3

H.—34a.

menfc, and given its greatest power of purchase through the supply of explosives at cost-price from the Defence Department of New Zealand. I was ordered to proceed to Oamaru simply to watch and report upon the proposed experiments. On my arrival I was met by the members of the committee who had the matter in hand, and, while disclaiming all responsibility for the experiments, I discussed the project freely with them, finding their idea was to seek favourable opportunities to cause the passing clouds to precipitate. They desired me especially to advise them as to these, and to indicate times when the air would be saturated with moisture, or, to adopt a phrase of the late meteorologist, Eev. Clement Ley, such a state of " unstable equilibrium " would prevail that it might possibly be disturbed, and the " water-dust "of the clouds be made to coalesce, and precipitation ensue. They did not hold that they were able to produce rain at any time, but firmly believed that they could only operate successfully in a cloudy and saturated atmosphere. Though I could not share their very sanguine hopes for such results as desired, yet I tried my best to meet their views, and to the utmost of my abilities heartily co-operated with the committee. I only wish that more of the committee could have witnessed the experiments, and have come, with the Press, to definite conclusions. Eain was badly wanted, and at first the committee were too much in earnest both in their faith and efforts to regard the experiments in the light of pure science. As is well known, rainfall is one of the most uncertain elements in meteorological prognostication for such a district, and the " probability of rain " with certain disturbances rarely amounts to absolute certainty ; but events were moving in such a manner that I could forecast periods of saturation in the near future. The times thought most favourable for rain, fortunately for the district, coincided very nearly with such widespread and abundant rainfalls as had not occurred for years, and on this account, unfortunately, my task of giving conclusive evidence as to cause and effect in the experiments was rendered more difficult. While admitting this, I desire most clearly to maintain that in no case was I able to trace such effect or success in rain-making, due to the explosions, as some local residents at the time claimed with considerable assurance. I have, moreover, read the records of similar experiments made on the 17th November, 1891, on Eaki's Table, and referred to with even greater confidence. Eain fell at that time, but I find from our records that the fall was heavy and general between Cape Campbell and Dunedin. The reports of the effects of the explosions on the clouds, and on the barometer and hygrometer, are interesting, but by no means of a convincing character. For example, before one experiment "the barometer stood at 28-95 in., and five minutes after the explosion it fell to 28 92 in., ten minutes afterwards to 27'75in., and," it is added, " was apparently continuing downwards when we left the Table." A fall of the barometer, in the open air, of ljin. at least in fifteen minutes would probably show a world's record for all time, and one need hardly discuss the possible effects of such a drop : we might almost speak of it as a "vacuum "in the atmosphere. The chief claim for further experiments was based on this reported change. In every case where we watched reliable barometers near the explosions only a slight quiver was noticed at the moment of detonation, while the instruments went on steadily rising or falling as at other places. The sites chosen for the experiments were lonely hills which commanded views of the whole district, and on that account had all been used as trigonometrical stations for the survey of the district. Eaki's Table, the chief site, is a flat-topped hill 1,059 ft. above sea-level and fourteen miles inland, as the crow flies, north north-west from Oamaru. Eound Hill, on the Totara Estate, is a remarkable cone with an elevation of 501 ft. above mean sea-level, and about six miles southwest from Oamaru. Dalgety's Hill, near Duntroon, is in the Waitaki watershed, and is about 811 ft. above mean sea-level, and fifteen miles north-west from Oamaru. The positions had been carefully chosen by the committee, and both the situations and elevations were admirable for the purpose. The aim was to work with the wind rather than against it, and it was hoped that we should be able to trace the effects of the explosions on the clouds over the area affected. The Fibst Secies of Expeeiments. On the afternoon of the 16th August the skies were dull—strato-cumulus clouds hung round the hills, and were scattered overhead. It appeared even to be raining at a distance away to the south, but the weather was quite fine for us on the way to Arnmore Station, near Eaki's Table. We arrived at Mr. P. S. Shand's residence about sunset, and, although heavy misty clouds were falling on the Table, and residents thought rain imminent, there did not seem to be sufficient density about the clouds. The air showed a relative humidity of 92 per cent, of saturation, and only needed a fall of the thermometer of 2-4° to reach the dew-point. The cool of evening was approaching, and the wind, though light, was in the rainy quarter, the south-east. On the whole the conditions were regarded as fairly favourable. It was regarded chiefly as a trial of the bombs, and for working the men together under Corporal Meikle, prior to using the other stations. The explosives used on this occasion were, — (1) 5.15 p.m. : 17-J lb. dynamite, lb. powder ; in keg. (2) 5.30 p.m. : 17i lb. " „ , 12| lb. „ ; (3) 5.45 p.m. ;40 lb. „ ,25 lb. „ ;in case. These behaved differently. The first shot gave off a good report, and the smoke rose and drifted gently away to the north-west. The second did not explode well, for the powder seemed to burn in the air without detonation. The third shot, which had a weight of 651b., gave a great concussion to the air, and vibrations were felt over a wide area. As far, however, as we could see there were no other than natural changes going on in the atmosphere. We left for Oamaru at 10 p.m., and the evening was quite fine. In the Oamaru Mail however, next day, the following paragraph appeared : " As showiug that the explosions which took place last evening, although modest compared with what are to follow, were not