The standardisation of time is, perhaps, one of the most important factors in modern civilisation. It forms the basis of all transportation services, not only in the compilation of timetables, but also in co-ordinating those timetables with the requirements of the general public. It is as unnecessary to point out the result of trying to catch a train, a bus or a car, when one's watch is ten minutes slow, as it is to draw a picture of the result of trying to operate a complicated timetable over a section of railway where every signalman, guard or driver, uses his own time standard. But the importance of time strikes even deeper than this. In navigation, it is one of the two co-ordinates which alone make it possible for the navigator to feel his way across oceans and maintain his course, clear of obstructions, straight to his port of destination. To do this he carries a clock regulated to the time of Greenwich, the meridian of which place has been accepted as zero. Every degree of longitude east or west of this meridian causes a variation of four minutes. The navigator, therefore, calculates the local time of his position at sea, compares it with his Greenwich Chronometer, and, by dividing the difference in minutes by four, arrives at his longitude east or west. This, together with a calculation for latitude, gives his position and enables his course to be maintained.

We generally associate time with watches and clocks, and these serve as our standard from day to day; but as no watch or clock will of itself keep absolutely accurate time some standard by which to check its error is required. The movement of the earth in relation to sun and stars provides this master clock, and it is to this movement, as taught by the science of astronomy, that we must turn for our standard.

The fundamental unit of time is the solar day, that is the successive return of the sun to the same point in the sky.

The earliest type of timepiece consisted of a vertical stake, the direction of the shadow of which served to indicate the amount of daylight that had elapsed since sunrise. Owing, however, to the fact that the earth's axis is inclined to the plane of its orbit, the shadow of a vertical stake does not move uniformly with time. The sundial as we know it to-day, overcame this difficulty. In this device the vertical stake was replaced by a vane inclined, according to latitude, till it lay parallel with the earth's axis, and the shadow then moved evenly throughout the hours of daylight.

As civilisation became more complex, methods of measuring time independent of the sun were developed, the principle of which being the water clock where water was allowed to enter a vessel at an even rate, the height of the liquid serving to indicate the number of time units that had elapsed since the filling process commenced. The sand glass, familiar to-day for timing the boiling of eggs, was also extensively used. Later the mechanical clock was invented and not till then was the accurate measurement of time possible.

Sun-rise and sunset are the most natural divisions of time. The earliest method of dividing the day was to separate the period of daylight into a number of equal divisions. With the advent of the mechanical clock, however, this method became unsuitable owing to the greater length of sunlight in summer than in winter, which caused the divisions to have varying values for different seasons of the year. From these early methods has gradually developed the present practice of reckoning time from midnight to midnight and dividing the period into 24 equal parts called hours.

With the advancement of scientific knowledge several truths fundamental to the accurate determination of time were revealed, the most important of which was the varying length of the solar day from noon to noon. A solar day is the interval between two successive crossings of the meridian of a place by the sun, but owing to its revolution round the sun, the earth requires to rotate slightly more than 360 degrees to again bring the sun on to the meridian of that place. The solar day is, therefore, slightly longer than one rotation of the earth on its axis. Again the orbit of the earth round the sun is not quite circular nor is the position of the latter quite central. In geometrical terms the earth's orbit is an ellipse of which the sun occupies one focus. The distance of the earth from the sun, therefore, fluctuates throughout the year. This page 29 results in a varying orbital velocity for the earth, greatest when closest to the sun and decreasing as the distance increases. Without going into details, the net result of this is that as the earth's orbital velocity increases, the solar day becomes longer and, conversely, shorter as the velocity decreases.

Still another factor disturbs the even flow of solar time. The plane of the earth's equator is inclined to the plane of its orbit and results in the solar day being slightly longer at the solstices than at the equinoxes.

In solar time, therefore, we have two sets of fluctuations, the first due to the ellipticity of the earth's orbits, with a period of one year, and the second, due to the obliquity of the earth's axis, with a period of six months. To overcome these irregularities and produce an evenly flowing time, a fictitious mean sun has been invented, and is assumed to move at a uniform rate along the earth's equator but never departs far from the position of the real never departs far from the position of the real sun. In other words, the fluctuations of solar

Equation of Time
The Curved line indicates the combined effect on time during each month of the year caused by the obliquity of the ecliptic, and the ellipticity of the earth's orbit. The equation is the correction, in minutes, to be applied to the apparent time given by a sun-dial to obtain mean solar (or clock) time.

time are smoothed out, one set being used to compensate the other throughout the year. The time given by this fictitious sun is called “mean time.” Throughout the year solar time varies from “mean time” as follows:—Even on 25th December, 14½ minutes slow by 11th February, even by middle April, 4 minutes fast by middle of May, even on 2nd June, 6¼ minutes slow on 27th July, even on 1st September, 16¼ minutes fast early in December, and even again by 25th December.

“Mean time” is that distributed from time stations and shown by well regulated clocks. Solar time is that indicated by a sundial. Each place on earth has its own “mean” or “apparent” (or solar) time, which is the same for all places in the same longitude and which differs from points east and west by four minutes for each degree.

So far we have dealt with time in relation to the earth and sun and, by the introduction of “mean time,” have produced a uniformly flowing system, but to check the error of our clocks, a complicated equation is involved. An alternative method simplifies the process. First, let it be mentioned that the movement of the sun is so far as we are here concerned, only apparent and is due to the combined daily rotation and annual revolution of the earth. The apparent movement of the stars is due solely to the earth's rotation which proceeds with extreme regularity. If, therefore, we take the successive passages of any one star across the meridian of a place we are provided with a uniformly flowing system of time. The period between any two successive passages of a star across the meridian is termed a “sidereal” day. Reverting to the solar day, we saw that the earth had to rotate slightly more than 360 degrees between each successive passage of the meridian to compensate for the forward movement of the earth in its annual revolution. With the stars, this passage or transit takes place regularly with every neat rotation, so that a sidereal day is slightly shorter (about 4 minutes) than the solar day. Sidereal time is unsuitable for general use since the four minutes difference between it and solar time is cumulative and in the course of a year sidereal midnight moves completely round the clock. Thus the stars make 366 revolutions to the sun's 365. But since sidereal time is constant its translation to mean time becomes a simple calculation.

The computation of sidereal time involves the use of the transit or meridian circle telescope. This is a telescope mounted on horizontal bearings and swinging in the plane of the meridian. Any star when centrally placed in the field of view of this telescope is either due north or south of the point of observation. If, therefore, a suitable star is fixed to read zero, sidereal time, it is necessary to adjust the observatory clock only to read zero at the moment the transit is made, and twenty-four hours later to again observe the successive transit of the same star. The clock should again read zero, and any deviation therefrom denotes its error and enables adjustment to be made. In this way the actual times of transits of all the stars may be catalogued and sidereal time checked at any time during the night. Delicate mechanism is employed to ensure accurate comparison of transits with the clock and calculations are reduced to so fine a point that clock errors of 1–100th of a second may be detected.

It has already been stated that time varies with longitude at the rate of 4 minutes for each degree. In countries such as Australia, Asia, Europe and America, where vast distances page 30 separate their eastern and western boundaries, the variation of time through difference of longitude may be as much as several hours. Time as calculated on the eastern coast is, therefore, quite unsuitable to western requirements, and such countries are faced with the problem of two or more different standards of time operating simultaneously. To overcome undue complications arising from this the earth has been divided into 24 zones, each 15 degrees of longitude in width, and a standard time is calculated for each zone. Since 15 degrees represents one hour difference in time, all that is necessary in passing from one zone to another is to adjust one's watch by this amount forwards when passing from west to east, and backwards when passing in the opposite direction. In countries where the greatest distance is from north to south such as in New Zealand and the total difference in longitude between eastern and western shores is one or two degrees only, one standard time suffices. When a time line passes through such a country, it is varied slightly east or west to make one standard time operative.

New Zealand “mean time” is calculated in Wellington by the Government Astronomer. From the observatory it is transmitted to the General Post Office, and at 9 o'clock each morning is flashed throughout the entire length and breadth of the country by the telephone and telegraph systems. The call “L. S.” a few minutes before 9 o'clock each morning is too familiar to Railwaymen to require further comment.

The sleeping compartment of the North Island Royal Train-H. R. H. The Duke of York's bedroom.

Installed at Hillside Workshops.

Electric Spot Welding Machine.

This is the first Electric Spot Welding Machine to be used in the New Zealand Railway Workshops. It was designed by Mr. B. de B. Gates, of Dunedin, and is installed at Hillside Workshops. Foot pressure is applied to the pedal that brings the two electrodes together. The plates to be welded are placed between the points of the electrodes, and upon contact being made, the metal becomes welded in less than one second.

To state the economy effected by this type of machine, 8,000 welds were made at Hillside on 1,000 trays by one man, in eight hours, at a cost for electric current of 1s. 10d.

Under the old riveting method 8,000 rivets would have cost 8s. and the time taken to complete the same work would be 32 hours at the least.

The machine is absolutely fool proof, a feature being that there is no possibility of the operator receiving an electric shock,—another instance of new methods replacing the old.

Many joys may be given to men which cannot be bought for gold, and many fidelities found in them which cannot be rewarded with it.

“The Greatest National Service.”

Mr. E. W. Beatty, Chairman and President of the Canadian Pacific Railway, has recently given prominence to a fine expression of the attitude of railwaymen towards the railway which may be regarded as of importance not merely within the Dominion of Canada, but wherever railway services operate.

He writes as follows:—

“A railway may be considered a sort of machine; but the simplest kind of machine requires a human being to work it and care for it. To say that the “man is everything” is, of course, an exaggeration, yet the importance of the human element in a railway enterprise can hardly be exaggerated.

As some parts of a great machine are infinitely more difficult and delicate than others, so the operation of a great railway system includes the utmost variety of duties, from those which can be easily performed, with little skill, to those which demand long training and experience, technical ability, scientific knowledge, wide versatility, sure judgment and high capacity for organisation and management-talents as valuable as they are rare.

It is a curious fact-yet a fact undeniably-that those who work for railroads seldom divorce themselves from railroad work. There is a charm in the movement and variety of work on a railroad which voluntarily, cheerfully and loyally holds men to long hours and arduous tasks, and the same spirit of frank loyalty is evident right through the service-a willingness and desire on the part of all departments to co-operate, which could only exist where harmony and loyalty are outstandingly predominant.

It may be added that the employees of the Canadian Pacific Railway, having a high average of intelligence, and endeavouring to secure the best possible return on their own savings and investments, large or small, recognise that a good return on the money invested by others for the creation and improvement of the railway is both just and necessary. Without such a return, with returns uncertain or poor, the credit and stability of an enterprise are weakened and undermined.

On the foundation of that credit and stability alone, rests the Company's whole power to maintain and improve its lines and its services and to give employment on the present gigantic scale. From this employment, half a million men, women and children in Canada draw their livelihood, not to speak of the hundreds of thousands more who indirectly share in the disbursements of the Company. More than that-last year alone-outside of regular maintenance, operation, publicity and other expenditures, the Company, for the purchase of new equipment etc., set aside fifteen million dollars, which will ultimately pass into the pockets of the people of Canada.