Time in History: Views of Time From Prehistory to the Present Day
Page 22
Since the days of Maskelyne all marine chronometers had been tested and checked at the Royal Observatory. In 1833, when John Pond was Astronomer Royal, the Time Ball service was installed there, whereby a ball on the turret of Flamsteed House fell at exactly 1 p.m., so that the time kept by ships on the Thames near Greenwich could be checked thereby. Airy greatly expanded the public service based on GMT by arranging for that time to be distributed throughout the country by means of electric signals. These were transmitted in cables alongside railway tracks, so that for years GMT was called by most people 'railway time'. In his Annual Report of 1853 Airy wrote, 'I cannot but feel satisfaction in thinking that the Royal Observatory is thus quietly contributing to the punctuality of business throughout a large portion of this busy country.'15
The advent of railways greatly influenced the family habit of taking an
-161-
annual holiday, a custom that had previously been restricted to the wealthy. It was the growth of this habit that led to the development of seaside resorts. Not everyone, however, welcomed the new mode of transport and the changes that it produced. For example, when in 1844 the first excursion train to Cambridge was planned, the prospect of an influx on a Sunday of 'foreigners and other undesirable characters to the University of Cambridge on that sacred day' was so unwelcome to the Vice-Chancellor of the time that he wrote to the Directors of the Eastern Counties Railway to complain that 'such a proceeding would be as displeasing to Almighty God as it is to the Vice-Chancellor of the University of Cambridge.'16
The revolution in transport affected the tempo of many forms of human activity, particularly the dissemination of news. Although the origin of newspapers, in England at least, can be traced back to the pamphleteering of the different factions at the time of the civil war in the 1640s, it was not until the closing years of the eighteenth century, with the introduction of the mail-coach, and the nineteenth century, with railways, that it became possible for the latest news and informed comments on it to be brought rapidly to towns and villages throughout the land. This spreading of fact and comment far and wide was, of course, also greatly facilitated by the abolition, in the middle of the nineteenth century, of that heavy tax on knowledge, stamp duty on newspapers.
The unprecedented speeding-up of communication, both nationally and internationally, following the introduction of telegraphy and the laying of the transatlantic cable in 1858, revolutionized the conduct of government at home and abroad. An ultimatum could be sent off in the heat of the moment demanding an immediate reply, public opinion could be rapidly influenced and armies mobilized overnight. Such was the march of progress that sudden panic on the New York Stock Exchange in the afternoon could lead to a businessman in London shooting himself before breakfast the following morning. With the advent of wireless telegraphy early in the present century, the rate of dissemination of information all over the world became even more rapid and widespread. No major catastrophe, however remote, now fails to produce agonizing all over the world as soon as it has happened and indeed often while it is still going on.
During the nineteenth century people's attitude to time in countries like England was greatly influenced by the Victorian work-ethic, which led to 'spare time', that is, the time when in principle one was free to do
-162-
as one liked, being regarded as a reward for hard work. This 'spare time' came to be regulated by the day, week, and year. Previously, holidays had been the forty or more holy days that occurred intermittently throughout the calendar. In England the Puritans, who were in power for over a decade in the middle of the seventeenth century, regarded the traditional Christmas festivities as a pagan relic. They tried to abolish them, but they were soon restored after Charles II returned in 1660. On the other hand, in Scotland Puritan influence persisted and Christmas became far less a time for general celebration than the New Year, a tradition that continued into the present century. The industrial revolution led, however, to the general abolition of holidays based on religious festivals because it was uneconomic to have plant that was expensive to maintain frequently lying idle. In place of the former holy days, four compulsory 'bank holidays' were eventually instituted by law, and it gradually became customary for workers to be given annual holidays of a week or more in the summer. Physical recreation, such as football, came to be organized on a weekly basis, usually on Saturday afternoons.
The nineteenth century saw a great proliferation of pocket watches, although the most important improvement in their mechanism (apart from the balance spring) had already been introduced the previous century. This was the lever escapement invented by Thomas Mudge ( 1715-94). Later, the mechanism of watches was further improved by Abraham Louis Breguet ( 1747-1823), who also designed, in 1815, an observatory clock to strike each second--the forerunner of the modern time-signal. A prominent early nineteenth-century English horologist who had an important and lasting influence on watchmaking in other countries, notably France and Switzerland, was John Arnold (see p. 146). By the middle of that century Sir John Bennett, whose firm had been founded in 1843, recognized the danger of the growing competition from the Swiss watchmaking industry. He therefore arranged for watch mechanisms to be imported into England so that his firm could put the necessary finishing touches to them and sell them as British. He spent lavishly on advertising his wares at the Great Exhibition of 1851. Later in the nineteenth century the modern mass-production of watches began in USA, but it was taken up and greatly extended by the Swiss, who soon dominated the industry.
One of the most surprising facts in the history of horology is that, long after the invention of more precise devices, makers of domestic clocks and watches continued to make use of the verge escapement. This was because it proved to be particularly well-suited for withstanding the
-163-
rigours of domestic use and portability, whereas escapements such as the anchor type needed to be kept on level surfaces if they were to function satisfactorily.
Not only do most workers nowadays have to clock in and clock out when they begin and end their working day, but timekeeping applies no less generally to sporting activities. Indeed, anything, however idiotic, can now be regarded as a sport so long as it can be timed and can be used to set up a 'record'. Kevin Sheenan, of Limerick, acquired a kind of fame by talking non-stop for 127 hours, and in the USA a preacher established another record by delivering a sermon that lasted forty-eight hours. (This achievement would not have amused Queen Victoria who is said to have had placed conspicuously in all the pulpits used by her chaplains a sand-clock that ran for only ten minutes!) In these and many other ways most of us have become more and more subservient to the tyranny of time. As Lewis Mumford has so pertinently remarked, 'The clock, not the steam-engine, is the key-machine of the modern industrial age.'17 The popularization of timekeeping that followed the mass production of cheap watches in the nineteenth century accentuated the tendency for even the most basic functions of living to be regulated chronometrically: 'One ate, not upon feeling hungry, but when prompted by the clock; one slept, not when one was tired, but when the clock sanctioned it.'18 A good example of how strange our modern preoccupation with time seemed to someone used to a very different way of life is provided by the diary kept by the Nepalese ruler Jang Bahadur on his visit to Britain in 1850. According to the translation by John Whelpton of a biography of him in Nepali published in Katmandu in 1957 and containing excerpts from this diary, he remarked: 'Getting dressed, eating, keeping appointments, sleeping, getting up--everything is determined by the clock . . . where you look, there you see a clock.'19
Although by 1855 about 98 per cent of the public clocks in Britain were set to GMT, acceptance of this time generally throughout the country encountered difficulties. For example, in the case of Curtis v. March at Dorchester assizes on 25 November 1858, the judge took his seat on the bench at 10 a.m. by the clock in the Court, but as neither the defendant nor his lawyer were present he found for the plaintiff. The de
fendant's counsel then entered the Court and claimed to have the case tried on the ground that it had been disposed of before ten o'clock by the town clock, whereas the clock in the Court was regulated by Greenwich time, which was some minutes before the time in Dorchester. On appeal, the assize judge's decision was reversed, on the ground that 'ten
-164-
o'clock is ten o'clock according to the time of the place'. This decision was held to define legal time in Great Britain until 1880.20 In that year The Times published a letter from a 'Clerk to the Justices' pointing out the difficulties of officials conducting parliamentary elections in deciding the correct time to open and close the poll. Later that year an Act of Parliament was passed giving legal sanction throughout Great Britain to Greenwich Mean Time.
Soon afterwards steps were taken to standardize timekeeping throughout the world. In 1882 the United States passed an Act of Congress authorizing the President to call an international conference to decide on a common prime meridian for time and longitude, and in October 1884 delegates from twenty-five countries assembled in Washington for the International Meridian Conference. With only one country ( San Domingo) voting against and two others ( France and Brazil) abstaining, it was agreed to recommend that the Prime Meridian of the world should pass through the centre of the instrument at the Observatory at Greenwich known as the Airy Transit Circle and that the Universal Time should be GMT. This was not surprising, since the invention of the marine chronometer by John Harrison and the introduction of the Nautical Almanac in 1766 by the Astronomer Royal Nevil Maskelyne had already led many mariners of all nations to use Greenwich time and the Greenwich meridian. By the early 1880s nearly three- quarters of the ships throughout the world used charts based on the Greenwich meridian. Until 1925, however, as mentioned on p. 15, astronomers continued to begin their day at noon, because it meant that the date did not change in the middle of a night's observing. Another important consequence, although not specifically recommended by the Conference, was the setting-up of a time-zone system throughout the world as had originally been suggested by an American professor, Charles Dowd, in a pamphlet published in 1870. The need to co-ordinate timekeeping was much greater in a large country such as the United States than in Great Britain, but the crucial factor that influenced Dowd was the different times kept by the many railway companies that sprang up after the Civil War and the great inconvenience that they caused to the travelling public. For example, at Pittsburgh, Pennsylvania, there were six different time-standards for the arrival and departure of trains. Dowd's proposal was a scheme identical in principle with the standard time system used throughout the world today.
As long ago as 1881 an American, G. Beard, wrote a book called American Nervousness to point out that the widespread and increasing
-165-
emphasis on punctuality was causing men to worry that 'a delay of a few moments might destroy the hopes of a lifetime'. Among those in Europe who were anxious for time to be standardized was Count Helmuth von Moltke, who pleaded with the German Reichstag in 1891 for the abolition of the five different time-zones in Germany because they severely impeded the co-ordination of military planning.21 The resulting adoption of a single standard time greatly facilitated German mobilization in 1914. On the other hand, in France, where the lack of time-standardization was much worse than in Germany, a journalist, L. Houllevigue, writing in La Revue de Paris in July 1913, admitted that the delay in correcting this until 1911 was primarily due to Anglophobia. Indeed, the law that came into force defined legal time in France as nine minutes and twenty seconds later than Mean Paris Time. 'By a pardonable reticence, the law abstained from saying that the time so defined is that of Greenwich, and our self-respect can pretend that we have adopted the time of Argentan, which happens to be almost exactly on the same meridian as the English observatory.'
One of the main reasons for the catastrophic failure of diplomacy to prevent the outbreak of the First World War in August 1914 was the inability of diplomats to cope with the enormous volume and unprecedented speed of telegraphic communication in the last days of July. The rate at which messages could be sent from one capital to another necessitated rapid and often ill-considered responses. Ironically, the main reason for the failure of the Schlieffen plan for attacking France through Belgium was the unprecedented success of German mobilization, with thousands of trains ferrying troops to the front so rapidly that they outran their own timetable and consequently the supplies they needed failed to keep pace with them.
The decisive weapon in that war was the machine-gun with its rapid firing. On the Western front it has been estimated that it caused four- fifths of the casualties. Of the 60,000 casualties that the British army suffered on the first day of the battle of the Somme, 1 July 1916, most occurred in the first hour--probably in the first few minutes. One of the social consequences of the First World War was the increased use of wrist-watches. Many men had considered them unmanly until they became standard military equipment. The battle of the Somme began when hundreds of platoon leaders blew their whistles as soon as their synchronized wrist-watches showed that it was 7.30 a.m. Thus, whereas Einstein had shown ten years before that in the physical world simultaneity was a 'private' concept rather than a 'public' one (see
-166-
ch. 11), in the world of human action it had become far more important than it had ever been.
The introduction of the radio time-signal early this century for the dissemination of time for navigational purposes led to the final abandonment of the lunar-distance method of determining longitude at sea, since it now became possible to check a ship's chronometers directly. (The lunar-distance method had been used occasionally to check chronometers at sea when no other method was available.) Since the First World War radio, and later television, and the ever-increasing speed of the new modes of transport made possible by the invention of the internal combustion engine have led to our dependence on the clock becoming ever greater. In recent years the most spectacular example of this has been provided by space vehicles and the associated requirement of ultra-precise timekeeping.
In the early 1920s the accuracy of civil timekeeping was significantly improved by W.H. Shortt, a railway engineer, who in association with the horologist F. Hope-Jones and the Synchronome Company perfected what came to be known as the Shortt free-pendulum clock. The material used for the pendulum was a virtually temperature-independent alloy of steel and nickel called 'invar', first produced some years before in France. Any interference with the free motion of the pendulum was reduced to a minimum by the ingenious use of a subsidiary 'slave dock'. Shortt clocks were the standard timekeepers at the Royal Observatory, Greenwich, from 1925 to 1942. Previously, the best clock-accuracy was about one- tenth of a second (100 milliseconds) a day, but Shortt clocks were accurate to about 10 seconds a year, that is, about 30 milliseconds a day. In the 1930s still greater accuracy was obtained by utilizing the mechanical vibrations of the crystalline mineral quartz, instead of the vibrations of a pendulum in the earth's gravitational field. The quartz crystal clocks which replaced the Shortt clocks as the standard timekeepers at the Royal Observatory in 1942 were accurate to about two milliseconds a day.
For centuries the time kept by our clocks and watches was controlled by the rate of rotation of our planet, but with the invention of more accurate clocks it was found that the rotating earth is not a sufficiently accurate timekeeper for modern needs, because it is subject to small variations. The earth is a solid body surrounded by water and air, and seasonal changes in these, for example the melting and freezing of the polar ice-caps, affect the earth's rate of rotation so that the length of the day fluctuates during the year by just over a millisecond (thousandth of a second). There are also small irregular changes attributed to processes in
-167-
the earth's deep interior. Besides these changes there is a progressive slowing down of the earth's rate of rotation caused by tidal friction in shallow seas that produces an increase i
n the length of the day of about 1.5 milliseconds a century. As a result in 1952 the rotating earth was displaced as the fundamental timekeeper by Ephemeris Time, based on the length of the year, which is decreasing by about 0.5 seconds a century but can be predicted. However, even this did not prove entirely satisfactory and because of the increasing demand for high-precision time- measurement it has become essential to have some more fundamental standard of time than any that can be derived from astronomical observations. Such a standard is given by the frequency of a particular spectral line of an atomic or molecular vibration. The most successful method of this type has been developed by Dr L. Essen of the National Physical Laboratory.22 Consequently, in 1967 a new definition of the second was made in terms of the electromagnetic radiation generated by a particular transition in the ground state of the caesium atom. It is called the 'SI second' (Système Internationale). It is formally defined as the duration of 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the caesium-133 atom. In this transition the spin of the outermost electron of the atom 'flips over' with respect to the spin of the nucleus. (A quartz crystal oscillator is controlled by means of a known relationship between its frequency and that of the radiation generated by this transition.) The caesium atom was chosen because the frequencies concerned are in the radio range and can be measured by standard techniques. In recent years there has been much technical discussion concerning the relation between TAI ('International Atomic Time'), obtained by the continuous summation of time-intervals deduced from these measures of frequency, and the time-scales used by astronomers. The accuracy of astronomical time, which is still required for practical purposes, is checked by means of the frequency of this radiation. This atomic frequency standard is now so precisely determined that in individual cases its accuracy can be as high as one part in 1014, which is equivalent to an error of only one second in three million years.