of life has increased.
W h a t is th e ex p lan a tio n ? I s it n o t in th e application of science? N o t th e a p p li
cation of a p a rtic u la r science, but the con
tin u e d advance of science all along the fro n t. W ith o u t advances in m edical science we could n o t h ave ta k e n advantage of th e advances in physical science th a t have enabled u s to live fu ller lives— to save o u r tw o m in u te s h ere and th e re , to crowd so m u ch m ore into th e d a y ’s w ork and play. All th e sciences help u s to live m ore dangerously, m ore ad v en tu ro u sly , “ to fill th e unforgiving m in u te w ith sixty seco n d s’
w orth of d istan ce r u n .” I t h as becom e a condition of su rv iv al, in th is tu rb u le n t and h u rry in g age, th a t th e pro d u ctio n of goods should be speeded up to th e sam e e x te n t as th e je t propulsion ex p erts are speeding up a ir tra n sp o rt. To accom plish th a t in creased rate of p roduction is th e fu n ctio n of m odern m an ag em en t , and of m odern in d u stria l science. T here is no room for the slow , for th e slacker, in th ese days of speed. Those, w ho rem em b er th e spacious life of ¿50 y ears ago, w hen w e k ep t b u sin ess a p p o in tm en ts by tr a in , or drove to th em in a horsed cab— som e of u s w alked an d th a t helped to keep us f i t !— will u n d e rsta n d the c o n tra st betw een th e “ n au g h ty n in e tie s and th e “ ferocious fo rties ” in w hich we live to-day. Those who have n ev er know n th e m ore leisurely days of th e V ietorinns, a t once m ore gracious and m ore sq u alid , can n o t fully u n d e rsta n d th e ch a n g e ; and th a t in itself is a trib u te to th e resilience of th e h u m an body an d th e h u m a n m ind.
B u t, w h at shall w e do w ith th e tw o m in u te s we have saved by o u r ru s h and b u stle ? One answ er is th a t w e shall use it to do som e m ore w ork. T h a t is th e very- general reply, and th e u su al p ractice. I n itself, how ever, it m ean s th a t le isu re w hen it com es m u s t also be p u t to good use.
" To live rem ain s a n a r t , ” a philosopher
h as told u s, “ qn a r t w hich everyone must, learn and w hich no o n e. can te a c h .” If science show s us how to b u stle, com pels us to live at high pressu re, and enables us to do so— high p ressu res being th e fashion to-day in c h em istry and as in life— it is th e a rts w hich show us how to use our leisu re. L eisu re an d co n tem p latio n have gone o u t of fashion, b u t th e re is m uch to be said for using in th is way som e a t least of th e tw o m in u te s w e save by b u stlin g . W e recollect w ords w ritte n by S ir Ja m e s F ra s e r w hile he w as a professor at C am bridge U n iv ersity : “ T he w indow s of m y stu d y look on to th e tra n q u il c o u rt of an a n c ie n t college, w here th e sundial m ark s th e silent passage of th e hours. . . H e re , if any w h ere, rem ote from th e tu m u lt and b a ttle of th e w orld, w ith its pom ps and v a n itie s an d am b itio n s, the s tu d e n t m ay hope to h ear th e still voice of tr u th , to p e n e tra te th ro u g h th e little tra n sito ry questions of th e h our to th e realities w hich ab id e, w hile g en eratio n s com e and g o .”
W ith o u t a b re a th in g space for co n tem p la
tio n and q u iet th o u g h t, all our m odern speed ends in b eating th e air. I t is fatally easy to be busy and to accom plish n o thing.
T h e holiday season, fully stag g ered , and a u g m en ted by victory celeb ratio n s, is upon us. I t is in cu m b en t upon , us to use our leisu re to good effect th a t we m ay prepare ourselves fo r th e w ork of th e y e a r th a t lies ahead. H ow shall w e do it? H ow shall w e an sw er th e question of o u r C hinese frien d , from a civilisation half as old as tim e ? I n th e tru e holiday sp irit w e offer th ese lin es, w ritte n by a w ell-known ed u ca
tio n a list of a p a st g e n eratio n , A rth u r H u g h Sidgw ick, killed a t P operinghe in 1917, as one w ay of sm oothing aw ay th e m en tal furrow s g en erated by th e speed of m odem life :
“ On the cabin roof I lie G azing into vacancy.
Make no noise and break no jesi, I am peaceful and a t rest-.—
“ Somewhere back in days gone by I did som ething—was it I ? Do not ask : I have forgot W hether it was I or not.
“ Sometim e I may have to do Som ething else; but so may you.
Do not argue, but adm it T h at we need not th in k of it.
‘‘ T hought has ever been my foe;
T h at is so. Yes, th a t is so.
On th e cabin roof I lie G azing into vacancy.”
H ap p y holidays 1
Ju n e 8 , 1 9 4 6 THE CHEMI CAL AGE 6 3 1
N O T E S A N D C O M M E N T S
R e se a rc h in T e ch n ic al C o lleges
L
A ST w eek, in a le tte r to The T im e s, a n u m b e r of d istin g u ish ed c o n su ltan ts expressed th e ir m isgivings ab o u t th e w isdom of som e of th e recom m endations made, in th e M in istry of E d u c a tio n 's circu lar (No.
94, of April 5), the te rm s of w hich w ere d is
cussed in Th e Ch e m i c a l Ag e on A pril 2 0
(p. 417). T hey take exception p a rtic u la rly to th e suggestion th a t “ an y sc ie n tist or technologist serv in g on th e staff of a te c h nical college who is com p eten t to act as a c o n su lta n t to in d u s try should be encouraged ( to do s o ,” and su b m it th e objection th a t such a p ractice w ould be .contrary to the best in te re sts of edu catio n . T hey fu rth e r claim th a t th e average te a c h e r, how ever high h is academ ic qualifications, usually lacks sufficient p ractical know ledge of in d u s try to p erform th e fu n ctio n in d icated . In a la te r le tte r to th e sam e jo u rn al, how ever, Sir W illiam L ark e gives stro n g su p p o rt to th e M in istry ’s recom m endation, p o in tin g o u t th a t it is th e te a c h e rs’ associa
tion w ith in d u s try w hich has revolutionised scientific and tech n ical tra in in g for in d u s
tr y ; th e in tro d u ctio n of a new type of stu d y by professors w ith a know ledge of in d u s
tria l problem s and req u irem en ts has been th e m ain sp rin g of th is revolution. T h ere appears little d o u b t th a t S ir W illiam L u rk e ’s point is m ore in accordance w ith m odern educational id e a s; b u t th e re is a n o th e r side to th e m a tte r. Tt does seem a little u n fa ir th a t m em b ers of th e staff of colleges w hich are d irectly subsidised by public fu n d s should be encouraged to e n te r in to com p etitio n w ith in d ep en d e n t consul
ta n t s ; and from th is aspect th e affair savours stro n g ly of a n o th er a tta c k on p riv a te e n terp rise.
Fu el T e ch n o lo g y E d u cation
T
H E stim u la tin g p resid en tial address delivered by D r. E . W . S m ith a t th e last an n u a l corporate m eetin g of th e I n s titu te of F u el has ju s t been c irc u la te d , a n d , as m ig h t have been expected, it is found to contain m uch m a tte r of in te re st. N ot le a st im p o rta n t is th e schem e outlined for th e b e tte r edu catio n of fuel technologists, a m a tte r of som e urgency w hen th e s ta te of th e fuel supply of th is co u n try is as precarious ¡is we all know it to be. As a re s u lt of the d eliberations of th e I n s t i t u t e ’s E d u c a tio n C o m m ittee, and collaboration w ith th e C ity and G uilds of L ondon I n s t i
tu te , a really sound schem e has been d e veloped by th e C ity and G uilds I n s ti
tu te . M em bership exam in atio n s w ere held for th e first tim e u n d er th is schem e ’from May 27 to J u n e 3, for it is essen tial th a t a typical series of ex am in atio n papers should be available to teac h ers and c a n d i
d ates as soon as possible. M eanw hile, a d m ission to m em b ersh ip is 011 equivalent, qualifications a tta in e d a t tech n ical schools and colleges, a t u n iv ersities, an d through oth er related professional bodies, to g eth er w ith satisfactio n of th e “ C h a rte r ” clauses relatin g to p ractical tra in in g and experience. T h is, as D r. S m ith pointed o u t, is th e only possible proceedure u n til th e education schem e of th e I n s titu te be
com es fully o p erativ e, so th a t p ractical experience has to be ta k e n as satisfy in g c e rta in of th e re q u ire m e n ts, w hich la te r will be th e su b je c t of specific e x a m in a tions. R egional J o in t E d u c a tio n C om m it
tees of th e M in istry of F u e l and Pow er and th e S ections of th e In s titu te are also being set up, w ith th e p rim a ry fu n ctio n of developing facilities for tra in in g in fuel technology for all g rades, from th e furnace- m an to the professional fuel technologist.
As in d u stry will be fully rep resen ted on th ese th e re is every reason to feel th a t th is developm ent is th e beginning of a g reat ste p forw ard in technological education in th e fuel field.
T h e F u tu re of T in P ro d u ctio n
C
O N S ID E R A T IO N is now being given by th e vario u s tin -p ro d u cin g com panies in M alaya to th e a m o u n t th e y w ill need of th e prom ised G overnm ent a ssistan ce, to help them to rehabilitat’e th e ir property and eq u ip m en t dam aged d u rin g th e J a p a n ese occupation. F u n d s , as has already been announced, are to be m ade av ailab le to th em th ro u g h th e M alayan G o v ern m en t for schem es approved by th e M in istry of Supply. I n te re s t is to be 3 per c e n t., b u t no in te re s t will be payable u n til .1 9 5 0 ,Som e com panies have already applied for a g ra n t, and re-equipm ent is proceeding, b u t i t is too early y e t to say how m any dredges will be capable of operation by A ugust 1. F ig u res published la st D ecem ber sta te d th a t 41 o u t of 126 w ere suscep
tib le of rep air by th a t d a te , provided th a t sp a re p a rts and lab o u r w ere forthcom ing, an d i t seem s likely th a t th is figure is not u n d u ly o p tim istic . M eanw hile, s ta te s th e
6 3 2 THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
F inancial T im e s, discussions are proceed
ing betw een th e G o v ern m en t an d th e N ig erian tin producers on th e renew al of th e bulk p urchase c o n tra c t w hich expired la s t D ecem ber. T h e producers have r e fused to accept renew al a t th e form er price of J ‘300 per ton, and it is understood th a t th e G ov ern m en t has as y e t issued no reply.
Research and the Public
T
H R E E -D IM E N S IO N A L illu stra tio n is undou b ted ly m ore vivid to th e lay m ind th a n th e m ost graphic w ritin g or th e m o s t skilfully reproduced p h o to g rap h s; and th e C hem ical R esearch E x h ib itio n , organised by I .C .I ., and opened on W ednesday la s t a t th e Tea C entre) L ow er R egent S tr e e t, L ondon, is, am ong o th er th in g s, a successful endeav o u r to b ring hom e to th e public— not fo rg ettin g our visito rs from o v erseas— the benefits th a t th e y owe to m o d ern B ritis h chem ical research. W e have alread y outlined th e n a tu re of th e ty p e s of research th a t are illu strated (see
Th e Ch e m i c a l Ao e, M ay 1 1 , p. 5 2 4 ) : now w e would co m m en t ra th e r on th e actual la y -o u t of th e ex h ib its. T h e chief arch itect of th e exhibition is M r. B asil Spence \w h o holds the sam e office for th e forthcom ing
" B ritain Can M ake I t ’’ exhibition), and h e has done an excellent job in evolving th e general design, an d in co-ordinating th e work of a b rillia n t te a m o f young a rtis ts . L ik e Spence him self, these are m ostly new ly dem obilised officers, including .John H u tto n (a N ew Z ealan d er, d esig n er of th e ce n tra l m u ral), J a m e s G ard in er (chief d e sig n er to “ B rita in Can M ake I t and L in to n L a m b , all of w hom w ere engaged on cam ouflage w ork d u rin g the w ar. The d istin g u ish ed foreign a rtis ts , H e n rio n , of F ra n c e (for th e u p sta irs room s), and R o tte r, o f Czechoslovakia (for d o w n stairs), have added a to u ch of th e ir special experience.
Chem istry Displayed
R E A T in g en u ity in th e use of planes of p lastic m a te ria l has been show n in b u ild in g up th e e x h ib its, and strik in g ly d ecorative effects have been a tta in e d by th e disposition of m o lecu lar formulas in th e
■conventional “ ball-and-rod ” co n stru ctio n . W o w ere p a rtic u la rly im pressed by th e
“ electro lier ” com posed of a g ia n t version of th e sy m m etrical form ula of polythene.
D iag ram s, transparencies," m odels, p h o to g rap h s, and c u t-o u ts, n o t to m en tio n actual exam ples of lab o rato ry a p p a ra tu s, an d a fair supply of ex p lan a to ry notices, should
serve to b ring hom e to th e m ean e st in te lli
gence' th a t so m eth in g has been going on here w hich m u s t have a beneficial effect on hum an h ealth , food, and clothing. T he exhibition has now been opened to th e public by Professor S ir R obert R obinson, P .R .S . As th e first chem ist since Sir H u m p h ry D avy to be elected to th e p resi
dency of th e R oyal S ociety, S ir R obert is peculiarly fitted to th e ta sk of intro d u cin g to th e public a display of th e advances m ade
T h e p o ly th e n e “ m o l e c u l e ” a t th e C h e m ic a l R e s e a r c h E x h ib itio n . by B ritish c h em ists d u rin g th e la st 15 years— especially as he h im self is now e n gaged in a line of research w hich it is hoped m ay lead to th e p roduction of sy n th etic penicillin. S ir R o b ert w as in tro d u ced by Sir W allace A kers, research d irecto r of I .O .I ., w ho has ju s t rejoined th e com pany from th e D ire c to ra te of T ube Alloys, th e G o v ern m en t org an isatio n w hich controlled B r ita in ’s w ar-tim e research on atom ic energy. T h is com bined display o f . skilful design an d chem ical in g en u ity is a cred it to all concerned in i t ; a n d , in c id e n ta lly , is well w o rth a special visit— you have till J u n e 28.
Ju n e 8 , 1 9 4 6 THE CHEMICAL AGE 633
Electroplating D uring the W ar—I
Som e Im portant Applications of the Process
b y E . A . O L L A R D , A .R .C .S ., F .R .I .C ., F .I n s t.M ., a n d E . B . S M IT H
T
O the laym an, in years before the w ar, the term electroplating conjured up a pietfire of gleam ing cutlery on a w hite cloth, cigarette cases, and fittings for home and cars, together w ith a hundred oth er o rn a m ental and decorative objects. The dem ands of w ar, however, developed for the process of depositing one m etal upon another a fa r stern er application, th a t of protection against w ear and corrosion and the h ard en ing of surfaces to ensure g re a te r service, and it is these la tte r aspects of electropla'ing we wish to bring to our re a d e rs’ notice, since the war-tim e developm ents m ay be ap
plied with far-reaching effect to th e pro
ducts of peace.
Among the uses which have been found for electrodeposition are th e p rotection of steel p arts of airc ra ft, tan k s, guns, etc., the special protection of steel against tro p ical atm osphere, the building up of w orn or under-m achined p a rts w ith nickel o r chro
mium, the facing of bearings w ith lead to avoid running in, the building up of special bearings by electrodeposition, th e stopping- off on p arts w hich have to be hardened so th a t only the po rtio n requiring hardening is treated , the anodisiug of alum inium p a rts for protection, and the plating of electrical com ponents w ith silver or precious m etals to obtain satisfactory properties.
P r o t e c ti o n of S te e l P a r t s
Most sm all m achine p arts are m anufac
tured of steel, and while they may be used unprotected in places w here th ej' are reaso n ably sheltered from the atm osphere, e.g., in the inside of an engine which is kept well oiled, they will quickly tend to ru st and become unserviceable if exposed for any time to outdoor conditions. Thus all steel p a rts for aeroplanes, tanks, e tc ., w h ic h come into contact with the atm osphere m ust be satisfactorily protected.
In the early p a rt of th e w ar, aeroplane p arts were generally plated w ith cadmium.
Cadmium w as chosen in preference to zinc because in the first place it stood up well against humid conditions and, in the second, the finish it gives is generally somewhat more pleasing in appearance; also, it is som ewhat easiui to plate cadmium, p articu -- larly in a b arrel, and it has a b e tte r “ throw ” into th e more recessed p arts of articles.
Cadmium, however, is also used as a bearing m aterial, and supplies of cadmium have to be brought across the A tlantic as th ere are no sources in this country. D uring the B attle of the A tlan tic, several consignm ents of cadmium w ere lost and the position be
came very critical. I t therefore becam e necessary to tu rn over to zinc all the plating plants which had been using cadmium for the above purposes.
Cadmium is norm ally plated from a cyan
ide solution, and zinc can be plated from a very sim ilar solution, although it lias been found more satisfactory to use a solution containing a m ixture of the double cyanide of sodium and zinc, together w ith sodium zincate. This solution plates zinc quite satisfactorily, b u t th e conditions of o p era
tion are som ew hat different from those of cadmium p lating and the control of th e solution is ra th e r, more critical. W hile .%
cadmium solution w orks satisfactorily a t room tem p eratu re, a zinc solution has to be worked w arm . F u rth erm o re, w hile a c a d mium solution may be controlled analyti
cally by the estim ation of cadmium and cyanide only, w ith zinc it is necessary to estim ate the m etallic content, the to tal cyan
ide, and also the caustic present, as these factors have to be correctly balanced. I f the solution is properly ad ju sted , and th e tem p eratu re and cu rre n t density are co rrect, 110 g reat difficulty is experienced in the p ro cess; but a t the same tim e the zinc does not throw as well as the cadmium, th a t is to say, it tends to plate on the outstanding portions of the article, and w ith deeply re cessed articles th e-m o re rem ote p arts may
not cover satisfactorily. T herefore, th e solution does not w ork well on cast iron o r 011 sandblasted surfaces.
B a r r e l P la t in g
Even g reater difficulty is experienced when articles have to be tre a te d in a plating b arrel. A large num ber of articles to be plated are in the n atu re of small screws, nuts, bolts, etc., and these are barrelled be
cause it would be impossible to deal w ith them in any other way economically. I t is found, however, in certain cages, p a rtic u larly w ith screws having fine th re a d s, th a t it is extrem ely difficult to get them to cover satisfactorily. This -is due to some ex ten t to the fact th a t th e surface area is greatly increased by the fine th read , and a m uch higher c u rre n t m ust therefore be used. I t has thus been found th a t when such articles, are to be b arrelled, higher voltages m ust be- used on the b a rre l th a n w ere necessary for- cadmium, and this has caused a certain am ount of difficulty because often th e gener
ating equipm ent would not supply the volt
age required and special g enerators or- rectifiers had to be installed.
Even when suitable voltages w ere avail-
C>34 THE CHEMI CAL AGE Ju n e 8 , 1 9 4 6
able, difficulty was often experienced in getting certain small articles to cover satis
factorily. This, however, could be over
come to some extent by eith er giving the a rticles a (lash of tin before plating or by adding a sm all quan tity of sodium stannate to the so lu tio n ; and most of the p laters dealing w ith zinc were able ultim ately to get sa tisfa c to ry results on practically every type of article which had previously been cad mium -plated. Tow ards the end" of the w ar, th erefo re, cadmium w as used scarcely a t all and although it is possible th a t, for some purposes a t least, when supplies become norm al, it may again have its old applica
tion, it is probable th a t many people who have .not got used to the handling of the zinc b ath will continue to p late th e m ajo r
ity of th eir articles w ith zine since this m etal gives quite satisfactory resu lts in p rac
tice and is considerably cheaper.
The A .I.D . lnid down certain specifica
tions for the plating of a irc ra ft parts.
D uring th e w ar, these specifications were som ewhat relaxed because it was felt th a t the actual tim e the m achine w as in service
w as likely to be considerably less th an in peace tim e and therefore it was unnecessary to specify such a high perform ance. Since the prin cip al essential was to obtain as great a- protection as possible, the thickness of 0 .0 0 0 2 in. of zinc was allowed on all com
ponents. Tow ards the end of th e w ar, how
ever, th is thickness was raised to 0.00Q5 in.
except in the case of certain articles which
are norm ally barrelled, 011 which it would be somewhat difficult to obtain an even thickness satisfactorily. Also, if too thick a deposit is made on threaded portions, the nuts wilt not go o n ; if they are forced on,
they remove the deposit, and the last state is thus worse th an the first.
Zinc cau also be plated from an acid solution of zinc sulphate and this process is used w here very high cu rren t densities' are required. It can be used satisfactorily on wire sheets, etc., but the solution does not throw as well as cyanide zinc and it is not greatly used except for the purpose men
tioned.
T r o p ic a l R e q u ir e m e n ts
T11 1944, when the operations in the E u ro pean th eatre were draw ing to a close and in terest became focussed in th e Pacific, the question of the protection of the various com ponents against tro p ical atm osphere came to the fore. W hile zinc w ithstands corrosion of an in d u strial atm osphere as well as cadmium , if not b etter, it w as found th at in dam p hum id atm ospheres th e zine itself was quickly corroded, form ing a white corrosion product which was objectionable in connection w ith elec
tric a l ap p aratu s, e.g., radio chassis.
I t became desirable, therefore, to find some method of treatin g the zinc- p lated p arts so th a t they would w ith
stand the humid Pacific conditions.
It was found th a t zinc and zinc- plated articles could be “ passi- • v a te d .” T his process, consisted in dipping articles, im m ediately a fter plating, in a solution of sodium bi
chrom ate and sulphuric acid. T his treatm en t formed on the surface a
■chromate coating the exact com posi
tion of which has not been entirely explained. I t seems probable, how
ever, th a t th ere are both trivalent and hexavalent chrom ium in the coat
ing, which is undoubedly hydrated.
T he coating is probably in th e form of some type of a gel. F o r th is reason, a passivated coating m ust not be heated to too high a tem perature;
otherw ise it will lose its w ater and crack and become useless. ~ Tt is s ta n dard practice, therefo re, a fte r passi
vating, to dip in cold w ater and dry in warm air, tak in g care th a t the articles do not become overheated. If this process is satisfactorily carried o ut, an iridescent greenish-yellow film will be formed on the article. The colour of th is film may vary considerably with the conditions of form ation and it is possible to obtain alm ost any colour ranging from blue o r pink to a darkish brow n. I t has, however, been found th a t the dark- brown coatings are not very protective, and the iridescent types of coating are generally- p referred.
Ju n e 8 , 1 9 4 6 THE CHEMI CAL AGE 635 Zinc-plated articles treated in this m anner
will w ithstand tropical tem perature and atm osphere very satisfactorily and give a perform ance quite com parable w ith th a t of cadmium. Passivating is quite cheap to apply and, provided it is carefully carried out, it does not give a g reat deal of trouble.
W hen it was first introduced, however, some difficulty was experienced, since various G overnm ent departm ents insisted th a t the film should have some definite appearance specified by them selves. T his difficulty, however, was gradually cleared up and, w ith g re a te r experience of the process, producers and inspectors were able to agree.
In addition to the question of protection against corrosion, the w ar in the tropical countries dem anded finishes which would harm onise w ith the surroundings. T hus it was. even necessary to tr e a t a considerable am ount of equipm ent to produce a dark- greenish or khaki finish which did not show against a jungle background. M att finishes also were generally preferred, since they do not reflect the light. A passivated finish 011 zinc was often used for this purpose and proved quite successful on many articles of equipm ent. O ther equipm ent was bronzed or blacked to su it conditions.
C a r tr id g e C a s e s
Up to the outbreak of w ar, cartrid g e cases had been made of brass, but owing to the shortage of non-ferrous metals, it became desirable to make them of steel. The steel cartridge cases had to be protected from ru st, and it was therefore necessary to plate them . Zinc was the obvious choice as a p lating m aterial, b u t it was found th a t for some reason zinc did not w ork as well as brass in the breach of the gun and tended to jam . Also, the services were used to brass cartrid g e cases and for this reason alone p referred th a t they should rem ain b rass in appearance. It was, therefore, ultimately- decided to brass-plate the steel cartridge cases.
An enorm ous num ber of cartridge cases were required of various sizes and shapes, and for this reason it was desirable to install autom atic p lan t to deal w ith the output. A careful investigation was, therefore, made 011 the brass plating process and the condi
tions u nder which the brass bould be depo
sited at a high cu rren t density w ere estab lished. A 70/30 per cent, brass was depo
sited and this could be achieved w ith a c u rre n t efficiency of about 65 per cent.
Anodes w ere of the same composition as the brass deposit, namely, 70/30 per cent., and an anode cu rre n t density of about 40 am p ./
sq. ft,, could be used. The autom atic plant had a plating vat of 2500 gallons capacity and used 4000 am ps., 6 g. of brass being deposited per sq. ft. of surface. A fter p la t
ing, th e articles were given a dip in dichrom- ate to give a passivated surface som ewhat
sim ilar 10 th a t described for zinc, although in the case of brass the colour change is very slight.
C)ne of the problems when dealing w ith an article such as a cartridge case in an autom atic plant is th a t the inside m ust be drained out between operations. The plant is arranged to lift and tran sfer the articles from one tan k to another and th is is done by means of a set mechanism. The articles themselves are held on special jig s W hen the tra n sfe r has been made by hand, the operator tips the cartrid g e case to empty it before tran sferrin g it from the vat to the swill or vice versa. T his operation must therefore be conducted by the autom atic p lan t and th is was achieved by th e design of a special jig. The position of the lift of th is jig was somewhat different from th a t in which it hung when suspended in the tank.
T hus, when hanging in the tan k , the c artrid g e cases w ere tilted slightly w ith th e ir m outh upw ards so, th a t the a ir could come out of them , and thus they were completely filled w ith solution. W hen lifted, however, the position of lift was altered and centred over the closed eild of th e cartridge case so th a t they hung m outh dow nwards and the solution drain ed out of them .
The plant illu strated in Fig. 1 worked for some years and very little trouble w as ex
perienced with it. T he cartridge cases plated were in every way satisfactory and since under war-tim e conditions they did not have to be stored for any long period, the specified thickness of :0003 in. gave satis
factory protection. T he p lan t dealt w ith some G00 sq. ft. of surface per hour.
B u ild in g U p M a c h in e P a r t s So far, we have d ealt w ith the problem s of protection against corrosion. Kleciro- deposition, however, can be used for p ro ducing hard surfaces on w earing p a rts and also to bring the^e p a rts up to size.
In w ar time p articu larly , w here it is necessary to' conserve all m aterial, it is desirable to be able to reclaim a machine p a rt which has been badly worn or w hich, owing to inexperienced labour, has been m achined below, size. O ften it is only one small portion of the whole component th a t has to be brought up to size and th is makes it even more economically desirable to tr e a t th e p a rt so th a t it may be put back into service. Nickel is the m a te ria l'm o st gener
ally used for this purpose and although su p plies of nickel were som ewhat short during the w ar, allocations were available fo r such uses. It is possible to build up a deposit of nickel to almost any desired thickness by taking suitable precautions to ensure its adhesion, and satisfactory hardness and m echanical properties.
W hen a p a rt has to be built up it is first cleaned by any of the stan d ard m ethods and then stopped off so th a t only the portion to
