C.—2.

(e) Electricity at Collieries. (Regulation 243.) The following is a summary of the annual returns, in accordance with Regulation 243 (c), regarding electrical apparatus at collieries : — Number of collieries at which electrical apparatus is installed .. 58 Number of continuous-current installations .. . . .. .. 9 Number of alternating-current installations .. .. .. .. 50 Number of collieries electrically lighted .. .. .. .. 45 Number of collieries using electrical ventilating-machines .. .. 44 Number of collieries using electrical pumping plants .. .. .. 34 Number of collieries using electrical haulage plants .. .. .. 41 Number of collieries using electrical screening plants .. .. .. 28 Number of collieries using electrical coal-cutting machines .. .. 4 Number of collieries using electrical miscellaneous plants .. .. 27 Number of collieries using electrical locomotives .. .. .. 1 Total horse-power employed from motors on surface .. .. .. 7,793 Total horse-power employed from motors below ground .. .. .. 3,300J (/) Prosecutions. Twenty-nine informations were laid by the District Inspectors during the year for breaches of the Coal-mines Act and Regulations ; two of them were withdrawn and twenty-seven convictions obtained. Accounts of the individual prosecutions are given in the reports of the District Inspectors (Annexure A).

SECTION Y.—LEGISLATION AFFECTING COAL-MINES. There were no amendments to the Coal-mines Act or to the Regulations during the year. The District Inspectors have performed their duties in a most efficient manner, rendering help to all efforts to improve the safety of the mines and reduce the loss of coal by faulty methods of mining. Although coal-mining in the West Coast district has, so far, shown little sign of the otherwise general recovery of industry, the adoption of better mining methods almost invariably receives the support of the mine-managers there as well as in the more favoured Northern and Southern districts. I have, &c., George Duggan, Inspecting Engineer and Chief Inspector of Coal-mines.

ANNEXUKE A.

SUMMARY OF REPORTS BY INSPECTORS OF MINES. NORTHERN INSPECTION DISTRICT (William Barclay, Inspector of Coal-mines). In compliance with the Coal-mines Act, I have the honour to submit the following report:— Output op Coal. The Northern District, comprising coal-mines in the Waikato, North Auckland, and Taranaki Districts produced 807,413 tons of coal for the year 1934, compared with 626,926 tons for the year 1933, an increase of 28-8 per cent. The number of workmen ordinarily employed in and about the mines was 1,452, an increase of 5-7 per cent, on the number employed during the previous year. The increased output was due entirely to the increased amount of Waikato coal purchased by the Railway Department for locomotive use. No fatal or serious accidents (resulting in permanent disablement) occurred to any workman during the year. The application of coal-cutting machines to bord-and-pillar faces, and the fullness of time worked during the winter months resulted in the annual output per person employed being increased by 104 tons, or equal to 23 per cent., above the output for the preceding year. Mining operations ceased in the Hikurangi and Waro Collieries during the month of September, due to a combination of adverse circumstances, and, finally, to the fact that the installed pumping-machinery at the Hikurangi Mine failed to cope with an inrush of water encountered during the driving of a dip heading advancing under the Hikurangi Swamp area. The bord-and-pillar method of mining, on the panel system, is adopted in all mines. In the Waikato District the seams vary in thickness from 12 ft. to 20 ft. The bords of the first working are usually driven from 12 ft. to 14 ft. wide by 9 ft. high, and pillars from 50 ft. to 70 ft. square are formed in support of the roof-cover. The panels contain from 6 acres to 10 acres, and in districts where spontaneous combustion follows the extraction of the pillars small panels not exceeding 4 acres in extent are preferable, as affected areas can be more rapidly and effectively sealed off and the fires suppressed. In the Hikurangi and Taranaki Districts the seams vary in thickness from 3 ft. to 8 ft. The thin seams are generally worked by small parties of miners working on co-operative principles. Waikato t Cabbonization Plant. The low - temperature carbonization plant erected at Rotowaro operated intermittently during the year. Quantities of earbonettes and fuel oil have been produced and stored in anticipation of an increased demand.

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