International Conference Held at Washington Part 6

In the absence of any declared opinion to the contrary, we may take it for granted that the Delegates from all States here represented are deputed to "fix upon a meridian proper to be employed as a common zero of longitude throughout the globe," and to recommend the same for adoption to their respective Governments.

If, then, we are of one mind as to the desirability of a single prime meridian, and if we are fully empowered to make the selection, which may be taken as another way of saying that we are directed by our respective Governments to make the selection, we may proceed directly to the performance of this duty.

In the choice of a prime meridian, there is no physical feature of our earth which commends itself above others as the best starting point; nor does the form of the earth itself present any peculiarity which might be used as an initial point. If the refinements of geodesy should finally lead to the conclusion that the figure of the earth is an ellipsoid with three axes, yet the question of the direction of either of the equatorial axes must remain to such a degree uncertain that the extremity of the axis could not be a.s.sumed as the point of departure for counting longitude. Indeed, as an initial meridian must above all things be fixed in position, it would not answer to make its position depend upon any physical constant which is itself in the slightest degree uncertain; for in these days, when refinements in physical measurements are constantly leading to more and more accurate results, each advance in accuracy would necessitate an annoying change in the initial meridian, or, what would more probably result, the retention of the first chosen meridian, which would thus lose its dependence upon the original definition, and become as arbitrary as if taken by chance in the first instance.

We may then say that, from a purely scientific point of view, any meridian may be taken as the prime meridian. But from the standpoint of convenience and economy there is undoubtedly much room for a choice.

Considering this question of convenience in connection with the necessary condition of fixity already referred to, the prime meridian should pa.s.s through some well-established national observatory.

In making the choice of a prime meridian which is to serve for a great period of time, it is important to so fix and define it that the natural changes of time may not render it in the least degree uncertain. To this end, the nation within whose borders the chosen point may fall should engage to establish it in the most enduring manner, and protect it against all possible causes of change or destruction.

When taken in connection with other requirements, to be mentioned hereafter, this character of permanence will be best secured by making the adopted meridian pa.s.s through an observatory which is under the control of the Government.

Such observatory should be in telegraphic communication with the whole world, in order that the differences of longitude from the prime meridian may be determined for any point. These conditions of convenience are so important that they may fairly be considered imperative. To fulfil them one of the national meridians now in use should be selected. To select any other than one of these meridians, or a meridian directly dependent upon one of them, and defined simply by its angular distance from one of these national meridians, would be to introduce endless confusion into all charts and maps now in use.

To select as a prime meridian one which shall be a defined angular distance from one of the national meridians, must have for its object either to remove some inconvenience which results from the use of the national meridian itself, or it must be to satisfy a desire to deprive the selected meridian of any nationality.

The inconvenience of east and west longitudes, which results from having the prime meridian pa.s.s through a thickly populated portion of the world, will be removed by reckoning the longitude continuously from O to 360. At the same time an important advantage is secured by having the prime meridian occupy a central position with regard to the most densely populated part of the earth; because the distances which will then separate the various points from the central observatory marking the initial meridian will be a minimum, and consequently less liable to error in determination. The selection of a meridian by calculation, defined as a certain number of degrees east or west of one of the national meridians, would not thereby deprive the meridian thus selected of a national character; for though we may reckon longitude from a meridian pa.s.sing through the Atlantic or Pacific Ocean, yet the initial point from which all measurements of longitude must be made would still remain one of the national meridians. Again, if any other than one of the national meridians were selected, or a meridian dependent upon one of them, as, for example, a neutral meridian in the Atlantic or Pacific Ocean, it would necessitate a change in all charts and maps.

It is hardly necessary to say that no scientific or practical advantage is to be secured by adopting the meridian of the great pyramid, or by attempting to establish permanent meridian marks over a great length of the selected meridian, for even in the present advanced condition of astronomical and geodetic science it is not practicable to establish two points on the same meridian at a considerable distance from each other with such a degree of accuracy as would warrant the use of them indifferently as the initial point.

As a matter of economy as well as convenience that meridian should be selected which is now in most general use. This additional consideration of economy would limit our choice to the meridian of Greenwich, for it may fairly be stated upon the authority of the distinguished Delegate from Canada that more than 70 per cent. of all the shipping of the world uses this meridian for purposes of navigation.

The charts constructed upon this meridian cover the whole navigable globe. The cost of the plates from which these charts are printed is probably 75 per cent. of the cost of all plates in the world for printing mariners' charts, and is probably not less than ten millions of dollars. As a matter of economy, then, to the world at large, it would be better to permit those plates to remain unchanged which are engraved for the meridian of Greenwich and to make the necessary changes in all plates engraved for other meridians.

A very natural pride has led the great nations to establish by law their own prime meridian within their own borders, and into this error the United States was led about 35 years ago.

Should any of us now hesitate in the adoption of a particular meridian, or should any nation covet the honor of having the selected meridian within its own borders, it is to be remembered that when the prime meridian is once adopted by all it loses its specific name and nationality, and becomes simply the Prime Meridian.

Mr. RUTHERFURD, Delegate of the United States, stated that he did not propose to take up much of the time of the Conference; that he had listened with great pleasure to the exhaustive speech of his colleague, Commander SAMPSON, but that he wished to say a few words about the conditions of permanence in the prime meridian to which allusion had just been made. He said that he would call attention to the fact that the observatory at Paris stands within the heart of a large and populous city; that it has already been thought by many of the princ.i.p.al French astronomers that it should no longer remain there; that it has been, interfered with by the tremors of the earth and emanations in the air, which prevent it from fulfilling its usefulness; that for several years past strenuous efforts have been made to remove the observatory from Paris to some other place where it may be free to follow out its course of usefulness, and that the only thing which keeps it there is the remembrance of the honorable career of that observatory in times past. He added that he was sure that there was no one here who failed to recognize its claims to distinction; that there was no one here acquainted with the past history of astronomy but looks with pride upon the achievements of the human intellect effected there. At the same time, however, if a change is to be made, if sentiment should give way to practical reason, a locality, no doubt, will be found which may be calculated to fulfil the requirements of a prime meridian better than that one.

As to the fitness of Greenwich, he said that the observatory was placed in the middle of a large park under the control of the Government, so that no nuisance can come near it without their consent, and that it was in a position which speaks for itself; that he would only add one word more in regard to this matter, and that is, that the adoption of the meridian of Greenwich as the prime meridian has not been sought after by Great Britain; that it was not her proposition, but that she consented to it after it had been proposed by other portions of the civilized world.

Mr. JANSSEN, Delegate of France, said: We do not put forward the meridian of the observatory of Paris as that to be chosen for the prime meridian; but if it were chosen, and we wished to compare it with that of Greenwich as to the accuracy with which it is actually connected with the other observatories of Europe, it would not lose by the comparison. The latest observations of the differences of longitude made by electricity by the Bureau of Longitudes of France and our officers have given very remarkable results of great accuracy.

It is well known that what is important for a starting point in reckoning longitude is, above all things, that it should be accurately connected with points whose positions have been precisely fixed, such as the great observatories. There is, therefore, a slight confusion on the part of my eminent colleague, namely, that of not distinguishing between the conditions which require the exact connection of the starting point of longitudes with observatories, and the merits of the position of such a point in an astronomical aspect, which is here a matter of secondary importance.

Mr. LEFAIVRE, Delegate of France, said that he did not not know if his observation was well founded, but it seemed to him that what the Delegates of France had proposed had not been contested, but that the arguments used had rather been those in favor of the adoption of the meridian of Greenwich.

Mr. RUTHERFURD, Delegate of the United States, said that the observations which he had made were merely to be regarded as a negative of the proposition made by the Delegates of France, and not as a statement of the arguments in favor of the adoption of Greenwich.

The PRESIDENT said that the remarks of the Delegate of the United States were not out of order, inasmuch as they were intended to combat the proposition brought forward by the Delegate of France.

Mr. JANSSEN, Delegate of France, then spoke as follows:

GENTLEMEN: At the last session, when a proposition was made by my eminent colleague and friend, Mr. RUTHERFURD, to discuss and vote upon the adoption of the meridian of Greenwich as the common prime meridian, I thought it necessary to say that the proposal appeared to me prematurely made, and that we could not agree to the discussion proceeding in that manner. Mr. RUTHERFURD has informed me that he would withdraw his proposition for the present, in order to permit me to direct the discussion, in the first place, to the principle which should direct the choice of a common prime meridian. I here take the opportunity of thanking Mr. RUTHERFURD for his courtesy, and I no longer object to proceeding with the debate.

What we ask is, that after the general declaration of the second session as to the utility of a common prime meridian, the Congress should discuss the question of the principle which should guide the choice of that meridian.

Being charged to maintain before you, gentlemen, the principle of the neutrality of the prime meridian, it is evident that if that principle was rejected by the Congress it would be useless for us to take part in the further discussion of the choice of the meridian to be adopted as the point of departure in reckoning longitude.

We think, gentlemen, that if this question of the unification of longitude is again taken up after so many unsuccessful attempts to settle it as are recorded in history, there will be no chance of its final solution unless it be treated upon an exclusively geographical basis, and that at any cost all national compet.i.tion should be set aside. We do not advocate any particular meridian. We put ourselves completely aside in the debate, and thus place ourselves in a position of far greater freedom for expressing our opinion, and discussing the question exclusively in view of the interests affected by the proposed reform.

The history of geography shows us a great number of attempts to establish a uniformity of longitude, and when we look for the reasons which have caused those attempts (many of which were very happily conceived) to fail, we are struck with the fact that it appears due to two princ.i.p.al causes--one of a scientific and the other of a moral nature. The scientific cause was the incapacity of the ancients to determine exactly the relative positions of different points on the globe, especially if it was a question of an island far from a continent, and which consequently could not be connected with that continent by itinerary measurements. For example, the first meridian of Marinus of Tyre and Ptolemy, placed on the Fortunate Isles, in spite of its being so well chosen at the western extremity of the then known world, could not continue to be used on account of the uncertainty of the point of departure. That much to be regretted obstacle caused the method to be changed. It became necessary to fall back on the continent. But then, in place of a single common origin of longitude indicated by nature, the first meridians were fixed at capitals of countries, at remarkable places, at observatories. The second cause to which I just now alluded, the cause of a moral nature--national pride--has led to the multiplication of geographical starting-points where the nature of things would have required, on the contrary, their reduction to a single one.

In the seventeenth century, Cardinal Richelieu, in view of this confusion, desired to take up again the conception of Marinus of Tyre, and a.s.sembled at Paris French and foreign men of science, and the famous meridian of the Island of Ferro was the result of their discussions.

Here, gentlemen, we find a lesson which should not be lost sight of.

This meridian of Ferro, which at first had the purely geographical and neutral character which could alone establish and maintain it as an international first meridian, was deprived of its original characteristic by the geographer Delisle, who, to simplify the figures, placed it at 20 degrees in round numbers west of Paris. This unfortunate simplification abandoned entirely the principle of impersonality. It was no longer then an independent meridian; it was the meridian of Paris disguised. The consequences were soon felt. The meridian of Ferro, which has subsequently been considered as a purely French meridian, aroused national susceptibilities, and thus lost the future which was certainly in store for it if it had remained as at first defined. This was a real misfortune for geography. Our maps, while being perfected, would have preserved a common unit of origin, which, on the contrary, has altered more and more.

If, as soon as astronomical methods had been far enough advanced to permit the establishment of relative positions with that moderate accuracy which is sufficient for ordinary geography, (and that could have been done at the end of the 17th century,) we had again taken up the just and geographical conception of Marinus of Tyre, the reform would have been accomplished two centuries sooner, and to-day we should have been in the full enjoyment of it. But the fault was committed of losing sight of the essential principles of the question, and the establishment of numerous observatories greatly contributed to this. Furnishing naturally very accurate relative positions, each one of these establishments was chosen by the nation to which it belonged as a point of departure for longitude, so that the intervention of astronomy in these questions of a geographical nature, an intervention which, if properly understood, should have been so useful, led us further away from the object to be attained.

In fact, gentlemen, the study of these questions tends to show that there is an essential distinction between meridians of a geographical or hydrographical nature and meridians of observatories. The meridians of observatories should be considered essentially national. Their function is to permit observatories to connect themselves one with another for the unification of the observations made at them. They serve also as bases for geodetic and topographical operations carried on around them. But their function is of a very special kind, and should be generally limited to the country to which they belong.

On the contrary, initial meridians for geography need not be fixed with quite such a high degree of accuracy as is required by astronomy; but, in compensation, their operation must be far reaching, and while it is useful to increase as much as possible the number of meridians of observatories, it is necessary to reduce as much as we can the starting points for longitudes in geography.

Further, it may be said that as the position of an observatory should be chosen with reference to astronomical considerations, so an initial meridian in geography should only be fixed for geographical reasons.

Gentlemen, have these two very different functions been always well understood, and has this necessary distinction been preserved? In no wise. As observatories, on account of the great accuracy of their operations, furnish admirable points of reference, each nation which was in a condition to do it connected with its princ.i.p.al observatory not only the geodetic or topographical work which was done at home--a very natural thing--but also general geographical or hydrographical work which was executed abroad, a practice which contained the germ of all the difficulties with which we are troubled to-day. Thus, as maps acc.u.mulated, the need of uniformity, especially in those that referred to general geography, was felt more and more.

This explains why this question of a single meridian as a starting point has been so often raised of late.

Among the a.s.semblies which have occupied themselves with this question, the one which princ.i.p.ally calls for our attention is that which was held at Rome last year; indeed, for many of our colleagues the conclusions adopted by the Congress of Rome settle the whole matter. These conclusions must, therefore, receive our special attention.

In reading the reports of the discussions of that Congress, I was struck with the fact that in an a.s.sembly of so many learned men and eminent theorists it was the practical side of the question that was chiefly considered, and which finally determined the character of the resolutions adopted.

Thus, instead of laying down the great principle that the meridian to be offered to the world as the starting-point for all terrestrial longitudes should, have above all things, an essentially geographical and impersonal character, the question was simply asked, which one of the meridians in use among the different observatories has (if I may be allowed to use the expression) the largest number of clients? In a matter which interests geography much more than hydrography, as most sailors acknowledge, because there exist really but two initial hydrographic meridians, Greenwich and Paris, a prime meridian has been taken, the reign (practical influence) of which is princ.i.p.ally over the sea; and this meridian, instead of being chosen with reference to the configuration of the continents, is borrowed from an observatory; that is to say, that it is placed on the globe in a hap-hazard manner, and is very inconveniently situated for the function that it is to perform. Finally, instead of profiting by the lessons of the past, national rivalries are introduced in a question that should rally the good-will of all.

Well, gentlemen, I say that considerations of economy and of established custom should not make us lose sight of the principles which must be paramount in this question, and which alone can lead to the universal acceptance and permanence of its settlement.

Furthermore, gentlemen, these motives of economy and of established custom, which have been appealed to as a decisive argument, exist, it is true, for the majority in behalf of which they have been put forward, but exist for them only, and leave to us the whole burden of change in customs, publications, and material.

Since the report considers us of so little weight in the scales, allow me, gentlemen, to recall briefly the past and the present of our hydrography, and for that purpose I can do no better than to quote from a work that has been communicated to me, and which emanates from one of our most learned hydrographers. "France," he says, "created more than two centuries ago the most ancient nautical ephemerides in existence. She was the first to conceive and execute the great geodetic operations which had for their object the construction of civil and military maps and the measurement of arcs of the meridian in Europe, America, and Africa. All these operations were and are based on the Paris meridian. Nearly all the astronomical tables used at the present time by the astronomers and the navies of the whole world are French, and calculated for the Paris meridian. As to what most particularly concerns shipping, the accurate methods now used by all nations for hydrographic surveys are of French origin, and our charts, all reckoned from the meridian of Paris, bear such names as those of Bougainville, La Perouse, Fleurieu, Borda, d'Entrecasteaux, Beautemps, Beaupre, Duperrey, Dumont d'Urville, Daussy, to quote only a few among those who are not living.

"Our actual hydrographic collections amount to more than 4,000 charts.

By striking off those which the progress of explorations have rendered useless, there still remain about 2,600 charts in use. Of this number more than half represent original French surveys, a large part of which foreign nations have reproduced. Amongst the remainder, the general charts are the result of discussions undertaken in the Bureau of the Marine, by utilizing all known doc.u.ments, French as well as foreign, and there are relatively few which are mere translations of foreign works. Our surveys are not confined to the coasts of France and of its colonies; there is scarcely a region of the globe for which we do not possess original work--Newfoundland, the coasts of Guiana, of Brazil, and of La Plata, Madagascar, numerous points of j.a.pan and of China, 187 original charts relative to the Pacific. We must not omit the excellent work of our hydrographic engineers on the west coast of Italy, which was honored by the international jury with the great medal of honor at the Universal Exhibition of 1867. The exclusive use of the Paris meridian by our sailors is justified by reference to a past of two centuries, which we have thus briefly recalled.

"If another initial meridian had to be adopted, it would be necessary to change the graduation of our 2,600 hydrographic plates; it would be necessary to do the same thing for our nautical instructions, (sailing directions,) which exceed 600 in number. The change would also necessarily involve a corresponding change in the _Connaissance des Temps_."

These are t.i.tles to consideration of some importance. Well, if under these circ.u.mstances the projected reform, instead of being directed by the higher principles which ought to govern the subject, should take solely for its base the respect due to the established customs of the largest number and the absence on their part of all sacrifice, reserving to us alone the burden of the change and the abandonment of a valued and glorious past, are we not justified in saying that a proposition thus made would not be acceptable?

When France, at the end of the last century, inst.i.tuted the metre, did she proceed thus? Did she, as a measure of economy and in order to change nothing in her customs, propose to the world the "Pied de Roi"

as a unit of measure? You know the facts. The truth is, everything with us was overthrown--both the established methods and instruments for measurement; and the measure adopted being proportioned only to the dimensions of the earth, is so entirely detached from everything French that in future centuries the traveller who may search the ruins of our cities may inquire what people invented the metrical measure that chance may bring under his eyes.

Permit me to say that it is thus a reform should be made and becomes acceptable. It is by setting the example of self-sacrifice; it is by complete self-effacement in any undertaking, that opposition is disarmed and true love of progress is proved.

I now hasten to say that I am persuaded that the proposition voted for at Rome was neither made nor suggested by England, but I doubt whether it would render a true service to the English nation if it be agreed to. An immense majority of the navies of the world navigate with English charts; that is true, and it is a practical compliment to the great maritime activity of that nation. When this freely admitted supremacy shall be transformed into an official and compulsory supremacy, it will suffer the vicissitudes of all human power, and that inst.i.tution, (the common meridian,) which by its nature is of a purely scientific nature, and to which we would a.s.sure a long and certain future, will become the object of burning compet.i.tion and jealousy among nations.

All this shows, gentlemen, how much wiser it would be to take for the origin of terrestrial longitude a point chosen from geographical considerations only. Upon the globe, nature has so sharply separated the continent on which the great American nation has arisen, that there are only two solutions possible from a geographical point of view, both of them very natural.

The first solution would consist in returning, with some small modification, to the solution of the ancients, by placing our meridian near the Azores; the second by throwing it back to that immense expanse of water which separates America from Asia, where on its northern sh.o.r.es the New World abuts on the old.