Franci Galton, Memories of My Life,
General Sir E. Sabine--Sextants and watches--Now merged into National Physical Laboratory--Meteorological Committee, subsequently Council of the Board of Trade - Self-recording instruments, reduction of their tracings--Henry Smith
AN early friendship that exercised great influence in shaping my future scientific life was that of General Henry Smith afterwards Sir Edward, Sabine, R.A., and President of the Royal Society. At the time of which I am speaking he was its Treasurer; he also held two offices, in both of which I was his successor after some years. They were the Chairmanship of the Kew Observatory and the Secretaryship of the British Association, as already mentioned. General Sabine (1788-1883)devoted himself to the study of magnetism, to its geographical distribution and its periodic and irregular variations. He had joined an Arctic Expedition for the express purpose of making exact magnetical observations in high latitudes, and he had inspired zealous and capable men, at various stations about continuous and comparable observations. This involved careful examinations of the j'efined instruments about to be employed, and of instruction in their use. Means for doing all this were established by him at Kew.
The history of the Kew Observatory is far too complicated to be fully described here. It was first instituted owing to the desire of many of the foremost men in physical science, in the early days of the British Association, to have access to a place where physical experiments might be made, and new instruments tested. The Observatory stands in the Old Deer Park, Richmond, adjoining the Kew Gardens. It was originally built for the amusement of George III., while he was more or less insane, and it was begged for by the philosophers and allotted by Government to their use. Its maintenance was defrayed by considerable grants annually voted by the British Association, that mounted at one time to as much as L6oo. This became far too onerous a charge for their means, so various changes were made in its government and maintenance. At length it fell into the hands of the Royal Society, and was managed by a committee appointed by that body from among its members. It paid its way by charges made for standardising instruments, supplemented by occasional grants. Later on, the interest of a handsome endowment of L1000 made by Mr. J. P. Gassiott, of whom more presently, placed it in a fairly firm position.
At the time when Sir Edward Sabine caused me to become a member of the Managing Committee, the Kew Observatory had obtained, through his exertions, a high and wide reputation for the exactness of the observations made there, and it had become the place where the outfits of all magnetic observatories, English and foreign, were standardised, and where intending observers were instructed. It was, in fact, the Central magnetic Observatory of the world. It held an almost equally strong position in respect to the delicate pendulum apparatus by which the force of gravity is measured at different places on the globe, and again with regard to standard thermometers and meteorological instruments generally. Its Managers were eager to extend its operations to any kind of self-paying scientific experiment. Any person desirous of having a new invention tested could get it well done there at a cost that just repaid the trouble, subject, of course, to the permission of the Managing Committee and to the leisure of the staff.
One of the first things that I busied myself about, when I joined it, was to establish means for standardising sextants and other angular instruments. The cheaper kinds of these were unnecessarily bad, and many of the more costly were by no means so good as they should be for their price. I thought at first of utilising heliostats to give sharp points of reference by adjusting minute mirrors at distant points, flashing the sun on to them from larger mirrors at the Observatory, and using the return flashes as the points of reference. One of these small mirrors was fixed to the south obelisk, within a cage which may still be there. This arrangement was so far successful that beautiful stars of light were produced in response to flashes from the Observatory, but the uncertainty of sunshine in our climate showed the method to be of little practical value. Then Messrs. Cooke of York, who were among the foremost makers of large telescopes, devised an arrangement with collimators and artificial light. They made one for Kew, which is contained within a small dark room, and has acted perfectly, to a considerable improvement in the make of the cheaper sextants.
Another thing that I did was to contrive an apparatus by which thermometers could be rapidly and yet very accurately verified, and by which from ten to twenty thousand clinical thermometers are still annually tested. Mr. De la Rue gave me help in devising this. The few pence gained on each of these many thermometers amounted to a respectable sum, and confirmed the solvency of the institution, whose margin of profit over loss was always small and had been precarious. We were thus in a better position to extend our work and to add to our instruments, and we did so.
Another operation which I was among the first, if not the first, to suggest, was the rating of watches. This has been a real success. The performances of watches, when we first took the matter in hand, was by no means proportionate to their cost, more than one highly ornamented and expensive time-keeper failing to obtain a class-place equal to that of others of much inferior pretensions. Now a Kew certificated watch has a special and recognised value, and the makers of valuable watches are far more on their mettle than they used to be.
The influence of the Kew verifications as time went on extended in many other directions, as by testing the performance of telescopes and opera-glasses supplied to the army and navy, in order to ascertain whether their capabilities were up to the specified standard. Mariners' compasses of complicated and delicate construction were also dealt with. A beautiful apparatus devised by Sir Wm. Abney and Major Leonard Darwin was subsequently set up to test photographic lenses, and to enable appropriate certificates to be given them.
So the institution throve, and was a "going concern," but it was wholly unequal in its scale to the rapidly growing requirements of the day. This feeling found expression in the Anniversary Address to the British Association in 1895, by my cousin Sir Douglas Galton; powerful support was given to his suggestions and efforts, and finally the Kew Committee was merged into the much larger and more important National Physical Observatory, under the directorship of Mr. Glazebrook, which swallowed at a single gulp the whole of our thrifty savings.
I look back with pleasure to my long connection with the Kew Observatory, for its Committee always consisted of very capable men, who gave time without stint to the discussion of the new questions which continually arose, and which could be answered by experts only.
Mr. Gassiott (1797-I877), of whom I have spoken, succeeded Sir Edward Sabine as its Chairman. He was remarkable for solid sense and business acumen, and played a considerable part in the work of the Royal Society. His experiments on electric discharges in quasi-vacuo were very beautiful, and thought highly of at the time. He was a striking instance of the combination of scientific research with the direction of an important business, for he was one of the principal wine merchants, and said to be the largest importer of port wine in London.
Another instance of the same combination was his successor in the same office, Mr. Warren De la Rue (1815-I889), the famous stationer, whose mechanical ingenuity, artistic taste, and business habits were most valuable. I have served with him on various Councils, where his help and influence were always felt. I shall have shortly again to speak of him. The pretty Kew monogram was his design:
I became Chairman of the Observatory in succession to Mr. De la Rue in 1889, and held that post until 190I, when it ceased to be an independent body. The Observatory has been fortunate in its particularly able Superintendents, Sir Francis Ronalds of electric fame, Dr. Balfour Stewart, subsequently Professor at Owen's College, Manchester, Mr. Whipple, a man of considerable natural gifts, and Dr. Cree, now President of the Physical Society. Many members of their staff were very trustworthy and valuable officials.
Much interest in the laws of the weather had been aroused long previously to I86o, and it was then clearly understood by those who studied them that future progress depended on securing numerous observations made at the same moment, during many years, at stations scattered over a wide area. The popular book of Maury in America and the writings of Admiral FitzRoy drew attention to this need; and Le Verrier, the French astronomer, issued daily charts of the Atlantic, based on such observations as he could obtain from ships and coast stations. But these were so few compared to the area over which they were scattered, and so unequally distributed, that too much guess-work was needed to combine their information into coherent and reasonable systems.
The only fairly well understood feature in those times, of movements of the air, was that of the cyclone, or the huge tropical whirlwind carrying destruction with it. It had been observed that when these whirlwinds occurred in the northern hemisphere they circled in the opposite direction to that of the hands of a clock, round a centre of low barometric pressure, and therefore round an area of uprush of heated and moist air, accompanied, as it would be, with heavy rains. This circling was justly attributed to the spherical shape of the earth in combination with its easterly rotation. An indraught, coming from the direction of the equator, was impressed with an excess of easterly movement, and one from the nearest pole With a deficiency; in other words, the latter had a westerly movement relatively to the place of observation. The observed twist was the necessary result of their coming together. An opposite direction of twist occurred, as would have been expected, in the two hemispheres; in the southern one, the whirlwind circled round the area of uprush in the same direction as the hands of a clock. It was also surmised, that the direction of the wind in ordinary weather was everywhere governed by the same twisting conditions as in the terrible cyclones of the tropics, where it had first been noticed.
I felt greatly disposed to examine more closely into these movements of the air, and it occurred to me that enough help for the purpose might be obtained in Europe from existing observatories, light-houses, and ships 'in the neighbouring seas. They would enable an experimental map to be made thrice daily for a month, in which the observations should be at stations much closer together than those in the maps of Le Verrier, and yet would embrace a sufficiently large area to exhibit the details of a complete weather system. I took a great deal of pains about this, and finally succeeded in 1862 in obtaining what was wanted.
It was with no small eagerness that I set to work to map out the data. The month began under cyclonic conditions; then, to my intense delight, as that system passed by, it was followed by a condition of affairs the exact opposite to the cyclone, and supplementary to it. The cyclone, as already said, is an uprush of air, associated with a low barometer and clouds, due to the hot and moist air becoming chilled as it rose, and it was fed, as just described, by an indraught with an anti-clock-ways twist in the northern hemisphere. That which I now found, during the latter part of the month in question, was a downrush of air associated with a high barometer and a clear sky, and with an outflow having a clock-ways twist. The one system was clearly supplementary to the other. So in the memoir I contributed on the subject to the Royal Society , I called the newly discovered system an "Anti-cyclone." Speaking broadly, the whole of the movements of the lower strata of the air are now looked upon as a combination of cyclones and anti-cyclones, which feed one another. The name established itself at once, and is now familiar.
The present daily weather charts of the Times, from data supplied by the Meteorological Office, began to appear at a subsequent date, and I took considerable part in their early construction. I had also made many previous attempts to represent the distribution of the weather in a form suitable for printing with movable types. With the aid of Mr. W. Spottis-woode I had types cut for me of appropriate forms, and casts from them were used in the set of my published charts based on the above-mentioned data (Meteorographica (Macmillan), 1863) [i7-1, but these were not a success. Later I tried the plan of cutting curves and arrows in soft material by a drill panta-graph, whence casts might be taken for printing. A drill pantagraph is made like an ordinary one, except that the pencil is replaced by a drill, which is rotated by a string that passes over the joints and does not hinder the movements of its arms. I do not know whether this plan of making the weather maps is still adopted. It was submitted to the Times by the Meteorological Council, through their Secretary, and I still have the first trial stereotype that was cast on this principle. I heard that there was trouble at first in finding a suitable soft material better than plaster of Paris and the like, but that this difficulty of detail was soon overcome.
I have already mentioned Admiral R. FitzRoy (1805-1865). He was captain of the surveying ship The Beagle, whose name became familiar to the public through Charles Darwin's Voyage of the "Beagle." He had always been most zealous in the advancement of weather forecasts and storm warnings. The "cone" was his device. A Meteorological Office was established under his superintendence in i854, entirely owing to his exertions, but it was on a very small scale. His publications unfortunately failed in scientific solidity, and were occasionally open to serious criticism. I myself ventured to attack them in some particulars which it is needless now to recall.
On his lamented death it was determined to reconstruct the office, and a small Departmental Committee of the Board of Trade was named to consider the question. It consisted of Mr., afterwards Lord, Farrer (I819-I899), who was then the Secretary of the Board, the then Hydrographer, Captain, afterwards Sir Frederick, Evans ( i8i 5-i885), and myself. We reported in x 866, and I. must here pay a tribute to the singular grasp and thoroughness of Lord Farrer, whose occasional brief notes to me, in the course of the inquiry, were models of clearness combined with cordiality.
The result was the formation of a Meteorological Committee in I868, of which I was a member, for giving storm warnings to seaports, for procuring data for marine charts of weather, and for maintaining a few standard Observatories with self-recording instruments. An annual grant was made to meet its expenses. This avowedly provisional arrangement worked well for some years, when it was felt that the Scope of the Meteorological Committee ought to be somewhat enlarged and its constitution reconsidered. So a second Government Committee was appointed by the Board of Trade and the Treasury jointly, of which I was again a member, and in consequence of their Report the "Meteorological Committee" was changed into the "Meteorological Council," with an enlarged grant. It continued in this form until x9o5, a little after I had retired from it owing to increasing deafness. It has subsequently been modified anew, and is now under the Directorship of Dr. W. N. Shaw, with a large governing body, whose meetings are much less frequent than those of the Council had been, and interfere less in details.
My long connection with the able men with whom I co-operated for nearly forty years on the Meteorological Committee and Council has given very great pleasure to me, and I had the satisfaction in its earlier days, when new instruments and methods were frequently called for, of being able to do my full share of the work.I will mention only one or two things about whichI was much occupied, as examples.
Part of our action was to maintain a few well-equipped self-recording Observatories--that is to say, where the instruments wrote down their own movements, photographically or otherwise. For instance, a sheet of photographic paper was moved slowly by clock-work in front of a barometer. The barometer stood in front of a slit in a screen, with a lamp on the other side. The light of the lamp passed freely through the empty portion of the glass tube on to the sensitive paper, but was shut off by the mercury. Ilour lines were automatically marked upon the paper. The result was technically called a photographic "tracing," which showed at each momd'nt of time how the barometer then stood. An analogous contrivance was' adapted to every one of the other instruments.
All the instrumental data were recorded by these tracings, but they were much too cumbrous in form and size for easy comparison. The question then arose whether it would not be possible to reduce these voluminous documents and print them in a compendious yearly volume. If so, the tracings would require very much more reduction in breadth than in height, for the photographic mark made by the recorder was so broad that the scale of the tracing had to be proportionately wide open; otherwise the neighbouring irregularities would blur together. A sharp line drawn along the middle of the tracings might, however, be much compressed laterally and yet show all the irregularities distinctly. I designed a compound drill pantagraph for the purpose, which reduced the tracings in height independently of the reduction in length. One part of the machine worked the drill forward and backwards, the other part moved the plate from side to side upon which it worked. The result was to express the tracings by fine grooves cut into a piece of soft metal. These were again reduced by an ordinary pantagraph. The whole process required thinking out in numerous details, but it proved quite a success. It is described in the annual Report of the Meteorological Office for 1869.
Squares of zinc, one for each day, were grooved by the drill pantagraph so as to show every one of the data without confusion. They referred to Wind Velocity and Direction, Barometric Height, Rainfall, Dry and Wet Thermometer, together with a line to show the amount of Humidity in the air, which was mechanically calculated from the combined traces of the two thermometers. These squares were placed beneath a large and beautifully designed German pantagraph, whose pointer was directed along the grooves in the zinc, while the diamond point of the scribe scratched the varnish on a copper plate, which was then etched by acid. The result was to produce quarto copper plates, each containing the whole of the instrumental data for each of the seven stations for five consecutive days. The original tracings are reduced to the ratio of 6: I in horizontal and 2: I in vertical measure. This work was steadily pursued for twelve years, which is long enough to include a complete cycle of solar sun-spots. The illustration is a facsmile of the upper two lines of one page, from which the fourth and fifth days have been removed, for want of space.
It surprises me that meteorologists have not made much more use than they have of these comprehensive volumes. But there is no foretelling what aspect of meteorology will be taken up by the very few earnest and capable men who work at it. Each of them wants voluminous data arranged in the form most convenient for his own particular inquiry.
I take this opportunity of mentioning another attempt of mine which was not brought into practice but may hereafter be useful; at all events, it is of interest. The object was to gain some knowledge of the upper currents of the air, such as are now being obtained by small balloons or kites, which carry self-recording instruments. It seemed to me that the cloud made by a bursting shell fired high in the air over the sea, at a little frequented part of the coast, as that of West Ireland, when no vessel was within the possibility of damage from falling fragments, ought to give what was needed. The first questions to be answered were as to the height to which a shell of appropriate size could be sent, the visibility of the result, and the cost of each experiment. Sir Andrew Noble kindly undertook to make experiments for the Office, using a I o-pounder gun that happened to be at the Armstrong Works at Elswick. It had been designed especially for shooting at balloons, and was furnished with the necessary spring for preventing harm from recoil. The results were very good and consistent. The shells burst at a constant height of about 9000 feet, and gave a conspicuous and durable cloud of smoke, whose drift could be easily seen and its rate calculated. I designed a camera-obscura arrangement to do this conveniently. The recorded interval of time between the explosion as seen and as heard, was an adequate measure of the distance of the shell-burst. It could be ascertained with more care when desired, and in more than one way. The cost of each shot was about ten shillings. This method of observation was not followed up, as none of the existing stations were thought suitable, and it was difficult to find one that would be so, considering that easy telegraphic connection with the Meteorological Office was a necessity. Again, the method would be useless in cloudy weather. It may possibly be of future service for inquiries into the varying thickness of the Trade winds in particular localities.
Yet another attempt of mine may be mentioned. Chiefly through the initiative of Admiral Fitzroy, "Wind roses," as they are called; were calculated for the various Ocean districts, bounded by lines of latitude and longitude lo degrees apart. They formed adjacent rectangles or "squares" in the maps used by seamen, which are always drawn on "Mercator's projection." The "rose" consists of divergent spikes directed towards each of the sixteen primary points of the compass, whose several lengths are proportional to the frequency of winds in their direction. A shade or other sign shows the proportion of the winds above a specified strength. Consequently the roses afford means for judging which of two competing courses receives, on the average, the greater share of favourable winds. But it is no easy matter to calculate by mother-wit the relative efficiency of the winds as expressed by roses, upon the run of a ship along any particular course. Almost every wind can be utilised to some degree; we want to know the aggregate effect in the required direction of the average of the winds from all the sixteen primary points. I showed how this could be found mechanically for any ship whose sailing qualities were known, and suggested that "passage roses" should be calculated for a typical vessel wherever wind roses existed. I think this would have been taken in hand, had not steam begun to largely supersede sails, and was doing so at a rapidly increasing rate.
I was rather scandalised by finding how little was known to nautical men of the sailing qualities of their own ships, along each of the sixteen points of the compass, assuming a moderate sea, and a moderate wind blowing steadily from one direction. I think, if I had a yacht, that this would be the first point I should wish to ascertain in respect to her performances.
When the Meteorological Council was established, its first President was that most accomplished classical scholar, as well as mathematician, Professor Henry Smith (I826-x883)of Oxford, to whose memory the highest tributes have been paid, notably by Sir Mountstuart E. Grant Duff. It was delightful to watch his facility in dealing with difficulties, whether of administration or expression. The Chairman usually has to remain in the Office after the meetings are closed to write letters connected with what has just been transacted. The Secretary, Mr. Robert Scott, was of course present at those times, and he told me of a peculiarity of Henry Smith that I should never have guessed, namely, that when an important letter had to be written, it was his habit tO begin by filling a half-sheet and then tearing it up to begin afresh. I myself am very familiar with the way in which the mind settles itself while writing the address and date and the "Dear Sir," but should have thought from the exceptional rapidity of the ordinary working of Henry Smith's mind that he would have been the last person to need a long pause to give his ideas time to crystallise.
Notwithstanding his multifarious duties and interests, he worked hard at the inquiries of the moment. In one of these I was closely associated with him, namely, in an attempt to armlyse the extremely complex system of ocean currents round the Cape and up the West Coast of South Africa. They admit of being identified and distinguished partly by their direction and partly by their temperature. Volumes of cold water coming from the direction of the South Pole sometimes plunge far below the surface and reappear in the midst of an otherwise unbroken surface current.
It was a great shock and grief to us all when, without previous forewarning, intelligence reached us of Henry Smith's death, after a brief but singularly painful illness in 1883.
We all looked to General, afterwards Sir Richard, Strachey (1807-1908) to succeed him, which he did. He too has died only two days before I write these lines. A prominent place ought to be given to him in my "Memories," for we have been connected in our pursuits very frequently and in very different ways. He was one of the hardest and most unobtrusive of workers, who exercised a powerful influence in many great matters, especially in India, but shrank from publicity and ostentation. Like most master minds, he had a characteristic way of looking at things that is hard to describe. It often led to his taking an unpopular side in discussions, though by treating the question very clearly from his own point of view he caused his opinion to be at last accepted. He has been a steadfast friend to me throughout my life. I cannot refrain from quoting the official letter he wrote as Chairman of the Meteorological Council, when I resigned my seat, it is so gracefully and kindly expressed.
May 9, 1901
"DEAR MR. GALTON, The new body of Directors of the Office held their first meeting on Wednesday, 4th April. In the letter from the Royal Society notifying their appointment, there was a paragraph intimating that the resignation of your seat on the Council had been accepted.
It was only natural that the first act of the new body should be to recall the long period during which you have occupied a seat either on the original
Meteorological Committee or the Council, and to endorse, with the emphasis arising from their full knowledge of your work, the appreciation which the President and Council of the Royal Society recorded in their letter.
It therefore becomes a duty, by which I am no little honoured, to convey to you the feeling of the Council upon the termination of your official services as a Member of the body on which we have so long worked together. This task I undertake with a full sense of the difficulty of adequately expressing the extent to which the work of the Meteorological Office is indebted for its success and utility to your services, which have extended over thirty-four years.
It is no exaggeration to say that almost every room in the Office and all its records give unmistakable evidence of the active share you have always taken in the direction of the operations of the Office. The Council feel that the same high order of intelligence and inventive faculty has characterised your scientific work in Meteorology that has been so conspicuous in many other directions, and has long become known and appreciated in all centres of intellectual activity.
"With the Office entering upon a new phase of its service to the public, it is impossible for the Council not to feel that the work of the past thirty-four years has only opened the way, as all good work does, for further development. I am confident that you will still be interested in the success of the undertaking in which you have had so great a share,'and the Council will value in the future, as they have done in the past, any suggestion you may make about the work of the Office.
Believe me, very faithfully yours,
(Sgd.) RICHARD STRACHEY, Chairman"
It is needless to say more than that I was greatly touched by this letter. I was also so much impressed with its literary skill, that on calling shortly after on Sir Richard I begged him, as a matter about which I felt curious on purely literary grounds, to tell me its origin. He said that it was really his own writing, though based on a draft prepared at the Office, and added, "And it is all strictly true." Persons are to be envied who can express their feelings so gracefully as in that letter.