bluuebunny/crossref_metadata_2025 huggingface dataset:
3. Laboratory Notes by Professor Tait - 1. On Anomalous Spectra, and on a simple Direct-vision Spectroscope
Authors: Tait
Published: June 2016

When I first saw Le Roux's account of his very singular discovery of the abnormal refraction of iodine vapour, I was inclined to attribute the phenomenon to something similar to over-correction of an achromatic combination. In fact, if a hollow prism be filled with a mixture of two gases or vapours, one of which is more refractive than air, the other less refractive; while the second body is more dispersive than the first; it is easy to see that Le Roux's result might be obtained, although each of the substances employed is free from anomalous refractive properties. In a recent conversation with Mr Talbot, I happened to mention the subject, and I learned from him his remarkable observation just laid before the Society.
4. On the Structure of the Palœozoic Crinoids
Authors: Thomson Wyville
Published: June 2016

The best known living representatives of the Echinoderm Class CRINOIDEA are the genera Antedon and Pentacrinus—the former the feather stars, tolerably common in all seas; the latter the stalked sea lilies, whose only ascertained habitat, until lately, was the deeper portion of the sea of the Antilles, whence they were rarely recovered by being accidentally entangled on fishing lines. Within the last few years Mr Robert Damon, the well-known dealer in natural history objects in Weymouth, has procured a considerable number of specimens of the two West-indian Pentacrini, and Dr Carpenter and the author had an opportunity of making very detailed observations both on the hard and the soft parts. These observations will shortly be published.
2. Experiments and Observations on Binocular Vision
Authors: Sang Edward
Published: June 2016

This communication was chiefly directed to the question whether the idea of distance be obtained from the adjustment of the eyes to distinct vision, or from the convergence of their axes. The case of the chameleon was cited as one in point, since that lizard directs its eyes each to a separate object, but habitually, when about to strike its prey, brings both eyes to bear upon it. Several experiments, mostly suggested by Wheatsone's inquiries, were cited, and the conclusion was arrived at, that, although the adjustment for direct vision concur in the formation of the estimate of distance, the convergence of the eyes plays the principal part.
4. Mathematical Notes by Professor Tait - 1. On a Quaternion Integration
Authors: Tait
Published: June 2016

A problem proposed to me lately by my friend T. Stevenson, C.E., for constructing what he calls a Differential Mirror, when attacked directly led to the equation

where a is a unit-vector, perpendicular to β.

By another mode of solution it was easy to see that the integral must be of the form

It may be instructive to consider this question somewhat closely, as the form of the unintegrated expression is certainly (to say the least) at first sight unpromising.
3. On some Abnormal Cones of Pinus Pinaster
Authors: Dickson Alexander
Published: June 2016

In their celebrated essay, “Sur la disposition des feuilles curviseriées,” the brothers Bravais describe a cone of Pinus Pinaster (Pin maritime), where the lower part of the cone exhibited secondary spirals 7S, 12 D (series ), while towards the apex the arrangement, in consequence of the disappearance of one of the spirals by 12, changed to 7S, 11D (series ). They describe another cone of the same species, in which the lower four-fifths exhibited secondary spirals 9 S, 13 D (series ), changing at the upper fifth to 8S, 13 D (ordinary series ) by suppression of one of the spirals by 9. Such cases, along with some others chiefly in the capitula of Dipsacus sylvestris, lead these authors into a discussion of the general question of the possible transition from one discussion of the general question of the possible transition from one arrangement to another by change in the number of secondary spirals.
At the request of the Council, Professor Tait gave an Address on Spectrum Analysis
Authors: Tait
Published: June 2016

I should not have thought of appearing before you to-night to lecture on so hackneyed a subject, had I not been assured by several members of the Council that such an address was really desired by many Fellows of the Society. It is a subject to which I have not paid very special attention, partly because it is in so many and such good hands, and partly because (except from the point of view of theory) it requires for its extension, especially to astronomy, very costly instrumental appliances and a great sacrifice of time.
2. On some Optical Experiments. By H. F. Talbot - I. On a New Mode of observing certain Spectra
Authors: Talbot H. F.
Published: June 2016

The attention of the scientific world has been for some years past fully awakened to the importance of observing the spectra exhibited during the combustion of chemical substances. But in making an extensive series of such experiments, it must often happen that the observer has to test substances of which he only possesses a very minute quantity. In that case, before he has viewed the spectrum long enough to feel fully satisfied of its nature, his stock of the substance is exhausted, and he is obliged to leave his observation imperfect. He might perhaps be testing some mineral in his cabinet, of which the native locality was unknown, and he might surmise it to contain a new metal, from its yielding a ray not before seen in the spectrum, yet after a short time his observations on it would come to an end, and he would have no means of showing this ray to other observers.
Mathematical Notes by Professor Tait - 2. Relation between corresponding Ordinates of two Parabolas
Authors: Tait
Published: June 2016

Two projectiles are anyhow projected simultaneously from a point, what is the relation between their vertical heights at any instant?

This simple inquiry, which was instituted in consequence of some results recently obtained from thermo-electric experiments (see ante p. 311) carried on at high temperatures, where the indications given by two separate circuits, immersed in the same hot and cold bodies. were used as ordinate and abscissa, leads to a very curious consequence.

Let

and

be any two parabolas whose axes are vertical, and which pass through the origin.
1. On the Computation of the Strengths of the Parts of Skeleton or Open Structures
Authors: Sang Edward
Published: June 2016

The first part of the paper is devoted to the computation of the strengths of the parts of a structure destined to resist given strains, taking into account, along with those strains, the unknown weights of the parts. The results obtained by this process necessarily give the best possible arrangement of the strengths, since, if any one part were made weaker, the whole structure would be weakened; or, if a part were made stronger, the unnecessary weight thus thrown upon the other parts would also go to weaken the fabric. It is believed that this investigation has now been given for the first time.

It was pointed out that this method enables us to determine the utmost limit of magnitude of a structure having a given general configuration.
4. Note on Pendulum Motion
Authors: Tait
Published: June 2016

Mr Sang's papers in recent parts of the Transactions of the Society have reminded me of some geometrical constructions which are to a certain extent indicated in Tait and Steele's Dynamics of a Particle (1856). Some of these were suggested to me by a beautiful construction given (I believe by Clerk-Maxwell) in the Cambridge and Dublin Math. Journal, Feb. 1854, the others by a very simple process which occurred to me for the treatment of oscillations in cycloidal arcs. The former enables us easily to divide the arc of oscillation of a pendulum, or the whole circumference if the motion be continuous, into two, four, eight, &c., parts, which are described in equal times; also to solve by simple geometrical constructions problems such as the following: —Given any three points in a circle, find how it must be placed that a heavy particle, starting from rest at one of them, may take twice as long to pass from the second to the third as it takes to pass from the first to the second.
5. On the Decomposition of Forces externally applied to an Elastic Solid
Authors: Rankine W. J. Macquorn
Published: June 2016

The principles set forth in this paper, though now (with the exception of the first theorem) published for the first time, were communicated to the French Academy of Sciences fifteen years ago, in a memoir entitled “de I Equilibre intérieur d'un Corps solide, élastiqne, et homogène,” and marked with the motto, “Obvia conspicimus, nubem pellente Mathesi,” the receipt of which is acknowledged in the Comptes Rendus of the 6th April 1857 (vol. xliv. p. 706.)

The author quotes a theorem discovered by him, and previously published in the Philosophical Magazine for December 1855, called “the Principle of Isorrhopic Axes,” viz., “Every self-balanced system of forces applied to a connected system of points, is capable of resolution into three rectangular systems of parallel self-balanced forces applied to the same points.”
2. On the Curves of the Genital Passage as regulating the movements of the Fœtus under the influence of the Resultant of the Forces of Parturition
Authors: Duncan J. Matthews
Published: June 2016

The observer of the current literature of Midwifery finds nothing more characteristic of it than the number of papers on the mechanism of natural parturition. These papers indicate for the most part an enlightened zeal, for they are engaged with a most important branch of this mechanism, namely, the mode of action of the force of labour upon the fœtus and upon the passages, and the explanation thereby obtained of the changes which take place in these as natural labour advances.
3. On a Method of Determining the Explosive Power of Gaseous Combinations
Authors: Dewar James
Published: June 2016

The author describes an apparatus by means of which the explosive power of gaseous combinations can easily be determined, and from this, by Bunsen process, the temperature may readily be calculated. The essential feature of the apparatus is the registration of the ‘compression volume’ of a given initial volume of air, on which the gaseous explosive mixture has been allowed to act. As the duration of the pressure is all but instantaneous, the well-known formula

may be employed to ascertain the final pressure, more especially as the sudden rebound prevents any great loss of heat.
1. On the Connection between Chemical Constitution and Physiological Action—Continued. On the Physiological Action of the Salts of Trimethylsulphin
Authors: Brown Crum , Fraser Thomas R.
Published: June 2016

In the former parts of this investigation we studied the physiological action of the salts of a considerable number of ammonium bases—that is, of the salts formed by the union of an ether with the nitride of one or more alcohol radicals. Thus—

The examination of the physiological action of such salts proved that, while differing from one another in many respects, there are two points in which they agree—they all paralyse the end-organs of the motor nerves, and none of them possess that stimulating action of the spinal cord which we observe in such a substance as strychnia.
4. On the Motion of Rigid Solids in a Liquid circulating Irrotationally through Perforations in them or in any Fixed Solid
Authors: Thomson William
Published: June 2016

1. Let ψ, φ … be the values at time t, of generalised co-ordinates fully specifying the positions of any number of solids movable through space occupied by a perfect liquid destitute of rotational motion, and not acted on by any force which could produce it. Some or all of these solids being perforated, let χ, χ′, χ″, &c., be the quantities of liquid which from any era of reckoning, up to the time t, have traversed the several apertures.
1. On the Extraction of the Square Root of a Matrix of the Third Order
Authors: Cayley
Published: June 2016

Professor Tait has considered the question of finding the square root of a strain, or what is the same thing, that of a matrix of the third order— A mode of doing this is indicated in my “Memoir on the Theory of Matrices” (Phil. Trans., 1858, pp. 17–37), and it is interesting to work out the solution.

The notation and method will be understood from the simple case of a matrix of the second order. I write to denote the two equations, x1 = ax + by, y1 = cx + dy.
4. Notice of a Large Boulder in the Parish of Rattray, and County of Perth, having on one of its sides Cups and Grooves, apparently artificial
Authors: Home D. Milne
Published: June 2016

About a year ago, the Council of this Society appointed a Committee to make inquiry about boulders in Scotland.

The Committee intend to submit to the Council a general report of their proceedings, showing the progress made.

The object of the present notice is to give to the Society an account of one of the boulders reported to the Committee, as a specimen of the information which they have been obtaining.
4. On the Temperature of the Electric Spark
Authors: Dewar James
Published: June 2016

The author begins this paper by calculating the highest hypothetical temperature that could be produced by the chemical combination of the most energetic elements if all the heat evolved could be thrown into the product. This would not exceed 19,500° C. in the case of silica, and 15,000° C. in the oxides of aluminum and magnesium, and these are the highest results. The estimation of the temperature of the electric spark is based on the thermal value of each spark, together with the volume of the same. The methods of observing these quantities are fully detailed in the memoir. The general result may be stated thus,—the temperature of the electric spark used in the experiments ranged between 10,000° C. and 15,000° C.
1. On the Action of Water on Lead
Authors: Christison Robert
Published: June 2016

After summarising the conclusions at which he had arrived from numerous experiments made more than forty years ago, as published in his Treatise on Poisons, and in the Transactions of this Society, the author alluded to various blanks left at that time in the inquiry which had not been yet filled up, and to various criticisms and doubts which had been recently expressed relative to the facts and principles formerly announced.
1. On the Chemical Efficiency of Sunlight
Authors: Dewar James
Published: June 2016

Of all the processes proposed to measure varying luminous intensities by means of chemical effects, not one has yet been expressed in strictly dynamical measure. This is owing to the very small amount of energy to be measured necessitating very peculiar processes for its recognition. The chemical actions generally induced by light are of the “Trigger” or “Relay” description; that is, bear no necessary relation to the power evolved by the transformation. There is one natural action of light continuously at work of a very different kind in the decomposition of carbonic acid by plants, necessitating a large absorption of energy, and thus enabling us to ascertain the proportion of the radiant power retained, through the chemical syntheses effected.
1. On Dimorphic Flowers of Cephaelis Ipecacuanha, the Ipecacuan Plant
Authors: Balfour
Published: June 2016

I have reported already to the Society (p. 688) the results of the cultivation of the Ipecacuan plant in the Botanic Garden, and its successful propagation by Mr M'Nab by root-cutting. By this means it has been sent in considerable quantity to Calcutta, under the direction of the Secretary of State for India. From the Garden at Kew, in 1863, a plant was sent out to Dr King, and of late he has been successful in propagating it by cuttings of the stem above ground. So that from both sources there seems to be every prospect of the plant being extensively cultivated in India, the climate of which in many places is favourable for its growth. The so-called root of the Ipecacuan may be said to be composed of a sort of underground stem capable of producing leaf-buds, as well as true roots.
6. Remarks on the Deep-Water Temperature of Lochs Lomond, Katrine, and Tay
Authors: Buchan Alexander
Published: June 2016

In the communications made by Sir Robert Christison to the Society in December and April last on the deep-water temperature of Loch Lomond, from observations made by him with a Miller-Casilla thermometer, these important facts were stated:—

(1.) On 12th October 1871, the temperature at the surface was 52·°0, from which it fell, on descending, till at 300 feet below the surface it stood at 42°·0, and this temperature of 42°·0 was uniformly maintained at greater depths or to 518 feet, the depth of the loch at the place of observation.
2. On a New Variety of Ocular Spectrum
Authors: Aitken John
Published: June 2016

If we look for a short time at any object, and afterwards turn the eye in another direction, we see a spectral image of the form of the object first looked at.

Again, if after we have looked at any coloured object we turn the eye in another direction, we see a spectral image of a colour complimentary to that first looked at.

In addition to these spectral forms and colours, I find there is another and distinct kind of ocular spectrum, which we may call a motion spectrum. It is seen when we look first at a body in motion and afterwards direct the eye towards an object at rest. The object at rest, when seen under these conditions, seems to be in motion, and the direction of its apparent motion is the opposite of that of the moving body first looked at.
5. Laboratory Note
Authors: Tait
Published: June 2016

Last autumn I received from Mr Maclachlan of Lower Green, Mitcham, some specimens of india-rubber tape which had been for several years wound, under considerable tension, helically round copper Wire. At ordinary temperatures, after being peeled off, the material shows no tendency to contract; but Mr Maclachlan found that in hot water it almost instantly resumes its original dimensions.

I have recently reproduced almost exactly the same results by stretching sheet india-rubber, slightly warmed, helically round glass tubes, and immersing it for a short time in a freezing mixture.
3. Further Note on the Distribution of Temperature under the Ice in Linlithgow Loch
Authors: Buchanan J. Y.
Published: June 2016

In continuation of the observations into the condition of the water of frozen lochs, which were communicated to the Society at the meeting of the 20th January 1879, I have been able to repeat the observations in Linlithgow Loch on two separate days, and also to visit Loch Lomond. The observations in Linlithgow Loch were made on the 25th January and 1st February, both times at the same spot, from which the Court House Flagstaff bore N. 150½° E., and the Rickles Island N. 63½° E., the depth being 48 feet. On the 25th January there was a diminution of pressure under the ice, so that when it was pierced the air rushed in with a roaring noise for about a minute, when it stopped, and the water rose in the hole. On the 1st February, on the other hand, the ice was cracking and resounding on all sides, and water rose at once in the hole when the ice was pierced, there being at the same time a considerable escape of air. These two stations have been numbered respectively 6 and 7; they are exactly in the same spot, a few yards distant from that of No. 4. The ice was very decidedly thicker than it had been.
5. Laboratory Notes. Measurements of the Electromotive Force of the Gramme Machine at Different Speeds
Authors: Tait
Published: June 2016

The following measurements were made by means of a Gramme machine, recently procured for the University. I desired to make use of it, not only for electric light, but for electrolysis, the exciting of electromagnets, and various other purposes for which we have hitherto used from 4 to 40 or so Bunsen cells. I therefore arranged the driving-gear so that with the same motor (a 3½ h.p. gas-engine) it was easy to use either of three speeds. These are, approximately, 800, 533, and 320 turns per minute. The electromotive force varies, of course, not only with the speed but with the resistance of the whole circuit—falling off at first rapidly and then more slowly for any one speed, as the resistance is increased. As I had no means of measuring the speed directly, I was somewhat puzzled at first to find the electromotive force at any one speed rise to a maximum, and then rapidly fall off as the whole resistance was gradually diminished.
2. The Principles of the Algebra of Logic. Part III.—Application to certain Problems in the Theory of Probability
Authors: Macfarlane Alexander
Published: June 2016

The Algebra of Logic, being the science of Necessity and Probability, supplies a variety of methods of great power for solving problems in the theory of Probability. I propose to bring before the Society a few examples extracted from my work on the “Principles of the Algebra of Logic,” which is about to be published. A large class of problems, some of which have created considerable diversity of opinion among mathematicians of eminence, can be solved by means of a single theorem.
Observations on Boulders and Drift on the Pentland Hills
Authors: Somervail Alex
Published: June 2016

Besides the boulders described by the late Mr Charles Maclaren in his “Geology of Fife and the Lothians,” and also by Professor Geikie in the “Edinburgh Memoir of the Geological Survey,” as having been carried from the Highlands, there are others which would indicate a transport from a different direction.

On the highest summits of the Pentland Hills (Scald Law, Carnethy, South Black Hill, North Black Hill, and others which are composed of various varieties of porphyrites) are found numerous boulders of fine conglomerates, grits, and sandstones, intermingled with a few boulders of quartz, greenstone, and other rocks, all partially or entirely covered by a deposit of peat, which in some places on and near the summits of the hills attains a thickness of nearly six feet. The sandstone boulders vary in size from mere fragments up to large masses which I was unable to dig up.
1. Notice of the Death of the President of the Society
Authors: Grant Alexander
Published: June 2016

Sir Alexander Grant said:—

Gentlemen,—We cannot pass to the proceedings of this evening without some reference to the calamity which has befallen the Royal Society of Edinburgh, and under the sorrowful impression of which we now meet—the sudden death of our honoured and well-beloved President.

We knew, alas! gentlemen, that his health had been failing of late, and that when, only six months ago, he first took his seat as President of this Society, his vigour was impaired, at all events for the time.
2. Why the Barometer does not always indicate the Real Weight of the Mass of Atmosphere aloft. A continuation of the Paper on this subject laid before the Society in Session 1876 and 1877
Authors: Tennent Robert
Published: June 2016

Meteorological phenomena are in all cases to be regarded as being both a cause and an effect; owing to this, and also to the imperfect state of our knowledge on this subject, it may be safely asserted that exception proves or tests the rule. Taking up the subject in this point of view, much assistance is in this way to be acquired when attempts are made to explain the phenomena which are under consideration, and hence these negative conclusions can to a large extent be taken advantage of. As an illustration of this, can it be assumed that a barometer placed on the surface of the earth, and which always correctly indicates the amount of pressure on its cistern, will also always correctly indicate the weight of the mass of air aloft, both when it is at rest and when it is in rapid motion, accompanied by the important element of friction.
2. On another Method of Preparing Methylamine
Authors: Morrison R. Milner
Published: June 2016

On a former occasion I drew attention to methyl sulphate of ammonium as a suitable material for the preparation of methylamine by heating it with quicklime. There is another and better method of arriving at the same result, the extreme simplicity of which was probably the cause of its being overlooked at the time.
5. Additional Observations on Fungus Disease of Salmon and other Fish
Authors: Stirling A. B.
Published: June 2016

In a paper read to the Society in June last, “Proceedings,” June 1879, on the fungus disease affecting salmon and other fish, I discussed the various theories which were advocated, as to the cause of the disease; the effects of the fungus upon the fish, the vegetative and reproductive aspects of the fungus, and the belief that salt water had a curative effect upon salmon affected with fungus disease, on their reaching and remaining for some time in that element.
1. The Trigonometrical Survey of Palestine
Authors: Conder Claude Reignier
Published: June 2016

The survey which forms the subject of the present paper extends over an area of 6000 square miles, bounded by the Jordan on the east, the Mediterranean on the west, the river Leontes and the springs of Jordan near Dan on the north, and the desert of Beersheba on the south. Within these limits a complete triangulation, with two bases each about four miles long, has been extended, and the whole of the country mapped to the scale of one inch to the mile. The work occupied five years in the field, and nearly three years more in preparing the results for publication.
3. Remarks on Mr Crookes's Recent Experiments
Authors: Forbes George
Published: June 2016

The author explained that he was glad to be able to bring before the Society some apparatus illustrative of Dr Crookes's splendid researches on what he calls radiant matter. This he was able to do by the skill of Mr Gimingham, who had prepared some splendid vacuum tubes for him lately. He valued those researches very highly, because they brought most conclusive evidence to bear upon the truth of the kinetic theory of gases; because they gave us a clear insight into the action of the electric current and discharge; because they promise to help us in forming a notion of what electricity really is; and because we may also hope from these researches to get some knowledge of the nature of molecules.
4. Additional Note on Minding's Theorem
Authors: Tait
Published: June 2016

Professor Turner reported that in accordance with the remit made by the Society at last Ordinary Meeting, the Council recommended the following changes in the Laws of the Society:—

“That Law XVII be cancelled, and the following Law be established in its place:—

“That there shall be formed a Council consisting, first, of such gentlemen as may have filled the office of President, and, secondly of the following to be annually elected, viz., a President, six Vice-Presidents (two at least of whom shall be resident), twelve Ordinary Fellows as Councillors, a General Secretary, two Secretaries to the Ordinary Meetings, a Treasurer, and a Curator of the Museum and Library.”
2. Remarks on the Aborigines of the Andaman Islands
Authors: Brander E. S
Published: June 2016

I propose making a few brief observations on the relations in which we stand to the aborigines of the Andaman Islands, their place in the economy of this convict settlement, and their more noticeable habits and customs. In the consideration of the latter, I shall only state such information as I have obtained myself from conversation with, and personal observation on the manners of the natives. Detailed monographs on their ethnology, &c., have been written already by several observers, and are to be found in the “Transactions of the Anthropological Society,” &c.
2. On Comets
Authors: Forbes
Published: June 2016

The author commenced by stating that although these researches lead him to believe in the existence of two planets revolving in orbits external to that of Neptune, and although there was a great deal of evidence to show that he had actually determined the elements of the orbits, yet the latter point, being dependent on a coincidence of probabilities only, cannot be considered a certainty until the planets are observed.

The author accepts the theory of cometary orbits which supposes that these bodies, wandering through space, are attracted by the sun into the solar system so as to pursue parabolic orbits, and that some of these, in passing a planet, may have their velocity diminished, in which case they will afterwards describe an ellipse in a definite period.
1. The Topography of Jerusalem
Authors: Conder Claude Reignier
Published: June 2016

The subject on which I have the honour of addressing you this evening is one far more complicated and difficult than that of the paper which I read to the Royal Society of Edinburgh some short time since. We have to deal, not with the surface of a country and the position of places of which the ancient names are still extant, but with a ruined city, buried to a depth of from 30 to 50 feet in rubbish on which modern buildings having been erected, and with a topography in which, there is scarcely a single important point which has not been controverted by one or more well-known writers.
3. Meteorological Note by Mr Alexander Wallace
Authors: Wallace Alexander
Published: June 2016

On Monday, March 1, 1880, a strong breeze from the S. W., marked at 1 o'clock P.M. in meteorological observation, as equal to 15 miles per hour, prevailed, after which the force of the wind rapidly increased, shifting to W.N.W. until about 2 o'clock when it became a perfect hurricane, accompanied by a storm of snow and sleet. The velocity of the wind must have been betwixt 40 and 50 miles per hour, and partly from heavy black clouds covering the sky, and partly from the dense sheet of snow which was drifting along, everything became obscured.
4. On the Colouring of Maps
Authors: Tait
Published: June 2016

Some years ago, while I was still working at knots, Professor Cayley told me of De Morgan's statement that four colours had been found by experience to be sufficient for the purpose of completely distinguishing from one another the various districts on a map.

I had previously shown that if an even number of boundaries meet at each point on a diagram, two colours (as on a chess-board) will suffice for the purpose. But in a map, boundaries usually meet in threes.
3. On a Differential Thermoscope founded on Change of Viscosity of Water with change of Temperature
Authors: Thomson Wm
Published: June 2016

Water flows from a little cistern or reservoir R through a wide vertical tube S, about two metres long, thence through a horizontal capillary tube C', 50 or 100 centimetres long; thence through a wide horizontal metal tube T, 20 or 30 centimetres long; thence through a second horizontal capillary C; and lastly, out by a little constant-level overflow cup L. A vertical glass manometric tube M, a metre and a half long, standing up above the end of T next C to measure the pressure in T by a water column; and a means of giving any uniform temperature to the outsides of S and C, and any other uniform temperature, to the outsides of T and C; complete the instrument.
3. Note on the Present Outbreak of Solar Spots
Authors: Smyth Piazzi
Published: June 2016

The physical activity going on in the Sun is still increasing, and worthy of all admiration. There was a very large spot had come round on the North-following limb on March 29; and was after that the subject of observation from day to day as it approached the central Solar meridian. But when it arrived there, on April 3, behold two less large but still most notable spots had burst out clear and full within the previous twenty-four hours between the great spot and the preceding limb. And on this day, April 4, there are two more notable ones very close to the greatest spot, making in all five remarkable spots not only all visible at once, but working and seething positively before our eyes.
6. Researches in Thermometry
Authors: Mills Edmund J.
Published: June 2016

Having had occasion in the course of my work to investigate some of the properties of the mercurial thermometer, I have obtained a series of results which are comprised in a memoir now submitted to the Society. A brief summary of these is given in the following abstract.

1. After describing a simple method of calibrating a thermometer, I give a detailed proof (following Pierre) that the calibration unit gradually undergoes a slight diminution in value. In the course of five years this may amount, in a new thermometer, to as much as ·21 per cent. The 0°–100° interval, therefore, requires periodic verification.
3. On the Accurate Measurement of High Pressures
Authors: Tait
Published: June 2016

In the course of an examination of some of the “Challenger” deep-sea thermometers, I have recently had occasion for measurements, accurate to one or two per cent., of pressures such as five or six tons weight per square inch. The ordinary gauges showed themselves to be quite untrustworthy, and it was necessary to devise come plan of whose accuracy the experimenter can feel assured. The following process has proved completely successful, and is capable of any desired degree of accuracy.
5. On Two Masks and a Skull from Islands near New Guinea
Authors: Turner
Published: June 2016

These specimens have recently been presented to the Anatomical Museum of the University, by J. Wharton Cox, Esq., who had received them from his father, Dr Cox of Sydney, the well-known Australian naturalist.

The masks had been procured by Dr Cox from missionaries, and were either from the island of New Ireland or New Britain, in proximity to the north coast of New Guinea. They were both formed of the frontal and facial bones, on which a face had been modelled in a composition, formed of a mixture of a resinous substance with earth or clay. This artificial face had then been painted with red, black, and white pigments. The larger mask was hollowed out behind, by the removal of the sphenoid and ethmoid bones, so that it could be adapted to the face of a wearer, and a bar of wood was fastened transversely across the hollow, which the wearer had evidently used for holding the mask between his teeth; as the mask had both the eyelids and lips separated from each other, the wearer could both see and breathe through these openings.
2. Note on the Theory of the “15 Puzzle”
Authors: Tait
Published: June 2016

[After this note had been laid before the Council, the new number (vol. ii. No. 4) of the “American Journal of Mathematics” reached us. In it there are exhaustive papers by Messrs Johnston and Story on the subject of this American invention. The principles they give differ only in form of statement from those at which I had independently arrived. I have, therefore, cut down my paper to the smallest dimensions consistent with intelligibility.—P. G. T.]

The essential feature of this puzzle is that the circulation of the pieces is necessarily in rectangular channels. Whether these form four-sided figures, or have any greater (even) number of sides, the number of squares in the channel itself is always even. (This is the same thing as saying that a rook's re-entrant path always contains an even number of squares. This follows immediately from the fact that a rook always passes through black and white squares alternately. The same thing is true of a bishop's re-entering path, for it is a rook's upon a new chess-board formed by the alternate diagonals of the squares on the original board.) That there may be circulation in the channel, one of its squares must be the blank one.
5. On a New Telephone Receiver
Authors: Chrystal
Published: June 2016

The experiment which forms the subject of this communication was originally devised as an illustration of the explanation of all kinds of microphone receivers, suggested by the beautiful experiments of Mr Blyth, on loose contacts. My idea was to replace Mr Blyth's heated point of metal by a continuous portion of the circuit which should act in the same manner.

It was obvious, for two reasons, that this part must be of small diameter; 1st, in order that the resistance, per unit of length, might be great enough to make the variation of the heating sufficient to cause sensible longitudinal extension; 2d, in order that the section might be small enough to allow sensible cooling in, say the of a second. I had reason beforehand to believe that the second of these conditions could be fulfilled in practice; because, I found in my experiments on Ohm's Law (Brit. Ass. Rep. 1876, p. 58, et seq.) that, when currents of two different strengths alternated, even with great rapidity (60 times per second) in a fine wire, the resistance was sensibly higher during the passage of the stronger current.
2. On the Determination of the Specific Heat of Saline Solutions
Authors: Gray Thomas
Published: June 2016

The object of the present paper is to describe the results obtained and the mode of experimenting adopted in some determinations which I have made of the specific heats of solutions of salts. These experiments form part of a series which I am at present carrying out on the physical changes produced when salts are dissolved in different amounts of their solvents. From such an investigation I believe much information may be gained regarding the nature of solution.

The method of experimenting adopted in the experiments described below was that of mixtures; but as regards the mode in which the exact amount of heat added to the solution was measured, it differed from any process with which I am acquainted. This peculiarity consisted in using as heater a thin glass bottle of about 50 cubic centimetres capacity, and furnished with a long glass neck, just wide enough to allow an ordinary mercury-in-glass thermometer to pass through. This bottle was nearly filled with mercury, in which was immersed the bulb of a sensitive thermometer, and thus the temperature of the mercury in the bottle could be read off at any instant. The graduation of this thermometer was to fifths of a degree centigrade, and had been compared with the Kew standards. The distance between two consecutive divisions of its scale was about one millimetre.
4. On the Compressibility of Glass
Authors: Buchanan J. Y.
Published: June 2016

The experiments related in this paper were undertaken with a view to determine, by actual observation, the effect produced on solids by hydraulic pressure. The instrument used consists of a hydraulic pump, which communicates with a steel receiver capable of holding instruments of considerable size, and also with a second receiver of peculiar form. This receiver consists essentially of a steel tube terminated at each end by thick glass tubes fitted tightly. It is tapped at the centre with two holes, the one to establish connection with the pump and the other to admit a pressure-gauge or manometer. The steel tube may be of any length, being limited only by the extent of laboratory accommodation at disposal. The tube which I am using at present has a length of a little over six feet and an internal diameter of about three-tenths of an inch. The solid to be experimented on must be in the form of rod or wire, and must, at the ends, at least, be sufficiently small to be able to enter the terminal glass tubes, which have a bore of 0·08 inch, and an external diameter of 0·42 inch. The length of the rod or wire is such that, when it rests in the steel tube, its ends are visible in the glass terminations.
2. On Some New Crustacea from the Cementstone Group of the Calciferous Sandstone Series of Eskdale and Liddesdale
Authors: Peach B. N.
Published: June 2016

The species enumerated in this paper belong to the two orders Phillopoda and Decapoda.

Of the Phyllopods, the author describes two species of Ceratiocaris (Salter), which differ from their Upper Silurian allies in the enormously-developed abdomen and in the small size of the carapace, also in the comparative insignificance of the side spines of the tail compared with the telson. As far as the author is aware, these are the first obtained from the Calciferous Sandstone series, although carapaces of Ceratiocaris have been got from the Mountain Limestone of England. (C. Scorpioides, 1½ to 2 inches long; C. elongatus, 5 to 8 inches long.)
3. Gaseous Spectra in Vacuum Tubes
Authors: Piazzi Smyth
Published: June 2016

The work described in this paper consists of rather careful measurements, but under low dispersion only, of the spectra of twenty gas-vacuum tubes, generally of different gases and illuminated by small induction sparks, but seen very brightly by the end-on method of viewing.

A comparison of the different spectra thus obtained follows, and some curious results are elicited as to the prevalence of certain impurities among gases, as well as alterations and even transformations of some of them with time and use.

These facts are contained chiefly in Appendix 1 and Appendix 2; while a third appendix, kindly contributed by Professor Alexander Herschel, contains some further observations of his with the same apparatus but higher dispersion introduced. See his account of the same.
4. On the Diffusion of an Impalpable Powder into a Solid Body
Authors: Marsden R. Sydney
Published: June 2016

In a note on “The Effect of Heat on an Infusible, Impalpable Powder,” by Professor P. G. Tait, in the Proceedings of the Royal Society of Edinburgh, vol. ix. p. 298, for the year 1876–77, Professor Tait points out that such a powder becomes very fluid under the action of heat, and behaves in many respects in the same way as a liquid would do—viz., convection currents are distinctly to be observed, and small particles of the powder are thrown up from the surface, in the same manner as we perceive little drops of water thrown up from the surface of a glass of soda-water. And Professor Tait then asks the question—If, supposing we had two such infusible, impalpable powders, would they diffuse into one another as do gases and liquids ? This is a question which as yet has not been answered. Professor Tait and I have been engaged in some experiments on the subject for some time, but the difficulties (chemical and physical) to be overcome are much greater than at first sight appear, and at present we are unable to say definitely whether they do so or not. But I think an answer may be obtained from another source. In some recent experiments I had occasion to have a number of Berlin porcelain crucibles and amorphous carbon in an impalpable powder kept in contact with each other at very high temperatures for from ten to twelve hours, with the following effect, that, although the crucibles did not become fused, but retained their exact original form, yet the carbon found its way to a considerable distance into the crucible, and some of the particles penetrated the crucible throughout. This was not a case, therefore, of fusion and mechanical mixture.
12. Further Note on Graphitoid Boron and the Production of Nitride of Boron
Authors: Marsden R. Sydney
Published: June 2016

This note is a continuation of the paper on the “Preparation and Properties of Pure Graphitoid and Adamantine Boron,” by Dr R. M. Morrison and myself, published in the Transactions of this Society, vol. xxviii. p. 689, and its object is to correct a mistake which we have made in giving the properties of this substance. We say—

1st, It is not oxidised by air at a white heat, even superficially.

2d, It does not alloy with platinum at a white heat.

I have again prepared a quantity of this substance and examined its properties under Professor Wohler, and I find that the above statements are wrong. A very fine film of oxide does form on the surface of this substance when heated on platinum foil over the blowpipe, and this film, although very thin and difficult to observe, is sufficient to prevent all further action of the air, and also to prevent its combining with the platinum. This misled us when we previously examined it. If, however, a quantity of it be placed on a piece of platinum foil, and the foil folded over it and pressed down so as to exclude all the air, then on heating it intensely before the blow-pipe the boron at once combines with the platinum and perforates it.
II.—Further Invariant Theory of two Quadratics in n Variables
Authors: Turnbull H.W. , Williamson J.
Published: June 2016

In the following pages we propose to clear up certain difficulties which have arisen in the theory of invariants belonging to two quadratic forms homogeneous in n variables x1, x2, …, xn. We denote such a set by a single symbol x, and take it as fundamental that any non-zero set x represents a point in space of n – 1 dimensions. We deal with any number of cogredient sets, x, y, z, x1, x2, etc., each representing a point, of which n at most are linearly independent in this space Sn–1. A prime u is a space Sn–2, lying wholly in the Sn–1, and therefore determined by n–1 linearly independent points.
VIII.—A Case of Intersexuality inBos indicus, with a Theory of the Significance of the Genetic Male Intersex
Authors: Burt D. R. R.
Published: June 2016

The Ceylon trotting bull, a small but fast animal, is regarded as a variety of its larger Indian relative, the Zebu,Bos indicus. The case, furnishing the basis of this account, was brought to my notice after the animal had died, so there is no direct evidence regarding its reactions to males and females of the same species. But I am told that although it had been kept for many years in a field with mature cows and bulls it had shown no reaction towards either. Very little is known about the early history of the animal beyond the fact that it was considered to be about seven years old. Nothing is known of its parentage, and as these trotting or racing animals change hands many times in Ceylon, it is impossible to discover whether it had been a twin calf. The animal died of tetanus, and until a fortnight before its death it had been healthy, and, I believe, the winner of many prizes for racing.
XI.—On Changes of Rock Temperatures and Irregularities of the Earth's Rotation
Authors: Wrigley R.W.
Published: June 2016

This investigation is founded upon a long and unique series of readings of deep rock temperature taken at the Calton Hill, extending from the year 1837 to the present time. The thermometers were installed under the direction of the late Professor James Forbes and were described in detail by him to this Society. They were four in number, sunk in the rock at depths of 25·6 feet, 12·8 feet, 6·4 feet, and 3·2 feet, and consisted of large cylindrical bulbs 6 to 8 inches long and 1½ to 2½ inches in diameter, connected by long, fine capillary tubes with the surface of the ground, where they expanded into tubes of wider bore having degrees of convenient length for reading. The bulbs were inserted into tin cylindrical boxes filled with plaster of Paris as a precaution against fracture, and the liquid used was alcohol. Regular weekly readings were commenced in 1837. The thermometer at depth 12·8 feet was broken by frost in 1861, but the readings of the remaining three continued without interruption till the year 1876, when a Portuguese sailor from a ship in Leith scaled the Observatory wall one night and wantonly destroyed all the thermometers and their wooden shelter.
XVI.—A Simple Spectrum Comparator
Authors: Jack David
Published: June 2016

A problem which frequently presents itself to the spectroscopist is that of comparing photographs with a view to detecting differences which are not sufficiently conspicuous to make them obvious by simply superposing the plates. Differences of the kind in question may arise in the spectrum of a particular substance as the result of variations in the conditions of excitation of the spectrum which may produce changes in the distribution of intensities, changes in the nature of the lines, or the emission of new lines.