Various - International Conference Held at Washington for the Purpose of Fixing a Prime Meridian and a Universal Day. October, 1884.
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Various >> International Conference Held at Washington for the Purpose of Fixing a Prime Meridian and a Universal Day. October, 1884.
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Such principles are embodied in the recommendations which I am
permitted to place before the Conference. They involve, as an
essential requirement, the determination of a unit of measurement, and
it is obvious that such a unit must have its origin in the motion of
the heavenly bodies. No motion is more uniform than the motion of the
earth on its axis. This diurnal revolution admits of the most delicate
measurement, and, in all respects, is the most available for a unit
measure. It furnishes a division of time definite and precise, and one
which, without difficulty, can be made plain and manifest.
A revolution of the earth, denoted by the mean solar passage at the
Prime or Anti-prime Meridian, will be recognizable by the whole world
as a period of time common to all. By general agreement this period
may be regarded as the common unit by which time may be everywhere
measured for every purpose in science, in commerce, and in every-day
life.
The scheme set forth in the recommendations has in view three
principal objects, viz:
1. To define and establish an universal day for securing chronological
accuracy in dates common to the whole world.
2. To obtain a system of universal time on a basis acceptable to all
nations, by which, everywhere, at the same time, the same instant may
be observed.
3. To establish a sound and rational system of reckoning time which
may eventually be adopted for civil purposes everywhere, and thus
secure uniformity and accuracy throughout the globe.
But, in the inauguration of a scheme affecting so many individuals, it
is desirable not to interfere with prevailing customs more than
necessary. Such influences as arise from habit are powerful and cannot
be ignored. The fact must be recognized that it will be difficult to
change immediately the usages to which the mass of men have been
accustomed. In daily life we are in the habit of eating, sleeping, and
following the routine of our existence at certain periods of the day.
We are familiar with the numbers of the hours by which these periods
are known, and, doubtless, there will be many who will see little
reason in any attempt to alter their nomenclature, especially those
who take little note of cause and effect, and who, with difficulty,
understand the necessity of a remedy to some marked irregularity
which, however generally objectionable, does not bear heavily upon
them individually.
For the present, therefore, we must adapt a new system, as best we are
able, to the habits of men and women as we find them. Provision for
such adaptation is made in the recommendations by which, while local
reckoning would be based on the principles laid down, the hours and
their numbers need not appreciably vary from those with which we are
familiar. Thus, time-reckoning in all ordinary affairs in every
locality may be made to harmonize with the general system.
Standard time throughout the United States and Canada has been
established in accord with this principle. Its adoption has proved the
advantages which may be attained generally by the same means. On all
sides these advantages have been widely appreciated, and no change
intimately bearing upon common life was ever so unanimously accepted.
Certainly, it is an important step towards the establishment of one
system of universal time, or, as it is designated in the
recommendations, Cosmic time.
The alacrity and unanimity with which the change has been accepted in
North America encourages the belief that the introduction of cosmic
time in every-day life is not unattainable. The intelligence of the
people will not fail to discover, before long, that the adoption of
correct principles of time-reckoning will in no way change or
seriously affect the habits they have been accustomed to. It will
certainly sweep away nothing valuable to them. The sun will rise and
set to regulate their social affairs. All classes will soon learn to
understand the hour of noon, whatever the number on the dial, whether
six, as in Scriptural times, or twelve, or eighteen, or any other
number. People will get up and retire to bed, begin and end work, take
breakfast and dinner at the same periods of the day as at present, and
our social habits and customs will remain without a change, depending,
as now, on the daily returning phenomena of light and darkness.
The one alteration will be in the notation of the hours, so as to
secure uniformity in every longitude. It is to be expected that this
change will at first create some bewilderment, and that it will be
somewhat difficult to be understood by the masses. The causes for such
a change to many will appear insufficient or fanciful. In a few years,
however, this feeling must pass away, and the advantages to be gained
will become so manifest that I do not doubt so desirable a reform will
eventually commend itself to general favor, and be adopted in all the
affairs of life.
Be that as it may, it seems to me highly important that a
comprehensive time system should be initiated to facilitate scientific
observations, and definitely to establish chronological dates; that it
should be designed for general use in connection with railways and
telegraphs, and for such other purposes for which it may be found
convenient.
The Cosmic day set forth in the recommendations would be the date for
the world recognizable by all nations. It would theoretically and
practically be the mean of all local days, and the common standard to
which all local reckoning would be referable.
With regard to the reckoning of longitude, I submit that longitude and
time are so intimately related that they may be expressed by a common
notation. Longitude is simply the angle formed by two planes passing
through the earth's axis, while time is the period occupied by the
earth in rotating through that angle. If we adopt the system of
measuring time by the revolution of the earth from a recognized zero,
one of these planes--that through the zero--may be considered fixed;
the other--that through the meridian of the place--being movable, the
longitudinal angle is variable. Obviously the variable angle ought to
be measured from the fixed plane as zero, and as the motion of the
earth by which the equivalent time of the angle is measured is
continuous, the longitude ought to be reckoned continuously in one
direction. The direction is determined by the notation of the hour
meridians, viz., from east to west.
If longitude be so reckoned and denoted by the terms used in the
notation of cosmic time, the time of day everywhere throughout the
globe would invariably denote the precise longitude of the place
directly under the mean sun. Conversely, at the epoch of mean solar
passage at any place, the longitude being known, cosmic time would be
one and the same with the longitude of the place.
The advantages of such a system of reckoning and nomenclature, as
suggested in the recommendations which I now submit, will be, I think,
self-evident.
RECOMMENDATIONS FOR THE REGULATION OF TIME AND THE RECKONING
OF LONGITUDE
1. _That a system of universal time be established, with the
view of facilitating synchronous scientific observations,
for chronological reckonings, for the purpose of trade and
commerce by sea and land, and for all such uses to which it
is applicable._
2. _That the system be established for the common observance
of all peoples, and of such a character that it may be
adopted by each separate community, as may be found
expedient._
3. _That the system be based on the principle that for all
terrestrial time reckonings there be one recognized unit of
measurement only, and that all measured intervals of time be
directly related to the one unit measure._
4. _That the unit measure be the period occupied by the
diurnal revolution of the earth, defined by the mean solar
passage at the meridian twelve hours from the Prime Meridian
established through Greenwich._
5. _That the unit measure defined as above be held to be a
day absolute, and designated a Cosmic Day._
6. _That such Cosmic Day be held as the chronological date
of the earth, changing with the mean solar passage at the
anti-meridian of Greenwich._
7. _That all divisions and multiples of the Cosmic Day be
known as Cosmic Time._
8. _That the Cosmic Day be divided into hours, numbered in a
single series, one to twenty-four, (1 to 24,) and that the
hours be subdivided, as ordinary hours, into minutes and
seconds. Note.--As an alternative means of distinguishing
the cosmic hours from the hours in local reckonings, they
may be denoted by the letters of the alphabet, which,
omitting I and V, are twenty-four in number._
9. _That until Cosmic Time be admitted as the recognized
means of reckoning in the ordinary affairs of life, it is
advisable to assimilate the system to present usages and to
provide for the easy translation of local reckonings into
Cosmic Time, and vice versa; that, therefore, in theory, and
as closely as possible in practice, local reckonings be
based on a known interval in advance or behind Cosmic Time._
10. _That the surface of the globe be divided by twenty-four
equidistant hour meridians, corresponding with the hours of
the Cosmic Day._
11. _That, as far as practicable, the several hour meridians
be taken according to the longitude of the locality, to
regulate local reckonings, in a manner similar to the
system in use throughout North America._
12. _That, in all cases where an hour meridian is adopted as
the standard for regulating local reckonings, in a
particular section or district, the civil day shall be held
to commence twelve hours before and end twelve hours after
the mean solar passage of such hour meridian._
13. _That the civil day, based on the Prime Meridian of
Greenwich, shall coincide and be one with the Cosmic Day.
That civil days on meridians east of Greenwich shall be
(according to the longitude) a known number of hours, or
hours and minutes in advance of Cosmic Time, and to the west
of Greenwich the contrary._
14. _That the surface of the globe being divided by
twenty-four equidistant meridians (fifteen degrees apart)
corresponding with the hours of the Cosmic Day, it is
advisable that longitude be reckoned according to these hour
meridians._
15. _That divisions of longitude less than an hour (fifteen
degrees) be reckoned in minutes and seconds and parts of
seconds._
16. _That longitude be reckoned continuously towards the
west, beginning with zero at the Anti-prime meridian, twelve
hours from Greenwich._
17. _That longitude, generally, be denoted by the same terms
as those applied to Cosmic Time._
I submit these recommendations suggestively, and without any desire
unduly to press them. I shall be content if the leading principles
laid down be recognized by the Conference.
With regard to the more immediate question, I have come to the firm
conviction that extreme simplicity of reckoning and corresponding
benefits would result if longitude be notated in the same manner, and
denoted by the same terms as universal time. If, therefore, the
Conference adopts the motion of the distinguished Delegate of the
United States, which, I apprehend, is designed to cause as little
change as possible in the practices of sea-faring men, I trust the
claims of other important interests will not be overlooked. I refer to
all those interests, so deeply concerned in securing accurate time on
land, and in having easy means provided for translating any one local
reckoning into any other local reckoning, or into the standard
universal time. In this view I trust the Conference will give some
expression of opinion in favor of extending around the globe the
system of hour meridians which has proved so advantageous in North
America. In an educational aspect alone it seems to me important that
the hour meridians, one to twenty-four, numbered from the anti-prime
meridian continuously toward the west, should be conspicuously marked
on our maps and charts.
Prof. ADAMS, Delegate of Great Britain. I wish, Mr. President, to
express my entire adhesion to the proposition which has been made by
the Delegate of the United States, Mr. RUTHERFURD. It seems to me to
satisfy one of the principal conditions that we have had before us to
guide our decision; that is, that we should pursue a course which will
produce the least possible inconvenience.
Now, I think if we keep that in mind, we shall have very little
difficulty in coming to the conclusion that we should reckon longitude
eastward, as positive or plus, and westward as negative or minus. This
mode of reckoning would be attended with the least inconvenience; in
fact, it will not be attended with any inconvenience at all, because
it will keep to the present mode of reckoning. For my part, I see no
adequate reason for changing that. There is no scientific reason, and
certainly there is no practical reason. There is no scientific reason,
because, as I stated yesterday, if in mathematics you measure from the
zero a distance in one direction and consider that positive, you must,
by the very nature of the case, consider the distance measured in the
opposite direction from the same zero as negative. One follows
mathematically and necessarily from the other, and by adopting this
resolution you thus include both in one general formula.
It seems to me quite as scientific, to say the least, to start from
zero and go in both directions, distinguishing the longitudes by the
signs plus and minus, according as the directions are taken east or
west, as to reckon longitudes in one direction only from zero to 360
degrees. It is, I say, just as scientific to do this, and practically
it is more convenient. Because if you go on reckoning from zero to
360 degrees continuously, you have to make a break at 360 degrees. You
do not count on after you have completed one revolution, but have to
drop the 360 degrees and start again at zero. But this is attended
with great inconvenience, because this break in counting occurs in
countries which are thickly inhabited. The longitude would be a little
less than 360 degrees on one side of the prime meridian, and on the
other side the longitude would be a small angle. This seems to me very
inconvenient.
On the other hand, if you count longitudes in one direction from zero
to 180 degrees as positive, and in the opposite direction from zero to
180 degrees as negative, you are, no doubt, obliged to make a break in
passing abruptly from plus 180 degrees to minus 180 degrees. But the
break would then occur where it would cause the least inconvenience,
viz., in mid-ocean, where there is very little land and very few
inhabitants, and where we are accustomed to make the break now. This
will require no change in the habits and customs of the people, and no
inconvenience whatever would be caused by the action of the Conference
if it decides on this method, which also has the minor advantage of
not requiring the use of such large numbers as the other. But to adopt
the reckoning of longitude from zero to 360 degrees would involve a
very considerable change, and I think it may be doubted whether it
would be generally accepted. Under the circumstances, I think the
resolution contains the most expedient course for us to adopt. I do
not object to anybody who chooses to do so reckoning on, for certain
purposes, from zero to 360 degrees, but I do not think it would be
well to make it compulsory.
With regard to the proposal of the Delegate of Great Britain, Mr.
FLEMING, I would say that it would be attended with great
inconvenience, because it departs from the usages and habits now
existing. That, to my mind, is a very great and insuperable objection,
and I do not see any countervailing advantage.
With regard to the subject of time that Mr. Fleming is anxious to take
into consideration, I think that nothing can be simpler, if I may be
allowed to deal with the question of time, than the relation between
time and longitude which is proposed to be created by the resolution
of Mr. RUTHERFURD.
By that resolution the longitude indicates the relation between the
local time and the universal time in the simplest possible way. What
can be easier than the method involved in the resolution of Mr.
Rutherfurd? It is this: Local time at any place is equal to universal
time plus the longitude of the place, plus being understood always in
a mathematical sense. The longitude is to be added to the universal
time if it is positive, and subtracted if it is negative. That is very
simple, the whole being involved in one general formula.
Now, I think it is perfectly impossible for Mr. Fleming to make a more
simple formula than that. The formula laid down in the proceedings of
the Roman Conference was far less simple, as it involved an odd twelve
hours. You got the universal time equal to the local time, minus the
longitude, plus twelve hours. This is far from simple. It makes the
calculation more complicated, and it seems to me that for other
reasons it is objectionable.
Mr. RUTHERFURD, Delegate of the United States. Mr. President, I do not
propose to take up the time of the Conference in reiterating the very
conclusive remarks in favor of this resolution made by the Delegate of
Great Britain. I wish, however, to allude, for a moment, to another
view of this question. Suppose we do not adopt this resolution. What
is the course before the Conference? We shall then be called upon, no
doubt, to decide that longitude shall be counted all around the world
from zero to 360 degrees.
That general proposition is one which would not probably meet with
violent opposition, but the next point is one that will divide us very
materially, and perhaps disastrously. Which way shall we count? Shall
it be towards the east or towards the west?
My conversations with the gentlemen here present have lead me to know
that there is a very great difference of opinion upon this point, and
I believe that if we should not adopt this resolution and should
decide to count longitude from zero to 360 degrees, a preference to
count it in one direction rather than the other would be established
only by a very close vote, nearly annulling the whole moral influence
of the Conference, and we should go back to our Governments without
much, if any, authority on the point in question.
And I doubt whether our resolutions would be accepted by these
Governments if we show ourselves to be divided upon a question of so
much practical importance.
It is simply a question of practice--of convenience. We all bowed to
the rule of convenience in selecting the meridian of Greenwich. And
why? Because seven-tenths of the civilized nations of the world use
this meridian, not that it was intrinsically better than the meridian
of Paris, or Washington, or Berlin, or St. Petersburg. Nobody claimed
any scientific preference among these meridians. It was simply because
seven-tenths of the civilized world were already using the meridian of
Greenwich.
If we accept this argument in favor of the first resolution for
selecting the initial meridian, why should we not be equally inclined
to recognize the fact that all the civilized world count longitude in
both ways? There is no difference of opinion on that point. There is
no difference of usage. Shall we break that usage? Shall we introduce
a new system, which may or may not be found practical or agreeable?
Shall we not rather adopt the rule of all nations, already in use
among their practised astronomers and navigators, by saying continue
to do as you have already done?
Sir FREDERICK EVANS, Delegate of Great Britain. Having for many years
mixed among the practical seamen of more than one nation, I confess I
look with some dismay on any other system for the notation of
longitude being adopted than the one proposed in this resolution.
My colleague, Mr. FLEMING, made the remark that he could not
disassociate longitude from time. If he had mixed with seamen, he
would have found out that there is very frequently a well-defined
difference between the two in their minds. Longitude with seamen
means, independently of time, space, distance. It indicates so many
miles run in an east or west direction. Consequently, I am not able to
look upon longitude and time as being identical.
Under these circumstances, this resolution also, as I understand it,
should be considered on practical grounds.
The question of universal time will come on for consideration
hereafter, and how that may be settled seems to me a matter of
indifference compared with the decision on this resolution. I
question, for myself, whether any other plan than that it proposes
would be generally accepted. That is what I am afraid of. Whatever
respect nations may have for this Conference, public opinion would be
very strong upon the point now at issue. When you further recollect
that all around the globe, in all these various seas, there are
colonies with histories; that their geographical positions and
boundaries were originally recorded by longitude according to the
notation of which I have spoken, I think it is to be over sanguine to
expect that those colonies will accept a new notation of longitude
without greater proof of the positive necessity of the change. It
would not be the fiat of this Conference, or the fiat of any
government, that would bring about the change. I say this with all
deference to the opinions of those who have advocated a change.
General STRACHEY, Delegate of Great Britain. At the risk of repeating
somewhat my remarks made to the Congress when we last met, I would add
a few words to what has now been said. It is our wish that the points
of real difference should, as far as possible, be clearly brought out
before the Conference comes to a vote.
As regards the counting of longitude in two directions, and the degree
of advantage or disadvantage that may arise in starting from zero and
treating east longitude as positive or plus, and west longitude as
negative or minus, let me ask the attention of the Congress to the
fact that longitude is already counted in these two directions, and
that, as a matter of fact also, latitude is counted in the same way,
in both directions from the equator, north latitude being plus and
south latitude minus. Nobody, so far as I have heard, has ever
proposed that we should abolish this method of reckoning latitude, and
substitute for it North or South polar distance, to be counted right
round the earth; and yet there is the same _quasi_ scientific
objection to the present method of counting in the one case as in the
other. As already stated, it seems to me that, for purposes of
practical convenience, it is extremely difficult, if not impossible,
to separate the ideas on which the reckoning of longitude must be
based, from those which must regulate the reckoning of time, and
especially the reckoning of time in the sense of adopting a universal
day over the whole world. Now, it appears to me that, as regards the
acceptance of the universal day, it certainly will be anything but
convenient, if it begins and ends otherwise than when the sun passes
the 180th meridian. On the contrary, I think it will be extremely
inconvenient. I think that if the world were to adopt the meridian of
Greenwich as the origin of longitude, the natural thing for it to do
would be to have the international day, the universal day, begin from
the 180th meridian from Greenwich--that is, to coincide with the
Greenwich civil day. That meridian passes, as I said before, outside
of New Zealand, and outside of the Fijee Islands; it goes over only a
very small portion of inhabited country. It appears to me, therefore,
that inasmuch as there must be an absolute break or discontinuity in
time in passing round the earth--a break of twenty-four hours--it is
much more convenient that this break should take place in the
uninhabited part of the earth than in the very centre of civilization.
If we adopt the universal day which coincides with the civil day at
Greenwich, then you will be able to have complete continuity of local
time over the whole earth, in harmonious relation with the universal
day, except at the break which necessarily takes place on the 180th
meridian. Otherwise this will not be possible. For instance, according
to the system proposed by the resolution, the local time
corresponding, say, to 0 hours of Monday at Greenwich, would, in
passing round the earth to the eastward from the 180th meridian,
gradually change from 12 hours of Sunday to 12 hours of Monday; and,
on returning to that meridian, the break of time would occur, and one
day would appear to be lost. But complete continuity both in the days
and hours, and harmony with the universal day, that is, the Greenwich
civil day, would be preserved for the whole earth, excepting on
crossing the 180th meridian.
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