May 20, 1909J 



NA TURE 



559 



■of carbon monoxide and oxygen brought about by 

 palladium cliarged with hydrogen in the presence of water 

 A'apour. A second effect is also briefly described, which 

 appears to be due to the causes which give rise to thermo- 

 luminosity. — The elastic limits of iron and steel under 

 •cyclical variations of stress : L. Bairstow. An explana- 

 tion of the fatigue of materials due to the repetition of 

 stresses of sufficiently great magnitude has been investi- 

 gated experimentally, and found to agree completely with 

 ■experiments to destruction. The theory was proposed by 

 Bauschinger in 1886, and states that fatigue occurs when 

 the cycle of stress is so great that the extensions produced 

 thereby are not wholly within the limits of elasticity of 

 the material. For this to be true for the whole of 

 AVohler's well-known experiments, the inferior and superior 

 elastic limits must be variable, but it must not be possible 

 to vary one limit independently of the other. The experi- 

 ments dealing with this question have been made in a 

 specially constructed testing machine, the repetitions being, 

 produced so slowly that the extensions of the specimen at 

 the extreme loads in the cycle could be observed under 

 the normal conditions of test. This new feature in experi- 

 ments on fatigue has led to the discovery that iron and 

 steel can be made to yield by the repeated application of 

 ■a cycle of stress in which the maximum stress is considcr- 

 ■ably less than the static yield stress. Such yielding 

 accompanies any change in the position of the elastic 

 Timils, the change being greater as the amount of the 

 ■yielding is greater. The position of the elastic limits has 

 "been found for a number of ratios of maximum to mini- 

 mum stress, and the relationship of the results to Wohler's 

 ■experiments shown. The well-known Gerber parabola is 

 *!hown to be only a rough approximation. — Functions of 

 positive and negative type : J. Mercer. 



Geological Society, April 28.— Prof. W. J. So'las, F.R.S., 

 president, and afterwards Prof. \\'. \V. Watts, F.R.S., 

 vice-president, in the chair.— The boulders of the Cam- 

 bridge drift: R. H. Rastall and J. Romanes. For 

 several years past a large number of boulders have been 

 collected from the Glacial drifts of Cambridgeshire, and 

 from the post-Glacial gravels which have been derived 

 from the drifts. These specimens have been classified 

 geographically, and then subjected to a careful petrological 

 ■examination, with' a view to the determination of their 

 origin. Rocks of, Scandinavian origin, and especially those 

 -of the Christiania province, are abundant throughout the 

 whole area. Rocks from the Cheviots and central Scot- 

 land_ are more abundant than was formerly believed, and 

 -specimens have also been identified from the Old Red 

 Sandstone conglomerates of P'orfarshire and from Buchan 

 Ness (."Vberdeenshire). Lake District rocks probablv also 

 ■occur in small quantity. Much of the Chalk and' flints 

 appear to be of northern origin. It is concluded that an 

 •older Boulder-clay, containing foreign erratics, the equiva- 

 lent of the Cromer Till, once exK-nded over the whole 

 district, but was subsequently incorporated with the Great 

 ■Chalky Boulder-clay. The Scandinavian ice advanced 

 from the direction of the Wash, bringing with it Red 

 Chalk and bored Gryphasas from the bed of the North 

 Sea, and carrying them as far west as Bedford. Rocks 

 from the north of the British Isles become progressively 

 scarcer from west to cast, and the distinctive types are 

 absent to the east of Cambridge. They appear to have 

 'been brought by an ice-stream coming from a northerly 

 direction, which probably to a certain extent replaced the 

 Scandinavian ice towards the east. — The nephrite and 

 magnesian rocks of the South Island of New Zealand : 

 A. M. Finlayson. The magnesian rocks described in this 

 paper are a disconnected series of intrusive peridotites, 

 forming a more or less defined belt along the western 

 portion of the South Island, parallel to the trend of the 

 island and to the structural and geographic axes of the 

 main Alpine range. The course taken by these rocks 

 apparently follows one of the main Pacific trend-lines, the 

 nature of which will be more fully understood with the 

 further elucidation of the structural geology of the region. 

 The rocks are intrusive into sedimentary strata of ages 

 ■varying from Ordovician to Jura-Trias,' and, so far as 

 •can yet be determined, all the exposures appear to be of 

 approximately contemporaneous origin. 

 NO. 2064, VOL. 80] 



Royal Anthropological Institute, May 4. — Mr. J. Giay, 



treasurer, in the chair. — Some stone circles in Ireland : 

 A. L. Lewis. The author described several large circles 

 in the neighbourhood of Lough Gur, co. Limerick. 

 These differ from the British circles, being thick banks of 

 earth faced on each side by large stones, but they are 

 furnished with outlying single stones in a manner similar 

 to that found at many of the circles in England and Scot- 

 land ; these outlying stones are apparently in the direction 

 of the rising of some star at a very early date. One of 

 the largest circles was " restored " shortly after i860, and 

 now consists of a wall, 150 feet in diameter and 5 feet 

 high, of stones, backed outside by a bank of earth 30 feet 

 wide, through which there is but one entrance, a passage 

 3 feet wide, lined with stones on each side ; this entrance 

 is in the direction of the rising sun in May. The author 

 suggested that, assuming the restoration of this circle to 

 be correct, it differed in construction from the others, and 

 possibly also in its purpose, and that it might have been 

 used as a pound for wild animals driven into it from out- 

 side over the sloping bank, and kept inside to be killed 

 as required. There were also circles of stones without 

 earthen banks, remains of cromlechs or dolmens, locally 

 called "giants' graves," and many other interesting ruins 

 belonging to various ages, and there was also the usual 

 melancholy tale of monuments of all sorts destroyed. In 

 another short note Mr. Lewis directed attention to some 

 concentric circular markings, similar to those found at 

 New Grange and other prehistoric places, faintly incised 

 on a stone on the Rock of Cashel, on which the early 

 kings of Munster were said to have been crowned, and 

 which now serves as a pedestal for a very ancient cross. 



Linnean Society, Mny 6— D'. D. H. Scott, F.R.S., f resi- 

 dent, in the chair. — Some Zoantlicne from Queensland and 

 the New Hebrides : Mrs. L. J. Wilsmore. — Two new 

 genera of Thysanoptcra from V'cnezuela : R. S. Bagrnall. 



Mathematical Society. May 13. — Sir W. D. Niven, 

 president, in the chair. — Ternary quadratic types : H. W. 

 Turnbull. — Gauss's theorem, and on the semi-convergence 

 of certain force integrals in the theory of attractions : Dr. 

 J. G. Leathern. — The continuity or discontinuity of a 

 function defined by an infinite product : J. E. Littlevwood. 



M.^NCHESTER. 



Literary and Philosophical Society, April 20. — Piof. 

 H. B. Dixon, F.R.S., president, and later Mr. F. Jones, 

 in the chair. — The Guatemalan earthquakes and eruption 

 of 1902 : W. S. Ascoli. The earthquake occurred on April 

 18, 1902, at about 8.25 p.m., the intensity being greatest 

 in western Guatemala, where the second and richest city 

 of the country, Quezaltenango, was completely destroyed. 

 Many other places suffered greatly, and about 1400 of the 

 20,000 people living in the disturbed region lost their lives. 

 Six months later, on October 24, 1902, there followed the 

 eruption of the neighbouring volcano, Santa Maria, the 

 ash of which covered an area of more than 125,000 square 

 miles. The region, over which nearly 8 inches of ashes 

 and pumice-stone fell, extended to about 2000 square miles, 

 and within it most of the houses and farm buildings fell 

 in under the weight of the ejectamenta, and in some places 

 were totally destroyed. It is estimated that 6000 persons 

 were killed. The cloud from the volcano was eighteen 

 miles in height, and the detonation was audible at Costa 

 Rica, 500 miles away. The whole of the side of the moun- 

 tain was blown out, exposing a perpendicular cliff 7000 

 feet high, and forming a crater seven-eighths of a mile 

 long, three-quarters of a mile wide, and 1500 feet deep. 

 — .'\pical pigment-spots in the pluteus of Echinus viiliaris : 

 F. H. Gravely. In advanced living plutei of Echinus 

 miliaris from the plankton of Port Erin Bay there are 

 present in close association with the apical plate two pairs 

 of pigment-spots, and one pair of tufts of stiff cilia. The 

 anterior pair of pigment-spots is small, and of a transparent 

 red colour. The posterior pair are smaller, and of an 

 opaque yellow. They are situated in the general cavity, 

 closely applied to the inner surface of the apical plate, 

 and are probably composed of the same substance as that 

 of similar cells described by !\I.icBride as being found in 

 other parts of the body — especially in large masses beneath 



