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151. So that you are not against taking samples of air ?—No, not where it is necessary; I have done it. 152. Do you get CO in any quantities in quartz-mining?—No, it is not present except in small quantities. 153. Is not that deleterious matter met with in the stopes when blasting?— Not very much. 154. Is that the injurious part?— Yes, it is injurious wherever it is found. 155. What is the injurious matter in the air in the stopes?—lt is the CO 2 given off by the breathing of the men; also from the candles and from a little gas from the explosives. 156. And that gas would be carbonic oxide, would it not? —Yes, I think so. 157. Do you know? —I do know, but just for the moment lam not certain. 158. Have you any recommendation to make as to the ventilation of rises?— The system generally adopted is the box method, with three compartments—one for air to go up into the rise, another for the debris from the stopes, and the third is a travelling-way with a ladder. By that means, they get a current of air passing along either by natural means or by a fan, and so get a circulation. Another method is to carry pipes up to the end and exhaust into the rise, and return the other way. 159. In spite of that, are the rises some of the worst ventilated places in the mines?—lf these means are adopted they would not be the worst; the dead-end would be the worst. 160. Are you in favour of fixing a definite distance beyond which men should not be allowed to work without pipes leading out?—No, because if you have a strong current of air it will drift into the face probably 30 yards; if you have a weak current it will drift 10 yards. It is a matter which should be left to the discretion of the Inspector. 161. We have heard a good deal about the ventilation in the mines here, to the effect that it is better under other conditions than it is at present, and I wish to ask you, Mr. Bennie, would the ventilation in those mines which we have visited be better in the summer-time than it is now?— Yes, I think this close muggy weather is the worst you can get. 162. And you consider the air good in these small mines? —Mostly. The other day when you visited the Sylvia you got the air in the worst possible condition. There was no velocity, but the air was fairly good. If it recurs like that often they will have to put a fan in. 163. You have heard the Royal Commission's report read by Mr. Whitley : do I understand that you disagree with the saturated standard?—l did not say so. 164. He said he agreed with the Royal Commission's recommendation : do you agree with Dr. Haldane that 78° saturated still air is the highest a man can conveniently work in? —Dr. Haldane said 80° moving air saturated was not worse than 100° dry. 165. You do not challenge what he says as to temperature?—No, because he is an expert. 166. Mr. Molineaux.~\ In any of your analyses of mine-air has the presence of carbonmonoxide been detected? —No. 167. Does the current of air enter a dead-end by diffusion of gases? You will have good air in the dead-end, but it will show no current: how do you account for that?—lt gets there by gravitation. The cold air will carry along the floor, and as it gets heated it will rise and go by the return along the roof. 168. The Chairman."] In connection with this candle test, I understand you to say that if COj were present to affect the candle CO might be present to counteract that effect, and thus the miner would be working in CO 2 and his candle might still burn brightly?—No, I have never known that state of things to exist so as to render the candle test unreliable. 169. Mr. Dowgrai/.] What amount of air, Mr. Bennie, would be necessary to dilute the fumes of gas from 1 lb. of gelignite? —That is a matter to which I cannot reply offhand. You are asking me questions which require calculation. 170. It requires a certain amount of air? —Yes, certainly. 171. Does it not necessarily follow, then, that the air ought to be circulating in the stopes?— The Mining: Act requires that the air shall be circulating in every place. 172. But where there is a greater amount of gelignite being used it follows that the air-current should necessarily be stronger? —Yes. 173. Did you take that into consideration when speaking as to whether the stope is ventilated or not? —Yes. 174. If the air is dull in a stope, and a considerable amount of gelignite is used, would there not be CO present? —There will be vitiated air, of course. 175. In reply to a question by Mr. Reed you stated that you tested the air always in the worst places : did you do that in the Deep Levels? —I think my statement to Mr. Reed was to the effect that these were the worst places under my supervision. 176. I understood your reply to mean that all the tests which you made were in the worst places, as it was not necessary to test it in the good places?— No. 177. Then you did not test the air in the worst places in the Deep Levels? —Yes, I did, right in the face, where I took the air-samples. 178. You apparently, according to the table which you have laid before the Commission, have not tested the air in the Deep Levels since March of this year?— Yes, I have. 179. Your last report in connection with the ventilation appears to have been made on the 23rd March? —Yes, but that is as to temperature and quantity of air. 180. You have-not tested it since then? —Yes, by volume. 181. Where is it in your report?—lf you look at the reference to the Saxon section you will find it. Under the Deep Levels, in the third column, " Where taken," you will find it referred to. 182. Were these samples taken prior to the installation of the blower? —Yes. 183. Have you taken samples since? —No. 184. Do you consider that that mine was adequately ventilated on Saturday when we visited it, from the chamber to the face?— The word " adequate " is very wide.

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