The Mining Magazine
M anaging Director and E d ito r : W . F. Wh i t e. A ssista n ts : St. J . R . C. Sh e p h e r d, A .R .S.M ., D .I.C ., F .G .S .;
F . Hi g h a m, A .R.S.M ., M .Sc., F.G.S.
P u b l i s h e d o n t h e 1 5 t h o f e a c h m o n t h b y M i n i n g P u b l i c a t i o n s , L i m i t e d , a t S a l i s b u r y H o u s e , L o n d o n , E.C. 2.
T elephone: Metropolitan 8938. T eleg rap h ic A d d re s s : Oligoclase. Codes: M cN eill, b o th Editions, & Bentley.
Br a n c h O f f tc r s -I New Y ork : A mer. In st. M. & M.E. J 12s. p er annum , including postage.
1 Chicago : 360, N . M ichigan Blvd. { U.S.A., $3 p e r annum , including po stag e.
Vol. X L V I I I . No. 2. L O N D O N , F E B R U A R Y , 1933.
P R I C E O N E S H I L L I N GC O N T E N T S
Ed i t o r i a l
N o tes ... 66
Geological Society A w a rd s ; The A nglo-Persian Oil D isp u te ; The New P resid en t of th e In stitu tio n . T ro p ical H y g ien e a n d M a laria C o n tro l 66 An account of th e proceedings a t th e J a n u a ry m eeting of the In stitu tio n . T h e R a n d a n d th e G old P re m iu m . . . 67
The position of th e S o u th African gold-m ining in d u stry is reviewed in the light of th e U nion’s d ep artu re from th e gold stan d ard . G old in K e n y a ... 68
The position in K en y a is re-exam ined in view of the recom m endations contained in Sir A lbert K itso n ’s second re p o rt. Re v i e w o f Mi n i n g... 7 0 Ar t i c l e s T h e C ard o x P rocess . . . . A . Ig n a tie ff A description of th e principles, construction, and applica tio n of this blasting m ethod to the m ining of coal. L ig h tn in g — I V Jo h n F . S h ip le y In this, th e last of a series of fo u r articles, the au th o r discusses th e n atu re an d causes of breakdow ns of electrical p la n t due to lightning. A llu v ial S am p lin g . . . . A . J . Peterson A review of some of th e difficulties stan d in g in the w ay of stan d ard izatio n of alluvial sam pling m ethods. T he I.M .M . B e n ev o len t F u n d ... T w elfth L is t of S ubscriptions. Le t t e r t o t h e E d i t o r “ G old M ining in R u ssia ” Bo o k Re v i e w s 7 3 80 85 G. T . Eve R ic k a rd ’s " M an a n d M etals ” S ir H arold Carpenter Longwell, K nopf, a n d F lin t’s " T e x tb o o k of Geology ” ...T . H . W hitehead G u te n b erg ’s " H a n d b u c h d e r G eophysik ’’ Dr. H . Shaw D a le ’s “ T he F o rm a n d P ro p e rtie s of C ry stals ” ...D r. D avid W illiam s G u rw itsch a n d M oore’s " T he Scientific Prin cip les of P etro leu m T echnology ” D r. M u rra y Stuart A m erican A ssociation of P e tro le u m G eologists’ " S tra tig ra p h y of th e P lain s of S o u th e rn A lb e rta ” Dr. M u rra y Stuart Ne w s Le t t e r s 91 92 93 93 93 J o h a n n e s b u rg ... 94
Gold Prem uim ; R hodesian M ineral P ro d u ctio n ; D iam ond In d u stry ; New Coalfield ; Aerial Survey of Mines ; D iam onds in R hodesia ; Asbestos. P A G E B r i s b a n e ... 95
M ount Isa’s Position ; M ount Isa W ork and P roduction ; The New Cracow Field ; M ount M organ, L td . ; M ount W andoo Gold Mine ; Central A u stra lia ; M ount Lyell Company. T o ro n to ... 97
Mineral P roduction of C anada in 1932 ; Gold P roduction of O ntario ; Sudbury ; Porcupine ; K irkland Lake ; O th er O ntario Goldfields ; N orth-W estern Quebec ; M anitoba. V a n c o u v e r... 100
Bridge R iver ; P o rtla n d Canal ; A tlin ; C ariboo ; Sheep Creek ; Y m ir ; L illo o e t; B o u n d ary ; R ock Creek ; Vancouver. P e r s o n a l ... 102
T r a d e P a r a g r a p h s ... 103
Geco E lectric S am pler ... 103
D en v er M echanical Gold P a n ... 104
M etro p o litan -V ick ers D evelopm ents ... 104
M e t a l M a r k e t s ... 105
S t a t i s t i c s o f P r o d u c t i o n ... 107
P r i c e s o f C h e m i c a l s ... 109 110
Sh a r e Qu o t a t i o n s Mi n i n g D i g e s t
E . J . K e n n y Dr. J . T . M cIn tyre T he B roken H ill Lode .
S crew -Type F a n s . . . . H ollinger M ine Geology
D r. L . C. Graton, H . E . M c K in stry, and others T he W ave-T ype Tube-M ill L in e r
E . D. M cIn tyre M anitou L ak e, O n tario . . . . J . E . Thom son M ining P etro leu m b y U n d erg ro u n d M ethods
George S. Rice P ow er for B roken H ill ... F. J . M ars M etallu rg ical R e s e a r c h ... S. L . H oyt Pashkokogan-M isehkow A rea, O n tario
111 115
Im p u ritie s in L ead
Sh o r t No t i c e s
W. S. D yer R . S. Russell
116 119 120 121 123 124 125 125
1 2 6 Re c e n t Pa t e n t s Pu b l i s h e d ... 1 2 7 Ne w Bo o k s, Pa m p h l e t s, e t c...1 2 7 Co m p a n y Re p o r t s ... 1 2 8 Bulolo Gold D re d g in g ; C hangkat T in ; N orthern Transvaal (Messina) C o p p e r; San Francisco Mines of Mexico ; Sungei W ay.
D i v i d e n d s De c l a r e d ... 1 2 8 Ne w Co m p a n i e s Re g i s t e r e d... 1 2 8
2— 3 65
E D I T O R I A L
T
H R E E of th e a n n u a l a w a rd s of th e G eological S ociety of L o n d o n will in te re s t m in in g m en . T he M urchison m e d al a n d fu n d goes to D r. A. L. d u Foit, w hose w o rk in S o u th A frica is w idely k n ow n, w hile th e B ig sb y m e d al h a s been a w a rd e d to Mr. E . J . W a y la n d in rec o g n itio n of h is a c tiv itie s in U g a n d a a n d elsew here. In a d d itio n a m o ie ty of th e L yell F u n d is to be p re se n te d to Mr. A. B. B ro u g h to n E d g e in re c o g n itio n of th e v alu e of h is geop h y sical w ork in its a p p lic a tio n to geological problem s.I
N th e la st issue of th e M a g a z i n e it w as a n n o u n c e d th a t th e A n g lo -P ersian d isp u te w ould com e before th e C ouncil of th e L eague of N a tio n s on J a n u a r y 23. A fter a s ta te m e n t of th e ir case b y th e B ritis h a n d P ersian G o v ern m e n ts, b o th p a rtie s w ere p ersu a d e d to m e et, M. B enesh being a p p o in te d rapporteur. U n d e r h is offices a n ac ce p ta b le fo rm u la w as fo u n d , w hich, it is h oped, w ill le ad to a sa tis fa c to ry solu tio n . T he resp e ctiv e G o v ern m e n ts h a v e ag re ed to su sp e n d p r o ceedings before th e C ouncil u n til M ay a n d m ean w h ile th e co m p a n y w ill open n e g o tia tio n s w ith th e P e rsia n a u th o ritie s for a new concession, its n o rm a l o p e ra tio n s being c o n tin u e d d u rin g th e progress of discussion.T
H E new p re sid e n t of th e I n s titu tio n of M ining a n d M e tallu rg y — for th e p erio d 1933-34— is Mr. G. W . G ray , w ho, it is in te re s tin g to n o te , g ra d u a te d from th e R o y a l School of M ines in m in in g in 1899, th e sam e y e a r as his predecessor. H e im m e d ia te ly p ro ceed ed to h is first p ro fessional a p p o in tm e n t as a s s is ta n t m a n a g e r of th e P a n u c o C opper Co., M exico, w h ere he sp e n t a b o u t a y ea r, su b se q u e n tly going to th e M o u n ta in C opper Co., C alifornia. I n 1902 M r. G ra y w as a p p o in te d m in e a n d m ill s u p e rin te n d e n t of th e L oem ar M ining Co., D u tc h W e st B orneo, b u t fo u r y e a rs la te r saw h is r e tu r n to M exico as m a n a g e r of m ines for th e R efugio S y n d ica te, a n d in 1908 he w en t to R u ssia as m in e m a n a g e r of th e K y sh tim C o rp o ratio n , only to r e tu r n to A m eric a in a b o u t th re e y e a rs to becom e m a n a g e r of th e P y rite s Co., V irginia, w hich b eg an his asso cia tio n w ith th e g ro u p he h a s since been alm o st c o n tin u o u sly id e n tified w ith . H is w o rk in S p ain co m m en ced in 1913 on h is a p p o in tm e n t as chief m in in gen g in eer a n d d e p u ty te c h n ic a l m a n a g e r to th e R io T in to Co. a n d e x c e p t for a n in te r v e n in g p erio d in c o n su ltin g p ra c tic e from
1921-27— w hen he w as in p a r tn e rs h ip w ith Mr. W illia m S elk irk — Mr. G ra y h a s re m a in e d w ith th e m ev e r since, h a v in g been te ch n ic al d ire c to r since 1929. T h e p re sid e n t-e le c t b ecam e a m e m b e r of th e I n s titu tio n in 1922 a n d w as p re s id e n t of th e R o y a l S chool of M ines (Old S tu d e n ts ) A sso c iatio n in 1931.
T ro p ica l H ygien e and M alaria C ontrol T h ere w as a good n u m b e r of m e m b e rs at th e J a n u a r y m e e tin g of th e I n s titu tio n to h e a r th e a d d re ss b y S ir M alcolm W atso n , D ire c to r of T ro p ica l H y g ien e in th e Ross I n s titu t e a n d H o s p ita l for T ro p ica l Diseases, on “ T ro p ica l H y g ien e a n d M a laria C ontrol on M ines a t V ario u s E le v a tio n s .” T h e d e a th of Sir R o n a ld R oss m u s t be fresh in th e m in d s of all a n d i t is now w id ely realized how g re a t a n effect his rese a rc h e s h a d on the fu rth e ra n c e of en g in ee rin g p ro je c ts in th e tro p ic s, w hile th e w o rk c a rrie d on in L ondon a t th e in s titu te b e a rin g h is n a m e h a s received w elcom e p u b lic ity b y re a so n of the p ro m in en ce giv en to its ac h ie v e m e n t in clearing th e co p p e r m in es in N o rth e rn R h o d e sia of m a la ria a n d co in c id e n t diseases.
In a d d itio n m a n y m e m b ers h a v e availed th e m se lv es of th e courses of in s tru c tio n in m a la ria l c o n tro l t h a t are h eld a t th e Ross I n s titu te each y e a r a n d th e p ra c tic a l advice g iv e n b y th o s e in c h a rg e h a s b een read ily acknow ledged, a re c e n t le tte r in th e se pages u n d o u b te d ly reflectin g th e g en e ral opinion.
M ining m e n realize w h a t m a y , p e rh a p s, be b est ex p re ssed in th e le c tu re r ’s ow n words, th a t “ th e tim e is p a s t w h en a n y business concern sh o u ld force its w ay in to th e tropics, b u ild its houses on th e w ro n g site, lose a large p e rc e n ta g e of its m en, a n d th e n begin to
‘ ta k ’ a th o u g h t a n d m e n d ” ; nev erth eless, ev e r eager for fu rth e r g u id a n ce , th e y form ed a n a tte n tiv e au d ien c e on th is occasion.
T h e e d u c a tio n of th e la y m a n in m a tte rs co n n e cted w ith m a la ria l c o n tro l is of suprem e im p o rta n c e , for, as Sir M alcolm p o in te d out, it is u p o n him th a t th e b u rd e n u ltim a te ly falls. One of th e m o st s tr ik in g p o in ts arising o u t of th e le c tu re a n d one w hich serv es to em p h asize th e n eed for m o re g en e ral in s tru c tio n in tro p ic a l h y g ie n e seem s to be t h a t if m a la ria is p re se n t efficiency is also lo st from o th e r diseases, in a sm u c h as th e m a lad y
F E B R U A R Y , 1933 67
te n d s to low er th e v ita lity of its v ic tim s a n d open th e w a y to a tta c k b y o th e r germ s, th e sta tis tic s co llected d u rin g c o n tro l w o rk in M alaya affording a s trik in g d e m o n stra tio n of th is . I n th e course of th e evening o th e r im p o r ta n t fa c ts— a lm o st d isc o n ce rtin g in th e ir n e g a tio n of preco n ceiv ed ideas—
em erged. F o r in sta n c e , tro p ic a l sw am ps are n o t re g a rd e d as necessarily m a laria l, th e ric e - fields of In d ia , M alaya, Siam , a n d o th e r places being, for exam ple, sin g u la rly free from th e disease, w hile th e sam e is sa id to be tr u e of a rtific ia l sw am ps c o n ta in in g m ine ta ilin g s. T h e reaso n for th is is a p p a re n tly t h a t th o se m o sq u ito es w hich c a rry m a la ria b reed , as a ru le, in clean w a te r a n d w a te r p o llu tio n — b y th e a d d itio n of m in e ta ilin g s or decom posing v eg etab le m a tte r — te n d s to lessen th e risk of infection. A gain, if it is im possible to k ill th e in fec ted insects, it is possible to m ove aw ay from th e d an g e r zone a n d sites a t a d ista n c e of only h a lf a m ile from in fec ted ru n n in g stre a m s h a v e been fo und to be safe dw elling places. T h ese th re e p o in ts seem to em erge from Sir M alcolm 's discourse, w hich w as concerned, as th e title of his p a p e r in d ic ates, w ith an e x a m in a tio n of w o rk c o n d u c te d on m in in g p ro p e rtie s a t v a ry in g a ltitu d e s, w hich h as ta k e n h im far afield, to M alaya, In d ia , A frica, a n d o th e r p a r ts of th e in fec ted tro p ic s. T h e im p o rta n c e of a su ita b le site for h e a d q u a rte rs is th e p la in lesson for th o se selecting a m ine cam p, w hile th e p ro sp e c to r in new c o u n tries is w arn ed no t to cam p n e a r a stre a m a n d also well aw a y from th e n e a re st n a tiv e v illage— p ra c tic a l lessons t h a t h av e a lre a d y been le a rn t b y th o se w ho h av e h a d ex perience in th e tropics.
T h e discussion w as open ed b y Mr. R . E . P alm er, w hose p a rtic u la r experience w ith m a la ria h as b een in s o u th e rn S pain. H is q u estio n s to th e le c tu re r w ere p e rtin e n t, p a rtic u la rly w hen he re fe rre d to th e n a tu ra l in stin c t of th e ex p lo re r to ca m p n e a r ru n n in g w ate r. T o all w ith tro p ic a l experience th is m u st seem b y far th e m o st difficult m ista k e to era d ic a te , for, a t th e e n d of a tirin g tre k , a clearing n ea r ru n n in g w a te r is irre sistib le to p ro sp e c to r a n d c a rrie rs alike. F ollow ing M r. P a lm e r w as Mr. A. D . S to rk e , w ho p o in te d o u t th a t m a la ria w as a serious m a tte r a t th e co m m encem ent of o p e ra tio n s a t th e R o an A ntelope m ine a n d th a t g re a t im p ro v e m e n t re su lte d im m e d ia te ly th e R oss I n s titu te ex p e d itio n to o k over th e w ork of control, b la c k w a te r fever being a th in g of th e p a s t in th e N o rth e rn R h o d e sia n cam ps. T he cost of th e w o rk a t R o a n A n telo p e is in te restin g ,
th e c a p ita l o u tla y h a v in g been ¿25,000, a sm all a m o u n t in re la tio n to th e c a p ita liz a tio n of th e co m p a n y a n d sm all in d e ed w hen rec k o n ed a g a in st th e r e s u lta n t gain in th e efficiency a n d h a p p in ess of th e m in e staff. D r. R am sey, w hose w o rk in I n d ia h a d been referre d to b y th e le ctu rer, follow ed a n d h is re m a rk s serv ed to show clearly th e n eed for fu rth e r research , for, as he s ta te d , th e p ro b lem is how to d ea l w ith a ty p e of anopheles m o sq u ito th a t b reed s in clear w a te r in exposed places a n d to find a p la n t to grow beside th e stre a m s in o rd er to sh ad e th e m . O th e r speakers in clu d ed Mr.
E . T. M cC arthy, D r. J . A. L. H en d erso n , an d Mr. S. H . de la M are, all of w hom h a v e h a d e x ten siv e experience in th e tro p ic s a n d whose qu estio n s a n d re m a rk s a d d e d to th e in te re st of th e discussion. Sir M alcolm W a tso n , in h is rep ly , show ed th a t th e re w ere alw ays difficulties p ecu liar to new sites a n d th a t co -o p eratio n b etw een th e m ed ical m a n a n d th e la y m a n in co n tro l is th e m ost im p o rta n t fa c to r in overcom ing th e rav a g es of disease a n d p ro m o tin g h e a lth y a n d efficient w ork in tro p ic a l places.
The Rand and the Gold P r e m iu m W h e n S o u th A frica left th e gold s ta n d a rd th e first ste p w as ta k e n w hich led to increased a tte n tio n being d ire c te d to R a n d gold-m ining shares a n d a t a m e etin g of th e T ra n sv a a l C ham ber of M ines la st m o n th Mr. Jo h n M a rtin , th e p resid e n t, m a d e a n im p o rta n t s ta te m e n t on th e policy of th e gold-m ining in d u s try co n seq u en t on th e n ew ly -c re ate d positio n . Mr. M a rtin p o in te d o u t th a t th e u n c e rta in exch an g e s itu a tio n h a d c re a te d m a n y difficulties lik e ly now to be rem oved, b u t rec o m m en d e d t h a t th e a d o p tio n of a ste rlin g basis sh o u ld be th e o b jectiv e of th e U n io n ’s m o n e ta ry policy. H e ex p ressed th e belief th a t th o se in ch arg e of S o u th A frican affairs h a d nev er been sufficiently im pressed b y th e s ta rtlin g progressive decline in th e in d u s try th a t w ould h av e been in e v ita b le u n d e r th e old co n d itio n s, even th o u g h th e rec o m m en d a tio n s of th e Low G rad e Ore Com m ission a n d th e e s tim a te s of th e G o v ern m e n t M ining E n g in e er w ere fresh in all m e n ’s m inds. T he in c re ase d p rice now o b ta in a b le for th e p ro d u ce of th e in d u s try d id m uch, in Mr. M a rtin ’s opinion, to im p ro v e its pro sp ects, th e q u estio n of b rin g in g low er- grad e ore a n d ore from g re a te r d e p th s in to p ro d u c tio n h a v in g been an o u tsta n d in g p ro b lem in th e econom y of gold, a n d he w as
T H E M IN IN G M A G A Z IN E
co n fid en t t h a t u n d e r th e d iffe ren t c o n d itio n s so m e th in g in th e n a tu r e of a new m in in g p o lic y w o u ld b e evolved, in w h ich full a d v a n ta g e w o u ld b e ta k e n to low er p a y lim its, to in crease th e ore reserv es, to a c c e le ra te th e d ev e lo p m e n t of ore-bodies a t p re se n t bein g w o rk ed , a n d to fo rw a rd th e e x p lo ra tio n of new reefs p rev io u sly re g a rd e d as u n p a y a b le . A t th e sam e tim e Mr. M a rtin foresaw th a t th e in c re ase d p rice of gold w ould en su re a s u b s ta n tia lly h ig h e r scale of w o rk in g pro fits, so t h a t to th e d e ta c h e d o b serv er th e re seem s so m e th in g c o n tra d ic to ry in h is review , w h ich m a k es th e p o sitio n w o rth y of closer e x a m in a tio n .
T h e m in in g of ore of low er g ra d e or, in o th e r w ords, in c re asin g rese rv e s b y th e a d d itio n of g ro u n d h ith e r to re g a rd e d as u n p a y a b le can h a rd ly m a k e for en larg ed pro fits, for th e tr e a tm e n t p la n ts a t th e p ro p e rtie s are n o t elastic a n d are in m o st cases a lre a d y bein g w o rk e d to th e ir full c a p a c ity . A n in c re ase d scale of p ro fits is only possible if th e in d u s try c o n tin u es to tr e a t ore of, le t u s say, 1932 g ra d e a n d th is cou ld o n ly m e a n th a t full a d v a n ta g e w as n o t being ta k e n of th e new c o n d itio n s to e x te n d th e lives of th e m ines. T h e in d u s try c a n n o t h a v e it b o th w ay s a n d to o b ta in in c re ase d p ro fits w hile m in in g low er-grade ore w ould o n ly be possible b y p la n t ex ten sio n s such as h a r d ly seem w a rra n ta b le , unless it is felt t h a t th e p re se n t co n d itio n s are o n ly lik e ly to be of sh o rt d u ra tio n . W ith re g a rd to c e rta in of th e low er-grade p ro p e rtie s— p ro p e rtie s on th e b o rd e r line of pro fit a n d loss— co n d itio n s are, of course, g re a tly im p ro v e d a n d in such cases a n increase in th e c a p a c ity of th e tr e a tm e n t p la n t m a y be ju stified a n d th e p ro fits are lik e ly to im p ro v e. A san e view w o u ld seem to be t h a t th e m a in effect of th e d e p a r tu re of th e U n io n from th e gold s ta n d a r d sh o u ld be to p rolong th e life of th e in d u s try r a th e r th a n to p ro v id e a n in creased r e tu r n to th e sh areh o ld ers, m u c h of w hich h a s been d isco u n ted b y e n h a n ce d p rice levels. I t w ould seem th a t good p ro fits over a longer p e rio d are b e tte r th a n in creased p ro fits over a s h o rt one, especially as th e in te n tio n s of th e U n io n G o v ern m e n t w ith resp e ct to new ta x a tio n a n d th e a ttitu d e of la b o u r to th e p re se n t w age levels are q u ite u n k n o w n .
T h ere is a n o th e r asp e c t o f th e p re se n t s itu a tio n t h a t seem s w o rth y of n o tic e . I t h a s o fte n been s ta te d t h a t sh o rta g e of gold is la rg e ly resp o n sib le for th e p re se n t w orld s itu a tio n a n d we h a v e been re m in d e d th a t
in som e p r o v id e n tia l w a y d e p re ssio n h a s in th e p a s t b een c o u n te re d b y th e o p p o rtu n e d isc o v ery of new fields. S om e ob se rv e rs c o n sid er a n y e x te n sio n of th e life of th e R a n d e q u iv a le n t to su c h a d isc o v e ry , b u t it is difficult to follow th e ir rea so n in g . T he p o in ts p re v io u sly rev ie w ed se rv e clea rly to show how m is ta k e n is such a n o tio n , for p re se n t c o n d itio n s c a n h a r d ly c o n triv e to s tim u la te p ro d u c tio n on th e R a n d — th e y m a y e v e n h a v e th e re v e rse effect, for it m u s t be re a liz e d t h a t la s t y e a r ’s p ro fits can be m a in ta in e d b y a low er o u tp u t. O ne is, th e re fo re , fo rced to r e tu r n to th e sa n e view a n d to a ssu m e t h a t th e g o ld p re m iu m is u n lik e ly to in c re ase th e a n n u a l o u tp u t of th e R a n d , b u t sh o u ld serv e to p ro lo n g th e life of th e m o st im p o r ta n t in d u s tr y of th e U nion.
G old in K enya
S p e a k in g a t a lu n c h e o n h e ld la s t m o n th in h is h o n o u r, S ir A lb e rt K its o n , w h o has r e c e n tly r e tu r n e d fro m K e n y a o n th e con clu sio n of h is w o rk of in a u g u ra tin g a geological su rv e y a n d m in e s d e p a r tm e n t for th e colony, rev ie w ed th e p ro s p e c ts of th e K a k a m e g a goldfield, w h ere h e s p e n t a good p o rtio n of h is tim e . I n th e co u rse of his re m a rk s, h e p o in te d o u t t h a t th e field was g ra d u a lly c h a n g in g fro m a p u re ly alluvial s ta te to one in w h ich th e reefs m u s t be ex p lo re d in d e p th a n d t h a t th e f u tu r e of the field d ep e n d s on th e d o w n w a rd a n d la te ra l e x te n sio n of th e reefs, m a n y of w h ich have p ro v e d to b e h ig h ly au rife ro u s. T h a t th e gold is th e re is a m p ly p ro v e d b y th e re tu rn s re c e n tly p u b lish ed , th e o u tp u t for th e te n m o n th s to O cto b e r, 1932, b ein g e s tim a te d at 8,112 oz., as c o m p a re d w ith 2,450 oz. for the sam e p e rio d of 1931. T h e in c re ase is m ainly fro m th e new K a k a m e g a field a n d comes a lm o st e n tire ly from th e a llu v ia l diggings.
A p a rt from th e fu n c tio n re fe rre d to , fu rth e r referen ce to th is field is called for in view of th e p u b lic a tio n of th e m a in conclusions of S ir A lb e rt’s second re p o rt on th e field, in w hich h e d ea ls p a rtic u la rly w ith th e ap p lic a tio n of T a n g a n y ik a C oncessions, L td ., for an exclusive p ro sp e c tin g licence o v er a n area of 5,900 sq u a re m iles su rro u n d in g th e field itself.
T he K a k a m e g a goldfield, as a t p re s e n t open to g en eral p ro sp e c tin g , lies in th e e a s t of C e n tral K a v iro n d o , th e a r e a a p p lie d for by th e co m p a n y m e n tio n e d ru n n in g in to N o rth e rn a n d S o u th e rn K a v iro n d o , in th e la tte r dow n to th e T a n g a n jd k a b o rd er. T he
F E B R U A R Y , 1933 69
in te n se o p p o sitio n felt in K e n y a itse lf to th e g ra n tin g of th is licence h a s a lre a d y been referre d to in th e se colum ns a n d it m a y be sa id a t once t h a t S ir A lb ert is in a g re em e n t w ith th e o p p o sitio n a n d w ould ad v ise th a t th e a p p lic a tio n , as it sta n d s, be n o t ap p ro v e d . T he offer of T a n g a n y ik a Concessions a p p a r e n tly p ro p o sed th a t a staff of 11 m e n — nine of w h o m w ould h a v e b een p ro sp ec to rs—
sh o u ld be e n tru s te d w ith th e w o rk of e x p lo ra tio n a n d it w as e s tim a te d th a t th is w ould m e an , in a d d itio n , th e em p lo y m e n t of 330 n a tiv e s . T h e m in im u m e x p e n d itu re in v o lv ed in th e w o rk w as e s tim a te d a t £20,700, s p re a d over a p erio d of tw o y ears. Sir A lb e rt K itso n considers th e p ro p o sed staff to ta lly in a d e q u a te for a p ro p e r e x p lo ra tio n of th e a re a a n d he h a s fo rm u la te d a schem e u n d e r w hich h e considers th e w o rk w ould be m ore th o ro u g h ly ca rrie d o u t. H e reco m m e n d s th e d iv ision of K a v iro n d o in to five sections— F irs t, p a r t of N o rth -W e st K av iro n d o (1,550 sq u a re m iles), e x ten d in g n o r th of th e p re se n t field ; secondly, th e are a w e stw a rd a n d so u th -w estw a rd of th e e x te n sion of th e K a k a m e g a field a n d ly ing m a in ly in C e n tral K av iro n d o (ap p ro x im a tely 1,000 sq u a re miles) ; th ird ly , so u th e rn C e n tral K av iro n d o a n d n o rth e rn a n d e a s te rn S o u th K av iro n d o (ap p ro x im a tely 1,720 sq u are m iles) ; fo u rth ly , w estern S o u th K av iro n d o (a p p ro x im a te ly 1,140 sq u a re m iles), an d , fifthly, th e G ori goldfield, in S o u th K av iro n d o (a p p ro x im a te ly 485 sq u a re m iles). Of these are as Sir A lb ert advises th a t th e second a n d fifth sho u ld be th ro w n open for general p ro specting, as it is a lre a d y know n t h a t gold occurs w ith in th e m , w hile th e o th e r th re e sho u ld rem a in for th e p re se n t closed, b u t t h a t T a n g a n y ik a Concessions sh o u ld be in fo rm ed t h a t th e G overnor is p re p a re d to g ra n t an o p tio n over one of th e m a n d to receive a p p lica tio n s from t h a t co m p an y , from o th e r com panies, or from in d iv id u als for p o rtio n s of th e rem ain in g tw o. In th e e v e n t of th e c o m p an y concerned refusing th e o p tio n , th e n a p p lic a tio n s should be receivable for all th re e for exclusive p ro sp ec tin g licences over one o r tw o y e a r p eriods a t a n a n n u a l re n ta l of 2s. per sq u a re mile.
I t is e v id e n t from th is su m m a ry of his re p o rt th a t S ir A lb ert K itso n is m o st critica l of th e offer of T a n g a n y ik a Concessions. H e c o n tra sts th e e x p e n d itu re p ro p o sed b y th e co m p an y w ith th a t lik e ly to be sp e n t b y K e n y a m in e rs if th e are as he recom m ends a re th ro w n open to g eneral p ro sp ec tin g . In such a case he foresees th e a c tiv itie s of 200
m e n em ploying a p p ro x im a te ly 3,000 n a tiv e s, w hich w ould m e a n , of course, a n a n n u a l e x p e n d itu re , a c tu a lly w ith in th e colony, of, say, th re e tim e s t h a t p ro p o sed b y th e co m p an y , w hile th e K e n y a m in e rs are now sufficiently ex p erien ced in local co n d itio n s a d e q u a te ly to p ro sp e c t th e g ro u n d th ro w n open a n d th e y h av e , in a d d itio n , a g re a te r in c e n tiv e to th o ro u g h w ork, as th e ir only re w a rd w ill be th e fru it of th e ir own e n d e av o u r. Such a course of ac tio n w ould seem to be of a c tu a l benefit to m ore pow erful in te re sts , for th e ir p ro sp ec tin g w ould, in a sense, be done for th e m a n d th e y w ould be in a p o sitio n to choose w hich discoveries are w o rth y of fu rth e r in v e stig a tio n . W ith resp e ct to th e co n d itio n s u n d e r w hich new exclusive licences are g ra n te d , Sir A lb ert in sists t h a t th e se sh o u ld in clu d e a co n sid erab ly increased m in im u m e x p e n d itu re , th e em p lo y m e n t of far m o re n a tiv e la b o u re rs, a n d a definite d e ta ile d p ro g ram m e, r a th e r th a n in d ic atio n s of a p ro p o sed course. I t is ev id e p t, th erefo re, t h a t Sir A lb ert does n o t in te n d th a t th e new m ines d e p a rtm e n t of th e colony sh o u ld be ig n o red a n d considers t h a t th e su p e r
in te n d en c e of th e re su lts of ca refu lly -p lan n ed w o rk w ould o ccupy its tim e fully.
T he p u b lic a tio n of th is new re p o rt— to w hich, as is s ta te d in a p re fa to ry n o te, th e K e n y a G o v ern m en t a tta c h e s th e g re a te s t im p o rta n c e — is likely to enlarge consider
a b ly th e a re as of n a tiv e la n d affected b y th e gold discoveries an d , if th e a u th o ritie s decide to th ro w o pen th e new areas, th e y are lik e ly to a c c e n tu a te th e c o n tro v e rsy th a t h as arisen over th e te m p o ra ry dispossession of th e n a tiv e s in th e reserve. T he re se rv a tio n of m in e ral rig h ts to th e G o v ern m en t in ord er th a t th e y m a y be w o rk ed to th e best a d v a n ta g e to th e c o m m u n ity h as n ev e r been qu estio n ed , so t h a t it is difficult to see how th o se w ho on a n th ro p o lo g ica l a n d h u m a n ita ria n g ro u n d s fea r for th e n a tiv e can com plain a t th e e x a m in a tio n of th e su rface of are as w here m in e ral is k n o w n to exist.
T he eagerness of th e n a tiv e s in th e reserv e to a c ce p t th e new em p lo y m e n t offered to th e y o u n g er m en seem s a sufficient answ er to th e tre p id a tio n s of th o se w ho fear th e w o rst a n d w ho ta lk o p en ly of th e likelihood of n a tiv e u n re st. B efore m ore c o u n try is th ro w n open to p ro sp ec tin g c e rta in critics insufficiently a c q u a in te d w ith C e n tral A frican co n d itio n s h a v e ask ed for fu rth e r d elib eratio n . I t m ig h t be as well to le t th e m h av e it, for it w ould show th e m th a t th e ir fears are u n w a rra n te d .
R E V I E W O F M I N I N G
I n tr o d u c tio n .— I h e in c re ase d a c tiv ity in S o u th A frican g o ld-m ining sh a re s, co n se q u en t on th e d e p a rtu re of th e U n io n from th e gold s ta n d a rd , h a s been a n o u ts ta n d in g fe a tu re of th e p a s t m o n th , b u t m a tte rs a t th e tim e of w ritin g a p p e a r to b e se ttlin g dow n to a n a p p re c ia tio n of th e rea l position.
In th e b ase-m etal in d u s try th e o u tlo o k of tin h a s been d is tin c tly im p ro v e d b y th e J a n u a r y s ta tis tic s , w h ich rev e a l a d im in u tio n of 1,500 to n s in th e w orld visible su p p ly , w hile th a t of zinc h a s been ad v e rsely affected b y u n c e r ta in ty as to th e ren ew al of th e In te r n a tio n a l C artel.
T ran svaal.— T h e o u tp u t of gold on th e R a n d for J a n u a r y w as 919,125 oz. a n d in o u tsid e d istric ts 48,332 oz., m a k in g a to ta l of 967,457 oz., as co m p ared w ith 980,618 oz.
in D ecem ber. T h e n u m b e r of n a tiv e s em p lo y ed in th e gold m in es a t th e e n d of J a n u a r y to ta lle d 222,005, as co m p ared w ith 221,008 a t th e en d of D ecem ber.
S h areh o ld ers of R a n d fo n te in E s ta te s h av e been in fo rm ed t h a t as th e h ig h e r p rice being o b ta in e d for gold h a s m a d e p ro fita b le a n ad d itio n a l large to n n a g e of ore it h as been decided to en larg e th e re d u c tio n p la n t, b rin g in g its c a p a c ity u p to 10,000 to n s a d a y . T he e s tim a te d co st of th e w ork is £210,000, w hile o th e r e q u ip m e n t a n d w o rk in c id e n ta l to th e larger scale of o p era tio n s will involve a to ta l c a p ita l e x p e n d itu re of a b o u t £700,000, sp re a d o v er tw o y ea rs. I t is ex p e c te d th a t th e p la n t ex ten sio n s will be co m p leted b y J a n u a r y , 1934.
As u su a l th e q u a rte rly re p o rts of th e R a n d m in in g com panies disclose several ite m s of in te re st, especially as reg a rd s th e o re-reserve positio n , as figures are ca lc u la te d on th e 1932 basis. In th e A nglo A m erican g ro u p S p rin g s’ reserv es show a n increase of 385,500 to n s as co m p ared w ith th e p revious y ea r, w hile th o se a t D ag g a fo n tein h a v e been in creased b y 99,000 to n s, a lth o u g h th e g rad e in th is case is a little low er. T h e ore reserves of W e st R a n d C o n so lid ated a t th e e n d of 1931 w ere e s tim a te d to be 5,028,000 to n s, av e rag in g 5'3 d w t., a n increase of 10,000 to n s in a m o u n t a n d 0T d w t. in v alu e as c o m p ared w ith a y e a r ago. T he S o u th S h aft a t th is m in e in te rse c te d th e M ain R eef a t 3,613 ft.
a n d d u rin g D ecem b er la st rea ch ed 3,776 ft., a t w hich No. 36 level s ta tio n , th e low est level c o n te m p la te d , w as being cu t. T h e re p o rt of th e N ew K lein fo n tein for th e th re e m o n th s e n d e d D ecem ber 31 la st discloses in te re stin g
d e v e lo p m e n ts in th e A pex sectio n , esp ecially th e fin d in g of th re e m o re p a y -sh o o ts on th e 1 0 th a n d 12th levels, in view of w hich a d d itio n a l e q u ip m e n t is to be in s ta lle d th a t will p e rm it 3,000 ft. of d e v e lo p m e n t per m o n th to be c a rrie d o u t in s te a d of 2,000 ft.
In th e G old F ie ld s g ro u p th e re p o rt of th e S ub N igel show s a n in c re ase in th e reserv es of 160,000 to n s a n d it h a s b een d ec id e d to in c re ase th e re d u c tio n p la n t to a c a p a c ity of a p p ro x im a te ly 41,000 to n s a m o n th , th e c o n s tru c tio n w o rk to s t a r t im m e d ia te ly .
T h e re p o r t of Crow n M ines for th e th ree m o n th s to D ec em b e r 31 la s t s ta te s t h a t an a p p lic a tio n h a s b een m a d e for th e u n d e r
m in in g rig h ts of a n a re a e q u a l to a p p ro x i
m a te ly 829 claim s a d jo in in g th e c o m p a n y ’s so u th e rn b o u n d a ry . I t is s ta te d t h a t th e c o m p a n y c o n te m p la te s e x te n d in g its t r e a t m e n t p la n t a n d in c re a sin g d e v e lo p m e n t.
T h e a c q u isitio n b y L u ip a a rd s V lei of th e block of claim s fo rm e rly w o rk e d by th e F re n c h R a n d a n d T u d o r co m p an ie s is e x p e c te d g re a tly to e x te n d th e life of the m in e a n d it is a n tic ip a te d t h a t effo rts will be m a d e to e x te n d th e scale of o p e ra tio n s.
I t is s ta te d t h a t a rra n g e m e n ts h a v e been co m p leted b etw e en th e S o u th A fric an L an d C o m p an y a n d th e A nglo A m eric an Cor
p o ra tio n t h a t will p ro v id e th e fu n d s necessary for p ro sp e c tin g th e fa rm W itp o o rt b y the B ra k p a n a n d W e st S p rin g s com panies.
T h e a c c o u n ts of th e T w ee fo n te in Colliery, L td ., for 1932 show a p ro fit of £20,200, w hich, a d d e d to th e su m b r o u g h t in , gave an a v a ila b le to ta l of £61,840. O f th is sum
£7,500 w as ab s o rb e d in th e p a y m e n t of a d iv id e n d a n d b o n u s for 1931, w hile £7,500 w e n t in p referen c e d iv id e n d s, leaving a b alan c e of £46,840. F ro m th is a m o u n t it is pro p o sed to p a y d iv id e n d s a t th e sam e ra te as la st y e a r, ab s o rb in g £10,500, while
£6,000 w ill be p la c e d to a d iv id e n d e q u a liz a tio n reserve, le av in g £30,340 to b e carried fo rw ard . T h e to ta l coal sold b y Tw ee
fo n tein U n ite d Collieries a m o u n te d to 654,756 to n s, a g a in s t 725,977 to n s fo r the p rev io u s y ear.
S ou th ern R h o d esia .— T h e o u tp u t of gold from S o u th e rn R h o d e sia d u rin g D ecem b er w as 52,096 oz., as c o m p a re d w ith 48,082 oz. for th e p re v io u s m o n th an d 50,034 oz. for D ecem ber, 1931. O th e r o u tp u ts for D ecem b er w ere : S ilv er, 8,559 oz. ; coal, 33,840 to n s ; ch ro m e ore, 941 to n s ; asb esto s, 1,944 to n s.
F E B R U A R Y , 1933 71
S h areh o ld e rs of R e zen d e M ines, L td ., were in fo rm ed la s t m o n th t h a t th e re d u c tio n of c a p ita l h a v in g b een sa n c tio n e d b y th e E n g lish C o u rt, th e d a te of re p a y m e n t of 6s. 6d. p er sh a re h a d been fixed for J a n u a r y 31 last.
I t w as an n o u n c e d la st m o n th th a t a cross
c u t on th e M otor N o. 27 level of th e Cam a n d M otor m in e h a d a t 311 ft. e n c o u n te re d o re a v e rag in g 79s. per to n o v er a w id th of 16 in., w hile a t 335 ft. a split p o rtio n of th e C e n tral R eef w as fo u n d w hich assay e d 387s. 6d. p er to n over 24 in.
N orth ern R hodesia. — S h areh o ld ers of th e R o a n A ntelope co m p a n y h a v e been in form ed t h a t it is proposed to d isc o n tin u e th e p u b lic atio n of m o n th ly o u tp u t re tu rn s, w hich will, how ever, c o n tin u e to be in clu d ed in th e q u a rte rly rep o rts.
G old C oast.— T he re p o rt of th e A sh an ti G oldhelds C orp o ratio n , L td ., for th e y e a r to S ep te m b er 30 last show s a profit of £689,299, w hich, w ith th e su m b ro u g h t in, g av e an av a ila b le to ta l of £775,440. O u t of th is sum tw o in te rim d iv id e n d s, each of 2 5 % , h a d been p aid , ab so rb in g £250,000, w hile a final d is trib u tio n of 25% a n d a cash b o n u s of 2s.
p er sh a re ab so rb e d £375,000. In a d d itio n
£100,000 h a s been p laced to d iv id e n d eq u a liz atio n reserve an d , a fte r m a k in g o th e r allow ances, £26,484 ca rrie d forw ard. T he ore tr e a te d d u rin g th e y e a r to ta lle d 158,330 to n s, y ielding 175,063 oz. of gold an d 10,717 oz. of silver. T h e ore rese rv e s a t S ep te m b er 30 la s t w ere e s tim a te d to be 642,100 tons, av e rag in g 23'6 d w t. p e r to n , as co m p ared w ith 667,400 to n s, av e rag in g 2 3 ’1 d w t., a t th e e n d of th e prev io u s year.
In a progress re p o rt issued to sh areh o ld ers of B ib ian i (1927), L td ., la st m o n th it was s ta te d t h a t th e erectio n of th e new pow er p la n t h a d been co m p leted a n d th a t t r e a t m e n t p la n t c o n stru c tio n w as p rogressing satisfacto rily .
A t th e a n n u a l g eneral m e etin g of th e A sh a n ti G oldhelds C o rp o ratio n held la st m o n th it w as a n n o u n c ed th a t a pooling a rra n g e m e n t h a d been e n te re d in to b y th e C onsolidated Gold L ields of S o u th A frica, L td ., th e A nglo A m erican C o rp o ratio n of S o u th A frica, L td ., th e A sh a n ti G oldhelds C orp o ratio n , L td ., a n d th e G old C oast Selection T ru s t, L td ., for th e fo rm a tio n of a d e v e lo p m e n t sy n d ic a te to o p e ra te in G old C oast Colony. T h e la st-n a m e d com p a n y offered its sh a re h o ld ers 300,000 unissued 5s. sh ares a t p a r on J a n u a r y 26. I t has engaged Mr. O. A. L. W hitelaw , la te geologist
to th e G old C oast G eological S urvey, w hose services will be placed a t th e disposal of th e new sy n d ic ate.
A u stra lia .— R e p o rts of th e M ount Isa co m p an y for th e y e a r e n d e d J u n e 30 la st w ere av a ila b le in tim e for th e general m e etin g held in S y d n ey in D ecem ber, b u t th e p re se n ta tio n of a b alan c e sh eet h a s been defe rred u n til th e p rese n t y ear. T h e re p o rt of th e general m a n ag e r shows th a t 454,604 to n s of ore w as m ined, co n sistin g of 345,656 to n s of c a rb o n a te ore, 97,690 to n s of su lp h id e ore, a n d 11,258 to n s of p y rite , a n d th a t 453,145 to n s w as d eliv ered to th e m ill sto rag e bins a n d 1,459 to n s to th e sm elter. T he m ill, w hich s ta rte d w ork in M ay, 1931, w as n o t o p e ra tin g p ro p erly u n til Ju n e , b u t u p to J u n e 30 la st 453,997 to n s of ore, h a v in g a n av e rag e v a lu e of 10'7%
lead, 4 '1 % zinc, a n d 5‘5 oz. silver per to n , w as tre a te d , p ro d u cin g 87,500 to n s of co n c e n tra te s a v e rag in g 44-4% lead, 5 '5 % zinc, a n d 21'9 oz. silver per to n . T h e o u tp u t of th e sm e lte r w as 38,008 to n s of lead bullion, of w hich 36,310 to n s w as sh ip p ed to E n g la n d for refining. T h e ore reserves a t th e en d of th e y e a r w ere e s tim a te d to be 19,027,000 to n s, m o stly in th e B lac k S ta r lode.
In te re s tin g d ev e lo p m e n ts w ere re p o rte d in J a n u a r y b y b o th th e G re at B oulder a n d B oulder P ersev e ra n ce com panies. A t th e G re at B oulder a d ia m o n d -d rill hole from R o b e rtso n ’s S h aft d epressed a t 45° s tru c k no few er th a n five lodes a t v e rtic a l d e p th s of 270 ft., 470 ft., 515 ft., 535 ft., a n d 550 ft., th e la st-n a m e d p o in t being 15 ft. w est of th e east b o u n d a ry . A ssay v alu es ran g e d from 8 d w t. to 184 d w t. per to n over w id th s of 72 in. to 9 in. A t th e B oulder P ersev e ra n ce th e 1,100-ft. level n o r th d riv e h a d been ex te n d e d 63 ft. n o r th of th e w inze a t th e beg in n in g of F e b ru a ry , th e ore a t th e en d of th e d riv e assay in g 36 d w t. over a w id th of
13 ft.
T h e re p o rt of th e W ilu n a G old C o rp o ratio n , L td ., for D ecem ber la st s ta te s t h a t tw o fu rth e r in sta lm e n ts of £25,000 each h av e been re p a id on th e issue of £300,000 6%
sev en -y ear n o te s g u a ra n te e d b y th e A u stra lia n G o v ern m e n t, red u c in g th e a m o u n t o u ts ta n d in g to £225,000. In view of th e sa tisfa c to ry progress m ad e w ith p la n t ex ten sio n s it is ex p e c te d th a t th e m o n th ly to n n a g e tr e a te d will g ra d u a lly be increased to 40,000.
S h areholders of S o u th K alg u rli Con
so lid ate d , L td ., w ere in fo rm ed la s t m o n th t h a t w hile b alin g w a te r on J a n u a r y 22 th e
T H E M IN IN G M A G A Z IN E
ta n k fell dow n th e sh a ft, d am a g in g th e tim b e rs below th e 500-ft. level a n d cau sin g a su sp en sio n of p ro d u c tio n . I t w as e x p e c te d t h a t re p a irs w ould be co m p le te d e a rly th is m o n th .
New Z ealan d .— I t w as a n n o u n c e d la s t m o n th t h a t th e N ew Z e a la n d a u th o ritie s h a d g r a n te d to a g ro u p of B ritis h a n d N ew Z e a la n d co n cessio n aires th e rig h t to d red g e for gold o v er n e a rly 20 m iles of th e M olyneux R iv e r b e tw e e n C rom w ell a n d A le x a n d ra a n d o v er a p p r o x im a te ly seven a n d a h a lf sq u a re m iles of th e a d ja c e n t fla ts for a p erio d of 40 y ears.
N ew G u in ea .— A n a n n o u n c e m e n t m a d e th is m o n th b y N ew G u in ea G oldfields re p o rts th e d isc o v ery of tw o new d re d g in g are as n e a r B ulolo. T h e first of th e se covers a n a llu v ia l flat 8 m iles long b y 1,500 ft. w ide, w hile th e second is 10 m iles b y 3,000 ft.
T h e a re a s a re a t p re s e n t bein g drilled . M alaya.— A t a n e x tra o rd in a ry m e e tin g of th e P e n a w a t (M alaya) T in D re d g in g Co., L td ., to be h e ld th is m o n th , it w ill be p ro p osed t h a t th e c a p ita l of th e co m p a n y be re d u c e d from $5,000,000 in $1 sh a re s to
$2,500,000 in 50 ce n t sh a re s b y can cellin g c a p ita l to th e e x te n t of 50 c e n ts p e r share.
T h e d ire c to rs co n sid er th is m e th o d th e b est w ay of c o u n te rin g th e fall in v alu e of th e c o m p a n y ’s asse ts a n d of p la cin g it u p o n a d iv id e n d -p a y in g b asis as soon as possible.
S h areh o ld e rs of th e L o n d o n T in C o rp o ra
tio n h a v e been in fo rm ed t h a t th e d ire c to rs h a v e d ec id e d to exercise th e o p tio n th e y h o ld o v er 150,504 sh a re s in S o u th e rn K a m p a r T in D red g in g , L td ., w hich a re h eld b y L ow er P e ra k T in D red g in g , L td ., a n d to offer 150,000 of th e se to sh a re h o ld e rs in th e C o rp o ratio n a t 21s. p e r sh a re . B y th is m e an s th e c a p ita liz a tio n of th e S o u th ern K a m p a r C o m p an y w ill be c o m p le te d a n d it w ill be possible to red e em th e £150,000 of 7% d e b e n tu re s p r iv a te ly p la c e d w hen th e c o m p a n y w as form ed.
S ia m .— A t th e b eg in n in g of F e b ru a r y th e d ire c to rs of K a m r a T in D re d g in g g av e p a r tic u la rs of a schem e b y w h ich it w ill be possible to red eem th e 8% d e b e n tu re sto c k o u ts ta n d in g , p ro v id e d fu lly -p a id sh a re s are a c c e p te d in p a y m e n t of h a lf th e holdings.
If th e schem e is ap p ro v e d , th e nec essary cash is to be p ro v id e d b y in c re asin g th e c a p ita l to £270,000 b y th e c re a tio n of 280,000 new 5s. sh a re s a n d issu in g 114,000 of th e new sh a re s a t p ar.
P a n a m a .— I t h a s b een an n o u n c e d b y th e P a n a m a C o rp o ra tio n (C anada), L td ., th a t th e
M a rg a ja p ro p e rty h a s b een le a se d to a C a n a d ia n m in in g g ro u p , w h ich h o p e s to s ta r t c ru sh in g in a b o u t 12 m o n th s ' tim e . As to th e R e m a n c e m in e , it is s ta te d t h a t th is h a s b een le ase d to a n E n g lish co m p an y , w h ich h o p es to re su m e m illin g o p e ra tio n s before th e e n d of th e y ea r.
B o liv ia .— T h e d ire c to rs of F r o n tin o Gold M ines, L td ., h a v e a n n o u n c e d t h a t th e recen t issue of 36,610 o rd in a r y sh a re s w as o v er
su b sc rib e d .
Y u g oslavia. — T h e r e p o r t of T rep ca M ines, L td ., for th e th r e e m o n th s to D ec em b e r 31 la s t s ta te s t h a t a n ag re em e n t h a s b een c o n c lu d e d w ith B e la sic a Mines, L td ., fo r th e a c q u isitio n of t h a t c o m p a n y ’s u n d e r ta k in g s , th e p u rc h a s e p ric e to be sa tisfie d b y th e issue o f 59,667 sh a re s in T re p c a M ines, c re d ite d as fu lly p a id . The B e la sic a c o m p a n y ow ns e x c lu siv e p ro s
p e c tin g r ig h ts o v er 358 ' s q u a re m iles of c o u n try a d jo in in g t h a t h e ld b y T repca.
T h e m ill a t T re p c a tr e a te d 136,704 m e tric to n s of ore d u rin g th e p e rio d u n d e r review , p ro d u c in g 15,254 to n s of le a d c o n c e n tra te s a n d 22,270 to n s of z in c c o n c e n tra te s .
C o rn w a ll.— In te r e s tin g d e v e lo p m e n ts a t th e E a s t P o o l m in e h a v e b e e n re p o rte d d u rin g th e p a s t m o n th . A c ro ss-c u t n o rth from th e M oreing lode d riv e a t 1,600 ft.
e n c o u n te re d ore a t 680 ft. on th e N o rth Pool s e tt, th e cro ss-c u t p a ssin g th r o u g h 4 | ft.
of g ro u n d a ssa y in g 35 lb. p e r to n b la c k tin . A fte r a n o th e r 8 ft. of m in e ra liz e d gro u n d a f u rth e r lode w as e n c o u n te re d , of w hich th e first 4^ f t. w e n t 23 lb . p e r to n a n d the la s t 2 ft. 80 lb., th e w hole 6£ ft. averag in g a b o u t 40 lb. p e r to n . A fte r a n o th e r b rea k of 24 ft. a th ir d lode, 3 ft. w ide, w as cut, th e ore a v e ra g in g 30 lb. p e r to n . D riving E . a n d W . h a s b een s ta r t e d on th e second lode a n d 5 ft. in ea ch d ire c tio n h a s been c o m p leted , th e ore a t th e face g o in g 85 lb.
p e r to n o v er a d riv e w id th of 8 to 9 ft.
A n g lo -C o n tin e n ta l M in es.— T h e re p o rt of A n g lo -C o n tin e n ta l M ines, L td ., fo r 1932 show s re a liz e d losses a m o u n tin g to £19,395, w h ich h a v e been m e t fro m re se rv e , red u cin g t h a t a c c o u n t to £36,354. T h e c o m p a n y is a t p re s e n t in v e s tig a tin g a b lo c k of 28 claim s in th e K a k a m e g a a re a , K e n y a , in con
ju n c tio n w ith th e F a n ti C o n so lid a te d I n v e s t
m e n t Co., L td .
V enture T ru st.— T h e a c c o u n ts of the V e n tu re T ru s t, L td ., for 1932 show a profit of £28,011, fro m w h ich a d iv id e n d e q u a l to 6d. p e r sh a re free of t a x is to be p a id , leaving
£15,700 to be c a rrie d fo rw ard .
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T h e a u t h o r gives a d e s c r ip tio n o f th e p rin c ip le s , c o n s tru c tio n , a n d a p p lic a tio n of th is b la s tin g m e th o d to th e m in in g o f co a l.
T he C ardox c a rtrid g e involves a n ac tio n differing in prin cip le from th e a c tio n of an explosive. A d esc rip tiv e ac c o u n t of th e principles, co n stru c tio n , a n d a p p lic a tio n to coal m in in g of th is ca rtrid g e should, th e re fo re, be of g en e ral in te re s t to th o se w ho follow th e p rogress of m o d e rn iz a tio n in th e co al-m ining in d u stry .
B ro ad ly , th e ac tio n of a n explosive w hen d e to n a te d p ro d u ces a su d d e n change of a chem ical com p o u n d from th e solid to th e gaseous sta te . T h is change in v o lv es b o th chem ical a n d p h y sic al re a c tio n s a n d is acco m p an ied b y g re a t te m p e ra tu re a n d p ressu re rises w hich are su d d e n ly ap p lied ;
T he p ressu re of th e d isc h arg e of gas is m ech an ically , a n d th e re fo re a c c u ra te ly , re g u la te d . A lth o u g h all th e sta g es of th is a c tio n are sw ift, ta k in g a b o u t l/2 0 t h of a second in tim e, th e u ltim a te disch arg e of gas h a s no shock-giving p ro p e rtie s a n d b re a k s th e coal alo n g its n a tu r a l cleavages w ith o u t s h a tte rin g . W ith explosives, h ow ever, th e b rea k in g is effected la rg e ly b y th e h am m er-b lo w of th e d e to n a tio n . T he gas o rig in a lly co n ta in e d in th e c a rtrid g e in a g re a tly in c re ase d v o lu m e after- th e d is
ch arg e sp rea d s alo n g th e n a tu ra l cleavages in th e coal s tr a t a as a w ave o r gaseous wedge.
T he disch arg e p ressu re, a c c u ra te ly contro lled
• o ■ s s s a a s s a q
Ditikargi Lap* Dite. H'mhrr. Hrawr Cogt. Wathtr, Firing Cap.
Hsattr.
Fi g. 1 .— St a n d a r d Ca r d o x Ca r t r i d g e a n d Co m p o n e n t Pa r t s.
th e se are exposed to th e coal in th e bore or shot-hole a n d m a y be a source of d an g e r in fiery m ines. A gain, th e r e s u lt of a n y explosive sh o t is influenced b y fa c to rs th a t are d ep e n d en t to som e e x te n t on th e skill an d experience of th e perso n in charge of b la stin g — e.g., th e a m o u n t of explosive charged in to th e sh ot-hole, th e a ir-tig h tn e ss of th e com plete ch arg e, o r th e in d iv id u a l explosive c a rtrid g es, etc. I t w ill be re a d ily seen, th e re fo re, th a t th e b re a k in g p ressure of a n explosive ch arg e c a n n o t be defin itely re g u la te d .
I n th e case of C a rd o x th e a c tio n is p u re ly p hysical, ta k in g p lace w ith in an in d e stru c tib le c y lin d rica l c o n ta in e r o r c a rtrid g e filled w ith a liquefied gas. T h e gas, in th e fo rm of liq u id a n d v a p o u r, is h e a te d w ith in th e c a rtrid g e a n d th e p ressu re is ra ise d u n til a ste el disc a t one en d of th e c a rtrid g e is ru p tu re d .
b y th e s tre n g th of th e disc, gives im p e tu s to th e la rg e volum e to p erfo rm its h ea v in g w ork on th e coal s tr a t a in e x p a n d in g to atm o sp h e ric p ressu re. W ith a w ell-placed sho t-h o le th e gaseous w edge w ill sp re a d u n til th e e n tire vo lu m e a n d p ressu re h a v e been d iss ip a te d as en e rg y in b re a k in g th e coal.
P r i n c i p l e s o f C o n s t r u c t i o n . — T he C ard o x c a rtrid g e in its basic p rin cip le is an alo g o u s to th e .a c tio n of a boiler, w ith th e ex c ep tio n of th e disc— th e sa fe ty -v a lv e of th e c a rtrid g e , w hich releases th e p ressu re alm o st in s ta n ta n e o u s ly a n d n o t g ra d u a lly as in th e case of th e sa fe ty -v a lv e of a boiler. T h e o rig in al design of th e ea rly c a rtrid g e in p rin cip le is sim ilar to th e old air-b o m b , e x c ep t th a t th e in n e r o r bore-hole en d of th e c a rtrid g e is fitte d w ith a r u p tu ra b le disc a n d th e c a rtrid g e is m ad e of in d e stru c tib le m a te ria l. T h e e a rly c a rtrid g e w as p laced in
74
Fi g. 2 . — Co m p r e s s o r f o r Ch a r g i n g Ca r d o x Ca r t r i d g e s— C 0 2 f l a s k s i n b a c k g r o u n d.
th e bore-hole a n d th e n filled w ith com pressed a ir or c a rb o n dio x id e u n til sufficient p ressure w as g e n e ra te d to r u p tu re th e disc.
C arbon d io x id e h a s a n u m b e r of p h y sic al p ro p e rtie s w hich are a d v a n ta g e o u sly u tiliz e d in th e fu n c tio n in g p rin cip le of th e C ardox c a rtrid g e —
(1) C arbon diox id e is easily liquefiable at m o d e ra te p ressu res a n d te m p e ra tu re s .
(2) L iq u id ca rb o n diox id e h as a low la te n t h e a t.
(3) T h e c ritic a l te m p e ra tu re of ca rb o n d ioxide is low. O th e r gases could be used, b u t c a rb o n diox id e lends itse lf p a rtic u la rly w ell for th e p u rp o se for w hich th is c a rtrid g e is designed.
All e a rly w o rk in conn ex io n w ith th e d ev e lo p m e n t of th e c a rtrid g e w as ca rrie d o u t in th e U n ite d S ta te s, b u t fu rth e r im p ro v e m e n ts in design h av e been m a d e here for th e p a r tic u la r c o n d itio n s a n d re q u ire m e n ts in th is c o u n try . T h ere h a v e been sev eral ty p e s of c a rtrid g e s ev o lv ed for v a rio u s ch arg es of liquefied c a rb o n d io x id e , th e first ty p e bein g know n as th e “ A ” c a rtrid g e . T h is m odel m e a su re d 39 in. long a n d h a d a n o u tsid e d ia m e te r of 3 ^ f in. a n d a liquefied
ca rb o n d io x id e c a p a c ity of a b o u t 4 lb. The d ia m e te rs of th e c a rtrid g e s h a v e been g ra d u a lly red u c ed , re s u ltin g in a s u b s ta n tia l re d u c tio n in w eig h t, to g e th e r w ith a red u c tio n in c a p a c ity of liquefied C 0 2.
T he fo u r ty p e s of c a rtrid g e s w h ich have been s u b m itte d to te s ts a t th e S a fe ty in M ines R e sea rch S ta tio n , a t B u x to n , an d a u th o riz e d b y th e M ines D e p a rtm e n t a re —
A p p ro x . Weight.
3 in. or G80 ty p e , C 0 2 c a p a c ity 48 oz.,
31 in. long . . . 40 lb.
2 J in. or C74 ty p e , C 0 2 c a p a c ity 44 oz.,
40 in. long . . . . 3 2 | lb.
I f in. o r B37 ty p e , C 0 2 c a p a c ity 22 oz.,
42 in. long . . . 18 lb.
I f in. or B20 ty p e , C O a c a p a c ity 12 oz.,
25 in. long . . . . 11J lb.
T h e choice of a n y ty p e of c a rtrid g e for use in coal depends, of course, on th e p a rtic u la r c h a ra c te ris tic s of a g iv e n se am a n d to a sm aller e x te n t on th e m e th o d of m ining.
B ro a d ly sp e ak in g , th e size of c a rtrid g e re q u ire d for a g iv e n seam is p ro p o rtio n a l to th e th ic k n e s s of th e seam , b u t o ften in a seam of o n ly m o d e ra te th ic k n e s s, if th e coal is h etero g en e o u s, a la rg e r-c a p a c ity
F E B R U A R Y , 1933 75
c a rtrid g e is p referab le to a sm a lle r-c a p a c ity ca rtrid g e , w hich w ould be a d v a n ta g e o u sly used in a seam of th e sam e th ic k n ess, b u t w ith th e coal of a m ore hom ogeneous n a tu re . In th e U n ite d S ta te s th e p ra c tic e is to use th e la rg e st possible c a p a c ity c a rtrid g e w here deep u n d e rc u ts are p re v a le n t, as it is obvious t h a t th e la rg e r th e volum e th e g re a te r th e s p re a d of C 0 2 in th e coal s tr a ta .
In th is c o u n try th e B37 I f in .-c a rtrid g e is u se d alm o st exclusively, as th is ty p e has been fo u n d to give th e b e st re su lts in th e seam s of m e d iu m th ic k n esses a n d th e p rev a ilin g d e p th s of u n d e rc u t.
T he pu rp o se of th e disch arg e cap is to p e rm it th e release of th e gaseous C 0 2 from th e c a rtrid g e in to th e coal. T he cap is screw ed in to th e c a rtrid g e a g a in st a steel disc. W hen th e d efla g ra tio n of th e h e a tin g elem ent is c o m p leted a n d th e p ressure of th e gasified C 0 2 is raise d sufficiently to r u p tu re th e steel disc th e gaseous c o n te n ts issue th ro u g h ax ial holes in th e disch arg e cap a n d com m ence th e ir b rea k in g ac tio n on th e coal. F ig. 1 shows th e co m p o n en t p a r ts of th e lf - i n . d ia m e te r B 37-type ca rtrid g e.
T he co m position of th e h e a tin g elem ent as ap p ro v e d b y th e B ritish a u th o ritie s is
Fi g. 3 . — Ch a r g i n g Be n c h ; t h e i n s u l a t i n g h o u s i n g o f t h e c o o l e r c a n b e s e e n i n t h e B A C K G R O U N D .
T he C ardox c a rtrid g e co n sists e ssen tially of a tu b e a n d th re e m a in co m p o n en t p a r ts know n as th e firing cap, d ischarge cap, an d h e a te r cage. T he ends of th e tu b e are screw ed in te rn a lly to receive th e firing cap a n d discharge cap. W hen th e c a rtrid g e is placed in to p o sitio n in th e bore-hole th e firing cap is a t th e o u te r e n d a n d th e d is
charge cap is a t th e in n e r en d o r b o tto m of th e bore-hole. T h e h e a te r cage is a sm all p e rfo ra te d ste el c o n ta in e r for c a rry in g th e h e a tin g elem en t or h e a te r w ith in th e c a rtrid g e .
T h e fu n ctio n of th e firing cap is—
(a) to fill th e c a rtrid g e w ith liq u id C 0 2 a n d (b) to co m p lete th e n ecessary electric c irc u it b etw e en th e firing b a t te r y a n d th e elec tric fuse of th e h e a te r.
in se n sitiv e to im p a c t a n d fric tio n a n d th e h e a tin g elem ent w ith a low -tension electric fuse is c o n ta in e d in a K ra ft-p a p e r tu b e , one en d of w hich ca rrie s th e electric c o n ta c ts to th e firing cap. T he firing cap h a s tw o tra n sv e rse holes, w hich are used for a tta c h in g th e sh o t-firin g cable to th e c a rtrid g e by m ean s of tw o tu b u la r in se rts fittin g in to th e se holes. T hese elec tric c o n ta c t p o rts o r holes are of p o sitiv e a n d n e g a tiv e p o la rity resp e ctiv ely . T he ce n tre, o r positiv e, hole co n n ects to th e h e a te r in te rn a lly th ro u g h a c e n tra l spin d le o r electro d e, w hile th e ec ce n tric hole carries th e n e g a tiv e re tu r n th ro u g h th e ste el b o d y of th e c a rtrid g e .
W hen assem bling th e c a rtrid g e for charging w ith liq u id ca rb o n diox id e th e h e a te r is placed in to th e h e a te r cage, w hich is plugged
