MacTutor
RALPH ALLEN SAMPSON was born at Skull, County Cork, on 1866 June 25. He was the fourth of the five children of James Sampson, a Cornishman, who was a metallurgical chemist by profession. When Ralph was five the family moved to Liverpool, and were subsequently impoverished by the combination of the illness of the father and the failure of the Cornish tin-mine industry in which Mr. Sampson's capital was invested. As a result of these straitened circumstances the son Ralph had very little education until he was fourteen, but it then became possible to send him to the Liverpool Institute and his ability soon made up for his earlier lack of opportunity. He eventually entered St. John's College, Cambridge, as a sizar, became a scholar of the College and graduated as third wrangler in the Mathematical Tripos of 1888. In the following year he gained the first Smith's Prize and was elected a Fellow of St. John's. At this time Sampson held a Lectureship in Mathematics at King's College, London, and was engaged in hydrodynamical research.
In 1890 an important academical event took place at Cambridge for which many students of astronomy have since had cause to be very thankful. This was the foundation, as a result of the munificent generosity of Mr. Frank McClean, of the Isaac Newton Studentship in Astronomy and Physical Optics. Sampson was the first holder of this Studentship, being elected in 1891. He accordingly returned to Cambridge and worked in astronomical spectroscopy with H. F. Newall, and the result of his activities was seen in 1893 when he published a paper of 62 pages in the Memoirs of the Society entitled, "On the Rotation and Mechanical State of the Sun." In the preface to this paper he wrote: "After proceeding a certain way with the theory of the Sun's rotation, it became evident that no conclusion could be reached without a satisfactory theory of the distribution of his internal temperature. With the existing theory of convective equilibrium I felt dissatisfied; accordingly I attempted the discussion of the distribution of temperature by radiation and absorption and arrived at a theory which is explained in Part I, Section 3."
Throughout his career Sampson showed himself to be essentially a pioneer, and like other pioneers he often initiated lines of study which were destined to be followed up and worked out by others. It is interesting to notice that his pioneering instinct was manifesting itself in these early days, and that it led him to advance the hypothesis of radiative equilibrium in a star's interior, a hypothesis which has since dominated the theory of the interior of a star. It is also interesting to contrast Sampson's earliest astronomical research with the considerations which probably influenced his decision to leave London and return to Cambridge as an Isaac Newton student. In his undergraduate days he had been a pupil of J. C. Adams, and his interest in astronomy was stimulated by this association. But Adams was primarily a dynamical astronomer, and one of the most important of Sampson's researches, the theory of Jupiter's satellites, was destined to be in the field of dynamical astronomy. But it was not in this field, but in the field of astrophysics, that his first research work was conducted, and it was to astrophysical research that Sampson turned at a later stage in his career when his heavy labours on Jupiter's satellites had been completed. Dynamical astronomy aroused the patient scholar in him, but astrophysics set the pioneer in action, and as we shall see presently, his later astrophysical activities were again noteworthy as being the first step into unoccupied territory.
In the autumn of 1893 Sampson was elected to the Chair of Mathematics in the Durham College of Science at Newcastle-on-Tyne, and in 1895 he removed to Durham itself as Professor of Mathematics at the University. He interested himself in the Durham Observatory, where he was responsible for the erection of the Durham Almucantar, a fundamental instrument of attractive principle, and it was at Durham that the work was commenced which eventually led to the award of the Society's Gold Medal in 1928.
The theory of the Four Great Satellites of Jupiter had engaged the attention of the great dynamical astronomers of the nineteenth century. It is a particularly fascinating subject on account of the relation between the mean motions of Satellites I, II and III. But the state of the theory in which it was left by Delambre was disappointing in view of the large residuals which remained after comparison with observations of the eclipses of the satellites. Part of the trouble was felt to be due to the rather unsatisfactory nature of the observations of disappearance and reappearance at eclipse, and Sampson felt that the advent of the Harvard photometric eclipse observations warranted a re-examination of the whole question. He began with a careful discussion of the eclipse observations themselves, which was published in Harvard Annals, 52, and incidentally he considered that the peculiarities of many of the light-curves gave evidence of the existence of an atmosphere to Jupiter, a conclusion which has since been verified by other evidence. From this work Sampson deduced a new set of elements by comparison with a theory which was based on Souillart's development of Damoiseau's work. But when the individual observations were compared with this theory, using the new elements, the remaining discrepancies proved to be substantial in many cases, and Sampson was of the opinion that the observations could not be blamed. It was also clear that the discrepancies could not be removed by an attempt to develop the existing theory further, and with characteristic patience he set to work out the theory afresh. This work was completed by the time he left Durham, and the tables based on the theory were published by the University of Durham in 1910 under the title, Tables of the Four Great Satellites of Jupiter. These are the tables which have since formed the basis for computing the phenomena for the National Ephemerides. It was not, however, until 1921 that the new theory itself was published in vol. lxiii of the Society's Memoirs. In the course of revision subsequent to the publication of the Tables a few omissions were found, and they are tabulated in the last chapter of the memoir.
But in spite of the refinements introduced by the new theory, substantial residuals still remained when comparison was made with observation. De Sitter, who subsequently completed a further theoretical development, found that, contrary to expectation, the photometric observations are affected by systematic errors of the same order of magnitude as those found in ordinary observations of the first and last speck of light. This being so, it is now seen to be inadvisable to derive elements from eclipse observations alone, which are apparently subject to errors which may be as large as 105, and De Sitter's work is based on other available observations, including the measurements made with the Cape heliometer. But Sampson's research remains as a necessary stage in our efforts to obtain a really satisfactory theory of Jupiter's Galilean Satellites, which, on account of the smallness of their periods of revolution, are of special importance for the study of secular and long periodic perturbations in addition to the interest introduced by the commensurability of the mean motions of the three inner ones.
During his Durham days Sampson had undertaken and performed a task which was very much after his own heart. The Cambridge University Press was publishing the collected works of J. C. Adams, who had been Sampson's tutor. The first volume comprising all the published papers appeared in 1896, but there remained many papers on various branches of astronomy which were left in an incomplete state among Adams' manuscripts.
The papers were practically devoid of arrangement; they were folded in parcels of a few pages each, and although the contents of the individual parcels were generally very clear in themselves, they carried no indication of their purposes or their relations to each other. Fortunately all the pages were dated and this permitted reference to a diary, but none the less the task of editing, which had been undertaken by Sampson, was almost herculean. However, he carried through with this difficult work, and the papers finally were published in 1900 as Part I of the second volume (Part II contained Adams' researches on Terrestrial Magnetism). The portion giving Adams' Lectures on the Lunar Theory was reprinted as a separate book, and in addition Sampson wrote a description (published in vol. liv of the Society's Memoirs) of Adams' manuscripts on the Perturbations of Uranus, with special reference to the 1843 manuscript containing his first solution of the problem, which was reproduced in facsimile in Sampson's memoir. Sampson's scholarly mind and great patience made him peculiarly fitted to undertake this kind of work, and in 1904 he was asked to undertake the task of editor-in-chief of a complete edition of Newton's scientific works and correspondence. He would doubtless have carried out this enterprise with conspicuous success, but unfortunately the scheme fell through. Sampson had prepared a memorandum setting forth the outline of the proposed edition, and in 1924, stimulated by J. L. E. Dreyer's Presidential Address "On the Desirability of Publication of Isaac Newton's Collected Works," delivered at the Annual Meeting of the Society in that year, he wrote a note entitled "On Editing Newton," which included the original memorandum together with some general remarks on Dreyer's proposal. This note was published in the Monthly Notices for March 1924.
In December 1910 Sampson was appointed Astronomer Royal for Scotland, and Professor of Astronomy in the University of Edinburgh in succession to F. W. Dyson. At that time the Royal Observatory, Edinburgh, had just completed a meridian catalogue of zodiacal stars, and was busily engaged in the measurement of the plates for three zones of the Perth (Western Australia) section of the Astrographic Catalogue. It fell to Sampson's lot to supervise the completion of this work, but as a result of very unfortunate circumstances the measures have not yet been published. During the first part of his regime double-star work and spectroscopic observations of the Sun were continued. By 1914 we find his Annual Report laying great stress on all matters connected with the determination of Time, and right up to the end of his career his interest in this branch of astronomy never flagged. He also maintained his earlier interest in optical problems, and a paper by him entitled "On a Cassegrain Reflector with Corrected Field" was published in 1913 in the Philosophical Transactions. A further paper "On Correcting the Field of a Newtonian Telescope" was published in the Monthly Notices for May in the same year. In this, as in other matters, Sampson was ahead of his time, but it should be placed on record that at this period he realised quite clearly the desirability and the possibility of correcting the fields of reflectors. And, as happened in other fields of activity, his suggestions were eventually destined to be followed up by others.
But to return to Sampson's interest in matters appertaining to Time. In spite of the curtailment of work occasioned by the war of 1914 to 1918, we see from his Annual Reports how he was pushing on with work of this kind. We now pass on to the post-war period, and in the Report for the year ending 1922 March 31 we find mention of "a valuable clock which has been lent to the observatory by Mr. W. H. Shortt, who devised and constructed it." This clock was the forerunner of the famous Shortt free pendulum clocks, and it is largely due to Sampson's co-operation in testing this type of clock that it has now become part of the standard equipment of so many observatories. The original model was subsequently presented to the observatory and is now known as Shortt No. o. Another free pendulum clock, Shortt No. 4, was installed in January 1925, by which time other observatories were already reaping the reward of Sampson's foresight and enterprise and were installing free pendulum clocks. Some years previously Sampson had published an important paper on clock errors and wireless time signals (M.N., 81, 1, 1920), in which he called attention to the serious discrepancies between time observations at different observatories. There can be no doubt that this paper greatly stimulated the interest of astronomers in the problem of time determination. As a result of the attention which has consequently been lavished on the problem, and of the appearance of the free pendulum type of clock, the discordances have now been greatly reduced.
A very striking example of Sampson's pioneering instinct is to be found in the work carried out at Edinburgh on the distribution of energy in the continuous spectra of stars. Sampson was interested in photometric research, and during the war years of 1914 to 1918 he instructed E. A. Baker to embark on photo-electric experiments. At this time the idea was to fit a cell on a telescope and obtain direct readings of stellar magnitudes (as has in fact been done by other workers), but the aim of the research changed and the result was the construction of a photo-electric photometer of the Koch type designed to measure the densities of star images on photographic plates. Then came the idea of applying the instrument to the measurement of images of stellar spectra. More research by Baker followed on the intensity-density relationship of photographic emulsions, and finally a spectrophoto-metric programme was commenced which yielded what have since become known as colour temperatures of stars, although Sampson used the term "effective temperature," which is now reserved to denote a different concept. The stress was now laid on the methods of photographic spectrophotometry as worked out by Sampson and Baker, and the photo-electric photometer took its place as an accessory instrument for measuring the densities of the spectra. The methods employed have since been copied and extended by other workers, who have found it necessary to calibrate each individual plate instead of using a single reduction curve for a whole batch as was done by Sampson. The results of the work appeared in two papers published in the Monthly Notices for January 1925 and May 1930, and it was in the first of these papers that Sampson introduced the conception of spectrophoto-metric gradient, which has now become commonplace in astrophysical literature. Sampson's gradients were all measured relatively to the star Polaris, and the whole system of gradients were reduced to colour temperatures by assuming a temperature for Capella. His papers show how valuable information can be obtained by the determination of relative gradients alone without the comparison with laboratory standards necessary to derive colour temperatures. Perhaps Sampson himself did not fully realise this, but his work was certainly responsible for stimulating others to concentrate on the measurement of relative gradients. Modifications in Sampson's original pioneer scheme were only to be expected, and it is now the custom to measure gradients relatively to the mean of a selection of Ao stars, thereby making them analogous with colour indices. But this and other subsequent modifications and improvements do not alter the fact that other workers in this field were inspired by Sampson's researches, and they know that their work is the logical continuation of the lead given at Edinburgh.
In the Edinburgh colour-temperature work the spectra were photographed with a 6-inch photo-visual to which an objective prism was attached. The exposures were necessarily long, and the programme was limited to stars brighter than the third magnitude. It had been obvious for some time that the observatory required extensive re-equipment, and in 1927 Sampson was able to announce that plans had been sanctioned for the erection of a 36-inch reflecting telescope and the acquisition of a new camera employing a 10-inch triplet lens. Provision was also made for a modern spectrograph to be attached to the 36-inch reflector and for other accessories. The new equipment was finally completed and installed in 1932.
Sampson's active career was now approaching its close. He continued in the direction of the observatory until 1937, when failing health hastened his retirement. For some months he travelled abroad, but eventually settled in the south of England, and on 1939 November 7 he died at Bath, being survived by his widow, a son and four daughters. He had been elected a Fellow of the Society in February 1892, and had been its President over the period 1915-17 and Vice-President for the two following years. In addition he served on the Council in the year 1909-10 and again from 1913 to 1915. He had been elected a Fellow of the Royal Society in 1903.
One of his most striking characteristics was his tremendous capacity for work. Mention has been made of his pioneering adventures, and it naturally happened that on occasions he embarked on a line of research which eventually proved fruitless; but his patience and persistence were wellnigh inexhaustible, and he would continue work in a particular direction long after a point had been reached at which other investigators would have given up the struggle. Beneath a superficially austere appearance he managed to conceal an essential geniality and a capacity for enjoying life. It cannot truly be said that he suffered fools gladly, he was no respecter of persons, and he judged others on a standard which was based on his own capacity for work. But to those who, in his eyes, came up to his requirements, he was essentially a helpful friend and colleague.
W. M. H. GREAVES
In 1890 an important academical event took place at Cambridge for which many students of astronomy have since had cause to be very thankful. This was the foundation, as a result of the munificent generosity of Mr. Frank McClean, of the Isaac Newton Studentship in Astronomy and Physical Optics. Sampson was the first holder of this Studentship, being elected in 1891. He accordingly returned to Cambridge and worked in astronomical spectroscopy with H. F. Newall, and the result of his activities was seen in 1893 when he published a paper of 62 pages in the Memoirs of the Society entitled, "On the Rotation and Mechanical State of the Sun." In the preface to this paper he wrote: "After proceeding a certain way with the theory of the Sun's rotation, it became evident that no conclusion could be reached without a satisfactory theory of the distribution of his internal temperature. With the existing theory of convective equilibrium I felt dissatisfied; accordingly I attempted the discussion of the distribution of temperature by radiation and absorption and arrived at a theory which is explained in Part I, Section 3."
Throughout his career Sampson showed himself to be essentially a pioneer, and like other pioneers he often initiated lines of study which were destined to be followed up and worked out by others. It is interesting to notice that his pioneering instinct was manifesting itself in these early days, and that it led him to advance the hypothesis of radiative equilibrium in a star's interior, a hypothesis which has since dominated the theory of the interior of a star. It is also interesting to contrast Sampson's earliest astronomical research with the considerations which probably influenced his decision to leave London and return to Cambridge as an Isaac Newton student. In his undergraduate days he had been a pupil of J. C. Adams, and his interest in astronomy was stimulated by this association. But Adams was primarily a dynamical astronomer, and one of the most important of Sampson's researches, the theory of Jupiter's satellites, was destined to be in the field of dynamical astronomy. But it was not in this field, but in the field of astrophysics, that his first research work was conducted, and it was to astrophysical research that Sampson turned at a later stage in his career when his heavy labours on Jupiter's satellites had been completed. Dynamical astronomy aroused the patient scholar in him, but astrophysics set the pioneer in action, and as we shall see presently, his later astrophysical activities were again noteworthy as being the first step into unoccupied territory.
In the autumn of 1893 Sampson was elected to the Chair of Mathematics in the Durham College of Science at Newcastle-on-Tyne, and in 1895 he removed to Durham itself as Professor of Mathematics at the University. He interested himself in the Durham Observatory, where he was responsible for the erection of the Durham Almucantar, a fundamental instrument of attractive principle, and it was at Durham that the work was commenced which eventually led to the award of the Society's Gold Medal in 1928.
The theory of the Four Great Satellites of Jupiter had engaged the attention of the great dynamical astronomers of the nineteenth century. It is a particularly fascinating subject on account of the relation between the mean motions of Satellites I, II and III. But the state of the theory in which it was left by Delambre was disappointing in view of the large residuals which remained after comparison with observations of the eclipses of the satellites. Part of the trouble was felt to be due to the rather unsatisfactory nature of the observations of disappearance and reappearance at eclipse, and Sampson felt that the advent of the Harvard photometric eclipse observations warranted a re-examination of the whole question. He began with a careful discussion of the eclipse observations themselves, which was published in Harvard Annals, 52, and incidentally he considered that the peculiarities of many of the light-curves gave evidence of the existence of an atmosphere to Jupiter, a conclusion which has since been verified by other evidence. From this work Sampson deduced a new set of elements by comparison with a theory which was based on Souillart's development of Damoiseau's work. But when the individual observations were compared with this theory, using the new elements, the remaining discrepancies proved to be substantial in many cases, and Sampson was of the opinion that the observations could not be blamed. It was also clear that the discrepancies could not be removed by an attempt to develop the existing theory further, and with characteristic patience he set to work out the theory afresh. This work was completed by the time he left Durham, and the tables based on the theory were published by the University of Durham in 1910 under the title, Tables of the Four Great Satellites of Jupiter. These are the tables which have since formed the basis for computing the phenomena for the National Ephemerides. It was not, however, until 1921 that the new theory itself was published in vol. lxiii of the Society's Memoirs. In the course of revision subsequent to the publication of the Tables a few omissions were found, and they are tabulated in the last chapter of the memoir.
But in spite of the refinements introduced by the new theory, substantial residuals still remained when comparison was made with observation. De Sitter, who subsequently completed a further theoretical development, found that, contrary to expectation, the photometric observations are affected by systematic errors of the same order of magnitude as those found in ordinary observations of the first and last speck of light. This being so, it is now seen to be inadvisable to derive elements from eclipse observations alone, which are apparently subject to errors which may be as large as 105, and De Sitter's work is based on other available observations, including the measurements made with the Cape heliometer. But Sampson's research remains as a necessary stage in our efforts to obtain a really satisfactory theory of Jupiter's Galilean Satellites, which, on account of the smallness of their periods of revolution, are of special importance for the study of secular and long periodic perturbations in addition to the interest introduced by the commensurability of the mean motions of the three inner ones.
During his Durham days Sampson had undertaken and performed a task which was very much after his own heart. The Cambridge University Press was publishing the collected works of J. C. Adams, who had been Sampson's tutor. The first volume comprising all the published papers appeared in 1896, but there remained many papers on various branches of astronomy which were left in an incomplete state among Adams' manuscripts.
The papers were practically devoid of arrangement; they were folded in parcels of a few pages each, and although the contents of the individual parcels were generally very clear in themselves, they carried no indication of their purposes or their relations to each other. Fortunately all the pages were dated and this permitted reference to a diary, but none the less the task of editing, which had been undertaken by Sampson, was almost herculean. However, he carried through with this difficult work, and the papers finally were published in 1900 as Part I of the second volume (Part II contained Adams' researches on Terrestrial Magnetism). The portion giving Adams' Lectures on the Lunar Theory was reprinted as a separate book, and in addition Sampson wrote a description (published in vol. liv of the Society's Memoirs) of Adams' manuscripts on the Perturbations of Uranus, with special reference to the 1843 manuscript containing his first solution of the problem, which was reproduced in facsimile in Sampson's memoir. Sampson's scholarly mind and great patience made him peculiarly fitted to undertake this kind of work, and in 1904 he was asked to undertake the task of editor-in-chief of a complete edition of Newton's scientific works and correspondence. He would doubtless have carried out this enterprise with conspicuous success, but unfortunately the scheme fell through. Sampson had prepared a memorandum setting forth the outline of the proposed edition, and in 1924, stimulated by J. L. E. Dreyer's Presidential Address "On the Desirability of Publication of Isaac Newton's Collected Works," delivered at the Annual Meeting of the Society in that year, he wrote a note entitled "On Editing Newton," which included the original memorandum together with some general remarks on Dreyer's proposal. This note was published in the Monthly Notices for March 1924.
In December 1910 Sampson was appointed Astronomer Royal for Scotland, and Professor of Astronomy in the University of Edinburgh in succession to F. W. Dyson. At that time the Royal Observatory, Edinburgh, had just completed a meridian catalogue of zodiacal stars, and was busily engaged in the measurement of the plates for three zones of the Perth (Western Australia) section of the Astrographic Catalogue. It fell to Sampson's lot to supervise the completion of this work, but as a result of very unfortunate circumstances the measures have not yet been published. During the first part of his regime double-star work and spectroscopic observations of the Sun were continued. By 1914 we find his Annual Report laying great stress on all matters connected with the determination of Time, and right up to the end of his career his interest in this branch of astronomy never flagged. He also maintained his earlier interest in optical problems, and a paper by him entitled "On a Cassegrain Reflector with Corrected Field" was published in 1913 in the Philosophical Transactions. A further paper "On Correcting the Field of a Newtonian Telescope" was published in the Monthly Notices for May in the same year. In this, as in other matters, Sampson was ahead of his time, but it should be placed on record that at this period he realised quite clearly the desirability and the possibility of correcting the fields of reflectors. And, as happened in other fields of activity, his suggestions were eventually destined to be followed up by others.
But to return to Sampson's interest in matters appertaining to Time. In spite of the curtailment of work occasioned by the war of 1914 to 1918, we see from his Annual Reports how he was pushing on with work of this kind. We now pass on to the post-war period, and in the Report for the year ending 1922 March 31 we find mention of "a valuable clock which has been lent to the observatory by Mr. W. H. Shortt, who devised and constructed it." This clock was the forerunner of the famous Shortt free pendulum clocks, and it is largely due to Sampson's co-operation in testing this type of clock that it has now become part of the standard equipment of so many observatories. The original model was subsequently presented to the observatory and is now known as Shortt No. o. Another free pendulum clock, Shortt No. 4, was installed in January 1925, by which time other observatories were already reaping the reward of Sampson's foresight and enterprise and were installing free pendulum clocks. Some years previously Sampson had published an important paper on clock errors and wireless time signals (M.N., 81, 1, 1920), in which he called attention to the serious discrepancies between time observations at different observatories. There can be no doubt that this paper greatly stimulated the interest of astronomers in the problem of time determination. As a result of the attention which has consequently been lavished on the problem, and of the appearance of the free pendulum type of clock, the discordances have now been greatly reduced.
A very striking example of Sampson's pioneering instinct is to be found in the work carried out at Edinburgh on the distribution of energy in the continuous spectra of stars. Sampson was interested in photometric research, and during the war years of 1914 to 1918 he instructed E. A. Baker to embark on photo-electric experiments. At this time the idea was to fit a cell on a telescope and obtain direct readings of stellar magnitudes (as has in fact been done by other workers), but the aim of the research changed and the result was the construction of a photo-electric photometer of the Koch type designed to measure the densities of star images on photographic plates. Then came the idea of applying the instrument to the measurement of images of stellar spectra. More research by Baker followed on the intensity-density relationship of photographic emulsions, and finally a spectrophoto-metric programme was commenced which yielded what have since become known as colour temperatures of stars, although Sampson used the term "effective temperature," which is now reserved to denote a different concept. The stress was now laid on the methods of photographic spectrophotometry as worked out by Sampson and Baker, and the photo-electric photometer took its place as an accessory instrument for measuring the densities of the spectra. The methods employed have since been copied and extended by other workers, who have found it necessary to calibrate each individual plate instead of using a single reduction curve for a whole batch as was done by Sampson. The results of the work appeared in two papers published in the Monthly Notices for January 1925 and May 1930, and it was in the first of these papers that Sampson introduced the conception of spectrophoto-metric gradient, which has now become commonplace in astrophysical literature. Sampson's gradients were all measured relatively to the star Polaris, and the whole system of gradients were reduced to colour temperatures by assuming a temperature for Capella. His papers show how valuable information can be obtained by the determination of relative gradients alone without the comparison with laboratory standards necessary to derive colour temperatures. Perhaps Sampson himself did not fully realise this, but his work was certainly responsible for stimulating others to concentrate on the measurement of relative gradients. Modifications in Sampson's original pioneer scheme were only to be expected, and it is now the custom to measure gradients relatively to the mean of a selection of Ao stars, thereby making them analogous with colour indices. But this and other subsequent modifications and improvements do not alter the fact that other workers in this field were inspired by Sampson's researches, and they know that their work is the logical continuation of the lead given at Edinburgh.
In the Edinburgh colour-temperature work the spectra were photographed with a 6-inch photo-visual to which an objective prism was attached. The exposures were necessarily long, and the programme was limited to stars brighter than the third magnitude. It had been obvious for some time that the observatory required extensive re-equipment, and in 1927 Sampson was able to announce that plans had been sanctioned for the erection of a 36-inch reflecting telescope and the acquisition of a new camera employing a 10-inch triplet lens. Provision was also made for a modern spectrograph to be attached to the 36-inch reflector and for other accessories. The new equipment was finally completed and installed in 1932.
Sampson's active career was now approaching its close. He continued in the direction of the observatory until 1937, when failing health hastened his retirement. For some months he travelled abroad, but eventually settled in the south of England, and on 1939 November 7 he died at Bath, being survived by his widow, a son and four daughters. He had been elected a Fellow of the Society in February 1892, and had been its President over the period 1915-17 and Vice-President for the two following years. In addition he served on the Council in the year 1909-10 and again from 1913 to 1915. He had been elected a Fellow of the Royal Society in 1903.
One of his most striking characteristics was his tremendous capacity for work. Mention has been made of his pioneering adventures, and it naturally happened that on occasions he embarked on a line of research which eventually proved fruitless; but his patience and persistence were wellnigh inexhaustible, and he would continue work in a particular direction long after a point had been reached at which other investigators would have given up the struggle. Beneath a superficially austere appearance he managed to conceal an essential geniality and a capacity for enjoying life. It cannot truly be said that he suffered fools gladly, he was no respecter of persons, and he judged others on a standard which was based on his own capacity for work. But to those who, in his eyes, came up to his requirements, he was essentially a helpful friend and colleague.
W. M. H. GREAVES
Ralph Allen Sampson's obituary appeared in Journal of the Royal Astronomical Society 100:4 (1940), 258-263.