Timekeeping

“ These questions lead us at once into another department of inquiry of immense importance in science—the measurement of time, and more especially the measurement of minute periods of time. We all recognise more or less the value of time, and the busier we are the more we value what we call fragments of time. On a long summer day in the holidays, when we have not much to do except gratefully to enjoy the beauties of nature and the sense of physical well-being, a quarter of an hour, or even an hour, is not appreciated as of much value ”

“ The sense of responsibility, of importance, which such a wonderful little piece of mechanism gives to them, the alacrity with which they thenceforth note the flight of time and compare the working of all other time-pieces, is remarkable. One of the first things usually done by the juvenile with his or her watch is, curiously enough, to challenge thereby the performance of the old-established time-pieces in the house,—even the infallible old Hall Clock, a very Nestor among clocks, does not escape scrutiny. ”

“ And, on the other hand, if you set a clock forward even so little as ten minutes, you take away that much from the future, and you make the coming hour only fifty minutes long. Now, no human being has a right to take anything away from the future, or to make the hours shorter than they were intended to be. I desire, my dear niece, that you will earnestly think over what I have said, and I am sure that you will then see for yourself how unwise it would be to trifle with the length of the hours which make up our day. And now, Arla, let us talk of other things. ”

“ Leaving, then, this constant error in time-appreciation, we will pass to the variable and more palpable errors in the retrospective measurement of time. Each person's experience will have told him that in estimating the distance of a past event by a mere retrospective sense of duration, he is liable to extraordinary fluctuations of judgment. Sometimes when the clock strikes we are surprised at the rapidity of the hour. At other times the timepiece seems rather to have lagged behind its usual pace. ”

“ But the moon alone moves with sufficient rapidity to act as a time indicator for terrestrial voyagers. It is hardly necessary to explain why rapidity of motion is important; but the following illustration may be given for the purpose. The hour-hand of a clock does in reality indicate the minute as well as the hour; yet, owing to the slowness of its motion, we regard the hour-hand as an unsatisfactory time-indicator, and only consider it as showing what hour is in progress. ”

“ In estimating the time-keeping qualities of a watch or clock, the error of rate is of no consequence. It is simply due to the timekeeper going too fast or too slow, and this can easily be corrected. What is wanted for a good watch is that the rate, whatever it is, shall be constant. The daily error is of no account provided it is a uniform daily error and not an irregular one. Hence the object of the trials is to determine not merely the daily rate but the variations of the daily rate, and on the smallness of these the value of the watch as a time-keeper depends. ”

“ The local time kept by clocks is an average of solar time, and is properly designated "mean time," as distinguished from the variable time shown by the sun-dial. No clock or watch can be made to keep the time as shown by the sun-dial, and this new system of time-keeping, therefore, became necessary when clocks and watches were invented. The relation between mean and apparent time, and what is meant by "the equation of time," may be seen at a glance by reference to the accompanying diagram. ”

“ Why, you might almost say it ran by clock-work! The millions of watches in millions of pockets, the millions of clocks on millions of walls, all running steadily together—these were what kept the complicated machinery of modern life from getting tangled and confused.
Yes; but what did people do before they had such timepieces? Back in the very beginning, before they had invented or manufactured anything—far back in the days of the caveman—even those people must have had some method of telling time. ”

“ Man, being more perfect than the sun, makes a clock that keeps regular time. Also, he calculates how far the sun is ahead of its schedule or behind. The difference between the sun's position and the position where the sun ought to be if it were a decent, self-respecting sun, man calls the Equation of Time. Thus, the navigator endeavouring to find his ship's position on the sea, looks in his chronometer to see where precisely the sun ought to be according to the Greenwich custodian of the sun. ”

“ Calendar work on watches is, of course, fatal to great accuracy of time-keeping, and is very complicated. A watch is made to record days of the week and month, and to take account of leap years usually by the aid of star-wheels with suitable pauls and stops. The type of this mechanism is to be found in the calendar motion of an ordinary grandfather's clock. ”

“ For if we suppose the time marked to be an hour, the space passed over by the minute hand, that is, the circumference of the dial, has no relation with the hour except what the artificer gave it by so constructing the watch that the minute hand would make one revolution every hour. ”

“ It is well that modern clocks have no wise saws and [Pg 32] mottoes telling of the unalterable hand of Time; "Old Time, the clock-setter, that bald sexton, Time," as Shakespeare says in King John.
Early Mechanism.—The problem for the old clockmakers who wished to supplant the primitive measurement of time by candle, by the hour-glass, and later by the sundial, was to produce a piece of mechanism which would in twenty-four hours, the prescribed period of day and night, indicate the flight of time hour by hour. ”

“ The improvement of the balance-watch upon the clepsydra or the hour-glass and other early time-keepers caused the change to be made from apparent to mean time, and the increasing requirements of a complex civilization demand more and more attention to the keeping of accurate standard time. ”

“ The Winding and keeping in order is, as we have said, a less laborious task as respects modern clocks than those which were made fifty years ago, inasmuch as, although it is the duty of a clock-winder to watch daily the action of the time-piece under his charge, he need not perform his winding duties oftener than once a week. ”

“ But the regulating, as a matter of course, requires a regulator, or standard, of time, which is not always to be found in country places, nor even is the man in charge of clock-winding always in possession of a watch sufficiently accurate to convey the time from the regulator if there were one to the Church clock. Of late, Church clocks are made to go eight days, and so the labour of frequent winding has been saved, while at the same time by extra care in the [ 145] manufacture and fixing of a clock, there need be no necessity for frequently regulating it. ”

“ To railroad-men and watch-makers as a matter of necessity, to manufacturers and business-men as a matter of economy, and to individuals as a matter of convenience, it has come to be highly important to know what is the exact time of day to the second, in circumstances where half a century ago it would have quite sufficed to know the minute or even the hour. ”

“ Time has proved how well it can keep time. It is looked after by a gentleman learned in the deep mysteries of horology, who won't allow its fingers to get wrong one single second, who used to make his own solar calculations in his own observatory, on the other side of Jordan (street) , who gets his time now from Greenwich, who has drilled the clock into a groove of action the most perfect, and who would have just cause to find fault with the sun if antagonising with its indications. ”

“ Our only way of knowing it accurately is by counting, or noticing the clock, or through some other symbolic conception. When the times exceed hours or days, the conception is absolutely symbolic. We think of the amount we mean either solely as a name, or by running over a few salient dates therein, with no pretence of imagining the full durations that lie between them. No one has anything like a perception of the greater length of the time between now and the first century than of that between now and the tenth. ”

“ These dry facts may serve to whet the curiosity of the student in regard to the measurement of time and its origin. They add a piquancy to the clock dial as we now know it. Scientific it is, as one of man's most exact recorders of natural phenomena. That an exact timekeeper should be found in the pocket of every schoolboy would seem an astounding miracle to our ancestors two hundred years ago, or even less than a hundred years ago:
'Tis with our judgments as our watches, none
Go just alike, yet each believes his own,
writes Pope in his Essay on Criticism in 1725. ”

“ While I am walking with Michael some one often comes to me to ask the time of day. Few of the people, however, are sufficiently used to modern time to understand in more than a vague way the convention of the hours, and when I tell them what o'clock it is by my watch they are not satisfied, and ask how long is left them before the twilight. ”

“ We find, say, that as compared with our watch time, one clock is two minutes fast, the next three minutes fast, the next one minute slow, and so on, two or three perhaps being as much as six or seven minutes fast, and two or three being as much as three or four minutes slow as compared with the watch. We note, however, that these wider ranges of difference occur only in the case of clocks presumably inferior—cheap clocks in small [Pg 68] shops, old clocks in buildings where manifestly the flight of time is not much noted, and so forth. ”

“ Hubert. Do you think that it was as long as 1 hour after you awoke that the call came from Little Lynn?
Mr. Senator. I don’t think so. You know this is very complicated when you try to make a timepiece out of this. It really is. I mean especially if you are not watching the time and don’t know the time. It is just a complicated thing trying to place a time together.
Mr. Hubert. That is true, but on the other hand when we have a fixed time, sometimes we can relate events to that time in terms of hours and half hours and so forth. ”

“ But for the primitive intellect the year is a very long period, and it is only with difficulty and at a later stage that it can be conceived and surveyed as a whole. Day and night, on the other hand, are short units which immediately become obvious. Their fusion into a single unit, the day of 24 hours, did not take place till later, for this unit as we employ it is abstract and numerical: the primitive intellect proceeds upon immediate perceptions and regards day and night separately. ”

“ Absolute, true, and mathematical time, in and of itself, of its own nature, without reference to anything external, flows uniformly, and is otherwise called duration. Relative, apparent, and commonplace time is any sensible and external measure, whether accurate or approximate, of duration by means of motion. This kind of measure, for example, hour, day, month, year, is used by common people instead of true time. ”

“ But how can we test a time-piece whose motions32 we select to regulate every other time-piece? If a man sets his watch every morning by the clock at Westminster, it is clearly impossible for him to test the accuracy of that clock by the motions of his watch. ”

“ Let me illustrate my case by analogy. The working of a clock is a model of uniform action; good time-keeping means uniformity of action. But the striking of the clock is essentially a catastrophe; the hammer might be made to blow up a barrel of gunpowder, or turn on a deluge of water; and, by proper arrangement, the clock, instead of marking the hours, might strike at all sorts of irregular periods, never twice alike, in the intervals, force, or number of its blows. ”

“ It must be particularly noted that there is a distinct difference between time study and time recording. Any job, the slowest or fastest in the whole factory, may be time-recorded by merely observing the time with a stop-watch, but this is not a time study. ”

“ The other men were Blank, the Editor afore-mentioned, a certain journalist, and another—a quiet, shy man with a beard—whom I didn't know, and who, as far as my observation went, never opened his mouth all the evening. There was some speculation at the dinner-table about the Time Traveller's absence, and I suggested time travelling, in a half jocular spirit. The Editor wanted that explained to him, and the Psychologist volunteered a wooden account of the "ingenious paradox and trick" we had witnessed that day week. ”

“ In exhibits of this kind much must be left to the taste of the critic. Watches and chronometers, on the other hand, can be submitted to the minutest tests. The care and trouble which these require are not small, but the issue is sufficiently important to warrant all the labor which the judges in horology brought to their work. Time-keepers that can be relied upon in all weathers and in all climates, and that are within reach of all classes, are a luxury of no common order, but to a large number of persons they are a necessity also. ”

“ The writer does not believe at all in the policy of spying upon the workman when taking time observations for the purpose of time study. If the men observed are to be ultimately affected by the results of these observations, it is generally best to come out openly, and let them know that they are being timed, and what the object of the timing is. There are many cases, however, in which telling the workman that he was being timed in a minute way would only result in a row, and in defeating the whole object of the timing ”