Part 6 (1/2)
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 s.h.i.+pping 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 distinguis.h.i.+ng 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.