Friday Evening Discourse Research Articles

Popular Science

To apply the term ‘popular science’ to a book is generally sufficient to make a man of scientific training turn aside distrustfully. This is particularly unfortunate in these days of increasing specialisation, when it is more than ever desirable that specialists should be enabled to follow broad lines of advance in fields other than their own, but the fact remains that most popular science books are ‘written down” and simplified to the point of sheer inaccuracy. There is also an increasing body of laymen interested in the advances of science who rightly ask to have accurate though plain accounts of current work. Davy and Faraday showed one way in which both needs can be met: the scientific worker can come from his laboratory and explain his investigations. Faraday's Friday evening discourses at the Royal Institution are still regarded as models of exposition, and it may justly be said that Faraday's mantle has fallen on the present occupant of his post, Sir William Bragg. Sir William's course of Christmas lectures of 1923–24, “Concerning the Nature of Things”, forms an admirable introductory volume in a group of four published by Messrs. G. Bell and Sons, Ltd., in a new “Popular Science Series”(4s. 6d. net each). From that we may pass to “Engines”, by Prof. E. N. da C. Andrade, another course of Christmas lectures at the Royal Institution, and then perhaps to Prof. J. Kendall's “At Home among the Atoms”, described by its author as “A First Book of Con genial Chemistry”, which with its quaint chapter headings and unconventional diction will amuse as well as inform. Finally, there is Prof. Andrade's “The Mechanism of Nature”, a more ambitious work for the intelligent reader, surveying in plain language modern views on the structure of matter and radia tion. All these books have been published before, but in their new and tasteful ‘dresses’, any or all of them might well serve to solve the problem of the selection of a Christmas present for a young or an older reader.

Scope and Needs of Medical Research

SIR WALTER MORLEY FLETCHER delivered the Friday evening discourse at the Royal Institution on May 27, taking as his subject “The Scope and Needs of Medical Research”. He pointed out that medical research covers immensely wide and varied fields of scientific activity, indefinitely wider than the important part of it which concerns the healing profession as such. Its scope has been defined for Parliamentary purposes as dealing with “the proper development and the right use of the human body in all conditions of activity and environment, as well as with its protection from disease and accident, and its repair”. The development of the body includes the relatively new and rapidly growing studies of genetics on one hand, and of nutrition on the other. For the right use of the body we are concerned with personal hygiene as well as with the intricate group of problems belonging to industrial life. Here research is organised under the Industrial Health Research Board. Protection from disease covers the two great fields of preventive and of curative medicine. It deals with the genetic and nutritional control of disease, as well as with studies of infective disease at home and in the tropics. This infinitely varied field of work calls at every point for the intensive application of the primary sciences. This is well illustrated by the study of rickets, the detection of its dietetic basis, and the discovery of the relationship of light radiation to the fat-like substance in the skin from which vitamin D is produced. Further development has involved intensive team work by physicists, chemists, and biologists, leading to the production of calciferol, the actual substance of vitamin D. This has not only made important contributions to organic chemistry as such, but also has brought improved practical powers to the medical administrator.

The Varley Brothers

IN an interesting address on the brothers Varley, who did much valuable pioneering work in telegraphy and electrical engineering, Col. Lee, of the Post Office, in a lecture on May 5 to the Institution of Electrical Engineers, pointed out that the whole progress of telegraphy during the constructive period up to the laying of the Atlantic cable was largely the history of Cromwell and Samuel Alfred Varley. This year is the hundredth anniversary of the birth of S. A. Varley. Cornelius Varley, the father of the two brothers, was a well-known scientific worker, and delivered the fourth Friday evening discourse at the Royal Institution. He was a descendant of Oliver Cromwell. The first attempts to lay an Atlantic cable having failed, Cromwell Varley served on a committee appointed by the cable company which issued a most valuable report. Later on, Cromwell Varley and Sir William Thomson (Lord Kelvin) entered into partnership as consulting engineers, being joined later by Fleming Jenkin. Cromwell Varley wrote many scientific papers, one of them published by the Royal Society describing experiments on luminous phenomena which came very near to discovering the electron. Samuel Alfred Varley did much valuable work in telegraphy. During the Crimean War, he laid the first field telegraph in 1854. His greatest invention was the self-exciting dynamo, on which he had been experimenting since he was seventeen years of age. On technical grounds the priority of this invention is generally attributed to others. At the International Inventions Exhibition in 1885, he was awarded a gold medal for inventing a self-exciting dynamo. He championed the cause of the electrical industry against the Brush patent for the compound wound dynamo. Varley's precedence in the invention was upheld after an appeal to the House of Lords and the Brush patent was declared invalid. Both the brothers Varley and the late Earl of Crawford played a leading part in founding the Institution of Electrical Engineers. Among the seventy-one founder members were four of the Varley family.

Faraday and Benzene

THE Royal Institution audience at the Friday evening discourse on May 20 had a stimulating experience when Prof. Henry E. Armstrong addressed them with “Faraday at the Sign of the Hexagon” as his subject; “Coal Colour and Constitution” was the alleged theme of the evening, but this venerable Lewis Carroll of chemistry allowed himself freely to be led only by the spirit of the moment. With the lecture room decorated like an Eastern bazaar, with fabrics of every pattern and hue, the ‘lecturer’ was evidently content to appear as a benevolent ‘high priest of colour’, wearing himself as regalia a waistcoat of the genuine nursery sky blue and pink. The ordinary symbols of the orthodox chemist were discarded for this occasion, “as people won't take the trouble to understand their meaning”; so straight-chains and ring compounds were replaced by the backbone of a mackerel and by a whiting with tail in mouth ready for the kitchen; also buttons on safety-pins deputised for the unwieldy formulæ of the dyes chemist, all used to illustrate the genealogy of benzene, that “pallid infant of the sober Faraday”, “taken as mistress by Hofmann”, with progeny the “gentle Ani-line” and her numerous offspring whose “hectic and chromatic careers” were vividly described. Nor must Miss Hook of Holland be forgotten, who left her seat by the chairman to display her famous many-hued petticoats, as illustrations of the dyes which the chemists' control of colour has produced from the same base.

The Expanding Universe

SIR ARTHUR EDDINGTON'S recent work is of extraordinary interest, though there is some difficulty in getting hold of the right end of the stick. His recent Friday evening discourse at the Royal Institution appears elsewhere in this issue, however, and he also gave a rather fuller account of the work in his presidential address to the Physical Society last November.

Faraday's Work in Electrochemistry

The subject of Sir Harold Hartley's Friday evening discourse at the Royal Institution on March 4 was “Michael Faraday and Electrochemistry”. From 1832 until 1834 Faraday was mainly occupied with electrochemical researches. He first showed that amounts of electricity which produced the same effect on a galvanometer also liberated the same amount of iodine when passed through a solution of potassium iodide. He then went on to systematic investigation of the amounts of different elements which are liberated when the same current is passed through a series of solutions or fused substances, and established the two fundamental laws of electrolysis which still stand

Earth Pressures

AT the Friday evening discourse at the Royal Institution on Feb. 19, Prof. C. F. Jenkin discussed the mechanics of shifting sand. Prof. Jenkin explained why experiments intended to measure the pressure exerted by granular material, such as sand, fail, and showed that the failure is due to arching, a necessary consequence of the property of dilatancy, discovered by Osborn Reynolds. The latest design of apparatus for measuring the forces on a retaining wall was shown, and the results of a test made with it were described. With this apparatus the old earth pressure theories have been tested and the truth in them separated from the error. As a result, a revised wedge theory has been formulated. The apparatus was shown to be capable of measuring the forces not only on plane walls, of any batter, but also on stepped walls and on L-shaped walls, and also of measuring the forces under water. Finally, by an ingenious device, a wall of sand has been tested and the true friction angle between two sand faces measured. The reaction, that is, the force exerted by the wall on the sand, was described and its importance illustrated by an account of the partial failure of a great weir in Australia. The apparatus described can only deal with one-quarter of the whole problem of earth pressures; it cannot measure the forces under a foundation, and it cannot measure either horizontal or vertical forces exerted by clay.

Weather Forecasting

IN his Friday evening discourse at the Royal In stitution on Feb. 5, Dr. G. C. Simpson discussed weather forecasting. In 1859, Admiral FitzRoy, who was then the head of the department of the Board of Trade which had recently been established to study marine meteorology, commenced to collect weather reports by telegraph from a number of ports in the British Isles, and so a new science was created and a new term added to the English language. FitzRoy's innovation was not approved by scientific men, and on his death in 1865 forecasting ceased.

The Expanding Universe

IN his Friday evening discourse at the Royal Institution on Jan. 22, Sir Arthur Eddington discussed the expansion of the universe. Outside our own galaxy of stars there exists a vast number of external galaxies, each containing many millions of stars, which appear as nebulae. These are to be found running away from us almost unanimously; and the farther away they are, the faster they recede. This effect has been observed up to a distance of more than a hundred million light-years; the speed there reaches 20,000 km.—a sec.as fast as an alpha particle. It looks at first as though the nebulæ must have a particular aversion to us, but it is not difficult to see that the recession is the effect of a general expansion of the universe, and is not especially aimed at us. An effect of this kind has been anticipated theoretically. Einstein's law of gravitation contains a term representing repulsive force, which is ordinarily minute and negligible; but at very great distances the repulsion—becomes large and overmasters the ordinary gravitational attraction, so that very remote objects tend to scatter apart. The theory, however, does not predict the magnitude of this ‘cosmical repulsion’, and hitherto it has only been possible to evaluate it from direct astronomical observations of the nebulæ. Sir Arthur is convinced, however, that precisely the same cosmical term is concerned in the theory of the atom and supplies the standard which determines, for example, the radius of an atom. So that out of the theory of the atom (without any astronomical observations) we can predict the rate of recession of the nebulæ or alternatively, astronomical observation of the distances and velocities of the nebulæ is a method of determining the masses of the electron and proton. Sir Arthur stated that, in his opinion, this astronomical phenomenon of the expanding universe is the main clue by which we can ultimately unravel the mechanism of the atom.

The Spectroscope in Organic Chemistry 1

SOMEWHAT more than half a century ago, while engaged, with the assistance of Faraday, in preparing experiments for a Friday evening discourse in this institution, Stokes observed that the spectrum of the electric light extended to five or six times the length of the visible spectrum when he employed prisms and lenses of quartz instead of glass. This extension occurs at the violet end of the spectrum, and consists of rays of high refrangibility, to which the eye is insensitive, but which can be made apparent by means of a fluorescent screen.

XXV.—Thermo-Electric Diagram from −200° C. to 100° C., deduced from the observations of Professors Dewar and Fleming

In 1895 Professors Dewar and Fleming made an extensive and careful series of observations connecting temperature and the thermo-electromotive force of some twenty metals compared with lead. The greatest care was taken in the preparation for, and in the conduct of, the experiments, and about thirty readings, at temperatures ranging over the 300° between the boiling point of oxygen and the boiling point of water, were recorded for each metal. A full description of the mode of experimenting, with the results for each metal, was published in the Philosophical Magazine, July 1895. In their discussion of the results a further examination of them was promised, but has not appeared. Professor Fleming, however, in a Friday Evening Discourse at the Royal Institution in 1896, indicated that the lines of thermo-electric power did not appear as straight lines although they were approximately so.

The British Association

Sectional Forecast. THE destruction of the Colston Hall by fire, just when the preparations of the Local Committee for the Bristol meeting were complete, has given rise to serious difficulties. The best arrangements possible under the circumstances have been made. The People's Palace has been secured for the Presidential Address and for the Friday evening Discourse.

The Nitric Organisms

I MUCH regret to learn from your last issue that Mr. Waringon considers that I failed to do justice to his work on this subject in my recent lecture at the Royal Institution, and which was reprinted in your columns of the 9th inst. Mr. Warington complains that I have attributed to Winogradsky, and not to himself, the separation of the nitric ferment; I think, however, that Mr. Warington does not correctly understand the sense in which I employ the word “separate,” or rather “isolate” (that is the exact word which I did use), for it does not appear to me that Mr. Warington has ever claimed to have isolated this ferment; thus, on referring again to his most recent publication on this subject, I read, “An attempt to isolate the nitric organism by the dilution method failed, but apparently only one other organism—a stout bacillus, growing on gelatin—was present in some of the cultures” (Chem. Soc. Journ., July 1891). In an exhaustive memoir, due reference to the above attempt of Mr. Warington's would, of course, have been made; but in the impressionist sketch, which is alone possible in a Friday evening discourse at the Royal Institution, I take it that a lecturer must be allowed to use his own discretion as to what does and what does not fit into the small frame of sixty minutes without laying himself open to the imputation of having unjustly neglected or emphasized the work of individual investigators. Mr. Warington's name is so indissolubly connected with the subject of nitrification that it is the more surprising to me that he should have taken exception to the passage in question of my lecture.

The Geological Evidences of Evolution

FEW chapters in the “Origin of Species” are more impressive, from their perfect candour and their far-sighted prescience, than those dealing with the objections which might be. urged against the author's hypothesis, on the ground of the comparatively small palæontological evidence in its favour. But this evidence, as every student knows, has been almost surprisingly strengthened and augmented during the thirty years which have elapsed since the publication of Darwin's great work. It is, however, owing to the nature of the case, scattered up and down various scientific periodicals, many of which are practically inaccessible to the general public, so that both its amount and its force are under-estimated, and the old objections are confidently reiterated by that still numerous class to whom “Darwinism” is a bugbear, and the very name of “evolution” an absolute abomination. As Prof. Heilprin states in his preface, “There has not thus far appeared, to the knowledge of the author, any collective or consecutive statement of the evidence which geology and palæontology present in support of organic transmutation;” so “with the view of partially filling this gap in the literature of Darwinism, the author has prepared, at the request of many of his friends, the following pages, which represent, somewhat broadened, the substance of a Friday evening discourse delivered at the Academy of Natural Sciences of Philadelphia.” Thus this little book, while scientific, in conception and method, is popular in style. While there is no attempt at an appeal to prejudices, scientific terminology is as far as may be avoided, and the illustrations appended enable any reader, with a very moderate knowledge of natural history and palæontology, to comprehend the line of reasoning followed by the author. The Geological Evidences of Evolution. By Angelo Heilprin, Professor of Invertebrate Palæontology at the Academy of Natural Sciences of Philadelphia. (Philadelphia: Published by the Author, 1888.)

III. On the limiting distance of speech by telephone

The law that determines the distance to which speaking by telephone on land lines is possible, is just the same as that which determines the number of currents which can be transmitted through a submarine cable in a second. The experimental evidence upon which this law is based was carried out in 1853 by Mr. Latimer Clark (whose assistant I then was). The experiments were made by me in the presence of Faraday; many were his own; he made them the subject of a Friday evening discourse at the Royal Institution January 20, 1854, and they are published in his ‘Researches’ (vol. 3, p. 508).

Notes

THE following are the Lecture arrangements at the Royal Institution for the ensuring Session:—The Christmas Lectures will be given by Prof. Tyndall, on Light and the Eye. Before Easter-Prof. W. C. Williamson on the Primeval Ancestors of Existing Vegetation, and their Bearing upon the Doctrine of Evolution; Prof. R. S. Ball, four lectures on the Supreme Discoverie in Astrnomy; Prof. Dewar, nine lectures on the Spectroscope and its Applications; Mr. R. Bosworth Smith, four lectures on Episodes in the Life of Lord Lawrence; Dr. W. H. Stone, three lectures on Singing, Speaking, and Stammering; Mr. H. H. Statham, two lectures on Music as a Form of Artistic Expression. After Easter—Courses will be given by Professors Tyndall, McKendrick, A. Geikie, and Turner (of St. Petersburg). The Friday Evening Discourses will probably be given, among others, by Mr. R. B. Smith, Dr. G. J. Romanes, Sir W. Thomson, Mr. M. D. Conway, Prof. W. C. Williamson, Mr. W. H. Pollock, and Prof. Tyndall.

The Excitability of Plants 1

IT will be in the recollection of many who are present this evening that in February of last year I had the honour of delivering a Friday evening discourse on a subject which included that which has been announced for to-night. In that lecture I had hoped to present to you a comprehensive view of the excitatory motions both of plants and of animals; that is, of those motions which they perform in response to transitory impressions received by them from outside. I was desirous that the statements that I made to you with reference to animal excitability should be as fully as possible illustrated by experiments, in the carrying out of which much more time was lost than I had reckoned for; so that I was unable even to enter on the second part of my subject. The time at my disposal will not permit me to summarise my last lecture, however advantageous it might be to do so. I must content myself with recalling your attention to one or two fundamental points.

Energy and Force 1

[ON March 28, 1873, Clifford delivered a Friday evening discourse on this subject at the Royal Institution. By some accident no trace of it, not even the date or title, appears in the printed Proceedings. Thus the lecture escaped notice when Clifford's literary and scientific remains were collected in the summer of last year. A few weeks ago I lighted on my own rough notes of it taken down at the time, probably the only record now in existence. These I have written out, with only so much alteration and addition (indicated by square brackets) as necessary to make them intelligible. The paper thus produced has been seen by Clifford's friend and mine, Mr. J. F. Moulton, who (besides his general competence in mathematical physics) was thoroughly acquainted with Clifford's mathematical work and ideas. Mr. Moulton has added, by way of introduction, some remarks founded on this intimate knowledge, which will explain the aims of the discourse and supplement the too meagre report which is all that I am able to reconstruct from my notes.—F. POLLOCK.]

Mr. Ruskin on River Conservation

Mr. Ruskin on River Conservation

The Life and Letters of Faraday

IF none but Apelles was fit to paint Alexander, where shall we find a biographer worthy of Faraday? Shortly after his death, many sketches of his character and work appeared, among which that of De la Rive may be specially mentioned. These were succeeded by Tyn-dall's two Friday evening discourses on “Faraday as a Discoverer,” which were afterwards embodied in an admirable little book. But a more complete biography was wanted, and the question was frequently asked, “Who understood him sufficiently well to draw his portrait?” Eventually it was rumoured that the materials had been placed in the hands of Dr. Bence Jones. First there appeared an unusually long obituary notice in the Proceedings of the Royal Society, consisting of little else than a catalogue of the papers published, lectures delivered, reports written and honours won by the great philosopher in each year during half a century; showing that Dr. Jones had a rare collection of interesting documents, so as to whet our appetite for the coming work. Now it is before us—“The Life and Letters of Faraday” in two goodly octavo volumes. The Life and Letters of Faraday. By Dr. Bence Jones. Two vols. 8vo. (Longmans, 1869.)