Repeating an Arabian Experiment of One Thousand Years Ago
The upper photograph shows a beam of light being bent when passing from air to water and back to air. This is a repetition of Alhazan's experiment (page 42). The apparatus shown is such as is used to-day. In the lower photograph the beam of light is being reflected by the surfaces of the water.
I may remark in passing, that in order to obtain the photograph facing this page, it was necessary to shake a chalky duster in the air. This photograph serves to illustrate another important experiment which was made by Alhazan. It was known to Ptolemy, and was referred to in his early book on Optics. In demonstrating it Alhazan took a glass vessel filled with water, and not being able to have dust floating throughout the water, he added a little milk, which served the same purpose in the water as the dust particles did in the air. In the modern form of the experiment it is usual to replace the milk by a little red ink or other fluorescent substance, and to use a powerful lantern to produce the beam of light. Of course, the object of the demonstration is to show how the beam of light is bent, upon passing from one medium to another.
But why bring these facts about the Arabs into a chapter entitled "Roger Bacon"? Because there seems to me to be a clear connection; Roger Bacon was a keen student of the scientific writings of the Arabs, and in particular the works of Alhazan. In this way our hero links together the Ancient and the Modern Sciences, for although Bacon had no immediate followers, we may consider him as the founder of Modern Science.
The position of Science as Bacon found it was most unsatisfactory. He tells us that he found only one teacher who really understood Aristotle, and this one teacher was modest, passing unnoticed, while the others, with a great show of learning, became famous. This so aroused the indignation of Bacon that he wrote a scathing criticism of the teachers, pointing out that they were totally ignorant of the true foundation and method of Science. It goes without saying that this did not add to our hero's popularity. However, after having spent sixteen years in Paris, the seat of learning, and having gained the degree of Doctor of Theology, he returned to Oxford.
Roger Bacon, who was then about thirty-six years of age, became a Franciscan monk. The fame of his learning spread in Oxford, but as he made a practical study of Chemistry and Physics, he was supposed to be aided in his experiments by infernal spirits, and there was a feeling of suspicion concerning him.
To realise what the world thought of this Scientist one has only to peruse an old book which was translated into English three centuries ago under the title The Famous Historie of Fryer Bacon. Here we find the sort of magic with which the people credited this English monk. We are told that he was summoned before the King and Queen to show his magic powers to them.
This Famous Historie relates how, by the waving of his wand, he summoned excellent music, such as had never; been heard before; then there came forth, from nowhere, people who danced and then vanished away as they had come. By another wave of the magic wand there appeared tables covered with the richest fruits, and so on, and so on. It is even related in this Historie that the King and Queen did eat some of the rich fruits which had, been conjured up from nothingness.
This supposed history of Roger Bacon ends with a description of his death in a cell, in which he had locked himself, after making a bonfire of all his writings, the very last episode being "his grave he digged with his owne nayles, and was laid there when he dyed."
It does seem strange that people should believe such utter nonsense, and yet for centuries Roger Bacon was considered to be some sort of wizard. Even in the beginning of the eighteenth century Bacon was looked upon as nothing more than an ingenious Alchemist, so that it is only in comparatively recent times that a true history of Roger Bacon has been made out, chiefly from a study of his own works.
We need not be surprised to find that Bacon sought for the Philosopher's Stone, and that he believed also in Astrology. We shall find many great minds still believing in these "Sciences" several centuries after his time. But Bacon's studies were all serious; he did not practise Alchemy or Astrology for any personal gain. His advance in knowledge is most remarkable if we consider his surroundings. The mass of the people were quite unlearned. If a man could write, or even if he could read, that was proof that he was one of the clergy.
Even most of the monks in Bacon's time were ignorant of Mathematics. He tells us most of those who applied themselves to Mathematics in those days stopped at the fifth proposition in Euclid, and it is interesting to note that the title by which we knew this proposition in our schooldays—"Pons Asinorum" (The Asses' Bridge)—was given to it in Bacon's time. It is clear that Bacon must have given a great impetus to Mathematics, for we find an old monkish historian writing of one of the Franciscan monks: "Friar Bungay was profoundly versed in Mathematics; which was either the work of Satan or of Roger Bacon."
Bacon had not been back in Oxford for many years when the Head of his Holy Order interdicted his lectures at the University, and he was sent back to Paris to be placed in confinement under the Head of the Franciscan Order there. No doubt the reasons advanced would be that Bacon was not orthodox, and that he employed magic in his experiments, but from what happened later one may suppose the real cause to be his open criticism of the ignorance and vice of the clergy.
For ten years Bacon was confined in Paris, prohibited from publishing any writings, and kept under constant supervision. We have no details of his solitary confinement there, but it is said that he suffered great privations, being denied even sufficient food. It is difficult for us to realise what this imprisonment must have meant to a man of such great genius, who saw so much farther ahead than any of his captors. He had given up all hope of ever communicating any further knowledge to the world, when a request from Pope Clement IV reached him, desiring to see his scientific writings. The Pope had been Papal Legate in England while Bacon was at. Oxford, and he had heard of Bacon's fame; indeed, this high dignitary had desired to see Bacon's writings at that time, but the interdict prevented his wish being gratified. Now that he was Pope he could set aside the orders of the Parisian dignitaries.
That Bacon was immensely pleased to receive this request during his imprisonment is evident from a personal description of his circumstances and feelings at that time, of which he tells us in the opening chapter of one of his great works. But he had no writings to send; he had been forbidden to publish anything, and he no doubt believed that anything he might write would be destroyed. However, he had plenty of scientific knowledge in his head, and he lost no time in putting his ideas down in writing. It is remarkable that in less than two years he had completed three large treatises. These he wrote, of course, in Latin, which was the written language of the educated at that time. He dispatched his writings to the Pope by the hand of one of his students who is known to us as "John of London." It was unfortunate that just about the time the manuscripts reached Rome the Pope was taken seriously ill and did not recover, so we have no record of what Clement IV thought of the works. It is significant, however, that Bacon was released from his confinement and permitted to return to Oxford.
Once more a free man, Bacon devoted all his time to scientific study, and more particularly to experimental Physics.
But Bacon could not refrain from urging the necessity of more efficient study on the part of the monks, and in his writings he denounced their ignorance and vices. The result of these noble outbursts was that, after three years' freedom, he found himself thrown into prison, and all his books condemned. For about fourteen years he remained a prisoner, and entering at the age of sixty-four he would be an old man of seventy-eight years before he was once more set at liberty. This last liberty was granted at the request of several influential English noblemen. Even at this advanced age Bacon wrote a Compendium of Theology. He passed away about the age of fourscore years.
It is well to note that Roger Bacon was not the inventor of gunpowder, nor of the telescope, although his name was associated with these inventions for a long time. Gunpowder, while referred to by Bacon in his writings, was known for several centuries before his time. The telescope was not invented for centuries after Bacon, as we shall see when we come to consider the life of Galileo. Bacon knew the use of optical lenses, and he invented the magnifying-glass, which, however, is not the same as a telescope.
The first title which I had noted for the present chapter was "The Two Bacons," but I feared that many readers might object to the inclusion of Francis Bacon as a Scientist, and I doubt if he fulfils the definitions with which I set out in the first chapter. He did not add any thing of importance to our knowledge of Science, but it is debatable how far modern Science has been influenced by the writings of Bacon.
While Francis Bacon was a great man of letters, a famous lawyer, and so on, that does not bring him within the scope of the present subject, but I do think there is a real connecting-link in this way. Francis Bacon, who lived about three hundred and fifty years after Roger Bacon, was a prominent figure in the Court of Queen Elizabeth, and Dr. William Gilbert, who did much for Science, was one of Queen Elizabeth's physicians at that time, so I think it is reasonable to suppose that Gilbert would be influenced by Francis Bacon, who declared so very vehemently that Science was altogether on the wrong track. He declared that the true philosopher should not be a mere disputant, but an experimentalist, and it is well known that Gilbert was a great experimentalist. We should remember that at this time public thought was divided into two classes. Science was thought to be impossible, or it was considered to be complete already. Francis Bacon has some claim of mention in the present subject because of his attempted reformation of Science, but he himself made no scientific discoveries. Under these circumstances, I have thought it sufficient to give only a very general outline of this great man.
Francis Bacon was born in the Strand, London, in the year 1561, and after being taught at home he went to Cambridge, and later to Paris. Francis was the youngest son of a large family, and his father, Sir Nicholas Bacon, was arranging to purchase an estate for Francis, but before this had been arranged the old gentleman died suddenly. Although all the other sons were well provided for by the father, they only let Francis get his share of the residue of the estate. In this way he was left tolerably poor, considering his father had been so wealthy. Francis made this poor beginning much worse by borrowing money, with the result that he was always in debt.
Although a Member of Parliament, he received no remunerative post from Queen Elizabeth, but in the reign of King James he became Attorney-General and Lord Chancellor. His actions when holding these high posts brought about his imprisonment in the Tower of London at the age of sixty years, but his sentence was remitted. It is very doubtful if Bacon was guilty of any real bribery, but he confesses to receiving money in the form of gratuities when cases had been tried and the verdicts made known. Before this time he had been raised to the peerage.
After the release from his short imprisonment, Bacon devoted himself to his scientific writings, but his famous Advancement of Learning was written at a much earlier date and during one of the vacations of Parliament.
We have noted that Francis Bacon was not an experimental Scientist himself, although he was a very strong supporter of the experimental method. But I think sometimes that Bacon might have become a great experimenter had his time not been so very fully taken up with Parliamentary and State duties, for at the age of sixty-five we find him making an experiment, which unfortunately was indirectly the cause of his death.
Driving in his carriage one winter day through the Highgate district of London he wondered if snow would act as a preservative of animal flesh. He stopped his carriage at a cottage, where he purchased a fowl, which, when killed, he asked to be stuffed with snow. He himself assisted in the operation, and during the experiment he contracted a sudden chill, and became so seriously ill that he had to be taken to the neighbouring house of the Earl of Arundel, where he died after a few days' illness, being then only in his sixty-sixth year.