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Following on two fatalities from sulphuretted hydrogen in the Millerton Mine, a research was undertaken at the request of the Mines Department into methods for detecting and estimating this gas underground. A convenient form of detector has been evolved, and laboratory experiments with it are in progress prior to trials underground. The chemical work on the subject of iodine in relation to the incidence of goitre is now completed and will be published at an early date (in conjunction with the Department of Health). Research for the Plant Research Station on the chemical composition of spraying-materials for fruit-trees has given valuable results, and is being continued. The comparative values of New Zealand and imported hydrated lime for industrial use were investigated. Laboratory research in connection with the extraction and refining of kauri-gum was advanced sufficiently to justify the working-out of conditions on a commercial scale. An extraction plant that lay idle in Auckland was modified in some details and operated for several weeks extracting swamp gum. The results were up to expectations. A considerable quantity of refined gum was produced, parcels of which were sent to numerous manufacturers abroad. Their comment is being awaited with interest. Owing to withdrawal of the financial support of the Coal-mine Owners' Association, the Fuel Research Association was disbanded during the year. This is a matter for great regret, as a large amount of useful work was being accomplished. The last bulletin published by the association dealt with briquetting, and, as a consequence, the briquetting of slack coal will soon be in commercial operation in the Dominion. GEOLOGICAL SURVEY. The field-work of the Geological Survey was restricted this year by the shortage of funds. In two districts the geologists boarded where, and bow they could, and in a third, Naseby, where population is sparse, a camp of minimum size was maintained. In all, about 1,000 square miles of country was mapped. Geological investigation was continued in the Eketahuna Subdivision, and another season's work should complete the mapping of this district. There are indications of oil at many points along the eastern slopes of the North Island, and the whole of the northern half of this petroliferous region has now been examined, but the Eketahuna Subdivision is the first district of the southern half to be explored in detail. Work was resumed in the Amuri Subdivision. In this area important limestone deposits occur and some bands of phosphatic pebbles, which may have future value. In this treeless region of low rainfall the effects of recent earth-movements are as well preserved as in any part of New Zealand, and the study of these may help to a better understanding of the relative frequency and severity of earthquakes. Owing to the greatly increased value of gold, alluvial fields till recently regarded as practically worked out have regained economic importance, and are being tried by a new generation of prospectors. Partly on this account the geological exploration of the Naseby Subdivision was begun last season. Good progress has been made in the mapping of the district, which covers most of the basin of the upper Taieri and contains several famous alluvial goldlields, a number of auriferous quartz veins, thick deposits of lignite, as well as beds of light-burning clays, diatomaceous earth, and fine high-grade quartz sands. The examination of alluvial diggings begun last year was continued, one officer spending the whole of the season on this work in Otago and another a few months on the Wesl Coast. In Otago several areas of river-flat were examined to determine if the geological conditions indicated the presence of buried stream-channels the position of which could then be lixed by geophysical methods. In the same region structure studies in the Manuherikia Valley indicate that mountain-building pressure has raised a low fold of Tertiary strata in front of the Dunstan Range. The quartz conglomerates at the base of the Tertiary sequence are richly auriferous at several points where upturned at the foot of the mountains, and this fold may bring portions of the same beds now covered with younger deposits within mining depth. The success attending the use of geophysical methods of prospecting for minerals in other parts of the world has directed attention to the possibility of using this means of increasing the output of gold. The geophysical work so far has been confined to attempts to locate deposits of detrital gold. The methods depend on the use of delicate instruments to detect differences in the physical properties of material buried beneath the surface. Gold occurs in such small proportions even in high-grade wash that its physical properties cannot be made use of in this work. Rut since streams tend to concentrate other heavy materials present in the gravels in far greater amount than gold along with that metal, geophysically detectable deposits of these heavy minerals are of interest to the gold-miner if they occur in gold-bearing country. In effect, all that geophysical investigations can do is to direct the miner to the most likely places to prospect. The cost of such prospecting is thus reduced, but prospecting is by no means rendered unnecessary ; and the public, for their own protection, should take care that the value and amount of the wash of the claim in which they are investing has been adequately determined by boring, shafting, driving, or other well-proved methods. During the year the two officers engaged on soil survey carried out a reconnaissance survey of the soils of 650 square miles of Taranaki and mapped in detail the soil of 80 square miles of closely settled farm lands in Waipa County.

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