The Mining Magazine
Managing Director and Editor : W. F. W h i t e . A ssistants : S t . J. R. C. S h e p h e r d , A .R .S.M ., D .I.C ., F .G .S ., F . H i 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 5t 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 E ditions, & Bentley.
Br a n c h O r r . c s s { L T '_________________________________ Su b s c r.p x.o n{ ^
Vol. XLVI. No. 5. L O N D O N , MAY, 1932.
onem&
ng C O N T EPAGE Ed it o r ia l
Notes ... 258
Inauguration of a Geological Survey in K enya Colony ; Institution A w a rd s ; D ecentralization Policy in Malaya ; M emorial to R ichard T revithick. Testing Alluvial D eposits ... 258
A review of one of th e p ap ers read a t th e April m eeting of the In stitu tio n , to g e th er w ith a sum m ary of the tentative conclusions of th e alluvial com m ittee. Gold in K enya and U ganda ... 260
In view of a rec e n t ru sh in K enya Colony, prospects in these colonies are exam ined. Ore Deposition ... 261
An account of th e conclusions reached b y D r. H. C. Boydell in a new p ap e r on th e Camp B ird ore-body, subm itted to th e April m eetin g of the In stitu tio n . Re v ie w o f Mi n i n g... 2 6 2 Ar t ic l e s Daggafontein Mines . . .F . A . Unger, S. E . T . E w in g , a nd J . L . W ille y 265 An account of th e h isto ry , developm ent, an d eq u ip ment of this F a r E a st R and mine. Some Experiences in E cuador B ernard B eringer 279 The au th o r describes a prospecting trip in th e Province of Esm eraldas. Terrain an d Topographical Effects in Gravim etric Surveys Dr. W . G. G. Cooper 282 A suggested m ethod of co m p u tatio n in survey work w ith the E otvds to rsio n balance. The I.M.M. B enevolent F u n d ... 285
T hird L is t of S ubscriptions. Le t t e r t o t h e Ed i t o r The Goldhelds of D u tch W est Borneo M . W . von B ernew itz 286 Bo o k Re v i e w s G audin’s " F lo ta tio n ” . . B . W. H olm an 287 L uyken a n d B ie rb ra u e r’s “ D ie F lo ta tio n ” B . W. H olm an 288 Ne w s Le t t e r s Johannesburg ... 288
Diamonds n ear P o rt E lizabeth ; M anganese C orpora tion ; C anadian C apital for th e U nion ; Geological S u rv e y ; Dr. A. L. H all’s S u cce sso r; Mining in Swaziland ; A dvances in U nderground P ractice ; The Pongola Beds. 5—3 N T S PAGE B risbane ... 290
M ount Isa C apital ; Home-M ade Coke ; Progress a t M ount Isa ; Oil in Queensland ; Cloncurry Copper M in in g ; A ustralian Gold Yield ; Newnes Petrol. Ipoh ... 291
D epletion of Ore R e se rv e s; D eclared S to c k s ; D ecentralization ; M alaria Prevention. V ancouver... 292
Lode-Gold in B.C. ; Prem ier G o ld ; Bridge R iv e r ; Sheep Creek ; Y m ir. T oronto ... 294
Porcupine ; K irkland Lake ; O th er O ntario Gold A r e a s ; S u d b u r y ; N orth-W estern Q u e b ec; M anitoba ; G reat B ear Lake A rea ; O n tario Radium Mine ; M ineral P roduction. Pe r s o n a l... 296
Tr a d e Pa r a g r a p h s ... 296
R ansom es a n d R a p ie r f cu. yd. E x c a v a to r. 297 M avor a n d C oulson Jo y L o ad er ... 298
Me t a l Ma r k e t s ... 299
St a t i s t i c s o f Pr o d u c t i o n ... 301
Pr i c e s o f Ch e m i c a l s... 303
Sh a r e Qu o t a t i o n s ... 304
M i n i n g D i g e s t S am pling w ith a B a n k a D rill .. P. R. Lake 305 T h e A lderm ac Mill ... R. C. Rowe 309 C an ad ian P la ce r Geology W. E . Cockfield 313 T em p era tu re of O re F o rm a tio n Dr. H . C. Boydell 315 S o u th ern K av iro n d o , K e n y a Colony E . J . W ay land and Dr. A . W. Groves 317 C o n c en tratin g T u n g sten O res a t A tolia, C alifornia ... W. O. Vanderborg 318 Sh o r t No t i c e s... 318
Re c e n t Pa t e n t s Pu b l i s h e d ... 319
Ne w Bo o k s, Pa m p h l e t s, e t c... 319
Co m p a n y Re p o r t s ... 320
Buena T ierra M in in g ; Mason an d B arry ; N a rag u ta K aram a Areas ; Oroville D redging ; P atin o Mines ; W aihi Gold Di v i d e n d s De c l a r e d ... 320
Ne w Co m p a n y Re g i s t e r e d... 320 257
E D IT O R IA L
A
GEOLOGICAL survey of K enya will certain ly fill a long-felt w ant, th e lack of such a body being referred to elsewhere in th is issue. I t is welcome news, therefore, to learn th a t Sir A lbert E. K itson left last m o n th for K enya to inaugurate th is m uch- needed survey. He has as his assistan t Mr. R. M urray-H ughes, who will carry on th e w ork on th e re tu rn of Sir A lbert in about six m o n th s’ tim e.T
H IS year th e In stitu tio n has decided to aw ard two gold m edals, one to Sir H. C.H arold C arpenter, in recognition of his em inent services to m etallurgy, and a second to D r. T. A. R ickard, in recognition of his w ork in th e advancem ent of m ining engineering. The Consolidated Gold Fields of South A frica gold m edal goes to Mr. P. J.
Crowle for his w ork on ground m ovem ent and m ethods of support on th e K olar goldfield, and th e same com pany’s prem ium to Prof.
B. W. H olm an for his research on flotation reagents. T he W illiam Frecheville stu d e n ts’
prize is aw arded to M,r. G. F. H a tc h for his paper on “ Check Sam pling of D iam ond D rill Holes a t th e T repca Mines, Y ugoslavia.”
T
H E in ten tio n to erect a sta tu e to th e m em ory of R ichard T revithick, the inventor of th e steam locom otive and pioneer in th e use of high-pressure steam , was announced in our Camborne colum n in May, 1929. T he m em orial is to have a tw ofold character, th e erection of the statue and th e establishm ent of a scholarship fund to provide free in stru ctio n at the Cam borne School of M etalliferous Mining.
A rep resen tativ e g ath erin g is anticipated a t th e unveiling cerem ony b y Prince George a t Cam borne on M ay 17, w hen the Institu
tio n will be represented by th e president, Mr. Pellew -H arvey. I t m ight be added th a t an in terestin g pap er b y J . Harvey T revethick on th e life and inventions of his g re at-g ran d fath er w as sum m arized in Th e Mi n i n g Ma g a z i n e of O ctober, 1920.
I
N th e M a g a z i n e for D ecem ber last our Ipoh correspondent drew a tte n tio n to proposals w hich were th en on foot in M alaya favouring a policy of decentralization.F u rth e r reference to th is m a tte r is m ade in th is m o n th ’s le tte r and it is felt th a t such far-reaching changes as are ap p aren tly contem plated should receive w ider atten tio n . In effect, it would seem th a t local govern
m en t for each of th e S tate s in th e F ed era
tion is proposed in order th a t differences betw een adm inistrative m ethods in the F ed erated and U nfederated S tates m ay be lessened, th e seat of governm ent being rem oved to Singapore. The rem oval of the Mines D ep a rtm en t from th e principal mining d istrict can h ard ly be regarded as helping the in d u stry .
T estin g A llu v ia l D ep o sits A pap er b y Mr. W. R. R um bold presented before th e In stitu tio n of Mining and M etallurgy early in 1928 created a great deal of in terest am ong those engaged in alluvial m ining, th e discussion revealing such a d iv ersity of views on certain important aspects of th is branch of th e profession that it was finally decided b y th e council to set up a com m ittee to exam ine and report on th e conditions under w hich alluvial areas were tested. T he subject was again brought to th e fore a t th e A pril m eeting of the In stitu tio n b y th e first paper to be read—
“ S ystem atic Sam pling of Alluvial Deposits b y th e B an k a D rill,” by Mr. P. R. Lake.
The scope of Mr. L ak e’s thesis is examined here, while a more detailed sum m ary appears elsewhere in th is issue. T he attendance at th e m eeting was, perhaps, equally attracted b y th e prospect of hearing th e views of the com m ittee referred to, and those present could h a rd ly have been disappointed, th e discqssion on Mr. L ak e’s paper being keen and to th e point, while Mr. C. B.
Brodigan review ed the w ork of the com m ittee.
I t will be recalled th a t one of the most contentious points raised by Mr. Rumbold’s paper was th e d eterm in atio n of th e number of bores to be p u t down in a given area, or, as it m ight be called, th e holes-per- acre question. T he m any differing views ap p aren tly held by those well qualified to express an opinion were ce rtain ly calculated to create uneasiness am ong ju n io r members, who felt th a t th eir first task m ight involve a decision on such a point. I t m ay be said, however, th a t a stu d y of Mr. L ak e’s paper reveals a scheme of boring w hich should be of great assistance to those und ertak in g the 258
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examination of an alluvial area for the first time and in this respect a t least is of con
siderable value. The a u th o r’s scheme m ay be described, in his own words, as a system of uniform ly-decreasing squares, wherein every hole is given equal weight and bears the same responsibility, by which, it is claimed, the sampling of alluvial deposits is simplified, there being a t the same tim e a gain in economy and accuracy. Briefly, the various stages in the scheme are as follows : First, a series of scout bores at th e corners of 8-chain squares, w hereby the economic boundaries w ithin th e p ro p erty are roughly defined, th e series involving one hole per 6'4 acres ; secondly, norm al bores a t the corners of 4-chain squares, equal to one hole per T6 acre, workable boundaries being thus fixed to w ithin two chains ; thirdly, check bores at the corners of 2-chain squares
—one hole per 0-4 acre—proving up th e property; and, lastly, th e delineation of patchy areas by close boring, sinking holes at the corners of 1-chain squares—th a t is, a density of 10 holes per acre. The stage to which it m ay be considered necessary to follow this plan will depend, of course, on the uniformity of the results obtained, b u t the author claims th a t the system will elim inate to a large ex ten t the errors th a t are constantly occurring in th e m ineral valuation of such deposits. The paper also deals w ith the Banka drill and its use and w ith the recording of results, concluding w ith a description of the m ethod by which m ineral values are computed. A fter a brief introduction of his paper by th e author, the discussion was opened by Mr. E. T. M cCarthy, who had something to say on th e dangers of the standardization of drilling m ethods, a point stressed by several -of the later speakers, many of whom were of opinion th a t certain deposits—such as those along well-defined valleys—would be sam pled b e tte r by bores set out on lines laid a t right angles to the stream course. In addition to Mr. Brodigan, whose rem arks are dealt w ith in the following paragraph, those m em bers joining in the dis
cussion included Messrs. Morgans, Bolt, Inder
—who called a tten tio n to the im portance of correct estim ations of gravel sizes and to the correlation of drilling results w ith actual winnings—Naish, H atto n , Rum bold, and Underwood - Jarv is, the last-nam ed, since so m any had referred especially to the sampling of alluvial tin deposits, dealing w ith gold placer work. Members found m any points in th e paper where
th ey were a t variance w ith the author, b u t th ere can be little doubt th a t the presentation of a clearly-defined scheme of this n atu re should be of th e greatest value, especially, as already indicated, to junior m em bers of the profession.
The rem arks of Mr. Brodigan during the discussion were of more th an usual im port
ance, em bodying as th ey did the conclusions of th e com m ittee on alluvial valuations set up by th e council. This com m ittee, which comprised Messrs. Rum bold, Inder, Scrutton, T rew artha-Jam es, Pawle, Thorne, and Brodigan, the last nam ed acting as chair
m an, has progressed sufficiently far in its labours to offer certain ten tativ e conclusions for consideration. The speaker em phasized th a t in th e course of its work—which, it m ust be rem em bered, was in p a rt an a ttem p t to raise th e statu s of th e alluvial side of the profession—it had been realized th a t the present haphazard fashion in which reports on alluvial areas were sometimes presented to th e public was detrim ental, and it was, therefore, of the utm ost im portance th a t m em bers interested should respond to the com m ittee’s request for com m ent and criticism of th e provisional conclusions. The following notes summarize briefly the com m ittee’s findings, which are given under seven h e a d in g s : F irst, two holes per acre is considered a useful num ber of bores on which to report, unless th e engineer in charge has sound reasons for taking a different course, while th e check afforded b y calculating values on the sam ples from altern ate bores is recom m ended ; secondly, the m anner in which bore samples are m easured should be stated in the r e p o r t ; thirdly, sampling results should not be stated in term s of m ineral alone, other facts, such as yardage, dep th of ground, and weight of concentrate, should be given, while, in addition, prices on which values are based should be clearly stated, as well as factors which m ay affect subsequent working ; fourthly, widely differing sample values should be treated c a re fu lly ; fifthly, B ritish units are rec o m m en d ed ; sixthly,
“ ore ” should not be used in referring to alluvial deposits, “ wash ” being considered a b e tte r term ; and, finally, reserves should n o t be given in reports unless the m anner in which th e y have been determ ined is also given. I t will be seen, therefore, th a t w h at
ever be the outcome of the discussion on these recom m endations, th ey would, if th ey becam e standardized, afford a useful skeleton on which sound reports m ight be b uilt and
260 T H E M IN IN G MAGAZINE th e course of discussion upon th em will be
closely followed. Meanwhile m an y m em bers of th e profession cannot b u t feel th a t the form ulation of such a schem e as Mr. L ak e’s, together w ith th e guiding recom m endations of th e com m ittee, go a long w ay tow ards placing alluvial valuation on a surer basis.
G old in K enya and U gan d a The gold-producing potentialities of the W est Coast of A frica were exam ined in the J a n u a ry issue of th e Ma g a z i n e, owing to th e stim ulus afforded to prospecting by the prem ium created w hen th is co u n try left the gold stan d ard . I t is only fair, therefore, th a t th e possibilities for precious m etal discoveries in E ast Africa should receive equal atten tio n , p articu larly as regards K enya and U ganda, and we are in d eb ted to Dr. A. W. Groves, form erly of th e U ganda Geological Survey, for m uch of th e m aterial incorporated in this article. Elsew here in this issue the results of reconnaissance w ork in K enya are given and th e y form in terestin g reading. F o r m an y years it has been custom ary to regard K enya as a colony devoid of any m ineral w ealth beyond th e soda deposits of Lake Magadi, as perhaps was only to be expected in a cou n try generally overlain by volcanic rocks of com paratively late geological age. There are, however, large areas which, even if n o t altogether free from th e late volcanics, afford am ple o p p o rtu n ity for th e stu d y of the older rocks of th e country and it is clearly to these th a t th e prospector m ust tu rn . In p articular those p a rts of the colony bordering on Lake Victoria, betw een th e N andi E scarpm ent and th e K e n y a - U ganda border south of M ount Elgon, as well as th e co u n try southw ards from th e K avirondo Gulf to the T anganyika-K enya border are beginning to yield m aterial evidence of th e ir p o ten tiality to produce gold. Only recently th e colony experienced its first gold rush a t K akam ega, although if a w ell-equipped geological survey h ad been in existence in K enya some years ago it is reasonable to suppose th a t this discovery would have been m ade earlier. K enya has not been w ithout h er share of prospectors, b u t th eir investigations have been ham pered b y th e lack of a Geological Survey D e p a rt
m ent, although th e need of such a d e p a rt
m e n t m ust have been recognized, a m em ber of the Geological Survey of U ganda having on two occasions been lent to th e K enya G overnm ent to do reconnaissance w ork in th a t
colony. I t is satisfacto ry to learn, therefore, th a t the inauguration of an official survey is now well in hand.
K akam ega, the centre of th e recent gold rush in K enya, lies about 25 miles north of K isum u, the term inus of th e old main line of the K enya and U ganda Railway, on the shore of th e K avirondo Gulf of Lake Victoria.
W ith regard to its location, it will be recalled th a t Mr. W ayland pointed out in the course of an article in th e M arch issue of the Ma g a z i n e th a t “ the rem ark ab ly sharp turn of th e Nile below Nimule and th e continuation of th a t line in a south-easterly direction by th e Aswa R iver is strikingly brought out on th e m ap. B y projecting th a t line, which along th e Nile an d th e Aswa is known to be a fault or s h a tte r zone w ith crushing, it will be found to ru n u n d er the south-w estern part of M ount Elgon, and to ru n into the fault of th e N andi E sc a rp m e n t.” Kakam ega is only ab o u t 15 miles to th e w est of the foot of th e N andi E scarp m en t and on theoretical grounds, therefore, it appears very probable th a t th e mode and period of mineralization a t K akam ega will tu rn out to be comparable w ith th a t of th e earlier discovered gold- producing a re a to th e south of the Kavirondo Gulf.
As regards U ganda, th e protectorate has been more fo rtu n ate th a n K enya in having a Geological Survey D ep artm en t, which, comm encing w ith a sole m em ber in 1919, grew to six d u rin g 1929 and 1930. Prior to 1919 geological knowledge of U ganda was ex trao rd in arily m eagre, m uch more so than th a t of K enya a t th a t tim e. The discoveries of economic im portance in U ganda have all been m ade in th e last ten years or so, but progress is of necessity com paratively slow on account of th e n a tu re of th e country.
Gold has been found in sm all quantities in w idely different p a rts of th e protectorate, in the alluvials of the R iver K afu, th e streams of th e W est Nile district, th e Nile Valley in th e E a st Madi, in th e B ugishu district near M ount Elgon, th e shore sands of Lake Albert, and in th e Kigezi d istrict. T he occurrence in th e alluvials of th e R iver K afu has been fully investigated by th e Geological Survey, th e river now form ing a classical example of the difficulty which is experienced in prospecting qu ite a good proportion, though not all, of th e U ganda rivers in th a t it has suffered reversal, w ith th e resu lt th a t “ the best chance of discovery of placer deposits in m ineralized areas is in pre-reversal gravels, in w hat is now a dow nstream direction.
h This also applies, of course, to much of the prospecting for cassiterite. The source of the gold in each of these districts, as well as in Bugishu, is obscure, b u t it certainly appears to have come from the ancient gneisses of th e B asem ent Complex, together with its la te r igneous intrusions. Prom ising U discoveries of gold have recently been made
by a prospector in stream s in th e forest of Lubugole, known as the “ Im penetrable Forest,” in the Kigezi district and riorth- ,7 west of Kabale. The locality is a t an altitude
of over 7,000 feet in difficult country, w ith C juvenile stream s, heavy rainfall, and mists.
; The alluvial gold is coarse, shows little sign .7, of attrition, and is clearly near to its source.
Nuggets as heavy as h alf a gram m e have been found. A peculiar feature of the gold in this district is th a t it is frequently accom panied r ; by native copper and th a t when this is the
case a large proportion of the gold grains are then coated w ith a deposit of m etallic copper. Only a fraction of th e gold in such concentrates is visible u ntil the sample has been leached in hot nitric acid, when m any grains which originally appeared to be copper prove to be gold. It is apparent, therefore, th a t these two E ast African colonies possess im p o rtan t potentialities as gold producers and it is to be hoped th a t in
¡link any survey of Im perial m ineral resources they will not be ignored. The world m ay go off a gold basis— some d a y ; a t present, all that can be produced is badly needed.
r?i ______________
d u s
[hefe Ore D ep osition
hf ln August last, in th e course of a review
!ais«s, of proceedings a t one of the discussions in the ro®»! geological section of the B ritish Associa- f the !® tion’s centenary m eeting, the sta te of 1 qua® research on ore-genesis was exam ined in these rote# columns, th e views of practical m ining m en (i.tlit and of economic geologists on this question
Nile Vi being compared. The geologist’s view—
ijditf with which, it is felt, there is substantial ofLabJl agreement am ong technical m en—was then [IfCiiS expressed as one of alarm a t “ th e indifference gafafg of many m ining com panies tow ards research logicalon their chief asset—th e ore-body.” This
|ePj[!t indifference, it was stated , “ is, in fact, a Ijjpjsj disservice to them selves, th e h asty removal, j g i for ‘ economic ’ reasons, of the first of their
finds often destroying m uch valuable I "(Ik evidence th a t m ight have been applied to the
¡)epS search for new prospects.” I t will readily
¡,ersalf granted, of course, th a t researches on m ^ ore-genesis are often conducted at a serious
disadvantage, so m an y factors having to be assum ed. Nevertheless, th e use of new lines of a tta c k m ay often prove fruitful and on these grounds it is possible to welcome the efforts of Dr. H . C. Boydell, who has in the past endeavoured to apply physico-chem ical d a ta in the in terp retatio n of geological phenom ena. In th e second paper read a t the April m eeting of th e In stitu tio n Dr. Boydell once more retu rn s to th is type of subject, his paper on th e “ T em perature of an Epi- T herm al Ore-Deposit ” involving a m a th e m atical stu d y of certain factors affecting th e form ation of th e Camp Bird vein in th e San Ju a n region of Colorado. A t the m eeting th e paper was, in the absence of th e author, ably introduced by Professor Cullis, who infused general interest into a paper which not only appeared terrifying to th e ordinary reader, b u t w ith which he was him self in certain fundam ental respects in disagree
m ent. Discussion was lim ited, so m uch tim e having been taken by a previous paper, b u t it is hoped th a t w ritten discussions m ay prove helpful to Dr. Boydell and to others engaged in sim ilar studies.
The description of th e Camp Bird deposit has been carried out b y experienced authorities on ore geology, the w ork of Ransom e, Purington, and Spurr being well known, and for a general description of the deposit readers m ay be referred to their papers. I t will, however, be recalled, no doubt, th a t after S p u rr’s description of the Camp B ird “ Compound Vein D yke ” a con
troversy ensued between the author and Dr. Boydell over th e im portance of certain operative factors, in the course of which Mr. Spurr expressed th e view “ th a t in centres of active vulcanism , where ore- injection was in m any cases preceded and followed by lava eruptions,” the tem perature m ust have been greater th a n 150° down to a dep th of several thousand feet. By th e use of m athem atical d ata, based on th e work of Ingersoll and Zobel, Dr. Boydell, using F ourier’s series as a mechanism , has endeavoured to disprove this contention of S purr’s, his work showing th a t th e tem pera
ture rise in a basem ent rock due to the em placem ent of h o t lava upon it reaches nothing like 150°. I t will be felt, of course, th a t Dr. Boydell’s w ork only touches on p a rt of the question, heat in an area of active vulcanism having so m any other sources th an the one exam ined, although the novel tre atm en t of the subject m ay possibly throw new light on a controversial m atter.
R E V IE W O F M ININ G
In tro d u ctio n .—T he m ajor event of th e p a st m o n th has, of course, been th e in tro duction of th e B udget, followed by protective m easures of a m ore definite ch ara cter th a n those h ith e rto in force. The B udget, which has been a p tly described as a “ nothing-for- anybody ” m easure, represents, in effect, a continuation of the severe economies im posed last A utum n, while th e d u ties evidence th e sincere desire of the G overnm ent to redress th e adverse balance in trade.
T ran svaal.—The o u tp u t of gold on th e R an d for April was 901,894 oz. and in outside d istricts 47,902 oz., m aking a to ta l of 949,796 oz., as com pared w ith 960,035 oz.
in March. The num ber of natives em ployed on th e gold m ines a t th e end of th e m onth totalled 214,334, as com pared w ith 214,024 a t th e end of March.
T he rep o rts of th e Anglo A m erican group of m ines for 1931 were issued during the p ast m onth. The B rakpan Mines accounts show a profit of £556,426, which, added to th e sum of £50,377 brought in, gave an available to ta l of £606,803. Of th is am ount
£408,000 was absorbed as dividends, equal to 40% , and after m aking o th er allowances a balance of £55,331 was carried forward. The ore reserves a t th e end of th e year were estim ated to be 2,520,890 tons, averaging 7‘78 dw t. over a w id th of 51'59 in., a slight decrease w hen com pared w ith th e figures for th e previous year. T he tonnage milled during 1931 was 1,138,500, 414,537 oz. of gold being recovered, w orth £1,759,321.
T he results of Springs Mines show the profit to have been £839,971, the to tal sum available being £901,150. D ividends absorbed £581,250, equal to 38-f%, the am ount carried forward, after m aking other allowances, being £73,106. The ore reserves a t the end of th e year show an increase of 141,613 tons over the previous y e a r’s figures, th e am ount being 3,452,983 tons, averaging 9T4 dw t. over a stoping w idth of 48'4 in.
D uring the year 843,300 tons of ore was milled, 413,688 oz. of gold being recovered for a revenue of £1,755,808.
D uring 1931 W est Springs m ade a profit of
£165,944, th e to ta l sum available being
£257,565. D ividends paid absorbed £134,475, equal to 7£%, and, a fte r m aking other allowances, th ere was a balance of £103,849 to be carried forward. The ore reserve position shows little change w hen com pared
w ith the previous year, th e figures being 2,737,020 tons, averaging 5'85 dw t. over a stoping w id th of 53'15 in. The tonnage milled was 851,800 an d th e gold recovered 210,496 oz. w orth £892,942. Developments in th e southern area of th e property have im proved, recent bore-holes showing con
siderably larger reef w idths and b etter values th an were exposed above th e faults in this area.
The reduction p lan t at D aggafontein Mines was b ro u g h t in to operation on the last day of the y ear u n d er review — 1931—having been finished well on tim e. No. 3 shaft was com pleted and in a re p o rt for the first three m onths of 1932, issued subsequently, it is no ted th a t th e erection of headgear, winder, and boiler a t No. 2 shaft, preparatory to the com m encem ent of unw 'atering operations, is proceeding satisfactorily.
The re p o rt of th e Sub Nigel for the three m onths to M arch 31 shows th a t th e company has tendered to th e G overnm ent for the lease of th a t area of th e farm G rootfontein situated along th e eastern b o u n d ary of the present holdings of th e m ine. If th is tender is accepted th e m ining area held will be increased to over 6,580 claims.
A pressure b u rst in th e No. 3 vertical shaft of G eldenhuis Deep placed it out of com
mission for some days, affecting the monthly o u tp u t considerably'.
I t was announced tow ards th e end of last m o n th th a t th e b o ard of the C entral Mining and In v estm en t C orporation h ad decided to resum e the p ay m en t of dividends and at the annual m eeting to be held th is m onth the payunent of a dividend of 6s. per share, less tax , will be recom m ended.
T he profit of th e Anglo A m erican Corpora
tion of S outh A frica, L td ., for 1931 was
£113,303, to w hich m ust be added the sum of £204,884 b ro u g h t in from the last account. In addition £1,240,000 has been tran sfe rre d from reserve, giving an available to ta l of £1,558,187, of w hich £1,059,589 has been w ritten off th e value of shares, invest
m ents, and diam ond an d o th er interests and
£400,000 placed a t general reserve, leaving
£98,598 to be carried forw ard. The diamond and base-m etal in v estm en ts of the corpora
tion have suffered severely during the year u n d er review and th is m ainly accounts for th e considerable falling off in th e revenue.
In R hodesia th e w ork of th e Victoria 262
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Prospecting Com pany was continued, b u t, in spite of evidence of w idespread m ineraliza
tion, no im p o rta n t discoveries have been made and w ork will be stopped in th is area when the gran t expires on Ju n e 30 next.
During 1931 the Anglo-French E xploration Company m ade a profit of £11,373, which, added to the sum of £16,503 brought in, gave an available to ta l of £27,876, which was carried forw ard. W orking expenses have been substantially reduced, although the full effect of economies carried out cannot be felt until th e end of the c u rren t year.
The report of Rooiberg Minerals Develop
ment Co., L td., for the three m onths ended March 31 last shows th a t 19,101 short tons of ground was treated , 29'8 long tons of concen
trates being recovered. The alluvial plan t ran satisfactorily during th e q uarter, but operations were conducted a t a to tal estim ated loss of £1,530.
D iam on d s.—The rep o rt of the Con
solidated D iam ond Mines of South-W est Africa, L td ., for 1931 shows a m ining loss of £28,669, as com pared w ith a profit of
£366,530 in th e previous year. T he u nappro
priated balance brought in was £348,243 and, after adding £500,000 from general reserve,
£168,000 from preference dividend reserve and m aking various allowances, £525,427 was w ritten off diam ond stocks, leaving them valued at £1, th e balance of £372,196 being carried forward. O perations during the year were on a lim ited scale only, the E lisabeth Bay p lant being closed down in April, 1931, while, as announced in the March issue, all operations have now been suspended.
During 1931 th e New Vaal R iver Diam ond and Exploration Com pany suffered a loss of
£1,590, the credit balance being reduced to
£4,022 during th e year. The y e a r’s o u tp u t of diamonds totalled 5,173f carats, realizing
£23,237, or an average of £4 9s. 9d. per carat, against £6 11s. Id. per carat the previous year. In addition 1,376 carats were produced on the Pniel E sta te holding and this realized
£4,496, equal to £3 5s. 4d. per carat.
Southern R h od esia.—The o u tp u t of gold from Southern R hodesia during March was 47,239 oz., as com pared w ith 45,032 oz.
for the previous m onth and 42,278 oz. in March, 1931. O ther o u tp u ts for March last were : Silver, 7,938 oz. ; coal, 45,972 tons ; chrome ore, 1,823 tons ; asbestos, 1,000 tons ; copper, 3 tons.
N orthern R h od esia.—Shareholders of Luiri Gold Areas, L td ., have been inform ed of certain developm ents on their property.
On the old D un R obin reef it is sta te d th a t difficulty has been found in following the body on th e th ird level, while th e new D un R obin ore-body is said to have greatly im proved on th e same level. D evelopm ent has been sta rte d on th e Eclipse lode, some favourable assays being reported from the first level. A t C hitaba developm ent has also been commenced, th e lode having been exposed in th e shaft before operations were held up by surface w ater. A tria l run on ore from th e new D un R obin body is to be conducted during the present m onth.
T he rep o rt of th e Selukwe Gold Mining and Finance Com pany for the year ended M arch 31 last shows a profit of £368, increasing the credit balance carried forward to £1,358. The com pany is, through the K afue Copper D evelopm ent Company, still investigating the gold occurrence in B urm a m entioned in the March issue of the Ma g a z i n e.
G old C oast.—The re tu rn of the A shanti Goldfields Corporation for April is accom panied b y news of some interesting develop
m ents, cross-cut No. 22 N .E. on the 24th level showing a reef w idth of 17 ft., the values averaging 110 dwt. On No. 16 level cross-cut No. 25 N .E. shows th e A shanti reef to have a w idth of 13 ft. a t th a t point, th e values averaging only 2 dw t. The sinking of th e main shaft was advanced 21 ft.
d uring th e m onth. .
A circular to shareholders of A riston Gold Mines (1929), L td., embodies a report from th e consulting engineers, Messrs. C. B.
B rodigan and F ra n k B. Powell, on th e mine, in which th e y sta te th a t given a continuance of w idth and value in th e m ain ore shoot below th e 17th level, of which there is every indication, th e n ex t tw elve m onths should show a decided increase in reserves and allow for increase of ou tp u t. The report concludes w ith a note to the effect th a t w ith an additional £20,000 at the disposal of the m anagem ent developm ent could be much expedited an d th e board has decided to m ake an issue of £20,000 in 12J% Notes, the u n its being 2s. 6d., in order to raise this.
A u stralia.—D evelopm ents on th e No. 2 W est I,ode on th e p ro p e rty of th e W iluna Gold Corporation have, in the opinion of the board, provided ample evidence for regarding the new ore-body as of m ajor im portance.
I t has now been proved on the 290-ft., 450-ft., and 625-ft. levels and has an ap p aren t lateral e x te n t of a t least 1,700 ft. In view of this th e m anagem ent at the mine has
264 T H E M IN IN G M AGAZINE recen tly acquired, by pegging, a dditional
ground to th e w est a n d so u th of th e ir existing m ining area, in order to cover extensions of th is and o th er ore-bodies which m ay be disclosed b y fu rth e r exploration.
A recalculation of th e ore reserves of th e S outh K algurli m ine shows 40,000 tons blocked out on th e A ustralia lode having an average value of 9-5 dw t., to g eth er w ith 174,000 tons proved elsewhere averaging 8'25 dw t. T he probable reserves give an e x tra 94,700 tons of an average value of ab o u t 6 dw t.
M alaya.—T he re p o rt of Id ris H ydraulic Tin, L td ., for 1931 shows a profit of ¿15,273, which gave, a fter deducting the debit balance of ¿1,992 b ro u g h t in, an available to ta l of
¿13,281. Of this am ount ¿3,000 has been tran sferred to reserve, leaving ¿10,281 to be carried forw ard. T he o u tp u t of tin ore for th e year was 312 tons, as com pared w ith 353 to n s for 1930. The am ount realized from the sale of ore was ¿21,402, an average price of
¿68 11s. 4d. per ton, against ¿80 Is. 8d. the previous year.
B r a zil.—T he rep o rt of th e St. Jo h n D ’el R ey Mining Com pany for 1931 shows a profit of ¿142,292, giving, w ith th e balance of
¿41,369 brought in, a sum of ¿183,661 to be disposed of. D ividends for th e year absorbed
¿83,970, equal to 10% on th e o rd in a ry shares, while ¿60,000 has been transferred to ca p ital w orks account, leaving ¿39,691 to be carried forw ard. D uring th e year 221,800 tons of ore was crushed, yielding 115,473 oz.
of gold, w orth, a t p ar value, ¿488,429, a yield lower b y 7s. 6jd . per ton w hen com pared w ith th e previous year. T his decline was m ainly due to th e policy adopted of milling ore w hich w ould be unpayable w ith gold at par. T he ore reserves in th e Morro Velho m ine a t Decem ber 31 last were estim ated to be 1,522,271 tons, averaging over 4 oitavas per ton, an increase of 244,108 tons over the 1930 figures. T his am ount is exclusive of m uch ore w hich will be payable w ith gold a t a prem ium . Good progress has been m ade w ith th e new power scheme an d it is hoped th a t th e supply necessary for th e extension of m ining operations will be available tow ards th e end of th e cu rren t year.
In a circular to shareholders of the Ita b ira Iron Ore Com pany issued last m onth it w as sta te d th a t prolonged negotiations w ith th e B razilian G overnm ent over th e renew al of th e com pany’s concessions had brought th e com pany’s resources to the verge of exhaustion. I t is estim ated th a t
unless funds can be found im m ediately the com pany m ay be forced in to liquidation.
Colom bia^—A re p o rt from th e consulting engineer of V iborita Gold Mines issued last m o n th sta te d th a t an ore-body carrying gold values had been discovered during the driving of th e deep debris tunnel, w hich remained in lode for over 100 ft. Sam pling is in progress, b u t m eanw hile th e driving of the tu n n el is being carried on.
Y u g oslavia.—D uring th e three months ended M arch 31 th e w orking surplus of T repca Mines, L td ., was estim ated at
¿21,291, equal to 5s. 2d. per m etric ton m illed. The tonnage tre a te d was 82,151, averaging 10’63% lead, 8'51% zinc, and 4'05 oz. of silver per ton, which yielded 10,845 tons of lead concentrates, averaging 77'57% lead and 27'9 oz. silver per ton, to g eth er w ith 11,725 tons of zinc concen- rates, averaging 49'99% zinc.
London T in C o rp o ra tio n .—T he accounts of th e London T in C orporation for the year ended Septem ber 30 last show a loss of
¿1,777, while ¿800,000 was tran sferred from reserves, largely to cover depreciation in investm ents. These now sta n d in the com pany’s books a t ¿3,097,575, th e schedule accom panying th e re p o rt show ing th a t the N igerian in v estm en ts are slightly greater th a n those in E a ste rn com panies, while the Cornish in terests have been w ritten down to ¿1,396.
N a tio n a l M ining C o r p o r a t i o n . —During 1931 th e N atio n al M ining Corporation suffered a loss of ¿7,186, increasing the debit balance b ro u g h t in to ¿110,277. No new business was u n d ertak en during the year an d general conditions have prevented any im p o rta n t realization of th e corporation’s holdings.
T in .—A t a m eeting of th e International T in C om m ittee held in P aris last m onth it w as decided unanim ously to recommend a fu rth e r cu t in production a t th e rate of 20,000 tons a year, to be effective from Ju n e 1 next. S ubsequently it was announced th a t th e T in P ro d u ce rs’ Association had approved a still more d rastic scheme for cu rtailing o u tp u t, involving a complete cessation of operations for tw o m onths. If this proposal is ad o p ted production would be resum ed a t th e ra te of 40% of capacity until th e price of tin m etal rem ains a t ¿200 for one calendar m onth, w hen th e q u o ta would be raised to 5 0 % .. U nder th is scheme the Pool would n o t be p e rm itte d to release its holdings below ¿200 per ton.
IN T R O D U C T IO N
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This article deals w ith Daggafontein Mines, Ltd., a com pany holding a considerable mining area on the F ar E a st R and, and which commenced milling early in Jan u ary , 1932. The com pany’s predecessor, the Daggafontein Gold Mining Company, L td., was one of th e oldest on th e F a r E ast Rand. Shaft sinking was commenced over 20 years ago in the eastern p art of the farm, but th e ore which is now being stoped is draw n from th e north-w estern area of th e property. The com pany has had m any vicissitudes ; operations were suspended twice for lack of funds, and there were two financial reconstructions. The area was originally 1,437 claims, and is now 3,737 claims.
The history of w hat is now D aggafontein Mines, L td., is a record of struggles against adverse n atu ral conditions, setbacks due to lack of suitable equipm ent, com plicated by disinclination to p u t funds into mining investments during tim es of unrest and strife.
But it is also a record of faith in th e property, which is well situ ated in th e line of th e F a r East R and ore shoots, an advantage which will outweigh disappointm ents caused by difficulties in the past. I t is proposed to trace the developm ent of the com pany
from th e com m encem ent of operations down to th e present tim e. This will be done in th e first p a rt of this article, and will give an o p p o rtu n ity of touching on South African Mining Laws, a subject of which readers outside th e U nion of South Africa m ay have only a cursory knowledge, and for a description of th e m ining work. The grow th of th e com pany, th e increases of capital, and appeals m ade to shareholders for the raising of fu rth er funds, which provide a fine exam ple of m ining finance, will also be dealt w ith. This is con trib u ted by F. A. Unger, consulting engineer to th e Anglo American Corporation of South Africa.
A description of the surface p lan t is given in the second p a rt of th e article by Messrs. S. E. T. Ewing (consulting m echanical and electrical engineer) and J. L. W illey (consulting m etallurgist), of th e Anglo Am erican Corporation of South Africa, L td . The reduction p lant, while following in the m ain th e layout of the W est Springs plant, presents certain new features. The m echanical equipm ent on the surface follows the practice established by the la te r develop
m ents on th e Anglo Am erican C orporation’s mines and notes on th is subject are also given by th e authors.
itioi-
I —HISTORY, D E V E L O P M E N T , A N D E Q U I P M E N T O F T H E P R O P E R T Y
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By F. A . U N G E R Tr a n s v a a l Mi n i n g La w s.— U nder the
Transvaal Gold Law of 1908 th e rig h t to mine for precious m etals is vested in the Crown. If a farm has been proved to be gold-bearing, either by prospecting or by drilling, th e G overnm ent m ay give notice of its intention to proclaim this farm . The freehold owner of the farm has certain mineral rights under this A c t ; he can dispose of these rights while retaining the owner
ship of the surface. T he owner of these mineral rights is entitled to select one-fifth of the farm (or, to be exact, one-fifth of the area proclaimed) as his m ynpacht. The discoverer of th e precious m etal, who m ay or m ay not be th e owner of the m ineral rights, is also entitled to com pensation for his efforts. H is rew ard takes th e form of a number of claims (varying from a m inim um of 10 to a m axim um of 50) in proportion to the size of th e farm , b u t if th e reef is
discovered by shaft sinking or boring deeper th a n 1,000 ft., he m ay acquire a m axim um of 50 claims for every 1,000 ft. vertical dep th below th e surface th a t th e discovery is made. The m ining rights over th e balance of th e farm belong to th e State.
In the T ransvaal th e size of a farm is expressed in “ m orgen.” A morgen is 86,400 sq. Cape ft. (1 Cape ft. =- 1033 English ft.). A claim m easures 60,000 sq.
Cape ft. A m orgen is th u s 1-44 claim s.
E xpressed in acres, a morgen is equivalent to 2-1165 acres, while a claim m easures 1-47 acres. An exam ple will illu strate the rights of owners and discoverers. Suppose th a t on a farm 3,000 morgen in e x ten t, th e reef has been found by diam ond drilling to a vertical d ep th of 3,500 ft. The owner of the mining rights would be entitled to one- fifth of th is farm for his m ynpacht, viz.
600 morgen or 864 claims, while th e 265
266 T H E M IN IN G M AGAZINE discoverer is en titled to 175 claims. If the
owner and discoverer are the sam e person, his to ta l m ining area w ould th u s be 1,039 claims. On th e C entral R and, and in th e early days of outcrop propositions, this provided an am ple m ining area.
On th e F a r E a st R and there is, as a rule, only one w orkable reef, often th in , and only payable in p arts. On th e earlier C entral R an d mines, w here b o th th e Main Reef Leader and S outh Reef were generally payable, th e conglom erate beds well developed, an d w here th e Main Reef was som etim es m ined, as m uch as 70,000 tons per claim m ight be milled. On th e F a r E ast R an d there are large areas where th e mill tonnage is less th a n 5,000 to n s per claim.
N evertheless, these areas m ay constitute v ery a ttra c tiv e m ining propositions provided th ey are of sufficient size and, further, th a t th e w orkable portions of the conglom erate bed ca rry sufficient gold. I t follows, how
ever, th a t a m ining area of, say, 1,000 claims, m ay under certain conditions be insufficient to ju stify th e large capital expenditure required to bring it to production. T his was realized by th e Mines D ep artm en t and the G overnm ent, and in 1918 an A ct was passed, known as th e Mining Leases A ct, which provided for th e leasing of ground from th e G overnm ent. T he condition on which th e owner could secure th is ground was by giving th e G overnm ent a p articip atio n in profits according to certain m inim um term s, contained in a schedule to th e Act. These m inim um term s are in th e form of a sliding scale, th e G overnm ent’s particip atio n in profits increasing according to th e richness of th e ore. T his object was obtained by
basing th e scale on th e ratio betw een profit and yield, th e percentage of profits payable to th e G overnm ent increasing w ith this ratio.
On th e W itw ate rsran d th is ratio is generally referred to as “ x .” W ith a yield of 30s.
an d working costs of 20s. per ton, the ratio of profit to recovery would be gg, in other words, x expressed as a percentage would be 33g. T he G overnm ent’s participation is generally referred to as “ y .”
T he m inim um term s on which the owner of a m y n p ach t can obtain additional ground are as follows :—
m
.<0 p
Profits expressed Percentage of as a percentage profits payable o f revenue. to Government.
R atio " x . ” R a tio “ y ."
10% o r u n d er. N i l '
12% 2 -6 %
15% 6 -4 %
20% 12-9%
25% 19-3%
30% 2 5 -7 %
35% 3 2 -2 %
40% 3 7 -5 %
45% 4 1 -7 %
50% 4 5 -0 %
55% 4 7 -7 %
60% o r over. 5 0 -0 %
If th is sliding scale is p lo tted , it will be noted th a t th e first p a rt of th e scale is repre
sented by7 a straig h t line, and the second part by7 a curve. The equation for the straight line is app ro x im ately y = l-28x - 12-8 ;
• , , • - 1500
th e equation for th e curve i s y = / o -
Fi g. 1 .— Re l a t i o n o f Pr o f i t st o t h e Go v e r n m e n t Pe r c e n t a g e.
If th e area acquired from th e Government under th is arran g em en t were to represent, say7, 40% of th e to ta l com bined area, then th e G overnm ent’s p articip atio n in profits would be 40% of th is scale, and the curve p a rt w ould th u s be represented by the form ula y = 3 0 — . T his is practically th e form ula applying in th e case of D aggafontein, and th e various steps in the C om pany’s h isto ry leading to th is arrange
m en t will be d ealt w ith later.
In practice th is law has n o t proved a great success, due to th e fact th a t the Govern
m e n t’s share of profits under th e minimum term s is very high. T he Mines Department itself has realized th is sta te of affairs and legislation will sh o rtly be introduced which will do aw ay w ith th e m y n p ach t, b u t give th e owner th e rig h t to tak e up an area, not less th a n h alf th e size of th e farm , on a lease from th e G overnm ent.
Amortization Allowance.— T he taxation of gold m ines and th e G overnm ent’s
*" moi
net profits. Mining com panies are not taxed on th at p a rt of th e profit which represents a return of capital, and the same principle applies in the case of participation in profits.
The companies are allowed to set aside a sum each year, which, accum ulated over the life of the mine, will to ta l th e capital expenditure incurred on sh aft sinking, development, plant, and equipm ent. This sum is referred to as th e “ am ortization allowance,” and th e net or taxable profit is the gross profit m inus this am ortization allowance. The am ortization allowance, for the purpose of calculating th e G overn
m ent’s participation in profits, is th e equivalent of a sinking fund, which, compounded a t 3% interest over the life of th e mine, will re tu rn th e capital expenditure.
In regard to Income Tax, which is 15%
on gold m ining profits, th e am ortization allowance is calculated by dividing the to tal capital expenditure by the estim ated life of the mine. W hen D aggafontein Mines started producing, the capital expenditure incurred by the present com pany and its predecessor, and ranking for am ortization, amounted to over £2,800,000. The present shareholders will reap th e benefit of this expenditure in th e shape of a large am ortization allowance ; in other words, the allowable deduction from th e working profits will be very considerable.
Ea r l y Hi s t o r y. — D aggafontein was
a com paratively large farm , being over 4,960 morgen, or 10,500 acres, in extent.
A triangular portion in the northern corner of the farm , m easuring about 600 morgen, had been disposed of in the early days and coal mining conducted thereon. The remaining portion of th e farm , viz., 4,367 morgen, was the p ro p erty of the D agga
fontein Gold Mining Company, L td., which was registered in London as early as 1902.
After inform ation as to the dep th of the reef on this farm h ad been obtained by boring, shaft sinking was commenced in 1910.
No. 1 Shaft, of 7 com partm ents, was located on the eastern portion of the farm , some 7,000 ft. from th e eastern boundary. The reef was encountered early in Septem ber, 1914, a t a d ep th of 3,580 ft. Sampling results gave an average of 317 inch-dwt., approxim ately 40 dwt. over 8 inches.
Owing, however, to lack of funds and the impossibility of raising fresh money due to the o u tpreak of the E uropean W ar,
shaft allowed to fill w ith water.
First Reconstruction.— In 1916, under the aegis of the Consolidated Mines Selection Company, L td., the D aggafontein com pany was reconstructed and given th e new title of “ D aggafontein Mines, L td .” Lunds were raised for the dew atering of No. 1 S haft and for the com m encem ent of developm ent operations. The dew atering of th e shaft was quickly accom plished, and haulages were sta rte d in four directions, viz., north, south, east and west. The reef disclosed in th e n o rth , east and south haulages was narrow , b u t in m any cases of good value, while th e w estern haulage on th e whole exposed a wider reef.
The am ount of cash raised in th e first instance was com paratively small, as it was the intention to proceed w ith developm ent work on a lim ited scale, u ntil fu rth er funds became available from the exercise of certain options to subscribe for shares. An influential section of the shareholders, however, was in favour of commencing a second shaft at the earliest possible date so as to hasten forward th e tim e of production. No. 2 Shaft was therefore located 6,000 ft. west of No. 1, and by the end of 1916 the shaft was sunk 178 ft.
In 1917 a period of difficulties commenced.
W ater was encountered in the workings of No. 1 S h a f t ; th e station was lost, develop
m ent workings flooded, and hoisting accidents in th e shafts, due to the continuous baling, added to the troubles. H eavy rains interfered w ith th e tran sp o rt of coal and p u t a stop to baling. I t was th en decided to instal a pum ping p lan t a t No. 1 S h a f t; a station was cut on th e reef horizon and an in te r
m ediate station 2,000 ft. below th e surface.
In No. 2 Shaft also, w ater was en co u n tered ; here th e cem entation process was applied.
I t should be explained th a t, a t th a t time, owing to th e exigencies of th e W ar, no equip
m ent could be im ported for non-producing mines, and D aggafontein had therefore to carry on as best it could w ith second-hand m aterial. I t was not u ntil 1919 th a t develop
m ent w ork in No. 1 Shaft could be resum ed.
No. 2 Shaft at the end of 1918 had only reached a dep th of 1,028 ft. below the surface.
In 1919 this shaft was sunk 1,941 ft., and in August, 1920 the reef was exposed at a d ep th of 3,951 ft. The average value of the reef was 26-1 dw t. over 14-5 in., or 378 inch- dw t. In April, 1921, the connexion between the two shafts was made. The reef exposures
268 T H E M IN IN G M AGAZINE around No. 2 Shaft, supplem ented by
diam ond drilling, gave, for a to ta l length of 750 ft. east and w est from th e sh aft, a value of 23-9 dw t. over 16-2 in., or 388 inch-dw t.
Long before this, however, th e new C om pany’s funds h a d becom e exhausted.
T he Consolidated Mines Selection Com pany h ad come to th e rescue and, assisted by others, h ad advanced th e D aggafontein C om pany no less th a n £450,000. In Ju n e , 1921, operations were suspended, a n d th e w orkings an d shafts once more filled w ith w ater.
T he suspension of operations a t th a t tim e m ay seem difficult to u n derstand, in th e light of w h at is known to-day, b u t it m ust be rem em bered th a t in 1920 and 1921 th e position of th e gold m ines of th e W itw aters- ra n d h ad becom e very difficult. W orking costs h a d risen to th e high average of 25s. 8d.
per ton milled, labour troubles were threatening, and th e post-w ar depression h ad set in. In those days stoping was done by m eans of heavy reciprocating m achines, and stoping w idths of 60 in. and over were common practice. I t followed, therefore, th a t th e developm ent results quoted were n ot sufficiently a ttra c tiv e if considered in conjunction w ith th e high level of working costs, and a stoping w idth of 60 in. The change of conditions and th e im provem ent in m ining practice w hich have tak en place during th e last 10 years, however, have p u t
a com pletely different com plexion on the value of th e earlier disclosures. Since 1924 w orking costs for th e W itw atersrand as a whole have been under 20s. per ton, and th e stoping w id th has considerably decreased.
V arious F a r E a s t R an d properties are w orking a w id th of less th a n 50 in. For exam ple, during th e last 4 years the width of th e stopes in Springs Mines, wrhich adjoins D aggafontein Mines, has averaged less than 43 in., and th is figure is th e actual width based on tonnage hoisted.
D uring th is second active period, which lasted from 1916 u n til 1921, th e company first located its 179 discoverers’ claims around No. 1 S h aft and selected its mynpacht of 1,258 claims. Som ew hat later, it acquired a fu rth er 173 claim s, to th e n o rth of its m ynpacht, from th e Consolidated Mines Selection Com pany, and leased an area of 449 claim s from th e G overnm ent, which extended th e p ro p erty to th e joint Dagga- fontein-Springs Mines boundary7. Its holdings th u s to talled 2,059 claim s, as follows :—
A. D isco v erers’ claim s . . 179 claims B. M y n p a c h t a re a . . . 1,258 „ C. L eased from th e G o v e rn m en t . 449 „ D. A cquired b y p u rc h ase . . 173 ,,
2,059 claims T he d elim itation of these areas m ay be seen on th e plan (Fig. 2).
Second Reconstruction.— A fter closing down in 1921, no w ork was done for 6 years, but th e possibility of raising funds and resuming operations was alw ays k ep t in mind. The o p p o rtu n ity cam e in 1927, w hen certain developm ent faces in th e eastern p art of Springs Mines were approaching the D aggafontein boundary. T his rendered possible th e 1927 reconstruction. One difficulty h ad first to be overcome, viz., while Springs Mines developm ent headings were proceeding tow ards th e Daggafontein border, th e y were n o t approaching that p a rt of th e farm D aggafontein th en held by D aggafontein Mines, L td . T he Govern
m en t was therefore asked to lease to the com pany a fu rth e r area situ ated between th e eastern b o u n d ary of Springs Mines and a line draw n parallel th ereto a t a distance of 5,000 ft. fu rth e r east. T he company su b m itted a reconstruction scheme under w hich sufficient funds w ould be raised to inau g u rate developm ent w ork from Springs Mines into th e are a to be acquired.
As already stated , th e n o rth e rn portion of th e farm D aggafontein did n o t belong to the
