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9. Lighting. We are satisfied with the system of lighting in the ordinary working-places—namely, electric lamps, with a sufficient number of capable officials carrying flame safety-lamps. In isolated places one man at the face should, we think, be given a flame testing-lamp. Ross and his mate were using electric lamps. Had they been supplied with a testing-lamp, the presence of gas in their workingplace could have been detected on the flame. We note that the manager reported on the 21st February, 1924, an explosion of gas in a shaft which was being driven upwards. There was another explosion in a rise on the 23rd April, 1926, in which two men were burned. These two incidents should, we think, have warned the manager of the danger of encountering gas in a shaft or rise. Ross is a man very experienced in shaft-work, and though he is a contractor and not a certificated shot-firer, we would not have been inclined to take a serious view of his being allowed to do shot-firing if he had been supplied with a flame safety-lamp. It was suggested at the inquiry that a flame lamp should be issued as a spare lamp to each party at ordinary working-places. We do not think this is desirable, but there should be frequent inspections for gas by mine officials. 10. Explosives and Shot-firing. The explosive used is samsonite, which is a permitted explosive under the Coal-mines Act. The company admitted that Regulation 234 (b), with reference to the preparation for shot-firing, has not been obeyed. The manager issued on the 29th July, 1929, a notice under subclause (ii) of this regulation, specifying the minimum depth and width of holing, the minimum depth and height of sidecutting, and the position of the shot-holes. For some time after the visit of the Chief Inspector in July of the current year the terms of this notice were complied with, but the dangerous practice of " grunching," which was customary in the district before that, has again become common in the Linton Mine. The responsibility for this breach of the regulations as regards preparation for shot-firing rests, in our opinion, equally on the company and on the miners. We do not think that a proper compliance with this regulation is impracticable in this mine, and we recommend that it be enforced in normal working-places. We are bound to state, however, that this irregularity had, in our opinion, no relation to the explosion. It was further admitted by the company that the shot-firing in the construction of the shaft at C had, with the knowledge of the mine officials, been done by Robert Ross, he not being the holder of a shot-firer's certificate. It was further admitted by the company that detonators were issued to Ross, and that no proper check of such detonators was kept, and it was admitted by Ross that he kept unused detonators in the mine. These irregularities also had, we think, no connection with the explosion, but we think that greater care should be exercised in the issue and handling of explosives and detonators. This is fully provided for in the Act and regulations. We are of opinion that the number of shots fired by each shot-firer daily proves that there was insufficient time to carefully examine the places and supervise the charging operations. 11. Prevention and Treatment of Inflammable Dust.. The last analysis of dust from the north-west heading of No. 1 Mine was made on the 13th September, 1929, and the last previous to that on the 4th May, 1929, an interval exceeding the three months allowed by Regulation 238. There does not appear to have been any analysis earlier than this, though the regulation has been in force since 1926, and though there are numerous references to stonedusting in the defect notices given by the Inspector of Mines and in his correspondence from the 31st August, 1926, onwards. The analysis made on the 13th September showed, in three sections out of six, less than 50 per cent, of combined water and incombustible dust. Upon this being apparent the sections in question were, according to the reports, dusted again. It is impossible for us to say what was the percentage at the time of the explosion. Assuming that it was sufficient to comply with the regulation, then the percentage demanded by the regulation is insufficient, since it is clear that the explosion was propagated and extended by coal-dust. No test has ever been made to determine the percentage of incombustible dust and water necessary to counteract the inflammability of the Linton Mine coal-dust. The percentage required by the regulation is based upon tests made of the dust from Wairaki and other mines. We think that the present explosion throws some doubt upon the sufficiency of the percentage (50 per cent.) required by the regulation. We therefore recommend that, unless and until the scientific advisers of the Mines Department are satisfied on this point, the required percentage of combined moisture and incombustible dust should be raised to 60 per cent., and that the Chief Inspector be empowered in any given case to require a still higher percentage. Whatever percentage the regulations may ultimately require, we think that strict and immediate compliance with the present regulations should be insisted on. 12. Working and General Management. We have already indicated some matters in which the management has been at fault. Other matters to which we wish to draw attention, though not amounting to a breach of the law, seem to us to call for comment with a view to the improved working of the mine in future. The matters we refer to are :— (a) The Present Temporary Ventilation System. —The mine is at present ventilated by means of a forcing-fan. This, we understand, is to be replaced within a short time by a permanent system. We are of opinion that there has been a somewhat long delay in doing this. The permanent system proposed by the management contemplates the installation of a larger fan above the shaft C, and the use of that shaft as the return airway. The jig intended to give access to the shaft and to be part of the return airway has been in existence for many months, and all that was required to install the permanent system was the completion of the shaft of approximately 80 ft. It appears to us that this should not have been allowed to delay so long the installation of the permanent system.