Now there be some that are very inquisitive to have a way to get the longitude, but that is too tedious for seamen, since it requireth the deep knowledge of astronomy, wherefore I would not have any man think that the longitude is to be found at sea by any instrument; so let no seamen trouble themselves with any such rule, but (according to their accustomed manner) let them keep a perfect account and reckoning of the way of their ship. Davis, The Seamen's Guide (1594).
In these days of widespread training in the art of navigation, many of our citizens have come into close contact for the first time with the marine chronometer. Heretofore they probably knew of it only as a very accurate kind of clock, and that the watchmaker kept one in his show-window for the convenience of the passer-by. Even after they learn to use the instrument, moreover, it is probable that most accept its marvelous accuracy as a matter of course, and little realize perhaps that this modest-appearing mechanism is the very keystone of modern navigation, and that its advent was the answer to a mighty problem that had baffled the world for centuries.
The problem was one that had so gravely affected the progress of the great maritime nations and the lives of their people, that they offered princely rewards for any practical answer. A great observatory was founded merely to obtain the data that might allow a solution, and an eminent eighteenth-century astronomer gloomily averred that a satisfactory solution would never be achieved, then, after centuries of futile effort by eminent scientists, a humble, scantily educated watchmaker brought forth the first mechanism that would keep accurate time at sea, and in so doing solved the problem to a degree far beyond the most sanguine expectations. With the advent of this seagoing clock, from which our modern marine chronometer has evolved, there was launched a historic controversy, outstanding in its bitterness and duration. The controversy has gone down in history as “The Battle of the Lunars,” and in many respects it was remarkably like a standard melodrama, with a lowly, uncultured hero pitted against highly placed, powerful enemies, and winning fame and success only after years of unceasing struggle.
The mighty problem that had so baffled the world was nothing more than the discovery of any practical method of finding the longitude at sea a very simple and accurate operation nowadays. It had not existed in the early days when mariners remained always in sight of the land and rarely essayed the open sea. When they learned to guide their course by sun and star, they could strike out and still find their way about such landlocked waters as the Mediterranean without special difficulty. A safe landfall usually could be made with their small shallow, ships, and the actual position at sea was not of serious moment. But when they finally ventured past the Pillars of Hercules and out into the terrifying immensity of the Western Ocean, then the problems of navigation really began.
Much of the basic material necessary had been available for centuries before it was employed. The Chinese had learned at an early day the use of the magnetic compass, but it was well into the fourteenth century before the western nations adopted it. In 200 b.c., Eratosthenes of Alexandria had established the “declination” of the sun, and thus had given future navigators a gigantic yardstick for determining latitude. A few years later Hipparchus had made a catalog of over one thousand stars, and had devised the method of locating a point on a sphere by what we call latitude and longitude. Claudius Ptolemy had then written his great treatise on geography, which was to be the reference book for the skilled Arabian navigators of later years. Many centuries were to pass, however, before the art of navigation was to start its real development. Then with cross-stall or astrolabe, and some simple charts and declination tables, the navigator could determine his latitude with reasonable accuracy and could make his way about the trackless ocean with some assurance.
But there was still a gaping lack in the science of navigation. Determining the latitude was not enough to fix a ship’s position; the longitude also had to be determined— the angular distance east or west of some established reference line upon the rapidly spinning globe; and centuries of intensive search were to elapse before the world found a practical method of doing it. Of course a rough determination of the longitude could be made through pure dead reckoning, but even such a simple aid as the log line did not come into being until the seventeenth century, and the lack of such a device, coupled with the rough steering courses and all the variables affecting the way of a sailing vessel, made the dead reckoning of those early days a matter of great uncertainty.
As the great explorers began to extend the horizons of the known world, and close on their heels came the expanding commerce of their countries, this lack in the science of navigation became woefully apparent. The navigation of both merchantmen and men- of-war was crude and inaccurate at best, and with no practical means of determining longitude, a ship’s calculated position easily could be one hundred miles or more in error. And this was brought home to the world in grievous fashion as whole fleets of ships, with thousands of seamen, were lost on reefs and headlands through gross errors in their reckoning.
Thus the problem was literally one of life and death for seafarers, and from a material standpoint it was a tremendous and costly stumbling block in the development of trade. Their scientists had no practical solution to offer, so in desperation the great maritime nations set up magnificent prizes for any practical and reasonably accurate method of determining longitude. France, the Netherlands, and the Venetian Republic each offered huge sums of money for an answer. In 1598 Philip of Spain held forth land and gold for a solution, and he paid out large amounts for the many fallacious ideas that were brought to him. But even the lender of princely rewards was of no avail.
Of all the maritime nations there was none more deeply concerned than Great Britain. Her ships and lusty mariners were spreading out from their island kingdom, over the seven seas, but the appalling losses of ships clearly indicated a grievous lack in their navigation. Hence in 1714, when Queen Anne was on the throne, a petition was presented to Parliament by “several captains of Her Majesty’s ships, merchants in London, and commanders of merchantmen, in behalf of themselves and all others concerned in the navigation of Great Britain,” stating the pressing need of some accurate means of determining longitude and begging that Parliament assist in the matter. In answer Parliament set up a “Board of Commissioners for the Discovery of Longitude at Sea,” and the Board called upon the scientists and mathematicians of the kingdom for their advice. Among those called upon was the great Sir Isaac Newton. He could give what was really the correct answer, but for all of his mighty intellect he could not furnish the means, lie stated that what was required was “a watch to keep time exactly, but by reason of the motion of a ship, and the variation of heat and cold, wet and dry, and the difference of gravity in different latitudes, such a watch hath not yet been made.” Moreover, at the lime he spoke, such a watch seemed almost impossible.
After listening to the savants appearing before it, and having received no practical answer, the Board set up a list of magnificent prizes for anybody who could furnish a solution meeting certain conditions. Even by present-day values the prizes were truly magnificent, and considering the modest requirements for winning them, we can realize how formidable the problem seemed. The Board offered £20,000 to anybody who could bring forth a practical method of finding the correct longitude at sea within 30 miles; £15,000 for within 40 miles, and £10,000 for within 60 miles. Furthermore, £10,000 was offered for any method which would allow finding the longitude within “80 miles near dangerous shores.”
The tender of these magnificent prizes brought forth ideas by the hundreds, some of which were well thought-out and sensible, and others which reached depths of silliness and fantasy. The eternal lunatic fringe, always present at such times, emerged in force, and the crackpots of the kingdom had a Roman holiday as they harassed the Board with their fantastic ideas. Many of the more intelligent people were on the right track, as their suggestions involved simultaneous comparison of the time at the ship and the time at the reference-meridian. This was all right as far as it went, but the rub was—how to effect this time-comparison.
When Newton recommended a “watch,” the idea was not entirely new. Gemma Frisius had suggested a clock in the sixteenth century, almost 200 years before. But even by Newton’s time it was still only a theory. In the same sixteenth century, however, a much more plausible idea had been advanced. An earnest searcher had decided that in the moon’s rapid progress across the skies, against a background of seemingly fixed stars, there might be constituted a gigantic clock, and that this clock would provide a means of simultaneous time-comparison and hence of determining longitude. This was the birth of the idea of “Lunar Intervals” or “Lunar Distances,” later to be commonly known as “Lunars.”
Making this idea into a practical method was a herculean task, however, and it was to absorb the efforts of scientists for almost 300 years as they strove to make it workable. Basically the theory was simple enough. As I he moon moves across its background of stars, the apparent angular distances between the moon and prominent stars, as viewed from the earth, will change considerably in the space of every two- or three- hour period. Now these apparent angular distances might be predicted and tabulated for a year ahead, based upon dates and time- intervals at a reference-meridian. A navigator at sea then could observe the angle between the moon and a certain star, could derive from the tables and some calculations the corresponding time at the reference- meridian, and by comparison with the local time could then determine his longitude.
The theory thus was simple, but its application was something else. In the first place, there was little, if any, recorded knowledge of the moon’s irregular movement, and years of painstaking observation would be necessary before its position for a year ahead could be predicted with the slightest accuracy. In fact, hundreds of years were to elapse before even fairly adequate lunar tables had been compiled. Then, even with the most adequate tables, the method had an inherent weakness that made accurate longitude determination by the ordinary navigator almost impossible. This lay in the fact that because of the relative movements of the earth and moon, any error in observing the angular distance would be multiplied 30 times in the calculated longitude. Then there was the long and complicated mathematical procedure involved, which undoubtedly was beyond the capacity of most of our early mariners. Considering all this, combined with the scant hope of obtaining accurate observations from the deck of a tossing ship with the instruments then available, the problem was still far from a proper solution.
While some of the scientists went about the preparation of lunar tables, others cast about for a more practical method. The idea of employing lunar eclipses, which Hipparchus had once proposed, was recognized in its futility. When Galileo discovered Jupiter’s “moons” early in the seventeenth century, it was' suggested that the rapidly recurring eclipses of these tiny satellites might afford a means of time-comparison, and hence of determining longitude. This was obviously impracticable for navigators, however. As one idea after another was found wanting, the method of lunar distances seemed to hold the only possible answer, and in 1675 Charles 11 founded the now-great Greenwich Observatory solely for the purpose of preparing the requisite tables. Almost fifty years later, however, Halley, the then Astronomer-Royal, pessimistically stated that he doubted that longitude ever could be determined with any accuracy, and in fact any closer than within “60 miles.” Moreover, such doubt was so prevalent that in England then, and for many years afterward, the expression “discovering the longitude” was commonly used as a comparison for anything seemingly hopeless of achievement.
This brings us again to the Longitude Commission and the ideas that were placed before it. Strange, wonderful, and fantastic were most of them, but probably none reached the heights achieved in the solution solemnly proposed by an English cleric. In England at that time there was a peculiar belief existent regarding the bandages used on wounds. It was believed that if any of these bandages should be removed and reduced to powder, the dropping of a pinch of this powder into water at any time would cause the wounded person to experience a sharp stab of pain in his wound, at that same instant and no matter how far away he might be. This was known as “The Powder of Sympathy,” and the earnest divine proposed to utilize its properties by wounding and duly bandaging a number of dogs. Every outbound ship could take one of the wounded dogs, while powdered bandages from the animal would be kept at a reference point on shore. Then at the instant of noon each day at this reference point, a pinch of the powder would be dropped into a basin of water, the poor dog many leagues at sea would simultaneously emit a loud yelp, and there you had your time-comparison and solution of the longitude problem.
At this point enters the hero, a humble, poorly educated watchmaker. He was one John Harrison of Yorkshire, son of a country carpenter, who had started his career as a carpenter also, and then had learned the trade of watchmaking. He was a natural born craftsman, and soon displayed his skill and ingenuity by inventing the compensating “gridiron” pendulum and several other outstanding devices for the accurate functioning of timepieces. Moved undoubtedly by the huge rewards held forth, he undertook to make a seagoing clock that might furnish the answer. He was not the first to attempt this, as eminent horologisls had tried and had utterly failed, but in Harrison’s case his native craftsmanship probably was one of his greatest assets. Obviously weights and pendulum would be of no use at sea, so he employed a spring for driving the mechanism, and a spring balance and escapement for regulating its movement. To compensate for temperature variation he made the balance springs of brass and steel riveted together, and to prevent the irregularity that a tossing ship would engender he employed a system of four counteracting spring balances. With these and some other devices and refinements, he believed that lie had the answer, so he laid his clock before the Hoard in 1736.
The clock was a bulky affair in a rectangular wooden case, the whole weighing almost 65 pounds. Even some of the gear wheels and bearings were of wood. The Board accepted it for test and placed it on board H.M.S. Centurion for a voyage to Lisbon and return. On the voyage the clock gave a demonstration that impressed even the most skeptical, and upon return to England its entire accumulated error would have allowed a possible discrepancy of hardly more than 18 miles in longitude. It seemed unquestionable that the great longitude problem had been solved at last, and with results far beyond the Board’s requirements. But nevertheless John Harrison was not to get very promptly or easily the prize he so honestly had won. Moved by several influences, some of them not very praiseworthy, the Commissioners doled him out only £500 and urged him to continue his efforts. To win the rest he must submit more clocks for inspection and test, and he must surrender all his drawings and patterns to the Commissioners. This was rather shabby treatment and Harrison was bitterly resentful, but to no avail.
There were some powerful influences working against the lowly watchmaker, and foremost among them was a determined and highly placed band of advocates of the lunar method. This group refused to admit the obvious shortcomings and dubious prospects of the lunar method, in contrast with the demonstrated success of the clock, and they opposed the adoption of clocks with almost fanatical zeal. The affair soon developed into the hitter controversy mentioned beforehand, and it was to blaze fiercely for an incredible number of years, until its last feeble flicker expired after the turn of our twentieth century.
John Harrison and his friends had no powerful backing, and he had no course but to prove his case beyond any possible doubt. In 1740 he finished a second clock, much smaller and with fewer gear wheels. In 1758 he finished another and even better clock, and then in 1761 he brought forth his most successful one, which was shaped like a pocket watch, and about 5 inches in diameter. His son took the clock to Jamaica and back in H.M.S. Deptford. On the voyage this clock gave such a convincing performance that certainly there should have been no further doubt that John Harrison had fully earned the promised reward.
The controversy which had raged during all these years, however, still went on unabated. The lunar advocates still refused to admit the success of the clock and they strove by every means to have their cherished method accepted. Their prime need for a better observing instrument had been filled in 1781 when Hadley invented his quadrant, but this solved only part of their problem, as the lunar tables were yet very far from adequate, and there always remained the method’s inescapable faults.
Here enters what might be called the villain of the drama, the most prominent figure among the lunar advocates, and the bellwether of the devoted flock. He was Dr. Nevil Maskelyne, and his very name seems to fit the part, as John Harrison’s does the hero’s. He was one of the greatest scientists of his time, and his intellectual achievements have given him a deservedly high place in the history of science. But in the Walter of determining longitude there must have been a “dark sector” in that otherwise brilliant mind, and he set his face against the use of clocks with stubborn and lasting firmness. He fervently espoused the cause of the lunar method, and with this bitterly opposed the humble watchmaker.
He had become a lunar enthusiast at an early date, and when at the age of 29 he went to St. Helena to observe the transit of Venus, he worked many “lunar distances” on the long voyage. With all his skill and special instruments, he nevertheless could not attain any accuracy, and he admitted that he could not be sure of the longitude within a whole degree. But despite this and the fact that Harrison’s clock already had achieved results far beyond anything that even could be hoped for with “lunars,” he pursued the subject with indefatigable zeal. So in 1768 he brought forth The British Mariner's Guide, which dealt mainly with longitude by the lunar method. Then in 1765 he was appointed Astronomer-Royal, and with the power and prestige of this high office he was enabled to further his pet project, and at the same time lie could, and did, make things difficult for the humble watchmaker. In 1766 he brought forth the first Nautical Almanac, which also was largely devoted to “lunars,” and purported to show the superiority of the method. The manifold •assumptions, allowances, corrections, and intricate calculations necessary in his procedure, however, and all without the slightest assurance of any accuracy in the result, would appall any modern navigator.
John Harrison, now over 70, was seriously handicapped in his struggle by the fact that his lack of early education made it very difficult for him to express his ideas in writing. But by now he was not alone in his unequal battle. Accurate seagoing clocks were being built by other watchmakers, both in England and in France, and they all joined forces against the lunar advocates. However, the latter still had every advantage of place and power, and their influence was only too evident in the course of the battle. For in 1768, 27 years after John Harrison had first demonstrated his unquestionable right to the £20,000 prize, the Board grudgingly paid him only one-half of the amount, and refused to give him the rest. Then, incredible as it may seem, in 1774 the Commissioners set up another list of prizes for practical methods either by lunars or by clocks. All of this was undoubtedly the work of the lunar advocates, who still cherished the fatuous hope that their method might be made to prevail. These last prizes stood untouched, however, and some time in the 1820’s they were withdrawn and the Board was finally dissolved.
John Harrison was a weary old man worn by a lifetime of hard work and the years of bitter controversy, when in 1775 he was given the remainder of his fairly earned reward. That next year he died, at the age of 83, satisfied perhaps that his success was at last acknowledged, but passing too soon to witness the complete triumph of his handiwork. For as the eighteenth century drew on to its close, the use of the seagoing clocks spread rapidly. The name “chronometer” was born, to become a lasting symbol of time-keeping accuracy, and the art of navigation became something more than the crude approximations of former times.
The lunar advocates refused to admit defeat, however, and the nineteenth century found them gathered about (heir tattered banner, still in considerable force and shouting defiance. Dr. Maskelyne stuck to his guns until he died in 1811, and almost with his last breath he stated that he still preferred “the lunar method to any clock.” Though fairly adequate tables were now available, few if any navigators except those of scientific bent would attempt the method. The appearance of the mathematical procedure was enough to daunt the ordinary mariner.
As the nineteenth century progressed, the art of navigation steadily improved. Better charts, tables, and instruments all contributed to this, and the advent of the steam vessel made really accurate dead reckoning possible. The lunar method still was in the textbooks and almanacs but the practical navigator gave it little attention, and it became a matter of hardly more than academic interest as the years went on. But it still had its devoted advocates and they continued to voice their faith in the superiority of their beloved “lunars.”
The twentieth century opened and found “lunars” still in the textbooks and almanacs, but not many years afterward they disappeared altogether from the pages, never to reappear. Yet as late as 1905 there were in England a few last and vociferous survivors of the devoted band. Then even these passed on into silence; there came a generation of navigators who had never known it either in theory or in practice, and the method of “Lunar Distances” faded at last into history.
John Harrison’s clumsy wooden clock has now become the beautifully made instrument that plays such a vital part in the accurate high-speed navigation of today. Its story has many striking features, but in the light of our present-day knowledge probably none of these is more striking and at the same time more inexplicable than the attitude of Dr. Maskelyne and his lunar advocates. Yet such an attitude is not always rare among men of science and learning, and a possible explanation of it might lie in one of the gems of wisdom imparted to the writer in his youth by a certain elderly and beloved professor. In class one day he had cited some historical instances of blind, unreasoning opposition by the engineering profession toward the adoption of certain devices. Asked what was usually behind such action by men who ought to know better, the professor lowered his thick gray beard upon his chest and looked at the questioner over his glasses. “My boy,” he said, “bigots are not confined to religion; they’re prevalent in every profession.”