522 
Vee BORE 
[APRIL I, 1897 
holes issues at the end o1 the cylinder, whence it goes direct to 
the sorting house. The four sizes which pass through the screens 
flow to the same number of jigs. The bottoms of the jigs are 
covered with screens the meshes of which are respectively } 
inch, 3%; inch, 4 inch, and 2 inch square, thus corresponding 
with, but being a little coarser than the holes in the cylinder. 
Upon each screen is spread a layer of bullets to prevent the rich 
deposit from passing too rapidly through the screens. The jigs 
themselves are stationary, but from below an intermittent stream 
of water passes in rapid pulsations with an up and down move- 
ment. This pulsation keeps the diamantiferous gravel con- 
stantly moving—‘‘alive” is the expressive word used—and 
tends to sort out the constituents roughly according to their 
specific gravity, the heavier particles working to the bottom and 
the lighter material washing off by the flow of water and passing 
into trucks, whence it is carried to the tailings heap. The 
heavier portions by the up and down wash of the water gradually 
work their way under the bullets and pass through the screens 
into pointed boxes, whence the contents are drawn off at 
intervals and taken to the sorting room. 
SORTING OUT. 
The sorting room in the pulsator house is long, narrow, and 
well lighted. Here the rich gravel is brought in wet, a sieve- 
full at a time, and is dumped in a heap on tables covered with 
iron plates. The tables at one end take the coarsest lumps, 
next comes the gravel which passed the 2 inch holes, then the 
next in order, and so on. The first sorting is done by thoroughly 
trustworthy white men; for here the danger of robbery is 
greatest. Sweeping the heap of gravel to the right, the sorter 
scrapes a little of it to the centre of the table by means of a flat 
piece of sheet zinc. With this tool he rapidly passes in review 
the grains, seizes the diamonds and puts them into a little tin 
box in front of him.. The stuff is then swept off to the left, and 
another lot taken, and so on till the sieve-full of gravel is ex- 
hausted, when another is brought in. The stuff the sorter has 
passed to his left as temporarily inspected is taken next to 
another part of the room, where it is again scrutinised by native 
convicts again and again, and whilst diamonds can be found in 
quantity sufficient to repay the cost of convict labour, it is passed 
under examination. 
The diamond has a peculiar lustre, and on the sorter’s table it 
is impossible to mistake it for any other stone that may be present. 
It looks somewhat like clear pieces of gum arabic, with a sort of 
intrinsic lustre which makes a conspicuous shine among the 
other stones. 
Besides diamonds, the following associated minerals reach the 
sorting tables :— 
Pyrope (garnet), sp. gr. 3°7, containing from 1°4 to 3 per cent. 
of oxide of chromium ; zircon, in flesh-coloured grains, but no 
crystals, sp. gr. 4 to 4°7; kyanite, sp. gr. 3°45 to 37, discernible 
by its blue colour and perfect cleavage ; chrome diopside, sp. gr. 
3°23 to 3°5, of a bright green colour; bronzite, sp. gr. 3°1 to 
3°33; magnetite, sp. gr. 4°9 to 5°2; mixed chrome and titanium 
iron ore, sp. gr. 4°4 to 4°9, containing from 13 to 61 per cent. of 
oxide of chromium, and from 3 to 68 per cent. of titanic acid, in 
changeable quantities ; hornblende, sp. gr. 2°9 to 3°43; barytes, 
sp. gr. 4°3 to 4°7 ; and mica. 
In the pulsator and sorting house most of the native labourers 
are long sentence convicts, supplied with food. clothing, and 
medical attendance by the company. These men are necessarily 
well guarded, and all the white men in the works carry revolvers. 
I myself saw about 1000 convicts at work. I was told that in- 
subordination is very rare. Apart from the hopelessness of a 
successful rising, there is little inducement to revolt ; the lot of 
these diamond workers is preferable to life in the Government 
prisons, and they seem contented. 
Sometimes as many as S000 carats of diamonds come from the 
pulsator in one day, representing about 10,000/. in value. 
Prodigious diamonds are not so uncommon as is generally 
supposed. Diamonds weighing over an ounce (151°5 carats) are 
not unfrequent at Kimberley, and, were it necessary, there 
would be no cifficulty in getting together a hundred of them. 
Not long ago, in one parcel of stones at Wernher, Beit, and 
Co.’s office, I saw eight perfect ounce crystals, and one weighing 
two ounces. The largest diamond from the Kimbeiley mines 
weighed 4284 carats, or nearly 4 ounces troy. It measured 13 
inch through the longest axis, and was 14 inch square, After 
cutting, it weighed 228% carats, losing 200 carats in the process. 
pound. It was found at the Jagersfontein mine. Diamonds 
smaller than a small fraction of a grain elude the sorters and 
are lost. A microscopic examination of blue ground from 
Kimberley, after treatment with appropriate solvents, shows the 
presence of microscopic diamonds, white, coloured, and black, 
also of boart and carbonado, 
THE DIAMOND OFFICE. 
From the pulsator the diamonds are sent to the general office 
in Kimberley to be cleansed in a boiling mixture of nitric and 
sulphuric acids. A parcel of diamonds loses about half a part 
per 1000 by this treatment. 
After purification, the diamonds are handed to the valuators, 
who sort them into classes, according to size, colour, and purity. 
In the diamond office they are sorted into ten classes. In the 
year 1895 in 1141°8 carats of stones, the proportions of the 
different classes were as follows :— 
Close goods (best stones) 538 
Spotted stones 75'8 
Fine cleavage 79° 
Flats 39°5 
Macles tae 5 ees 36°5 
Ordinary and rejection cleavage soa)  2HB A 
Rejection stones dec na fer iy 43°2 
Light and brown cleavag " 569 
Rubbish ... 371'8 
1000°0 
Fine sand 141°8 
1141°8 
From two to three million carats of diamonds are turned out 
of the De Beers mines in a year, and as five million carats go to 
the ton, this represents half a ton of diamonds. To the end of 
1892, ten tons of diamonds had come from these mines, valued 
at 60,000,000/. sterling. This mass of blazing diamonds could 
be accommodated in a box five feet square and six feet high. 
In the year ending June 1895, there were found 2,435,5414 
carats of diamonds, realising 3,105,958/. During the same 
time the total expenditure amounted to 1,704,813/., leaving a 
profit of 1,401, 1452. 
About half these expenses represent mine wages or other 
local expenses. 
The De Beers Company could raise many more diamonds, 
but a superfluity would have the effect of lowering the price. 
The diamond is a luxury, and there is only a limited demand for 
it throughout the world. From 4 to 44 millions sterling is as 
much as is spent annually in diamonds ; if the production is not 
regulated by the demand, there will be over-production, and the 
trade will suffer. By regulating the output the directors have 
succeeded in maintaining prices since the consolidation in 1888. 
Diamonds to the value of about a million annually are pro- 
duced by outside companies and individuals. 
THE CoMPOUND SysTEmM. 
One great safeguard against robbery is the ‘‘ compound ” 
system of looking after the natives. A ‘‘ compound ” is a large 
square, about 20 acres in extent, surrounded by rows of one- 
storey buildings of corrugated iron. These are divided into 
rooms holding each about twenty natives. A high iron fence 
is erected around the compound, 10 feet from the buildings. 
Within the enclosure is a store, where the necessaries of life are 
supplied to the natives at a reduced price, wood and water 
being provided free of charge. In the middle is a large 
swimming-bath, with fresh water running through it. The 
rest of the space is devoted to recreation, games, dances, 
concerts, and any other amusement the native mind can desire. 
In case of accident or illness there is a well-appointed hospital, 
where the sick are tended. Medical supervision, nurses, and 
food are supplied free by the Company. 
In the compound are to be seen nearly all the best types of 
African tribes. Each tribe keeps to itself, and to go round the 
buildings skirting the compound is an admirable object-lesson 
in ethnology. At one part isa group of Zulus; next we come 
to Fingoes; then Basutos; beyond come Matabele, Bechuanas, 
The largest known diamond weighs 970 carats—over half a | Pondos, Shangains, Swazis, and other less-known tribes, each 
NO. 1431, VOL. 55] 
