Hardcastle was born in 1868, and educated at Harrow. He came of a distinguished family, since his parental grandfather (also named Joseph) had been a prominent Member of Parliament, while his other grandfather was no less a person than Sir John Herschel, whose third daughter, Maria Sophia, had married Henry Hardcastle.
It would have been surprising if young Joseph had not developed an interest in science, and in point of fact he showed his ability early on. He was head of the Modern side at Harrow, and won the Neeld Gold Medal for Mathematics in 1886. He then sat for, and passed, the examination for the Indian Civil Service, but instead he decided to go to Trinity College, Cambridge, to take a degree. This was in 1887. For family reasons he left Cambridge in the following year, and made up his mind to follow a business career. He settled upon brewing, which was at least much more down-to-earth than astronomy.
Unfortunately his health gave trouble in 1890, and from then onward he was never physically strong. English winters did not suit him, and he did his best to avoid them; sometimes he went to Switzerland and sometimes to Italy, while on one occasion he wintered in Egypt, working at a bank in Alexandria. An exacting business career seemed to be out of the question, so in 1897 he went back to Cambridge to take his degree - only to be stopped yet again by health difficulties.
In 1899 he married, and decided that the best course would be for him to abandon business entirely, giving his full time to lecturing about the subject which he really loved: astronomy. Becoming a free-lance is always somewhat hazardous, but in Hardcastle's case it proved to be a wise step. He was a first-class speaker, and he had the ability to make his subject really fascinating; for instance, he was a skilled maker of astronomical models. Before long he had become well-known, and was given what may be termed "official status" in 1901, when he was put on the list of lecturers of the Cambridge Extension Syndicate and the Oxford University Extension Delegacy.
His lecturing did not mean that he gave up actual research. He spent various periods working at the Oxford University Observatory, and in 1903 he went to live at Crowthorne, in Berkshire, specially to help in a new project. This concerned the positions of craters and other formations on the disk of the Moon.
The first good lunar map had been produced in 1837 by two Germans, W. Beer and T. H. Mädler. It was on a small scale, and was compiled with the aid of a small telescope - Beer's 3.75in. Fraunhofer refractor - but for its time it was extremely accurate. Later, more elaborate charts were produced, on larger scales; there was, in particular, the 1878 lunar map due to Julius Schmidt, also German by birth, but for many years Director of the Athens Observatory. But if a really accurate map were to be produced, photography had to be called in. Visual work had its limitations, and the British Association project in which Romney Robinson had been involved had never made much progress.
By the end of the century, lunar photography had developed very considerably, thanks to the construction of major telescopes (usually refractors). and also to the improvement in photographic techniques. At the Paris Observatory, some good lunar pictures were taken by Loewy and Puiseux, and were used to draw up the first true photographic atlas of the Moon.
Matters are complicated by the effects known as librations, which cause the Moon to show a very slow, slight "rocking" motion in the sky, uncovering first a little of one limb and then a little of the other. (The Moon has, of course, a captured rotation; 41 per cent. of the surface is permanently averted from Earth, and remained unknown until photographed by Russian rockets, first by Lunik III in 1959 and then by Zond III in 1965.) And though Schmidt's and other charts were excellent, they did not have that last degree of precision which was needed.
The only solution was to take good, large-scale photographs, and measure the positions of various formations with respect to some main reference point. Once a "control network" had been established, the positions on the disk of other features could be measured. A well-known British amateur, S. A. Saunder, decided to undertake the task, and he borrowed four fine negatives from Loewy and Puiseux. He also obtained the loan of a micrometer, from Oxford, and set to work. His main reference point was the brilliant small crater Mösting A, which is visible and identifiable whenever it is illuminated by the rays of the Sun.
Saunder was a master at Wellington College, and his time was limited. Help was needed, and he invited Hardcastle to join him.. Hardcastle was glad to accept; the project was a novel and worthwhile one, and appealed to him strongly. He moved to Crowthorne, the nearest village to Wellington College, and. spent much time in making more than 20,000 measures with the micrometer.
This was pioneering work, and will long remembered; it has provided the basis for much of the subsequent lunar charting. Generally it is attributed wholly to Saunder, but in fact much of the actual measuring was done by Hardcastle, who deserves a full share of the credit. The list was published by the Royal Astronomical Society, and has been reprinted many times since in various periodicals and papers.
Just before moving to Crowthorne, Hardcastle had joined the Royal Astronomical Society, becoming a Fellow in January 1902. He also joined the British Astronomical Association, which was a separate body of more recent origin; it had been formed in 1890, largely from the ruins of the old Liverpool Astronomical Society, and had been quick to make its mark. It was predominantly amateur, and included all the leading observers; in fact, it still does, and its record in the field of observational astronomy is second to none. Hardcastle was elected Secretary in 1904, and retained office until 1910, when his health broke down again. He was invited to become President, but refused simply because he knew that he was not well enough to take on extra duties. Instead, he became Vice-President, a position which was more or less honorary.
Another trouble was that he was forced to give up almost all his lecturing and teaching - which he regretted, since it was work that he enjoyed and could do superbly well. Still, there was no help for it, and at least he had more spare time to give to pure research. He was already a member of the Council of the Royal Astronomical. Society (from 1907), and he gave close attention to nebulae; in 1914 he produced a classification of all the nebulae shown on the series of 206 plates covering the entire sky, taken by John Franklin-Adams, an amateur who had taken up astronomy as a hobby when over fifty years old and had soon built up a reputation as a splendid astronomical photographer. The Franklin-Adams plates had been put at Hardcastle's disposal by the then Astronomer Royal, Sir Frank Dyson, which shows the high regard in which Hardcastle was held by professional astronomers. Naturally, he also served on the R.A.S. Committee dealing with the publication of Sir William Herschel's papers, and it was about this time that he came into close contact with Dreyer at Armagh.
By now the first world war was in progress. Hardcastle was well over military age, and was not strong enough for military service in any case, though he did some valuable work when he provided the Admiralty with tide predictions to help in the timing of the Allied landings at Gallipoli. When Dreyer resigned from Armagh; in 1916, Hardcastle was therefore available, and he seemed to be an excellent choice as Director. Dreyer certainly thought so, and Hardcastle, who now seemed to be stronger in health, was willing to come.
According to the Minute-book, he was at the Observatory in March 1917, and said that he hoped to be able to arrive in late May. Meanwhile, Faris had been continuing the meteorological records, but everything else was in abeyance.
In December 1916 Dreyer had written to Hardcastle, explaining the situation with regard to the weather-station at Armagh. Romney Robinson had agreed to supply information to the Meteorological Office in return for an annual payment of £50, and in 1867 he had sanctioned the building of a meteorological house, the Office to pay all expenses. But "owing to his great age", wrote Dreyer, "the Office corresponded directly with the assistant in charge, Mr. Call, though they took particular care never to acknowledge Mr. Call to be in their employment". When Dreyer arrived at Armagh he was promised £275 per year, on condition of his paying all expenses, but this arrangement lasted for only twelve months, since - as has been noted - the self-recording station was abolished as from the end of 1883. (Morning and evening recordings had been stopped during the time when the self-recording station had been in operation.) Since that time Faris had not been paid by the Meteorological Office, apart from the period which had elapsed since Dreyer had handed in his official resignation in 1916.
The weather records had been taken with meticulous care. Thermometers for measuring the temperatures at depths of 1 foot and 4 feet had been supplied by the Meteorological Office in 1904; the self-recording rain-gauge and the anemograph had also been kept going, and the results tabulated, to be sent weekly to the Registrar-General for Ireland.
Everything seemed to have been happily settled, and Hardcastle prepared to move to Armagh to take up his appointment. Then came sudden tragedy. Just as the move was about to take place, Hardcastle fell ill. He had to go hurriedly to his father's house at Oxford, and he died there on 10 November 1917. He was only forty-nine years old.
There are many astronomers still active today who remember Hardcastle, and all pay tribute to his ability, his enthusiasm and his personal charm. His wife had taken a keen interest in the Observatory, and had done much for the dwelling-house; in September 1918 the Primate, Archbishop Crozier, made an official presentation to her in the form of a silver replica of the Armagh Chalice. Mrs. Hardcastle's gracious letter of thanks is still in the Observatory files.
It was particularly sad that Hardcastle should not have lived to take up his position at the Observatory. That he would have made a fine Director there can be no doubt, and the news of his death was deeply regretted at Armagh and by his many friends all over the world.
Last Revised: 2010 January 4th