In 1938–39 the D'Arcy Exploration Company, Limited, sank a borehole (Eskdale well no. 2) to a depth of 5040 feet near Aislaby, Eskdale, Yorkshire, to test the oil or gas possibilities in the Permian Magnesian Limestone. As the well was some distance from any previous boring through the Permian salt series, the Company undertook to carry out continuous coring through this series in the public interest. The boring passed through Lias, Rhaetic, and Trias, and finished in the Permian Lower Magnesian Limestone. The geological results of this boring have been discussed by Lees and Taitt (1945), and fig. 1 has been reproduced from their paper. It can be seen that three evaporite beds were passed through; two in the Upper Permian salt zone, and one in the Middle Permian.

If the visitor standing at Wherry Town on the south-western end of the esplanade at Penzance looks seaward he will observe at low tide at some distance from the shore a low scaweed-clothed rocky shoal (fig. 1), and from his now very conventional surroundings it is difficult to realize that upon this shoal, always surrounded by water, there existed many years ago a rich tin mine, unique in the boldness of its conception, romantic in the extreme in its situation and execution, and withal the effort of a poor working miner.

Very fortunately in the year 1790, during the hey-day of its career, this remarkable mine was examined by a very competent observer in the person of John Hawkins (1761 ?-1841), F.R.S., of Trewithen, Cornwall, and Bignor Park, Sussex, and it is to him that we owe most of the details concerning its mode of working, &c. The Wherry mine and its history have always fascinated me, as they must have many others, and in re-telling the old story I have endeavoured to collect all the known facts, both as to the mine itself, its mode of working, and its mineral productions, and in so doing pay tribute to its gallant and resourceful originator Thomas Curtis.

The discovery of nigerite, a new tin-bearing mineral, by R. Jacobson and J. S. Webb claims more than the passing interest of an addition to the few known species containing appreciable tin. Nigerite is the first mineral to be discovered in which both tin and aluminium are essential constituents. Its chief interest to mineralogists lies in its close relationship to minerals like spinel and corundum based on a close-packed or nearly close-packed assemblage of oxygen ions.

Samples of nigerite submitted to us for investigation consist of brittle, lustrous, brown, weakly magnetic, hexagonal plates up to 5 x 2 mm. in size but mostly much smaller. These samples also contained grains of cassiterite, columbite, gahnite, sillimanite, quartz, andalusite, and chrysoberyl, which were easily separated by hand-picking.

Ankerites from the Northumberland coalfield were first described, with chemical analyses, some ten years ago (Hawkes and Smythe, 1935), when it was found that examples from veins exposed on the coast near Hartley and from sludge from nearby coal-washeries showed a remarkable uniformity in composition. The operations of the collieries concerned cover an area roughly 6 × 6 miles, and range from the Beaumont to the High Main Seam. In order to ascertain whether this uniformity is maintained over a wider area, five additional samples of ankerite from veinlets in rocks of Coal Measure age, and one from partings in the Lower Carboniferous Scremerston coal have been examined. The Coal Measure rocks cut by the veinlets have been proved to contain substantial proportions of ferriferous carbonates, while for comparative purposes two examples of rocks of similar age with carbonate but unaccompanied by ankerite veinlets have been investigated. The range in composition of ankerites in the coalfield has proved to be small.

The mineral here described was at first considered to be an iron-rich variety of turquoise and was described by myself as such when this paper was read before the Society in 1937. At that time only a partial analysis had been made; since then Dr. J. A. Smythe of King's College, Newcastle-upon-Tyne, has most kindly undertaken at my instigation careful analyses of the mineral from both of its localities, Bunny mine, St. Austell, and Castle-an-Dinas wolfram mine, St. Columb Major. As a result of these two analyses, which are in close agreement, it is evident that the mineral is a new one, intermediate between turquoise and the two minerals chalcosiderite and andrewsite, and forming a middle member of what is probably an isomorphous group.

Metahalloysite is one of the kaolin group of minerals with a composition approximating to the formuia Al2O3.2SiO2.2H2O, and its structure is generally considered to be built of composite layers of atoms of the kind found in other minerals of this group. It differs from them most strikingly in that it can be produced by the dehydration of the hydrated mineral halloysite, which has the approximate composition Al2O3.2SiO2.4H2O. Both minerals give comparatively poor X-ray diagranm showing relatively few lines attd bands. The lines correspond to reflections from a basal spacing of about 7·2 Å. in metahalloysite and 10·1 Å. in halloysite.

Some time previous to 1894 the late Sir Henry A. Miers, then an assistant in the Mineral Department of the British Museum, collected together all the books in the departmental library which gave a systematic account of the minerals of particular regions. Since then the set has been considerably added to, and it now forms a very valuable, probably unique, series. Its primary use was for the more precise labelling of the localities of specimens in the collection; and as it grew it became more and more useful for answering inquiries on the minerals of particular districts. In 1900 I started a note-book for collecting further references from the literature. This was added to by the late Mr. George Savigar, clerk in charge of the departmental library; and later Miss J. M. Sweet compiled a card-index of all the entries. The department also has card-indexes of the localities of mineral and rock specimens in the collection.

In a group of earlier publications details have been given of the application of multiple-beam interference methods to the study of mica. The characteristic structure of this mineral is exhibited by the Fizeau fringes which are produced when one side of a mica slip is silvered and placed against a similarly coated optical flat. The fringes show that the surface is violently contorted and crossed by cleavage steps, the heights of which appear to be integral multiples of the crystal-lattice spacing perpendicular to the basal plane of cleavage. If, however, a mica slip (thickness circa 1/100 mm.) is silvered on both sides then fringes of a totally different appearance are observed. It is frequently found that, despite the distortions on the surface, the Fizeau fringes are large areas of uniform illumination bounded by cleavage ‘lines’.

Among the specimens collected at the Benallt manganese mine in 1944 by Dr. A. W. Groves and myself was one (B.M. 1944,48) from the 60-foot level in no. 1 ore-body which showed on a face of dark, compact manganese ore colourless plates up to 7 mm. across and about ½ mm. thick. These plates proved to be uniaxial and negative with perfect basal cleavage. Heated in an ignition tube the fragments decrepirated, gave off water, and became pearly, white, and opaque. Qualitative tests showed Ba, Al, and SiO2 to be present. Preliminary X-ray photographs revealed hexagonal symmetry, but could not be matched with those of any known mineral.

Many examples of the hydrothermal synthesis of minerals are scattered throughout mineralogical literature. The present paper has been written to bring to the attention of mineralogists the fact that such hydrothermal syntheses are occurring continually in industrial boilers, particularly when control of water softening procedure is not completely efficient.

The experiments described below on the dehydration of halloysite were largely carried out in the laboratoire Central des Services Chimiques de l'État, Paris, where we enjoyed not only the excellent facilities of the laboratory but also the advice of Monsieur J. Méring and Mile R. Glaser who had made similar studies of montmorillonite. The use of a Guinier-type focusing camera with strictly monochromatic radiation was especially useful. These experiments were undertaken because little was known about the dehydration process beyond the recognition that it occurs very readily in dry atmospheres and at low temperatures. The main experimental difficulty lies in differentiating between water adsorbed oil external surfaces of the clay particles (adsorbed water) and water internally absorbed between the kaolin layers (interlayer water).

The contour and dimensions of a typical blast furnace are shown in fig. 1. The shell of the furnace consists of riveted steel plates, inside which is a lining of firebricks varying in thickness about 2–3½ feet. Molten iron collects in the crucible or hearth at the bottom of the furnace and is periodically run off through a hole in the side of the furnace known as the tap-hole. The hearth is lined with firebrick both around the sides and along the floor, the total thickness of brickwork below the hearth in fig. 1 being 3 feet 9 inches.

The earliest systematic catalogue of meteorite collections is that of Otto Buchner in 1863, in which he listed 264 meteorites preserved in 89 collections. Thirty years later E. A. Wülfing, after circularizing 350 mineralogical and other collections, gave preliminary results for more than 500 meteorites with a total weight of 18,514 kilograms (18½ metric tons) preserved in 105 collections. This information was further elaborated in his valuable book in 1897, in which is given the weight in grams of individual meteorites in each collection.

At that time Wülfing recognized 536 known meteorites. Now there are very many more–1347 according to the latest published list (C. F. Leonard, 1946, below) and 46 others have been noticed in ‘Mineralogical Abstracts’ since 1940. Wülfing's data, compiled for July 1893, is now, after more than half a century, much more out of date than he found Buchner's data after an interval of thirty years. To digest all the information now available would be an enormous task.

During the course of a detailed X-ray study of chrysotile, antigorite, and gümbelite by E. Aruja we were asked to confirm some interesting results he had obtained on heating chrysotile to various temperatures. This we were able to do and also to provide additional data which were recently referred to in a paper by A. Hargreaves and W. H. Taylor. Although we have not succeeded in providing a completely satisfactory explanation of the optical changes observed on heating chrysotile our observations for a limited range of temperatures in the neighbourhood of 1000° C. are here recorded.

The Tiree pink marble, a fine-grained, severely crushed limestone with evidence of earlier coarse crystallization, is exposed in several small areas up to 100 feet across on the farm of Balephetrish near the north coast of the island of Tiree in the Hebrides. It contains a remarkable quantity of dark silicate minerals and has discordant contacts with the adjacent Lewisian gneiss. The precise nature of its relation to the gneiss, and mode of emplacement, have been much discussed. The writer has been permitted to consult accounts of the literature, by Mr. V. A. Eyles, and of the petrography, by Sir Edward B. Bailey, and is also indebted to those authors for discussion of the problems. At the suggestion of Sir Edward Bailey the present work was undertaken as a contribution to the study of this problem from the mineralogical point of view. Most of the determinations were made in 1938, but it was not possible to complete publication at that time.