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Shag Point. The coal measures here flank the Horse Ranges and consist of several thousand feet of conglomerates, sandstones and shales. The uppermost beds of the series extend about 14 miles along the coast by about 1 mile wide and contain valuable coal seams estimated to yield about a million tons, and which are seen outcropping in the precipi. tous cliffs. The Shag Point Colliery works a seam of pitch coal 7 feet thick, which is followed to the deep under the sea. Green Island Coal Field, near Dunedin, has
area of about 8 square miles. The measures lie in a hollow of the older slates and have been preserved from denudation by the basalt and dolerite flows which cap the adjoining hills. There are five seams, but only one is worked, varying from 13 feet to 19 feet in thickness, of inferior hydrous brown coal. The roof is bad, so that only 7 to 10 feet of the seam is worked. There are 5 collieries, and the content of the field is computed at 28,000,000 tons.
The Clutha and Tokomairiro Coal Field covers about 40 square miles. The measures consist of conglomerates, sandstones, and clay shales, with several seams of Brown coal, and form a range of hills between the Kaitangata Lake and the sea coast, along which they are seen in section for 3 miles. The seam worked at Kaitangata is from 24 to 30 feet thick, of which from 20 feet to the full thickness is got. The field is estimated to contain one hundred and fifty million tons.
In Southland and the south and west of Otago a consid. erable extent of surface is occupied by beds of the Cretaceo Tertiary and Jurassic formations, it .d outcrops of coal have been found at many points, but the seams have mostly been too thin for profitable working. At the Nightcaps, Otautau, a seam of Pitch Coal 51 feet thick is being got on a limited scale, and at Mataura lignite 121 feet thick has been worked for some years.
Lignite deposits are found in many parts of Southland and Otago. Usually they occur in what are evidently old lake basins, in the surface of the slate rocks in the interior. They are often of great thickness and owe their origin to driftwood ; fragments of trees are common in which the woody tissue is perfect, the most usual being a species of Fagus, the “ Birch " of the colonists. These deposits are of quite recent Tertiary age, being usually covered only by brick clays, gravels, silts, or shingle. The lignites not uncommonly contain resinous matter (Retinite) in considerable quantity, when they burn very readily; where this is absent, or only present in very limited quantity, they burn slowly, smouldering like turf, giving off a disagreeable, fætid odour, and leaving a large quantity of light ash. They are worked at numerons points, usually as opencasts, and on a very limited scale, and where better fuel is scarce and costly they prove very useful for local requirements.
Distribution. From the preceding notes it will be seen that coal seams are widely distributed through both islands, and no parts except the east of the North, and the north-east of the South Islands are very distant from workable coal. A noteworthy point as compared with British coal fields is the limited vertical depth of measures to which good coal seams are confined; and most of the areas contain only one good workable seam.
Quantity and Duration.- In a new and imperfectly explored country the necessary data for estimating this are very incomplete. It appears that in known areas an available supply of 450 million tons has been ascertained. Any computation of the duration of this supply would in the present state of the colony be little more than a wild guess. The local consumption of coal in 1881 was in Great Britain 3.67 tons, and in New Zealand •86 tons per head of population. But the increment in population and the development of industries in the two countries are so dissimilar as to preclude our founding any estimate on this basis.
Present State of Coal Trade. --The following table shews the state of the coal mining industry for four years to 1881 :
Number of Mines...... 30 90 107 104 Workpeople Employed.... 513 807 1,089 986 Coal Imported,
Tons. 174,148 158,076 123,298 129,962
Increase Decrease Decrease Increase
18,162 16,072 34,779 6,664 Coal Exported, .... Tons. 8,921 7,195 7,021 6.626
Increase Decrease Decrease
3,274 174 395 Coal Produced ..... Tons. 162,218 231,218 299,923 397,262
Increase Increase Increase Increase 23, 234 69,000 68,705
37,339 Coal Consumed.... Tons. 332,445 | 382,099 | 416,200 460,598
Increase Increase Increase Increase 37,465 49,654 34,101 44,398
This table shews that the increase over each preceding year
10.6 During 1879 and 1880 the import diminished although the consumption increased, the inference being that native coal was gaining favour and supplanting the imported article ; but in 1881 this progress was not maintained, for not only did the rate of increase in the native production fall off more than half, but the increased consumption had to be met by increased imports—a state of things for which the writer cannot account and which he ventures to think should not have taken place. The returns for 1882 will be awaited with some anxiety, and it is hoped will shew a recurrence of the progress so markedly shewn in 1879 and 1880. Of the 104 collieries working in 1881, only 1 raised over 50,000 tons, 2 over 30,000, 8 over 20,000, and 6 over 10,000; the remainder are on a very in--. significant scale. The production per person employed in 1881 was in Great Britain 341 tons, and in New Zealand 342.
Quality of Coal.-In a previous part of this paper it was stated that though all the coals of New Zealand are of comparatively recent age, and might be termed Brown Coals, in various states of alteration, yet the qualities are very
various. The following are a few selected (commercial) analyses :
The large quantity of water contained in the hydrous varieties is a very serious drawback to their use for steam and manu. facturing purposes. For steam navigation it means bulky stowage and the carrying of a large proportion of an element not only worthless as a source of heat but seriously detrimental to the efficiency of the effective portions of the fuel which are wasted in evaporating this worthless constituent. For manufacturing and steam-raising on shore possibly the conversion of the fuel into heating gas by one of the many gas producers now before the public might mitigate the evil if it did not altogether surmount the difficulty.*
Tenure of Coal Mines. The ownership is with the freeholder as in England, and in these cases the owner may either work the mines himself or lease them on snch terms as may be agreed upon. In some instances the coal fields have been treated as reserves, and the Crown will grant the right of working the mines subject to royalty, reserving a small fixed rent and granting tne use of surface land for the erection of the requisite works. The Government has expended large sums in aiding the adventurers to search for and open
mines and in making railway and other works.
Government Inspection.-An Act was passed in 1874 to provide for the Regulation and Inspection of Mines, but for some years remained inoperative owing to the opposition raised by the mining interest. So matters were allowed to
* Should the “ Bull” process of smelting iron by gaseous fuel realise the expectations of its inventor, it migat meet the needs of New Zealand precisely.
drift on till a terrible explosion occurred at Kaitangata Mine on 21st February, 1878, which caused the loss of 34 lives, every person in the mine being killed. This startled the Colony and awoke the Government to a sense of its responsibility, and on the 28th of the same month the Act was pro;, claimed in force. Districts have been defined and Inspectors appointed, and since this was done a great improvement has taken place in the management of the mines.
The deaths from accidents of all classes per 1,000 persons employed were in 1881, in New Zealand 3.052, and in Great Britain 1.925: and the tons of coal produced per life lost were, in New Zealand 112,420, and in Great Britain 177,106. These figures can hardly be regarded as satisfactory when we consider the generally simple nature of mining in New Zealand compared with the greater risks incurred in the deep and fiery mines of Britain, and it would seem to indicate room for more skill and more care in the management. Possibly as the mines become individually more important it may be commercially practicable to employ a higher grade of technical skill in their supervision and management, and this may lead to more successful results both in the development of the mines, and in the saving of life.
The coal trade of the colony is yet struggling in its infancy, and one of its greatest difficulties would seem to be the want of better means of communication, more and better roads, more and cheaper accommodation by rail, improved harbours and ports, with specially-built steamers by sea. It certainly is curious that with such splendid resources at their feet the colonists should be content to receive so large a part of this prime necessity from their neighbours; and it is an anomaly to which they would do well to bestir themselves to put a speedy end.
IRON. The ores of iron are very numerous, more than a hundred varieties being known to mineralogists, but only some of the oxides and carbonates are used for the production of iron,