Part 15

"II. The cosmic day consists of twenty-four hours, and commences at midnight of the prime meridian.

"III. The earth is divided from the initial meridian into twenty-four hour spaces, counted in a direction contrary to the movement of the earth.

"We shall, then, have the following formula: F = A + R where R represents the difference reckoned from 0h. to 24h. between the local time of the prime meridian and the local time of each point of the globe; F the cosmic time, and A the local time."

The PRESIDENT. In order that this amendment may be presented more clearly to the Conference, I would propose a recess for a few minutes. If there be no objection, a recess will be taken.

No objection being made, the Conference took a recess.

* * * * *

The PRESIDENT having called the Conference to order stated that, unless further remarks were presented, the vote would be taken upon the resolution offered by the Delegate of Spain, Mr. PASTORIN.

No objection being made, the vote was then taken upon the amendment, and it was lost.

The PRESIDENT. The question now recurs upon the resolution offered by the Delegate of Sweden, Count LEWENHAUPT, which will again be read. The resolution is as follows:

"The Conference recommends as initial point for the universal hour and the cosmic day the mean mid-day of Greenwich, coinciding with the moment of midnight or the beginning of the civil day at the meridian 12 hours or 180° from Greenwich. The universal hours are to be counted from 0 up to 24 hours."

Professor ADAMS, Delegate of Great Britain. Mr. President, I intended to speak on the resolution offered by the Delegate of the United States, Mr. RUTHERFURD, but the remarks which I have put together apply equally well to the amendment to that resolution now offered by the Delegate of Sweden, which is identical with one of the recommendations of the Conference at Rome, because, in fact, in my remarks I discuss these propositions alternatively. Therefore, with your permission, I will lay before you the observations which I wish to make.

I beg leave to express my entire approval of the resolution which has been laid before the Conference by Mr. RUTHERFURD. There is only one point involved in the resolution which seems to call for or even to admit of any discussion.

It appears evident that the universal day and date should coincide with the day and date of the initial meridian. The only question, therefore, which we have now to decide is, when shall this day of the initial meridian be considered to commence? And the proper answer to be given to this question does not appear to me in any degree doubtful.

In modern times it is the universal practice to reckon dates by _days_ and not by _nights_. The word "day" is used in two different significations, being sometimes applied to the period of daylight and sometimes to the period of 24 hours, including both day and night; but in whichever of these senses the word _day_ is employed, the term mid-day has one and the same signification, viz., the instant of noon or of the sun's passage over the meridian. In the present case, where we are concerned with mean time, mid-day means the instant of mean noon, or of the passage of the mean sun over the meridian.

Accordingly, the civil day, by which all the ordinary affairs of life are regulated, begins and ends at midnight, and has its middle or mid-day at noon.

It appears, then, most natural that the universal day should follow this example, and should begin and end at the instant of mean midnight on the initial meridian, and should have its middle at the instant of mean noon on the same meridian.

I fail, therefore, to see the force of the reasons which induced the Conference at Rome to recommend that the universal day should commence at _noon_ on the initial meridian.

The only ground for making this recommendation is that astronomers, instead of adopting the use of the civil day, like the rest of the world, are accustomed to employ a so-called astronomical day, which begins at noon. The advantage thus gained is that they avoid the necessity of changing the date in the course of the night, which is the time of their greatest activity; but this advantage is surely very small when compared with the inconvenience of having two conflicting methods of reckoning dates, and of being obliged to specify, in giving any date, which mode of reckoning is adopted. If this diversity is to disappear, it is plain that it is the astronomers who will have to yield. They are few in number compared with the rest of the world. They are intelligent, and could make the required change without any difficulty, and with very slight or no inconvenience.

The requisite changes in the astronomical and nautical ephemerides would be easily made. As these ephemerides are published several years in advance, there would be plenty of time for navigators to become familiar with the proposed change in time-reckoning before they were called upon to employ it in their calculations.

I believe that they would soon come to think it more convenient and natural to reckon according to civil time than according to the present astronomical time. I am told that this practice is already universally adopted in keeping the log on board ship. To avoid any chance of mistake, it should be prominently stated on each page of the ephemerides that mean time reckoned from mean _midnight_ is kept throughout.

Whether or not astronomers agree to adopt the civil reckoning, I think we ought to adopt the instant of midnight on the initial meridian as the commencement of the universal day.

The relation between the local time at any place and the universal time would then be expressed by the simple formula:

Local time = universal time + longitude.

Whereas, if the proposition of the Roman Conference were adopted, we should have to employ the less simple formula:

Local time = universal time + longitude - 12 hours.

In recommending the mean noon at Greenwich as the commencement of the universal day and of cosmopolitan dates, the Roman Conference refers to this instant as coinciding with the instant of midnight, or with the commencement of the civil day, under the meridian situated at 12 h. or 180° from Greenwich. Now, this reference to the civil day and date on the meridian opposite to Greenwich appears not only to be unnecessary and to be wanting in simplicity, but it may also lead to ambiguity in the date, as expressed in universal days, unless this ambiguity be avoided by making an arbitrary assumption. No doubt the Greenwich mean noon of January 1 coincides with midnight on the meridian 12 h. from Greenwich, but with what midnight. What shall be its designation and the corresponding date given to the universal day? Shall we call the instant above defined the commencement of the universal day denoted by January 1 or by January 2? Each of these dates has equal claims to be chosen, and the choice between them must clearly be an arbitrary one, and may, therefore, lead to ambiguity.

By adopting Greenwich mean midnight as the commencement of the universal day, bearing the same designation as the corresponding Greenwich civil day, all ambiguity is avoided, and there is no need to refer to the opposite meridian at all.

Those are the ideas I wish to express with regard to the commencement of the universal day.

I may mention in connection with this subject that Professor Valentiner is one of the gentlemen who were invited, a week or two ago, to attend the meetings of this Conference, in order that, if requested, they might express their opinions from a scientific standpoint upon the questions before it; but as Professor Valentiner had to leave Washington before our sessions were at an end, I thought it would be expedient to ask him for his opinion in writing upon the matter which is now pending before this Conference. He has written a letter in German, expressing his opinion. I have caused that letter to be translated into English, and if the Conference allows me I will read it.

The PRESIDENT. If there be no objection to the proposition of the Delegate of Great Britain the letter will be read.

No objection being made, Professor ADAMS continued: It is well known that Professor Valentiner is an eminent practical astronomer, and I think that any opinion coming from him on this subject, which interests astronomers very much, will be considered of great weight. The letter runs as follows:

CHARLOTTESVILLE, VA., _October 12th, 1884_.

HONORED SIR: You had the kindness to ask me for my views as to the choice of the moment for the beginning of the day. As I cannot remain longer in Washington, I allow myself thus briefly to write to you.

When, as in the present case, the object is to introduce uniformity in the time-reckoning of the astronomical and the civil world, I am of the opinion that it is the astronomer only that must give way. For all purposes of civil life one cannot begin the day in the middle of the day-light--that is to say, in the middle of that interval during which work is prosecuted. In general it appears to me natural that the middle of the day, and not the beginning of the day, should be indicated by the highest position of the sun which governs all civil life. In fact, it would in civil life be simply impossible to bring about a change of date in the middle of the daylight. For the astronomer there certainly exist difficulties. His activity occurs mostly in the civil night, and he, therefore, has to make the change of date in the midst of his observations; and this difficulty is increased, since he almost exclusively observes according to sidereal time, so that often a computation must be made in order to ascertain whether the observations were made before or after the midnight or moment of change of date. However, this difficulty can be overcome by habit, and I believe that scarcely any doubt will occur as soon as a uniformnity of expression has established itself through the astronomical world. As regards the ephemerides, we already employ, in fact, the beginning of the date at midnight, since the places of planets and comets, are generally computed for 12 o'clock midnight of Berlin or Greenwich or other places. But these are points that have themselves long since been discussed.

I scarcely need to say anything further. I would not hesitate for a moment to give the preference to making the change of date take place at midnight, according to civil reckoning, in order to establish a uniformity with the customs of civil life.

It, perhaps, may be important to remark that we could not introduce this change immediately, since the ephemerides are already computed and published for three or four years in advance. It would, therefore, be well to fix the epoch of change of normal dates to some distant time, such as 1890.

I remain, very respectfully yours,

W. VALENTINER.

I may also mention that the practice that prevails among astronomers at the present time of reckoning the day from noon is by no means without exceptions. There are very important astronomical tables which reckon the day from midnight; for instance, in Delambre's Tables of the Sun; in Burg's, Burckhardt's and Damoiseau's Tables of the Moon; in Bouvard's Tables of Jupiter, Saturn, and Uranus, and in Damoiseau's Tables of Jupiter's Satellites, mean midnight is employed as the epoch of the tables. I may also mention that Laplace, in his Mécanique Celeste, adopts the mean midnight of Paris as the origin from which his day is reckoned. Hence there are great authorities, even among astronomers, in favor of commencing the day at midnight.

General STRACHEY, Delegate of Great Britain. Sir, I observe that a very eminent American authority is present in this room, I mean Professor Hilgard. As he was invited to attend the meeting of this Conference, I suggest that the views of the Conference may be taken, whether he may not be invited to express his opinion on the point now under consideration.

The PRESIDENT. With the concurrence of the Conference, the Chair will be most happy to ask Professor Hilgard to do us the favor to give us his opinion upon the question now before the Conference.

No objection was made to the proposition of the President.

Professor HILGARD arose and said. I thank you and the Conference very much for this invitation, and General STRACHEY for having proposed it to the Conference, but my opinion has been squarely expressed both in French and English in the report of a certain committee, that I am in favor of midnight at Greenwich as the beginning of the universal day, and of longitude being calculated both ways from Greenwich. I really cannot add anything to what has been said in the arguments already presented by Professor ADAMS, and I do not think that I ought to detain this Conference a moment by repeating the opinion he has expressed to all the experts in this matter.

I beg you will excuse me for not further ventilating my views. Absence from the city, I regret, has prevented me from availing myself of the invitation earlier.

Sir FREDERICK EVANS, Delegate of Great Britain. I have the honor to address the Conference once more upon the practical aspect of the subject before us as affecting the large body of navigators. I wish to say upon this point that there appears to me, in the address of my colleague, Professor ADAMS, somewhat of a mixing together of two subjects.

The question immediately before us, as I understand it, is whether the commencement of the universal day shall be midnight or noon of the initial meridian. That is what we practically have to decide. Now, I gather from Professor ADAMS' remarks that upon this question the ephemerides which we now employ have some important bearing. I do not think that that should influence us, for this reason, that the next resolution which will come before the Conference "expresses the hope that as soon as may be practicable the astronomical and nautical days will be arranged everywhere to begin at midnight."

This resolution, so far as I understand it, will be the warning to astronomers to begin to make the changes growing out of this resolution which may be necessary for seamen. Therefore, I consider that we may at once proceed to vote upon the question whether the day is to commence at midnight or noon, without any reference to the practice or interests of navigation. In reality, it does not appear to me to affect that subject at all.

I have given some consideration to the practical bearings of this question--whether it should be midnight or noon. What we ought to decide is what will be the least inconvenience to the world at large. I have ascertained from two of my colleagues, who have given this matter the greatest consideration, that the adoption of midnight will really cause less confusion than noon, for this reason, that all the great colonies of the world would be less affected; that is to say, that the times they are using now would be less affected by midnight than by noon. That being so, it appears to me to be an essential point in coming to a settlement of this question.

Mr. RUIZ DEL ARBOL, Delegate of Spain. I have only to say that I have listened to the remarks about navigators changing the reckoning of time. I do not know whether there are many navigators here, but it is a fact that seamen reckon the day from noon.

The PRESIDENT. I beg the pardon of the Delegate of Spain; but, in the United States navy, we reckon the day from midnight.

Mr. RUIZ DEL ARBOL, Delegate of Spain. I am speaking generally. Now, there is some reason for this rule among seamen, for the only way to find out the position of a ship is to observe the meridian altitude of the sun; and everybody requires to know, at sea, what has taken place in the course of every day, from the beginning to the last moment of the day; and I think that whatever the rule may be in the United States navy, navigators generally will count their time as they count it now.

I think that navigators will not change the rule now in force, no matter what we may adopt in this Conference.

Commander SAMPSON, Delegate of the United States. I think, Mr. President and gentlemen, that the change to the adoption of the universal day, beginning at midnight, would be a very decided advantage to navigators. The quantities as now given in the nautical ephemerides are for noon of the meridian for which they are computed, as Washington, Greenwich, &c. It is very evident that every navigator, in making use of the quantities given in the nautical almanac, must find the corresponding time at Greenwich, wherever he may be on the surface of the earth. Consequently, if we suppose that navigators are pretty equally distributed, one-half on one side of the earth and one-half on the other side, the Greenwich day for one portion would be the local night for the other.

The usual observations made by navigators at sea consist in a meridian observation of the sun for latitude, and a morning and possibly afternoon observation of the sun near the prime vertical for longitude. Consequently all navigators, when in the vicinity of the initial meridian, might have their day's work occurring in two astronomical days. On the other hand, those navigators who were in the neighborhood of the 180th meridian would have all their work of one day occurring in the same astronomical day. The first would have the advantage of interpolating for short intervals only, while the second would be obliged to interpolate for much larger intervals.

Consequently, on the whole, it would make no difference to navigators whether the quantities given in the nautical almanacs were for noon or midnight of the initial meridian. Another consideration, however, would make it very advantageous to have the quantities given for midnight. That consideration is this: if midnight were chosen, then the universal day would be identical with the nautical almanac day, and navigators would have only ship time and universal time to deal with, while, if the quantities were given for noon, they would have astronomical time, in addition to the other two. This consideration I think a very important one.

The PRESIDENT. The question will be on the amendment offered by the Delegate of Sweden, Count LEWENHAUPT, which has been read.

The vote was then taken, as follows:

States voting in the affirmative:

Austria, Sweden, Italy, Switzerland, Netherlands, Turkey.

In the negative:

Brazil, Japan, Chili, Liberia, Colombia, Mexico, Costa Rica, Paraguay, Great Britain, Russia, Guatemala, United States, Hawaii, Venezuela.

Abstaining from voting:

France, San Domingo, Germany, Spain.

Ayes, 6; noes, 14; abstaining from voting, 4.

The PRESIDENT then announced that the amendment was lost.

The question then recurred on the original resolution offered by the Delegate of the United States.

RUSTEM EFFENDI, Delegate of Turkey. Mr. President, I have listened with a great deal of interest and attention to the learned arguments bearing upon the proposition under discussion offered by the Hon. Mr. RUTHERFURD, the Delegate of the United States for the adoption of a universal hour.

This question is of such high importance, and of such interest to every one, that I consider it my duty to make a few remarks upon the subject, as I wish to state clearly the position my government proposes to take in the matter.

I do not pretend to discuss scientifically this subject, which has already been so ably treated by several of the gentlemen present. My task is of a different and inferior order. I merely propose to briefly examine the manner in which the proposition ought to be made, in order that it may be adopted by our respective governments.

The question of a universal hour is not of equal interest and importance to all. The United States of America, although comparatively a young nation, have done so much in the pursuit of science and scientific investigation that they must have more than a common interest on the subject. The vast expanse of their country, stretching over sixty degrees of longitude, with a difference of time of more than four hours, almost compels them to adopt a universal hour. The thousands of miles of railroad tracts covering this continent, facilitating the intercourse between distant places, necessitate a uniform system to avoid confusion. It was, therefore, natural that the United States and Canada should have taken the lead in proposing such a reform, which would likewise benefit other countries, as, for instance, the British Empire, Russia, and Germany. But there are, at the same time, other countries, like France, Spain, Italy, Scandinavia, etc., that may content themselves with a national hour, owing to the small difference in time within their dominion. For them, the adoption of a universal hour would only be of secondary importance, because it would only affect their international relations.

I hope I may be permitted to remind you of the conclusions arrived at by a commission consisting of scientists, railroad and telegraph officials, &c., appointed by the French Government to express their opinion upon this subject. If I am not mistaken, they recommended a universal hour, stating, however, at the same time, that the benefit to be derived from such an hour would be only of secondary importance for their country. The learned Delegate from France, Professor JANSSEN, will probably be kind enough to inform us whether I am right or not.

The few remarks I have made bring me to the point I wanted to consider more specially. I mean that the originators of the pending proposition, and those directly interested in it, should be induced to modify their proposition somewhat if they wish it to be adopted by other countries. In other words, to leave to each country the greatest latitude possible in adopting a universal hour.

With regard to the Ottoman Empire, I must state that it is placed in a somewhat exceptional position in this respect, and is, therefore, obliged to ask for more latitude even than the other countries concerned.

In our country we have two modes of reckoning time: one from noon to noon, or from midnight to midnight, as everywhere else, (heure à la franque), the other (heure à la turque) from sundown to sundown. In this latter case the hours count from the moment when the disk of the sun is bisected by the horizon, and we count twice from _0h._ to _12h._, instead of counting without any interruption from _0h._ to _24h._ We are well aware of the inconveniences this system of counting produces, because _0h._ necessarily varies from day to day, for the interval of time between one sunset and the one following is not exactly 24 hours. According to the season the sun will set earlier or later, and our watches and clocks at Constantinople will be at most about three minutes fast or slow from day to day, according to the season.

Reasons of a national and religious character prevent us, however, from abandoning this mode of counting our time. The majority of our population is agricultural, working in the fields, and prefer to count to sunset; besides, the hours for the Moslem prayers are counted from sundown to sundown.

Therefore it is impossible for us to abandon our old system of time, although in our navy we generally use the customary reckoning or "heure à la franque."