Megacephalon mileo. The reviewer corrects, by the way, my calling the Celebean whimbrel Numenius pheopus, saying that it is probably N. uropygialis, but these two names are synonymical, cf, for instance, Salvadori, Orn. Pap, iii., 332, 1882, sub N. mariegatay. As to its resting on small trees "small brushes" were intended to be unplied (see Legge, "Birds of Ceylon," 1880, p. 913). A. B. MEYER.

Royal Zoological Museum, Dresden, March 22.

Crystals of Lime.

It was pointed out to me by Mr. W. J. Pope, of the City and Guilds of London Institute, that a lime cylinder which had been used in the lantern during a lecture had become distinctly crystalline where affected by the oxyhydrogen flame.

lime.

Examined under the microscope by polarized light, the crystals are seen to be well-defined cubes with striated faces. When immersed in water they break up and give rise to minute doubly refracting plates of rhombic outline, behaving in this respect like ordinary lime; the cubic crystals, however, are less rapidly afected by exposure either to air or water than is amorphous Lime is commonly stated to be infusible at the temperature of the oxyhydrogen blow-pipe; and the only crystals previously recorded, so far as I know, are those obtained by Brugelmann, by fusing calcium nitrate (Annalen der Physik und Chemie, ii. p. 466, iv. p. 277, 1877 78). It seems, therefore, worthy of notice that they are possibly always formed upon the surface of the lime cylinders by the action of the oxyhydrogen flame. The crystals resemble in all respects those described by Brugelmann. The jet used on the present occasion was an ordinary blow-through jet. H. A. MIERS,

Foreign Substances attached to Crabs.

I AM glad to see that Mr. Garstang agrees with me in regarding the presence of the Ascidians on Hyas as accidental.

I had no intention of decrying the value of Mr. Garstang's experiments with Ascidians, but his rule might, perhaps, be limited to those members of the group to which it can be proved to apply. Under natural conditions it apparently fails to apply to P. corrugata and M. arenosa. As to the latter, Prof. McInto h Assures me that he has frequently found it in the stomach of the cod and haddock.

The appreciation of the cod for A. mesembryanthemum is, I think, sufficiently proved by the fact that the latter is one of the most successful cod-baits used here.

ERNEST W. L. HOLT. St. Andrews Marine Laboratory, March 29.

Wimshurst Machine and Hertz's Vibrator. It may interest those who wish to repeat Hertz's experiments up electro-magnetic radiation to know that many of these can be done very well by using a small Wimshurst machine in place of the usual induction coil and battery. The vibrator and resonator which we used were like those described in NATURE vol. xxxix P. 548), and the Wimshurst machine had two 12 inch plates (giving at most with the jars on a 4-inch spark). The wires from the vibrator, instead of being connected with an induction coil, were connected with the two outer coatings of the jars of the machine. The machine spark gap and the vibrator spark-gap should be so adjusted that when a spark occurs at the former one also occurs at the latter. With the apparatus described we got good results when the spark-gaps were 38 mm. and 3 mm. respectively. The outer coatings of the jars are only connected together by the wood of the machine, but it is some. times an advantage to put a few inches of damp string between the balls of the vibrator.

This combination is obviously a modification, adapted to work a Hertz vibrator, of one of Dr. Lodge's well-known Leyden jar

arrangements.

No doubt many persons have connected the vibrator directly with the terminals of the machine, but this arrangement does not work nearly so well. T. A. GARRETT. W. LUCAS.

THE INSTITUTION OF NAVAL ARCHITECTS.
THE
HE annual meeting of the Institution of Naval Ar-
chitects was held under the presidency of Lord
Ravensworth, on Wednesday, Thursday, and Friday of

last week. There was a fair list of papers on the programme, although at one time, shortly before the meeting... it was leared that there would be a sad lack of contributions from members. At the last minute, however, one or two papers came in, and the list, although perhaps below the average in the importance of the memoirs, was of passable interest.

The following is a consecutive enumeration of the business that was transacted at the meeting:

Wednesday, March 26th: morning sitting-Annual Report of the Council, and other routine business; Address by the President. Paper read and discussed-Notes on the recent naval manoeuvres, by Mr. W. H. White, F.R.S., Director of Naval Construction.

Thursday, March 27th: morning sitting-The Maitime Conference, by Rear-Admiral P. H. Colomb; strength of ships, with special reference to distribution of shearing stress over transverse section, by Prof. P. Jenkins; steatite as a pigment for anti-corrosive paints, by Mr. F. C. Goodall. Evening sitting-On the evaporative efficiency of boilers, by Mr. C. E. Stromeyer; on the application of a system of combined steam and hydraulic machinery to the loading, discharging, and steering of steam-ships, by Mr. A. B. Brown; the revolving engine applied on ship-board, by Mr. Arthur Rigg.

Friday, March 28th: morning sitting-On leak stopping in steel ships, by Captain C. C. Penrose Fitzgerald, R.N.; on the variation of stresses on vessels at sea due to wave motion, by Mr. T. C. Read; spontaneous combustion in coal ships, by Prof. Vivian Lewes. Evening sitting Experiments with life-boat models, by Mr. J. Corbett; on the screw propeller, by Mr. James Howden.

The annual dinner was held on the evening of Wednesday.

Out of the above list of a dozen papers there were fewer than usual of scientific interest, an, indeed, in one or two instances they were not either distinguished by practical interest. Mr. White's paper, which formed the pièce de resistance of the meeting, was of military rather than scientific importance, and was chiefly notable from the number of admirals that took part in the discussion; indeed, the whole naval contingent of the Board of Admiralty was present to hear the paper read. Admiral Colomb's paper on the recent Washington Maritime Conference was practically reduced to a consideration of the rule of the road at sea. The general opinion of the authorities assembled appeared to be that the present rule of the road is very well as it stands, with the exception that the "holding-on ship" should not be required, or even allowed, to slacken her speed. This seems in conformity with common sense. If two ships are converging towards a point, say at right angles to each other, and one shifts her helm to go under the other's stern, if the second, or holding-on ship, slacken speed, the probability will be that the giving-way ship will crash into the other's broadside or cross her bows; in the latter case, there is probability that the holding-on ship will give the other her stem. What is most wanted when danger of collision arises, is certainty on each vessel as to what the other may be going to do. If the holding-on ship never slacken speed--is not allowed to slacken speed-then the other vessel knows exactly what course to take; as the law stands, the quartermaster, or officer in charge, is never quite sure until the last minute, e-pecially at night, whether the other ship considers there is danger of collision or not, and, therefore, whether she will slacken or keep to full speed. We anticipate the proposed alteration, if put in force, will greatly lessen the list of collisions.

The memoir contributed by Prof. Jenkins on the strength of ships was decidedly the most important contribution to naval science of this year's meeting. The paper will open up to the majority of those practi

The paper contributed by Mr. C. E. Stromeyer had a most attractive title, "The Evaporative Efficiency of Boilers"; and a good many of the working marine engineer members of the Institution, who were acquainted with the thorough manner in which the author follows up all his work, had assembled to hear the paper read, and take part in the discussion. We are afraid it must have been somewhat of a disappointment to several of these gentlemen when they turned over the leaves of the paper as it was placed in their hands, and found that the matter was rather of a suggestive than of a conclusive character. There is so much business to be crowded into the three days' annual meeting of this Institution that it is necessary the papers should be read with despatch; and we quite sympathize with the engineer whose daily task is of an administrative rather than a contemplative nature, when he is asked to assimilate at a galloping pace two or three pages of mathematical formulæ of by no every-day character.

means an

Mr. Stromeyer confined himself chiefly to a consideration of the relative distribution of efficie..cy in the tubes. He points out that the distribution is governed partly by the temperatures in the combustion-chamber and smoke box, and partly by the resistance of gas in the tubes and this again depends upon the velocity and temperature of the gas, and on the loss of heat experienced by it. Mr. Longridge has found that the coefficient of transmission of heat through boiler-tubes or combustionchamber plates is eleven calories of heat per square foot per hour for every degree F. of difference between the gas and the water: 0091 is the reciprocal value, and is the resistance offered to the flow of heat under the above condition. This resistance is offered when heat passes from one medium to another, as, for instance, from the gas to the metal, from the metal to the boiler scale, or to the water, and it also includes the resistance offered by the metal to the scale. For iron and boiler scale the resistances are 0'00202 and 0'207 per inch thickness; so that a clean inch plate would offer o oo1 resistance; or, if covered with scale one-tenth inch thick, the resistance would be o'001 +0'021 = 0'022.

Arguing from these facts the author concludes that the chief resistance, about 80 per cent., is encountered at the surfaces; and he doubts whether the change of medium from iron to scale, and to water, influences the values very much. The chief difficulty in transmitting heat from the gas to the tubes is want of circulation, or admixture of gas in the tubes. He speaks favourably of draught retarders, corrugated tubes, and ribbed-tubes for the purpose.

Mr. Stromeyer next refers to the experiments of Haverez (see Ann. du Génie Civil, 1874), by whom it was shown that more heat is absorbed in the fire-box with flaming material than with flameless coke. It is well known that a luminous flame radiates more heat than one which is non-luminous; and it is for this reason that the latter may not be used in the Siemens-Martin furnace.

Mr. Macfarlane Gray, of the Board of Trade, was the chief speaker in the discussion which followed. He said he could not pretend at one reading to follow the author in all his reasoning. Mr. Fothergill, who is the superin tending engineer to a north country line of steamers, gave the meeting the benefit of his practical knowledge upon the subject. Mr. Fothergill is well qualified to speak on the question of the evaporative efficiency of marine boilers, as he has made an especial study of the matter in the actual working of vessels in connection with his well-known researches on the subject of forced draught on ship-board.

Mr. Brown's paper was one of unusual interest to the members of the Institution. In it he described the most recent development of that beautiful system by which he has so vastly improved the loading and discharging of cargo on steam-ships, and the steering of vessels. The paper was illustrated by several diagrams without the aid of which it would be impossible to make clear the details of the very ingenious methods by which the author has applied his combined steam and hydraulic practice to the purposes named. Briefly stated, it may be said that, m place of the usual deck winches, there is placed at every hatch a derrick, having mounted upon it the hydraulic cylinder which supplies the motive power to lift the goods.

The steering motor is placed directly on the quadrant of the tiller, and is actuated from the bridge by means of what the author describes as a telemotor. The transmission of the controlling force which governs the steering motor is through hydraulic pipes; a vast improvement on the rattling chains and rods now in com mon use. In fact the great virtue of Mr. Brown's system is its quiet working.

Mr. A. Rigg's revolving engine is an ingenious device, perhaps better suited to water than steam. It was fully described in Section G at the last Birmingham meeting of the British Association.

"Leak Stopping in Steel Ships" was the somewhat misleading title of a rather weak paper by Captain Fitzgerald. The only point the author suggested was that war-ships should be outside sheathed with wood in order that there might be some attachment to which leak stoppers could be affixed. The contention that the swelling of wood by moisture that takes place, or used to take place, when a shot cut through the side of an old man-ofwar is quite beside the mark, as we suppose no one proposes to make the wood sheathing of a modern steel steamer as thick as the sides of our old wooden walls Three or four inches of elm would do very little swelling when pierced by a modern projectile of any considerable size.

Mr. T. C. Read's paper on the variation of stresses at sex is another of those contributions which are the despair of the practical naval architect, not over-given to abstruse science, who attends the meetings of his Institution, hoping to take part in the discussions. We are quite at one with the speaker, Mr. Alexander Taylor, who proposed that a rule should be passed compelling contributors to send m their papers sufficiently early for them to be printed and distributed to members before the meetings. The exe cutive say it cannot be done, but it would be worth trying for a time.

Prof. Lewes's paper on the ignition of coal cargoes was quite a new departure in the practice of the Institution. When the members assembled they found an array of bottles, flasks, and chemical apparatus, that was not a little puzzling to those not in the secret, and must have reminded many of the dear old Polytechnic days and Prof. Pepper. However, the lecture, and the experiments by which it was illustrated, were of a thoroughly sound and practical nature. The question of spontaneous ignition of coal cargoes is one for the ship-owner rather than the shipbuilder; excepting that ship-builders have to replace the vessels which are destroyed by reason of such spontaneous ignition. The lecturer illustrated the influence of carbon in producing heating by the power it possesses of attracting and condensing gases upon its surface. The action of the bituminous constituents of the coal in spontaneous ignition was next dealt with, and the author then proceeded to point out the important part the action of iron disulphide, pyrites, or coal-brasses played in promoting spontaneous ignition. The remedy Prof. Lewes advises for the evils of spontaneous ignition are: firstly, non-ventilation of holds, so that oxygen may not be admitted to carry on the chemical processes by which heat is generated; secondly, by placing thermometers, suitably protected, in the mass of coal, so that, by electrical communication, warning may be given when the temperature rises to a dangerous point; and, thirdly, by placing flasks of liquid carbonic anhydride in the coals, the flasks to be sealed by an alloy with a low melting-point. This would be fused when the dangerous temperature was reached, and the carbonic acid, in expanding to its gaseous state, would cool the mass of coal to a safe temperature.

At the last sitting of the meeting, Mr. Corbett's paper on lifeboat models raised a lively controversy. The Royal National Lifeboat Institution had brought Mr. G. L. Watson all the way from Glasgow to meet the bold innovator who proposed to abolish their cherished selfrighting boats. Of course, who is right remained an open question, as it always does when the properties of lifeboats are concerned.

Mr. Howden's paper on the screw propeller was of great length, containing no less than twenty-four pages without the appendix. Mr. Howden, like many other people, has a theory of his own on the screw propeller, which is opposed to that of all other authorities on the subject; for he believes that Rankine, Froude, Cotterill, and others, have based their conclusions on erroneous premises. It will be evident that we cannot enter into this vast subject at the end of a notice such as this, but we may briefly record our opinion that the older authorities were right.

On the whole, the meeting passed off very well. The attendance was good, and Mr. Holmes, the secretary, had made his arrangements so that the business proceeded without a hitch, as, indeed, is invariably the case at this well-managed institution.

MR

BOURDON'S pressure GAUGE.

R. WORTHINGTON'S letter to NATURE, January 30 (p. 296), on the theory of this instrument, has excited some criticism and disagreement of opinion; so it is proposed to examine here how far it is possible to construct a theory which shall be quantitative, in addition to giving a general explanation of the action.

The instrument is in very extensive use, hardly a steam-boiler being in existence which is not provided with one; and the simplicity and strength of the construction are such that it does not easily get out of repair, while it can be made to register either the highest pressure of the hydraulic press, or to record in the form of a barometer the minute fluctuations of atmospheric pressure.

The principle of the instrument was discovered by accident, and the account of this had best be given in the inventor's own words, taken from the paper read by him before the Institution of Civil Engineers, printed in the Proceedings I.C.E., vol. xi., p. 14, 1851 :

"The author had occasion to construct a worm-pipe for a still, by bending a cylindrical tube into a spiral or helical form. The workman performed the operation awkwardly, and partially flattened a considerable portion of the tube. In order to restore its form, one end was closed and the other was connected with a force-pump, by which water was forced into the tube; as the flattened portion of the tube resumed its cylindrical form, it was observed that the spiral uncoiled itself to a certain extent, and it was immediately perceived that this action might be applied to the construction of a pressure gauge." To construct, then, a Bourdon gauge to register high pressures (vide figure, representing a gauge fitted to an indicator, not shown) a steel tube bored out of the solid bar to the requisite thickness for strength is taken, and purposely flattened, and then bent round into the arc of a circle so that the longer axis of a cross-section stands at right angles to the plane of the circle: one end of the

O

tube is screwed to a pipe which communicates with the liquid whose pressure is to be measured, while the other end is closed and joined by levers and racks to a shaft and a pointer, which traverses a dial on a box in which the curved tube is enclosed.

As the pressure in the tube is increased, the circular axis uncoils into a larger circle of smaller curvature, and the corresponding indications of the pointer on the dial are marked; and thus the instrument is graduated empirically by reference to some standard pressure gauge. As the pressure is again diminished, the elasticity of the tube brings it back to its original form, and the pointer retraverses the dial.

Lord Rayleigh gives an elementary explanation of the action of Bourdon's gauge in the Proc. Royal Society, No. 274, December 13, 1888; treating the movement of the walls of the tube as one of pure bending, he says:

"In this instrument there is a tube whose axis lies along an arc of a circle and whose section is elliptical, the longer axis of the ellipse being perpendicular to the general plane of the tube. If we now consider the curvature at points which lie upon the axial section, we learn from Gauss's theorem (that in the bending without stretching of an inextensible surface, the

product of the principal radii of curvature of the surface at any point remains constant) that a diminished curvature along the axis will be accompanied by a nearer approach to a circular section, and reciprocally. Since a circular form has the largest area for a given perimeter, internal pressure tends to diminish the eccentricity of the elliptic section, and with it the general curvature of the tube. Thus, if one end be fixed, a pointer connected with the free end may be made to indicate the internal pressure." Lord Rayleigh adds, "It appears, however, that the bending of a curved tube of elliptical action cannot be pure (e. unaccompanied by stretching), since the parts of the walls which lie furthest from the circular axis are necessarily stretched. The difficulty thus arising may be obviated by replacing the two halves of the ellipse, which He on either side of the major axis, by two symmetrical curves which meet on the major axis at a finite angle"

In fact some Bourdon gauges, notably those required for low pressures only, and requiring great sensibility but not much strength, are constructed in this manner, and the difficulty of manufacture is thereby considerably reduced. Barometers are constructed in this way, and give good results; the tube is partially exhausted of air, and closed at both ends; and now an increase of external atmospheric pressure tends to flatten, and thus curl up the tube.

In constructing any theory, we are then immediately brought up by the great difficulty at present engaging the attention of our mathematical elasticians, such as Rayleigh, Basset, Pearson, and Love; who are not agreed as to how far it is legitimate to theorize on the equilibrium of elastic shells, by treating separately the bending and the stretching as independent of each other, and considering the first- the bending-of the most importance. If we take a piece of thin sheet metal in our hands, we find we can bend it with comparative ease, but any stretching we can produce is quite insensible; and it is thence argued that bending only is likely to take place, so easily produced; and apparently reversing the ordinary mathematical procedure, the large stresses due to any stretching are neglected, as not likely to be in existence. These difficulties confront us in any attempt at a rigorous theory of the instrument, which would give quantitative results, enabling us to graduate the instrument from a formula.

as

The Rev. E. Hill has given in the Messenger of Mathematics, vol. i., 1872, an explanation of the Bourdon metallic barometer, treating the question as one of pure bending, and giving a quantitative formula for the change of curvature a of the total curvature in terms of the change in the semi-minor axis b, viz. a8 = x/b. But the determination of ab for a given change of pressure is as yet an intractable mathematical problem, even for the simplification of supposing the tube a straight elliptic cylinder.

When we attempt to determine mathematically the pure bending produced in an elliptic cylinder by an increase of internal pressure and consequent tendency of the cross-section to the circular form, we are baffled by the analytical difficulties of determining the change in the length of the axes of the section, subject to the condition of keeping the perimeter unchanged in length, this length being expressed by a complete elliptic integral of the second kind, of which the modulus is the eccentricity of the ellipse. This problem was mentioned by Sir W. Thomson at the British Association in 1888; but we have not yet seen any development of it published by

him.

Mr. Worthington, on the other hand, treats the question from the point of view of pure stretching; and now, with rectangular cross-section of the tube, as he supposes, a thrust in the inner wall due to the internal pressure will cause this wall to contract, while the pull in the outer

wall will cause this wall to elongate; and thus an increase of internal pressure would cause the tube to curl up, the opposite effect to what happens when the bending effect due to the outward bulging of the flat walls is considered the leading phenomenon.

Even with a circular cross-section the stretching hypothesis would prove that the tube curls up under internal pressure; but this effect would be so small as to be imperceptible, because of the enormously greater stresses required for stretching than for bending in a thin tube; and this is found to be practically the case, inasmuch as the circular cross-section of the tube destroys all indications; and further, that the indications of the tube are reversed in direction when the axes of the elliptical cross-section are interchanged so that the minor axis is perpendicular to the plane of the circular axis of the tube.

The action of Bourdon's gauge is a differential effect; the bending of the surface changes the curvature one way, and the stretching produced by the same pressure the other way; but the bending effect is so much greater than that of stretching, that the latter may be left out of

account.

In Gunnery we have, in a similar manner, two antagonistic causes producing a tendency for an elongated rifled projectile to deviate from a vertical plane of motion. If fired from a gun rifled with a right-handed screw, the vortex set up in the air by the spinning of the projectile causes differences of pressure, tending to deviate the projectile to the left, and this effect is sometimes very noticeable with golf or tennis balls; but, in addition, the forces set up by the tendency of the projectile to fly with its axis in the tangent of the trajectory urge the projectile to the right, and these latter forces are found to preponderate in practice.

A mathematician might be tempted to apply to the problem of Bourdon's gauge the formulas on the equilibrium of elastic plates and their change of curvature, anticlastic and synclastic, which are given in Thomson and Tait's "Natural Philosophy" (§§ 711-720), but these formulas apply only to a plate originally plane; and, besides, the applied pressures of the liquid complicate the analysis of the question to an extent which has not yet been overcome by elasticians.

The final conclusion would thus appear to be, that any quantitative formula cannot be hoped for yet, for a long time; but that Lord Rayleigh's reasoning, quoted above, gives a clear and concise descriptive explanation of the

THE half-yearly general meeting of the Scottish Meleorological Society was held in the hall of the Royal Scottish Society of Arts, Edinburgh, on Monday afternoon. The following papers were read :-Influenza and weather, with special reference to the recent epidemic, by Sir Arthur Mitchell and servatories of Ben Nevis, by T. Omond, Superintendent; Dr. Buchan; the temperature of the high and low-level Obthunderstorms at the Ben Nevis Observatory, by R. C Mossmann. In the last Report presented by the Council, reference was made to a proposed systematic observation of the numbers of dust-particles in the atmosphere with the instrument recently invented by Mr. John Aitken, and an opinion was

expressed that, for many reasons, Ben Nevis Observatory was the place where such observations could be most satisfactorily conducted. From the Report presented on Monday, we learn that a grant of £50 has been obtained from the Government Research Fund for commencing this novel and important investigation. Two instruments, constructed by Mr. White, of Glasgow, under the direction of Mr. Aitken, have been obtained -one to be placed permanently within the Observatory itself, and the other, a portable instrument, for outdoor observation. Both instruments are now at the Observatory, and the regular work of observation has begun. The Report also states that the delay in completing the buildings of the low-level Observatory at Fort William turned out to be more serious than was contemplated. This has arisen from various causes, chiefly from the great drought in the West Highlands last summer rendering it necessary that the ships conveying the stones for the building from Elgin be sent round the north and west coast instead of through the Caledonian Canal, which for the time was closed for through traffic; and also from the wet, broken weather of the past winter. In about three weeks the Observatory will be completed, and immediately thereafter the Meteorological Council will erect the self-registering instruments which were originally at Armagh, and otherwise supply a complete outfit of instruments for a first-class Meteorological Observatory. An additional observer has been engaged, and the staff of the two Observatories now consists of Mr. Omond, superintendent, and three assistants. By arrangement with the Post Office, direct communication will be opened between the two Observatories. The regular work of recording the continuous observations will be begun in May. The Directors of the Ben Nevis Observatory will thus soon be in a position to put scientific men in possession of two sets of hourly observations of the completest description, one at the top and the other at the foot of the mountain. With these observations, the changes of the conditions of the weather may be followed hour by hour; particularly those great changes, so vital and essential to the advancement of our knowledge of storms, which take place in the lowermost stratum of the atmosphere between the two Observatories. It is within this aerial Stratum, of a vertical height of 4406 feet, that the gradual development of many weather changes from hour to hour may be satisfactorily investigated.

THE Chemical Society held its first anniversary dinner at the Hotel Métropole on Thursday evening last. Among those present were the Presidents of the Royal Society, the Institute of Civil Engineers, the Society of Chemical Industry, the Institute of Chemistry, the Pharmaceutical and the Physical Societies, Sir F. Abel, Sir Henry Roscoe, Sir F. Bramwell, Mr. Thiselton- Dyer, Prof. J. Dewar, Dr. J. H. Gladstone, and Mr. W. Crookes. Dr. W. J. Russell, the President, in proposing posperity to the Chemical Society, sketched briefly the history of its rise and development. Sir Frederick Abel gave the toast of Kindred Societies and Institutions," referring to the far-reaching character of the science of chemistry. There was not, he said, a single society or institution which was not dependent up on chemists for, at any rate, some amount of the usefulness which it exercised. The Royal Society was the great parent of them all; and the Royal Institution demanded special homage on account of the splendid discoveries made under its auspices, so many of which were specially interesting to chemists. Sir G. Stokes, in response, said that though specialism had been gaining ground very widely of late years, and though each branch of science had its own particular exponents enrolled in their own association, yet the old society, with which he had the honour to be closely connected, was not altogether effete. He thought that chemistry had as much need of cognate societies as any other branch of scientific research. Sir Lowthian Bell also replied. Prof M. Foster, secretary to the Royal Society,

proposed "The Visitors," and the toast was responded to by Sir F. Bramwell and by Mr. Thiselton Dyer. The health of the chairman was proposed by Sir H. Roscoe.

ON Friday evening last the learned societies of Newcastle held their second annual gathering at the Durham College of Science. Among the societies represented were the following : the Durham College of Science, Engineering Students' Club, Foremen Engineers and Draughtsmen, Geographical Society, Philosophical Society, Medical Society, Microscopical Society, Institute of Mining and Mechanical Engineers, Literary and Natural History Society, N. E. C. Institution of Engineers and Shipbuilders, Pharmaceutical Association, Photographic Association, Society of Antiquaries, and Society of Chemical Industry. The Newcastle Daily Journal says that the professors of the Durham College of Science "worked hard for the success of the gathering," and that "the exhibits which they explained in the chemical, physical, geographical, botanical, and other departments in the building, afforded a vast amount of pleasure.” By permission of the trustees of the British Museum, the conversazione of the Society of Arts will be held this year at the Natural History Museum, South Kensington.

MR. WRAGGE, Government Meteorologist, Queensland, has been dangerously ill with fever caught some time since in his tours of inspection. He has now gone to the Darling Downs to recruit his heath, which has been seriously undermined.

THE following lectures on scientific subjects will probably be delivered at the Friday evening meetings at the Royal Institution after Easter :-Friday, April 18, Sir Frederick Bramwell, F.R.S., welding by electricity; Friday, April 25, Sir John Lubbock, Bart., M.P., F.R.S., the shapes of leaves and cotyledons; Friday, May 9, Mr. R. Brudenell Carter, colourvision and colour-blindness; Friday, May 16, Prof. Raphael Meldola, F.R. S., the photographic image; Friday, May 23, Prof. A. C. Haddon, manners and customs of the Torres Straits islanders; Friday, May 30, A. A. Common, F.R.S., astronomical telescopes; Friday, June 6, Prof. W. Boyd Dawkins, F. R.S., the search for coal in the South of England. AT the twenty-first annual meeting of the Norfolk and Norwich Naturalists' Society, held at the Norwich Museum on March 25, Mr. Henry Seebohm was elected president for the ensuing year. The treasurer's report showed that the financial condition of the Society was very satisfactory, and that during the past year there had been an increase of several members. The retiring president, Dr. Taylor, after briefly reviewing the work of the Society during the past year, delivered an address 'Microbes."

on

THE London Geological Field Class, under the direction of Prof. H. G. Seeley, F.R. S., has made arrangements for a number of excursions, in which many students might find it pleasant and profitable to take part. One set of excursions is specially arranged for the practical study of geography. Others are planned for the illustration of the geological structure of the London district.

A VIOLENT earthquake shock was felt at Trieste on March 26 at 20 minutes past 9 p.m.

AT the last meeting of the Scientific Committee of the Royal Horticultural Society, Mr. Morris alluded to the peculiar vegetation of St. Helena, now confined, for the most part, to a small area in the central and higher part of the island. Many of the trees formerly native to the island are now all but, or quite, extinct. Among them is a species of Trochetia, or Melhania. The trunks of this tree are embedded in the cliffs of the island, and are dug out by the inhabitants for the sake of manufacturing ornaments. The following quotation from Melliss's