Imagens das páginas

which it is seen that for a naked boiler, i.e. one without a glass cover, the maximum overall efficiency obtains when T=692° F. corresponding with a steam pressure of 21 lb. sq. in. abs. Or, of course, if equation (3) be differentiated with regard to T, and the result equated to o, we also obtain T=692° F., from which is obtained the maximum value of ..



[blocks in formation]

NE of the main objects of the investigation described in this paper is to ascertain the conditions which render it easiest to steer an aeroplane in a horizontal circle of any radius that is not too small, and the idea of "inherent controllability" has been introduced to denote the property which a system may possess of freely describing a circular path without any pressure on the controlling rudders. In such cases the rudders will act as guides by preventing the aeroplane from leaving the chosen path, and as the system without them must, from the nature of the case, be wanting in directional (lateral) stability it is necessary for the working of such a system that the addition of the rudders should render it stable. The conditions for this must be worked out by the methods described in the lecturer's book, "Stability in Aviation."

It will be found that there are several different ways of obtaining inherent controllability and that in circling flight the system turns about a point which in some cases is in front and in some cases behind the centre of gravity. The axis of x or horizontal line through the centre of gravity in the direction of forward motion thus envelopes a circle of radius, à, the "turning point" being the point of contact of the axis tangent with its envelope, and the lateral or sideways velocity of the aeroplane being proportional to the distance of the centre of gravity from the turning point. This length and the inclination of the aeroplane to the vertical constitute two independent variables which can be so chosen as to satisfy two conditions of lateral equilibrium, but as there are three, a third variable is in general required, and if a rudder plane is used, this latter variable may be taken to be the pressure on that plane. The condition for inherent controllability is that the three equations of lateral equilibrium should satisfy some further identical relation by which the number of variables is reduced to two, and there are several ways in which this may be done.

The results here summarised lead to some interesting conclusions which were quite unexpected when the paper was commenced. In particular, they show the differences in behaviour between wings that are bent up and down respectively, the advantages, in certain circumstances, of curved wings as contrasted with plane wings bent into a simple dihedral angle, and generally that the form and curvature of the wing areas may play a much more important part in circling flight than had been anticipated.

The applications to the flight of birds are obvious, and suggest much interesting material for discussion. At any rate, a good many peculiarities in the wing structure of the circling birds appear to admit of interpretation on dynamical principles.

With regard to the possible application of these results to actual areoplanes, it remains to be seen how far it is desirable or practicable to realise the conditions of inherent controllability in a real flying machine. But the lecturer suggested that a study of

1 Abstract of the third Wilbur Wright Memorial Lecture delivered before the Aeronautical Society on May 20, by Prof. G. H. Bryan, F.R.S.

the present work, followed by a few experiments, will either lead to improvements in the steering of aeroplanes, or if the present arrangements are the best, it will now be easier to understand the reason why.

Summary and Conclusions.

(1) In steady motion in a horizontal circle, both the longitudinal and the lateral equations of equilibrium are affected.

(2) The turning point may be in front of or behind the centre of gravity, its distance when in front being denoted here by b.

The axis of the aeroplane then envelopes a circle of a certain radius a, the real radius of the circle described being √(a2 + b2).

The system usually cants over sideways through a certain agle .

(3) Given the velocity and radius of the circle it is not usually possible to satisfy the three equations of lateral equilibrium by assigning suitable values to b and , but when this is possible the system is said to be inherently controllable.

In an inherently controllable system the rudder planes merely act as guides, and it is necessary that they should be so placed as to render the motion laterally stable.

In other cases steady motion can only be maintained by pressure exerted by the rudders or a couple applied by means of ailerons or some such action representing the third unknown variable required for the solution of the three simultaneous equations of lateral equilibrium.

(4) In a system of straight planes sin is proportional to the radius a of the envelope, but it also appears that the other conditions of lateral equilibrium are only possible when pressure is applied by means of a rudder, and when a and have certain definite values. The only way of varying the radius of the circle actually described is by varying the position of the turning point, which may be in front of or behind the centre of gravity.

The addition of boxed-in ends or vertical partitions improves the steering, but it still leaves sin proportional to a. The inference one would naturally derive from the formulæ is that all such systems would be liable to sway from side to side of the straight path in curved arcs of finite radius. In no case can the radius of the circular envelope exceed the limit corresponding to p=90°.

(5) With bent-up wings, as in the " Antoinette type," it is possible to satisfy the conditions of equilibrium so that a is no longer limited and no longer large. Such a system can be steered in a circle of large radius without being inclined at a large angle.

In general, circular motion can only be maintained when pressure is applied by means of a rudder or a couple applied by means of ailerons, but if the two principal moments of inertia about axes perpendicular to the line of flight are equal, the rudder exerts no pressure, and the system is inherently controllable, the inclination satisfying the relation U2 = ga tan ø.

(6) Another kind of inherent controllability" in which the system always remains level, the inclination being zero, is possible in certain systems. A necessary condition is that the wings should be bent downwards and not upwards at the tips, and it will be usually advantageous that they should be most bent down at their extremities. The condition representing this fact is that the space between the wings and a chord joining their tips should be as large as possible.

This arrangement of the wings somewhat reproduces the action of gulls' wings in circling flight, and it will be found that differences in the form and

curvature of the wings may have a considerable influence in the problems of this class.

(7) A third kind of "inherent controllability" is only possible when portions of the wing surface are in front of or behind the rest; and a possible solution exists in the form of a system suggested by the lecturer in the Aeronautical Journal, with front and rear planes, one set being turned upwards and the other downwards.

It appears, however, from the analysis that the necessary conditions cannot be satisfied in the case of surfaces of uniform breadth bent up into a plane dihedral angle at the centre or bent into a trihedral angle at some points intermediate between the centre and tips. They can, however, be readily satisfied by suitably curving the wings or by varying their shape so as to make them as a rule broader towards the tips than near the base. The present arrangement has the further advantage that the system would not tend to turn round sideways if struck by a side gust of wind, and this should be worth trying experimentally.

(8) Although no attempt has been made to discuss the analytical conditions of inherent stability further than has been done in "Stability in Aviation," it appears from general considerations that the rudder plane at least in an inherently controllable system should be placed on the opposite side of the centre of gravity to the turning point, and that difficulties, probably instability, must necessarily occur if the rudder is between the centre of gravity and the turning point. It seems almost certain that the best position for the rudder is when it and the turning point are in the relative positions of the centres of suspension and oscillations of the system when treated as a compound pendulum.


IN the April number of the Journal of the Royal Asiatic Society there is an article by Mr. Joseph Offord, entitled "The Deity of the Crescent Venus in Ancient Western Asia," which is of interest to astronomers as well as to archæologists, because it shows that the phases of this planet were undoubtedly detected at a very early era indeed.

The evidence adduced commences with a cuneiform inscription from Babylonia, of the time of Assurbanipal, which refers to the horn of the star, and another similar sentence is added from an undated tablet. Mr. Offord then proceeds to consider many statements, chiefly made in ancient inscriptions, as well as in the fragments of classic, Syrian, and Egyptian literature referring to the characteristics of Venus as a stellar goddess, which indicate that the crescent form of the planet at certain intervals was recognised and clearly set forth by the titles, myths, and observances connected with her as a deity. As is well known, Venus, the Asiatic Ishtar, Ashteroth, or Astarte, wore a horned headdress, and was called in consequence Ashtoreth-Karnaim-the Ashtoreth of the horns. The Chaldeans made her the daughter of Sin, the moon-god, because of her similar crescent phases to the moon.

Much of the confusion concerning the titles and attributes of Venus, as a deity, arose from different names being assigned to her as morning and evening star, whilst the classics sometimes erroneously ascribed any stellar goddess said to have crescent form to the moon, because they were unaware that the planet Venus possessed the same characteristic, although the Assyrians and other Semites had recognised this.

That Astarte of the Greeks, and Asheteroth of the Phoenicians was Venus is certain, and that she was only another name for the Chaldean Ishtar Mr. Offord shows definitely. That Ishtar was the morning star the cuneiform texts confirm in many ways. One of her titles, Dilbat, "the Announcer," is cogent in the case; also in a myth when seven evil spirits were said to have worsted the moon, temporarily (i.e. an eclipse), Ishtar became queen of heaven, because the moon's light having vanished, Venus had no rival in brilliancy. Moreover, Ishtar had titles such as Simua (horned) and Timua (curved), and is depicted as a COW. The exvotos in many Astarte temples were also cow-heads with large horns.

In the clear air of Mesopotamia it was possible to detect the phases of Venus, as Dr. Gretschel has shown is the case in Persia and Peru; and so IshtarVenus, the later Ashtoreth-Karnaim, is like so many other primitive concepts, a reasonable expression of astronomical symbolism, the horned emblem upon figures of the deity indicating the star associated with

her name.


BRISTOL.-Mr. G. A. Wills, and his brother, Mr. H. H. Wills, have just made an additional gift of 40,000l. to the University. Originally they gave 180,000l. for the purpose of erecting additional buildings, but as the accepted tender greatly exceeds that amount, they have now added 40,000l., making a total benefaction of 220,000l. The council has decided, therefore, to proceed forthwith with the erection of the buildings.

CAMBRIDGE.-The late Dr. W. Aldis Wright, vicemaster of Trinity College, bequeathed the sum of 5000l. for the use of the University library. The late Lady Margaret Huggins left 1000l. to the City of London School for the endowment of a scholarship in astronomy, tenable at Cambridge, to be called the "Sir William Huggins" scholarship.

Mr. A. E. Dixon has been reappointed assistant to the Downing professor of medicine, and Mr. R. H. Rastall has been reappointed additional demonstrator of geology.

LONDON. Her Majesty the Queen has given the sum of 250l. to pay for the training and expenses of a student at the London (Royal Free Hospital) School of Medicine for Women for a five years' course. The money is part of a gift to the Queen from the wives of Freemasons, to help members of the professional classes who may be in difficulties owing to the war. The council will award the scholarship in July, 1915, to a student who intends to begin a course of study in the October following. The scholarship will be of the value of 5ol. a year for five years, subject to the student pursuing her course to the satisfaction of the council.

At a meeting of the Senate on May 19, it was decided to close the science department of Goldsmiths' College at the end of the present session.

Dr. A. E. Boycott, F.R.S., has been appointed director of the Graham Research Laboratory in succession to Dr. Charles Bolton.

The D.Sc. in chemistry has been granted to Mr. Percy May, of University College.

There are few changes in the personnel of the Senate as the result of recent elections. Dr. H. B. Workman succeeds Dr. T. L. Mears as one of the representatives of arts graduates, and Dr. W. P. Ker succeeds Dr. Pollard as one of the representatives of the faculty of arts. Mr. J. L. S. Hatton and Dr.

A. D. Waller have been re-elected as representatives | vulpecula, with notes on some other Marsupials. The of the faculty of science.

A course of four lectures on the gases of the blood will be given in the Physiological Laboratory, King's College, Strand, W.C., by Prof. T. G. Brodie, at 4.30 p.m., on May 31, and June 2, 7, and 9. The lectures, which will be illustrated by experiments, are addressed to advanced students of the University and others interested in the subject. Admission will be free, without ticket.

IN recognition of his services to technical education, Sir Philip Magnus will be presented with an address and Lady Magnus with a piece of plate by the Association of Technical Institutions on Wednesday next, June 2. Mr. J. H. Reynolds, ex-president, will present the address, and Sir William Mather, the first president, will make the presentation to Lady Magnus. Sir Alfred Keogh, K.C.B., will preside.

It is announced in the issue of Science for May 14 that the Rensselaer Polytechnic Institute has received two substantial gifts recently. Mrs. Russell Sage has given 20,000l., and Mr. A. T. White, of Brooklyn, 10,000l. From the same source we learn that a trust fund of 1000l., to be known as the "Edward Tuckerman Fund," designed to increase the interest in the study of botany among the students of Amherst College, has been bequeathed to the college by the late Mrs. S. E. S. Tuckerman, wife of the late Prof. E. Tuckerman.

THE governing body of the Manchester Municipal School of Technology (University of Manchester) is offering not more than ten research scholarships in technology during the session 1915-16 at the Manchester School of Technology-one of the value of 8ol., three of the value of 751., and six of the value of 50l., all with fees remitted. Research may be undertaken in mechanical, electrical, or sanitary engineering; in any of seven branches of applied chemistry; and in textile industries. The scholarships are open to graduates of any university in the British Empire, and to other persons possessing special qualifications for research. Holders of the scholarships will be expected to devote the whole of their time to the prosecution of the research upon which they are engaged. The scholarships may be renewed for a second year on the recommendation of the Board of Studies. Forms of application and all information may be obtained, by letter only, addressed to the registrar, School of Technology, Manchester, and all applications must be received on or before Jure 21.


Zoological Society, April 27.-Prof. E. A. Minchin, vice-president, in the chair.-Mrs. R. Haig Thomas: White-collar Mendelising in hybrid pheasants. The paper was based on an examination of the relative numbers of dark-necked and ringed male pheasants shot during two seasons. The data collected were interpreted as providing evidence of the continual Mendelising which occurred in the collar of hybrid birds.-E. G. Boulenger: Two new species of treefrogs from Sierra Leone.-E. Heron-Allen and A. Earland Foraminifera of the Kerimba Archipelago, Portuguese East Africa. Part ii. The contents of this part were chiefly systematic, more than 470 species and varieties being dealt with, of which thirty-two are new to science.

May 11.-Dr. A. Smith Woodward, vice-president, in the chair.-Miss E. A. Fraser: The head-cavities and development of the eye-muscles in Trichosurus


usual eye-muscles, including a well-developed m. retractor bulbi, are present in the Marsupialia. large premandibular head-cavity, representing the first somite of the head, is found in all the Diprotodontia, and appears to be either absent or of very small size in the Polyprotodontia.-Dr. R. Broom: (1) The Organ of Jacobson and its relations in the "Insectivora."—Part ii., Talpa, Centetes, and Chrysochloris. In Part i. it was shown that Tupaia and Macroscelides and their allies must be separated from the typical Insectivores, such as Erinaceus and Gymnura, to form a very distinct and not nearly related order the Menotyphla. In Part ii. it is shown that Chrysochloris has no near relationship with either the Insectivora or the Menotyphla, and must be made the type of a distinct order, the Chrysochloridea. Centetes, which has hitherto been regarded as allied to Chrysochloris, is more nearly related to Erinaceus, though it differs from it in many points, and may later have been separated from it. Talpa shows many affinities with Erinaceus and a number of differences the value of which is at present not apparent. (2) The Anomodont genera, Pristerodon and Tropidostoma. Pristerodon, described by Huxley in 1868, is a very near ally of Dicynodon, differing mainly in having a series of molars which are smooth in front and have a series of denticulations behind. The males are tusked, the females without tusks. Oudenodon raniceps of Owen is a species of Pristerodon; while Opisthoctenodon agilis, Broom, and probably also Opisthoctenodon brachyops, Broom, are other species of Pristerodon. In 1889 Seeley described two occiputs under the names Dicynodon microtrema and Dicynodon (Tropidostoma) dunni. As pointed out by Lydekker, these belong to the one species, D. microtrema, and other specimens in the British Museum show that it differs from Dicynodon in the structure of the parietal region and in having molars very similar to those of Pristerodon, but fewer in number. This species is therefore placed in a distinct genus, for which the name Tropidostoma must be accepted. Mrs. H. L. M. Pixell-Goodrich : Minchinia a Haplosporidian. This papers deals with the life-history of Minchinia chitonis (Lankester), a protozoan parasite of the mollusc Chiton. Hitherto this parasite has been considered to belong to the Coccidia, but convincing evidence is here brought forward to show that it is a Haplosporidian. An account is given of the multiplication in the host by plasmotomy and sporogony, and a detailed description of the development of the very characteristic spores.

Linnean Society, May 6.-Prof E. B. Poulton, president, in the chair.-W. Percival Westell: Some bird problems. The author discussed anomalies of habit and structure in the order of the list recently issued by the British Ornithologists' Union, and asked for help in attempting to clear up some of the facts narrated. Dr. Sarah M. Baker and Miss Maude H. Bohling The brown seaweeds of the salt marsh.-II. Their classification, morphology, and ecology. Five of the species of Fucoideæ common in Britain as inhabitants of rocky shores are represented by peculiar varieties on the salt marsh. Evidence is brought forward to show that these forms, although they differ widely in their morphology from their rock ancestors, are to be regarded as adaptational varieties or "ecads " in the terminology of Clements. Two general methods have been used to study the correlation between the morphological peculiarities of the marsh Fucoids and the new chemical and physical conditions of their environment. The first is to study the distribution of natural varieties of one species, and the second to examine in detail exceptional cases. These methods have led to the conclusions that dwarf habit is mainly

conditioned by exposure and lack of nutrient salts. Vegetative reproduction is caused by the high humidity maintained over the marsh in the intertidal periods. This prevents the attainment of a limiting concentration in the cell-sap necessary as a stimulus to the formation of sexual reproductive organs. The cause of spirality is probably unequal distribution of nutrient salts. The same factors were shown to be operative in causing the change in morphology of the floating Sargasso weed. Brown seaweeds may function on salt marshes either as pioneer vegetation, undergrowth, or covering vegetation after erosion, and in these capacities often play an important part in the economy of the marsh.-H. N. Dixon : A collection of Borneo mosses made by the Rev. C. H. Binstead.

Geological Society, May 12.-Dr. A. Smith Woodward, president, in the chair.-G. Hickling and W. R. Don: Parka decipiens, Fleming. The paper is a joint statement of originally independent investigations of this Old Red Sandstone organism. The views of Fleming, Hugh Miller, Mantell, Lyell, Powrie, Page, and others are quoted to illustrate the chequered career of this enigmatical fossil in geological literature. To Dawson and Penhallow, supported by Reid and MacNair, belongs the credit of making the first serious attempt to obtain definite evidence as to its nature, and of establishing its vegetable character. The present account is based on the observation of great numbers of specimens in the field, and on the microscopic study of impression-material, of thin sections, and of macerated material. The plant is most abundant in the Lower Old Red of the KincardineForfar-Perth area, where it is by far the commonest fossil, especially in the shale-bands; Parka is confined to the lower two-thirds of the Caledonian Series. is recorded from a few other localities in central Scotland, and also from the Upper Ludlow and Lower Old Red of the "Hereford" area. The organism is shown to be a complete cellular thalloid plant, agreeing generally in its vegetative structure with certain algæ, but differing from all known algæ in the production of cuticularised spores.


Institution of Mining and Metallurgy, May_20.-Sir T. K. Rose, president, in the chair.-J. J. Beringer: The physical condition of cassiterite in Cornish mill products. This paper was in course of preparation when the author contracted an illness which ended fatally, and as a consequence it lacks the valuable summary of conclusions which the author would have compiled as the result of his exhaustive series of experiments in a subject to which his last few years had been largely devoted. He had, in fact, made most detailed investigations into the mode of occurrence of the particles of cassiterite in the ores of Cornish lodes and in the mill products resulting from the reduction of those ores, with a view to reducing the losses on the dressing floors. The chief conditions governing his investigations were: the actual measurement of the sizes of the particles; the determination of the rate at which particles of various sizes settle in still water and against upward currents, with methods of separating and collecting particles of a given size; the compilation of tables showing specific gravity and assay value of particles in relation to their size; a study of the action of particles of various sizes in their passage over various forms of concentrating machinery; and, finally, an investigation of some special mill-products, and a general study of the mineral cassiterite as found in some Cornish lodes. For reporting the mean diameter of particles as measured under the microscope the author used the micrometric unit of one-thousandth of a millimetre, and established a relationship between that form of measurement and a classification based on the rate of falling in still water and the different

rates of upward current between which the particles in a mixture can be separated. The paper contains an attempt to give a definite size value to the muchdiscussed terms "sand" and "slime," with further subdivisions of the latter condition into "silt," "fine silt," and "clay." A valuable section of the paper deals with the action of the material when passing over concentrating machinery, different types of which were experimented with in great detail. In an appendix are given valuable hints on the uses of the microscope in determining the size and nature of minerals, a subject which Mr. Beringer brought forward at a meeting of the institution shortly prior to the preparation of the material embodied in this paper.H. F. Collins: Note on the concentration of gold in bottoms in the converter. With a view of utilising the gold contents of converter copper which is not rich enough to make electrolytic refining profitable, by means of a partial oxidation of the bath of white metal to "pimple" metal and "bottoms," and the separation of the latter before completing the oxidation, the author devised a simple method of treatment which has been in actual practice for about a twelvemonth. In this method a small acid-lined converter is used, provided with a taphole opposite the tuyeres, which, during the process of blowing to precipitate, is closed by a plug of clay attached to an iron rod. When the metal is thoroughly molten, the bar is withdrawn and the copper allowed to run off into moulds until white metal appears in the stream, when the taphole is closed and the converter returned to position for the next similar operation. The success of the method depends primarily on running the charge hot, losing no time in skimming and not adding too much cold scrap after skimming, so that the reduced copper is well above the melting point of "pimple" metal.-Donald M. Levy and Harold Jones: The Morro Velho method of assay of gold-bearing cyanide solutions. The method here described is based on the precipitation of the gold by means of a zinc-lead couple from the boiling solution in the presence of suitable quantities of silver and lead salts. By this means, sufficient silver is introduced to yield with the gold a suitable parting alloy. The presence of the lead salts causes the production of a lead-zinc couple which facilitates the complete liberation of the metallic gold from solution, and yields a bulky precipitate of the lead and values which settles easily and thus ensures carrying down the precipitated gold.F. A. Eastaugh: The effect of different methods of crushing on the ash of coke. The object of the experiments here described was to find the true ash contents of the coke, in order to discover whether the discrepancies occurring so frequently between the amount of ash found by sellers and buyers are due to different methods of preparing samples for test purposes. In the experiments, all made from one parcel of metallurgical coke, remarkable differences resulted from the employment of different methods of crushing the samples.


Academy of Sciences, May 17.-M. Ed. Perrier in the chair.-G. Humbert: The positive binary quadratic forms.-D. Eginitis: Observations of the Mellish comet (19154) made at the Observatory of Athens with the Doridis equatorial (40 cm.). Positions are given for April 8, 10, 13, 14, 15, 21, and 22.-Ernest Esclangon: The quasi-periodic integrals of a linear differential equation.-Maurice d'Ocagne: Remarks on the subject of circular anamorphosis.-A. Buhl: New geometrical applications of the formula of Stokes.Daniel Berthelot: Calculation of the Despretz-Trouton constant. By combining the equation of Van der Waals with the law of the rectilinear diameter of Mathias, the ratio of the internal latent heat of

vaporisation to the absolute boiling point was found to be 9, or half the experimental value. But using the characteristic equation for a gas given by the author in 1900, in place of the Van der Waals equation, the Despretz-Trouton constant is 18, in exact accord with experiment.-E. Léger: Magnesium citrate and the supposed basic magnesium citrates.O. Bailly The synthesis of a-glycerophosphoric acid. Sodium allylphosphate, treated with potassium permanganate, gives the a-glycerophosphate free from the ẞ isomer. The solubilities of the calcium, barium, and strontium salts were determined.-J. Bergonié : The detection, localisation, and extraction of magnetic projectiles by means of the electro-vibrator. A summary of the advantages of this method as compared with the usual surgical operation with the assistance of the X-rays.-Félix Legueu : Biological reactions in prostatic adenoma.


Catalogue of the Ungulate Mammals in the British Museum (Natural History). Vol. iv. By R. Lydekker. Pp. xxi +438. (London: British Museum (Natural History); Longmans and Co., and others.) IOS. 6d.

The Principles of Agriculture through the School and the Home Garden. By C. A. Stebbins. Pp. xxviii+380. (New York: The Macmillan Company; London: Macmillan and Co., Ltd.) 4s. 6d. net.

Societal Evolution. By Prof. A. G. Keller. Pp. xi+338. (New York: The Macmillan Company; London: Macmillan and Co., Ltd.) 6s. 6d. net.

A Report on Library Provision and Policy by Prof. W. G. S. Adams to the Carnegie United Kingdom Trustees. Pp. 104. (Edinburgh: Neil and Co.) Three-Colour Photography: with Special Reference to Three-Colour Printing and Similar Processes. By A. Freiherrn von Hübl. Translated by H. O. Klein. Pp. 138. (London: P. Lund, Humphries and Co., Ltd.)

The Material Culture and Social Institutions of the Simpler Peoples. By L. T. Hobhouse, G. C. Wheeler, and M. Ginsberg. Pp. 299. (London: Chapman and Hall, Ltd.) 2s. 6d. net. Surveying and Field Work. By J. Williamson. Pp. xxii+363. (London: Constable and Co., Ltd.) 7s. 6d. net.

[blocks in formation]


ROYAL SOCIETY, at 4.-Probable Papers: Soil Protozoa and Soil Bacteria: E. J. Russell. The Chromosome Cycle in Coccidia and Gregarines: C. Dobell and A. P. Jameson.-The Influence of Gases on the Emission of Electrons and lons from Hot Metals: Prof. O. W. Richardson. -The Shapes of the Equipotential Surfaces in the Air near Long Buildings or Walls, and their Effect on the Measurement of Atmospheric Potential Gradients: Prof. C. H. Lees.-The Band Spectrum associated with Helium: J. W. Nicholson.

ROYAL INSTITUTION, at 3.-Methods of presenting Character in Biography and Fiction: Wilfrid Ward.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]
[blocks in formation]


The Utilisation of Solar Energy. (Illustrated.) By


A. S. E. Ackermann

The Rigid Dynamics of Circling Flight. By Prof. G. H. Bryan, F.R.S:


Early Recognition of the Phases of the Planet Venus

[ocr errors]
[blocks in formation]

Single-Phase Electric Railways. By E. Austin. Pp. xiv + 303. (London: Constable and Co., Ltd.)

21S. net.

La Science Allemande.

By Prof. P. Duhem. Pp. 143. (Paris: A. Hermann et Fils.)

Continuous Current Electrical Engineering. W. T. Maccall. Pp. viii+466. (London: University Tutorial Press, Ltd.) 10s. 6d.

[blocks in formation]


ROVAL INSTITUTION, at 9.-Engineering Problems of Mesopotamia and
Euphrates Valley: Sir John Jackson.
Oil Tank-ship: H. Barringer.
PHYSICAL SOCIETY, at 5.-Numerical Relations between Electronic and
Atomic Constants: Dr. H. S Allen.-A Method of Calculating the
Absorption Coefficients of Homogeneous X-Radiation: H. Moore.
Experiments Illustrating Novel Properties of the Electron Currents from
Hot Metals: Prof. O. W. Richardson. - High Permeability in Iron: Prof.
E. Wilson. --An Experiment showing the Relative Width of Hydrogen
and Neon Lines: T. R. Merton.

[blocks in formation]

University and Educational Intelligence

Societies and Academies

Books Received

Diary of Societies

Editorial and Publishing Offices: MACMILLAN & CO., LTD.,

ST. MARTIN'S STREET, LONDON, W.C. Advertisements and business letters to be addressed to the


Editorial Communications to the Editor.

Telegraphic Address: PHUSIS, LONDON. Telephone Number: GERRARD 8830,

« AnteriorContinuar »