As for Gregorie, he was at variance with Riccioli, De Angelis and Manfredi, and though we have only negative evidence, we hope that he was at one with the other great teachers of his time in Italy. Optica Promota had been much read on the Continent, and there the suggestion which he made that the solar parallax might be determined by the transit of Venus and Mercury had been accepted, and till a few years ago it was the method employed in finding out the distance of the sun. But after all, the most beautiful piece of Gregorie’s work was his telescope. ‘It consists of a parabolic concave speculum with a hole in its centre, having near its focus a small elliptic concave speculum. The image formed by the large parabolic speculum is received by the small elliptical one, and reflected through the aperture in the former upon a lens which magnifies it.’
In Padua his work took a more purely mathematical turn, and resulted in a book ‘pursuing a hint suggested by his own thoughts,’ of which he had only a few copies printed. It was entitled Vera Circuli et Hyperboles Quadratura, and Montucla in writing of it says that the title is misleading, and that the author does not claim, except approximately, through his infinite converging series to find the square of a circle or hyperbola. Collins, to whom a copy was sent, read part of it before the Royal Society. Lord Brouncker and Dr Wallis were enthusiastic in its praise, and under such encouragement Gregorie published it along with some fresh matter under the title of Geometriae Pars Universalis inservieus Quantitatum Curvarum Transmutationi et Mensurae. The book came out in Padua with the permission of the State of Venice, and was a great success. Before its publication the Royal Society showed their appreciation of it by making Gregorie a Fellow.
This was in January 1668; in March he was still in Padua, but in all the confusion of departure, and not long after he returned to Scotland, and back to his much loved Aberdeenshire, where happiness was awaiting him on all sides. There was Kinairdy to visit with its many charms, and there was Aberdeen, and at Elrick there was a cousin who was after all, it is easy to guess, the end of his journey. This was Mary Burnet, the widow of John Burnet, who to his great joy consented to become his wife, and was married to him in 1669.
The astronomer found love-making dreadfully time-consuming, and vaguely regretted it. You see, it was apt to interrupt his correspondence with Huygens and Halley, with Newton and Collins, with Dr Wallis and Lord Brouncker. Here is a pathetic letter from him written in the early part of the year to one of his mathematical correspondents—‘I have several things in my head as yet only committed to memory, neither can I dispose of myself to write them in order and method till I have my mind free from other cares.’
His wife was only twenty-three, although this was her second marriage, and even when after Mr Gregorie’s death she married Mr Ædis, she was still young and very beautiful. A rare piece of her work remains in the tapestries which adorn the Magistrates’ Gallery in St Nicholas Church in Aberdeen. Susannah and Jephtha’s daughter were her subjects, and there they are still, looking out of their panels, from the midst of their beautiful blue and green landscapes, with the rigid uncertainty of tapestry portraits. Bailie Burnet would have been proud if he could have foreseen what a combination of ecclesiastical and civic honour was to fall to his wife’s needlework.
Mrs Gregorie’s father, George Jameson the artist, drew the pictures for her. Walpole called him the ‘Van Dyck of Scotland,’ though it is difficult to know why, as there is really no resemblance in their work, but at least Jameson and Van Dyck were friends in Rubens’ studio, and the kindly appreciation of his fellow-citizens has remembered and repeated the phrase.
In 1670, James Gregorie was appointed to the Chair of Mathematics in St Andrews, where he had a successful if sometimes vexed life. His duties were to deliver two lectures a week, and to answer any mathematical questions that might be set before him. ‘I am now much taken up,’ he writes in May, 1671, ‘and have been so all this winter by-past, both with my public lectures, which I have twice a week, and resolving doubts, which some gentlemen and scholars propose to me. This I must comply with, nevertheless that I am often troubled with great impertinences, all persons here being ignorant of these things to admiration. These things do so hinder me, that I have but little time to spend on these studies my genius leads me to.’
He lived near the beautiful cathedral and almost under the shadow of St Regulus, and there his name is still remembered in Gregorie’s Lane and Gregorie’s Place. He worked in the long, many-windowed library, where the clock which he used is still at work, and where it has been keeping time these two hundred years, since Huygens, who invented the use of the pendulum in clocks, and Gregorie himself were laid at rest.
Huygens and Gregorie had a long feud about his Paduan book. Its faults as the Dutchman thought were lack of ‘distinguished perspicuity’ and intricacy in its invention. But Huygens must have lived to regret his criticisms, however well founded they were, for with a sudden burst of the M’Gregor spirit, Professor James sent forth a volley of answers, his official statements through the medium of the Philosophical Transactions, and his unofficial through his many letters. Neither his great opponent, nor his great opponent’s allies were spared. ‘I am not yet so much a Christian as to help those who hurt me. I do not know (neither do I desire to know) who calleth in that preface, Hugenius his animadversions of November 12th 1668, judicious, but I would earnestly desire that he would particularize (if he be not an ignorant) in what my answer, which is contradictory to Hugenius his animadversions is faulty; for in geometrical matters, if anything be judicious its contradictory must be nonsense. I do not know what need there was for an apology for inserting my answer, but to compliment Hugenius, and violently (if it be possible) to bear down the truth. I imagined such actions below the meanest member of the Royal Society, however, I hope I may have permission to call to an account in print the penners of that Preface.’ The account was never called for, because Newton in the meantime, gave the simpler solution, which Gregorie had been declaring an impossibility, but it must be remembered that Gregorie’s method although almost impossible to any but the most clear mathematical mind, was easy to him and was correct as far as it went. Can anyone help loving Huygens, even though they know no more of him than what is seen in his intercourse with Gregorie? What graciousness and kindness was returned in exchange for the thunderous treatment he received! Sick, as he thought he was unto death, he suggested Gregorie as a fit successor to him in the favour of Louis XIV., and we find his father, who was secretary to the Prince of Orange and a poet—the poet of the garden—similarly occupied, trying to influence the great folk with whom he came in contact to further Gregorie’s interests. But in spite of the recommendation of the Académie des Sciences, the Royal Society, and such friends as he had at court, Gregorie never received any Royal patronage; the want of which he took very calmly and with a great deal of broad good sense, never having expected any other result. ‘I have had sufficient experience in the uncertainty of things of that nature before now, which maketh me since I came to Scotland, how mean and despicable so ever my condition be, to rest contented and satisfy myself with that, that I am at home in a settled condition by which I can live. I have known many learned men far above me upon every account with whom I would not change my condition.’
In 1669 Gregorie’s books were suppressed in Italy, which came as a shock to him, and was all the more grievous because it deprived him of many of his most interested readers—and controversialists! Scotland, however, supplied the deficiency wonderfully well. There was a professor in Glasgow called George Sinclair, a mathematician, and a demonologist of great repute, who wrote a book on Hydrostatics. It was quite clever, and may have been more interesting to the general reader than books on Hydrostatics usually are, because of an appendix in which some strange things were included, amongst others, A Short History of Coal and the Story of the Devil of Glenluce. The humour of the combination was too much for Gregorie, and under the name of Patrick Mathers, Arch-Bedal to the University of St. Andrews, he wrote an answer to the scientific part of the Hydrostatics, which he called ‘The Great and New Art of Weighing Vanity.’ Witty, scurrilous, easily written and easily read, the book was a great source of merriment both to Gregorie and his colleagues at St. Andrews, and it raised a perfect hurricane in Glasgow. The very name was an impertinent play on the title of his antagonist’s former book Ars nova et Magna and the fact that Professor Sinclair was no mean adversary added zest to the battle, which continued many days. But Professor Sinclair had prepared an ill reception for his work by the edict which he had had printed and sent abroad to persuade people to order copies of it:—