Volume 14 — THE METRIC SYSTEM OF WEIGHTS AND MEASURES.

Speech in the Senate, on two Bills and a Joint Resolution relating to the Metric System, July 27, 1866.

May 18th, Mr. Sumner moved the appointment by the Chair of a special committee of five, to which all bills and measures relating to the metric system should be referred; and the motion was agreed to.

May 23d, the Chair appointed Mr. Sumner, Mr. Sherman, of Ohio, Mr. Morgan, of New York, Mr. Nesmith, of Oregon, and Mr. Guthrie, of Kentucky. Two bills and a joint resolution which had passed the House of Representatives were referred to the committee, and July 16th reported to the Senate by Mr. Sumner, with the recommendation that they pass, namely:—

“A Bill to authorize the use of the metric system of weights and measures.”

“A Joint Resolution to enable the Secretary of the Treasury to furnish to each State one set of the standard weights and measures of the metric system.”

“A Bill to authorize the use in post-offices of weights of the denomination of grams.”

July 27th, on motion of Mr. Sumner, these were taken up and passed.

MR. PRESIDENT,—At another time I might be induced to go into this question at some length; but now, in these latter days of a weary session, and under these heats, I feel that I must be brief. And yet I could not pardon myself, if I did not undertake, even at this time, to present a plain and simple account of the great change which is now proposed.

There is something captivating in the idea of weights and measures common to all the civilized world, so that, in this at least, the confusion of Babel may be overcome. Kindred is that other idea of one money; and both are forerunners, perhaps, of the grander idea of one language for all the civilized world. Philosophy does not despair of this triumph at some distant day; but a common system of weights and measures and a common system of money are already within the sphere of actual legislation. The work has already begun; and it cannot cease until the great object is accomplished.

If the United States come tardily into the circle of nations recognizing a common system of weights and measures, I confess that I have pleasure in recalling the historic fact that at a very early day this important subject was commended to Congress. Washington, in a speech to the First Congress, touched the key-note, when he used the word “uniformity” in connection with this subject. “Uniformity,” he said, “in the currency, weights, and measures of the United States is an object of great importance, and will, I am persuaded, be duly attended to.”[51] Then again in a speech to the next Congress he went further, in expressing a desire for “a standard at once invariable and universal.”[52] Here he foreshadowed a system common to the civilized world. It is for us now to recognize the standard he thus sententiously described. All hail to a standard “invariable and universal”!

I shall not occupy time in developing the history of these efforts on the part of our Government; but I cannot forbear mentioning that Mr. Jefferson, while Secretary of State, made an elaborate report, where he proposed “reducing every branch to the same decimal ratio already established in the coins, and thus bringing the calculation of the principal affairs of life within the arithmetic of every man who can multiply and divide plain numbers.”[53] Here is an essential element in the common system we seek to establish. This was in 1790, when France was just beginning those efforts which ended at last in the establishment of the metric system. The subject was revived at different times in Congress without definite result. President Madison, in his annual message of 1816, called attention to it in the following words:—

“The great utility of a standard fixed in its nature and founded on the easy rule of decimal proportions is sufficiently obvious. It led the Government at an early stage to preparatory steps for introducing it; and a completion of the work will be a just title to the public gratitude.”[54]

Out of this recommendation originated that call of the Senate which drew forth the masterly report of John Quincy Adams on the whole subject of weights and measures, where learning, philosophy, and prophetic aspiration vie with each other. After reviewing whatever had appeared in the past, and subjecting it all to careful examination, he says of the French metric system, then only an experiment:—

“This system approaches to the ideal perfection of uniformity applied to weights and measures, and, whether destined to succeed or doomed to fail, will shed unfading glory upon the age in which it was conceived and upon the nation by which its execution was attempted and has been in part achieved.”[55]

This was in 1821, when the metric system, already invented, was still struggling for adoption in France.

This brief sketch shows how from the beginning the National Government has been looking to a system common to the civilized world. And now this aspiration seems about to be fulfilled. The bills before you have already passed the other House; if they become laws, as I trust, they will be the practical commencement of the “new order.”

Before proceeding to explain the proposed system, let me exhibit for one moment the necessity of change, as illustrated by weights and measures in the past.

Language is coeval with man as a social being. Weights and measures are hardly less early in origin. They are essential to the operations of society, and are naturally common to all who belong to the same social circle. At the beginning, each people had a system of its own; but as nations gradually intermingle and distant places are brought together by the attractions of commerce, the system of one nation becomes inadequate to the necessities of the composite body. A common system becomes important just in proportion to the community of interests. Next to diversity of languages, discordant weights and measures attest the insulation of nations.

The earliest measures were derived from the several parts of the human body. Such was the cubit, which was the distance between the elbow and the end of the middle finger, being about twenty-two inches. Such also were the foot, the hand, the span, the nail, and the thumb. These measures were derived from Nature, and they were to be found wherever a human being existed. But they partook of the uncertainty in the proportions of the human form. When Selden, in his “Table-Talk,” wittily likened Equity, so far as it depended on the Chancellor, to a measure determined by the length of the Chancellor’s foot, he exposed not only the uncertainty of Equity, but also the uncertainty of such a measure.

Even in Greece, where Art prevailed in the most beautiful forms, the famous stadium was none the less uncertain. It was the distance that Hercules could run without taking breath, being six hundred times the length of his foot.

Our own standards, derived from England, are of an equally fanciful character. The unit of length is the barley-corn, taken from the middle of the ear and well dried. Three of these in a straight line make an inch. The unit of weight is a grain of wheat, taken, like the barley-corn, from the middle of the ear and well dried. Of these, twenty-four are equal to a pennyweight. Twenty pennyweights make an ounce, and twelve ounces make a pound. The unit of capacity is derived from the weight of grains of wheat. Eight pounds of these make one gallon of wine measure.

Nor are the extreme vagueness and instability of these standards the only surprise. There is no principle of science or convenience in the progression of the different series. Thus we have two pints to a quart, three scruples to a dram, four quarts to a gallon, five quarters to an ell, five and a half yards to a perch, six feet to a fathom, eight furlongs to a mile, twelve inches to a foot, sixteen ounces to a pound, twenty units to a score.

Then, as if the only ruling principle governing the selection were discord, we have different measures bearing the same name, such as the wine pint and the dry pint, the ounce Troy and the ounce avoirdupois. Take these last two measures as illustrating the prevailing confusion. Both seem to come from France. The Troy weight is supposed to derive its name from the French town of Troyes, where a celebrated fair was once held. The term “avoirdupois” is French, and seems to have been part of a statute which declared how weights should be determined. But Troy and avoirdupois are different measures.

These measures, having constant differences, had accidental differences also, in different parts of England, and also in different parts of our own country. Even where the names are alike, the measures are often unlike. In England the diversity was almost infinite, so that these same measures differed in different counties, and sometimes in different towns of the same county. Latterly in the United States the standard has been regulated by law, but the confusion from the measures still continues. The question naturally arises, why such confusion has been allowed so long without correction. The answer is easy. Except in rare instances, the triumphs of science are slow and gradual. Traditional prejudice must be overcome. Each nation is attached to its own imperfect system, as to its own language. Even though inferior to another, it has the great advantage of being known to the people that use it. To this constant impediment it is proper to add the intrinsic difficulty of establishing a uniform system of weights and measures which shall satisfy the demands of civilization in scientific precision, in immediate practical applicability, and in nomenclature.

Take, for instance, the application of the decimal system, which seems at first sight simple and complete. It is unquestionably an immense improvement on the old confusion; but even here we encounter a difficulty in the circumstance, long since recognized by mathematicians, that our scale of decimal arithmetic is more the child of chance than of philosophy. I know not if any better reason can be given for its adoption than because man has everywhere reckoned by his ten fingers. On this account it is often called “natural.” But, considering whether the number ten possesses any intrinsic excellence, convenience, or fitness, as a ratio of progression, good authorities have answered in the negative. It is the duplication of an odd number, which can furnish neither a square nor a cube, and which cannot be halved without departure from the decimal scale. In this scale we seem to see always those early days when “wild in woods the noble savage ran,” and for arithmetic used fingers or toes. An octaval system, founded on the number eight, would have been better adapted to the divisions of material things. Among us the decimal system is adopted for money; but you all know that we are not able to carry it into rigid practice. Thus convenience, if not necessity, requires the half-dollar, the quarter-dollar, the half-dime, and the three-cent piece. In fact, eight divisions to the dollar, as prevailed in Spain, are more available in the business of life than the decimal division. The number eight is capable of indefinite bisection. The progression beginning with two would proceed to four, eight, sixteen, thirty-two, sixty-four, and so on.

The decimal scale is made easy of use by the happy system of notation borrowed from the Hindoos, which might be applied equally well to an octaval scale; but at this time it would be vain to propose a change in the radix of the numerical scale. The number ten is the recognized starting-point, and gives its name to the scale. It only remains for us at present to follow other nations in applying it to an improved system of weights and measures.

A system of weights and measures born of philosophy, rather than of chance, is what we now seek. To this end old systems must be abandoned. A chance system cannot be universal: science is universal; therefore what is produced by science may find a home everywhere. If we consider the proper elements or characteristics of such a system, we find at least three essential conditions. First, the new system must have in itself the assurance of unvarying stability, and, to this end, it should be derived from some standard in Nature by which to correct errors creeping into the weights and measures from time or imperfect manufacture. Secondly, the parts should be divided decimally, as nearly as practice will warrant, in conformity with our arithmetic. Thirdly, it should be such as to disturb national prejudices as little as possible.

To a common observer the difficulties of finding an unvarying standard are not readily apparent. But philosophy shows that all things in Nature are undergoing change; so that there would seem to be no invariable magnitude, the same in all countries and in all times, as Cicero pictured the great principles of Natural Law,[56] by which a lost standard on an inaccessible island might be reproduced with mathematical certainty. There is but one magnitude in Nature which, so far as we know, approximates to these requisites. I refer to the length of the pendulum vibrating seconds, which in our latitude is about 39.1 inches. This length, however, varies in travelling from the equator to the pole, and it also varies slightly under different meridians and the same latitude; but the law of variation has been determined with considerable accuracy. One element in this variation is the difference of temperature. In his report on weights and measures, Mr. Jefferson proposed that we should find our standard in the pendulum. At the same time, the French Government, just struggling to throw off ancestral institutions, conceived the idea of a new system, which, founded in science, should be common to the civilized world.

The French began not only by discarding old systems, but also by discarding a measure derived from the pendulum. They conceived the idea of measuring an arc of the earth’s meridian, and finding a new unit in a subdivision of this immense span. The work was undertaken. An arc of the meridian, embracing upward of nine degrees of latitude, and extending from Dunkirk, in France, to the Mediterranean, near Barcelona, in Spain, was measured with scientific care. Illustrious names in French science, Méchain and Delambre, were engaged in the work, which proceeded, notwithstanding domestic convulsion and foreign war. The Reign of Terror at home and invasion from abroad did not arrest it. Seven years elapsed before the measurements were completed, when other nations were invited to coöperate in the establishment of the new system.

The unit of measure was one ten-millionth part of the distance between the equator and the north pole thus measured. It received the name of metre, from the Greek, signifying measure. A bar of platinum, representing this length, was prepared with all possible accuracy. This bar was deposited in the archives of France as the perpetual standard. Other bars have been copied from it and distributed throughout France and in foreign countries.

There is something transcendental in the idea of this measurement of the earth in order to find a measure for daily life. It was an immense undertaking. But the conception seems to have been vast rather than practical. There is reason to believe, from later labors, that there was a serious error in the work. Thus, the distance of 10,000,000 metres from the equator to the north pole, established by the French observers, is too small by 935 yards, according to Bessel,—by 1,410 yards, according to Puissant,—and by 1,967 yards, according to Chazallon. Sir John Herschell also testifies with the authority of his great name against the accuracy of this result. If there be an error such as is supposed, then the metre ceases to be what it was called originally, one ten-millionth part of the distance from the equator to the north pole.

Even assuming that there is no error, and that the metre is precisely what it purports to be, yet it is not easy to see how the artificial standard can be corrected by recurrence to the standard in Nature. The massive work originally undertaken will not be repeated. The astronomers of France will not verify the accuracy of the bar of platinum, which is the artificial standard, by another scientific enterprise, requiring years for completion. Therefore, for all practical purposes, the metre is really nothing else than a bar of platinum with a certain length preserved in the archives of France. It is not less arbitrary as a standard than the yard or foot, and it can be perpetuated in practice only by distribution of exact copies from the original bar, which is the assumed metre.

I have thus explained the origin and character of the metre, because I desire that the admirable system founded on it should be seen actually as it is. To my mind, it gains nothing from the theory which presided at its origin. Its unit is not to be regarded as a certain portion of the distance between the equator and the north pole, but as an artificial measure determined with peculiar care. Had the same or any other unit been selected without measurement of the earth, the metric system would not have been less beautiful or perfect.

Look now at the system. The metre, which is assumed to be one ten-millionth part of the distance from the equator to the pole, is, in fact, 39⅓ inches, or 39.37 inches, in length. It is especially the unit of length; but it is also the unit from which are derived all measures of weight and capacity, square or cubic. It is at once foundation-stone and cap-stone. It is foundation-stone to all in the ascending series, and cap-stone to all in the descending series.

The unit of surface measure, or land measure, is the are, from the Latin area, and is the square of ten metres, or, in other words, a square of which each side is ten metres in length.

The unit of solid measure is the stere, from the Greek, and is the cube of a metre, or, in other words, a solid mass one metre long, one metre broad, and one metre high.

The unit of liquid measure is the litre, from the Greek, and is the cube of the tenth part of the metre, which is the decimetre; or, in other words, it is a vessel where by interior measurement each side and the bottom are square decimetres.

The unit of weight is the gram, also derived from the Greek, and is the one-thousandth part of the weight of a cubic litre of distilled water at its greatest density,—this being just above the freezing-point.

Such are main elements of the metric system. But each of these has multiples and subdivisions. It is multiplied decimally upward, and divided decimally downward. The multiples are from the Greek. Thus, deca, ten, hecto, hundred, kilo, thousand, and myria, ten thousand, prefixed to metre, signify ten metres, one hundred metres, one thousand metres, and ten thousand metres. The subdivisions are from the Latin. Thus, deci, centi, milli, prefixed to metre, signify one tenth, one hundredth, and one thousandth of a metre. All this appears in the following table.

Metric Denominations and Values.Equivalents in Denominations in use.

Myriametre, 10,000 metres,6.2137 miles.

Kilometre, 1,000 metres,.62137 mile, or 3,280 feet and 10 inches.

Hectometre, 100 metres,328 feet and 1 inch.

Decametre, 10 metres,393.7 inches.

Metre, 1 metre,39.37 inches.

Decimetre, ⅒ of a metre,3.937 inches.

Centimetre, ¹⁄₁₀₀ of a metre,.3937 inch.

Millimetre, ¹⁄₁₀₀₀ of a metre,.0394 inch.

These same prefixes may be applied in ascending and descending scales to the are, the litre, and the gram. Thus, for example, we have in the ascending scale, decagram, hectogram, kilogram, and myriagram,—and in the descending scale, decigram, centigram, milligram.

In this brief space you behold the whole metric system of weights and measures. What a contrast to the anterior confusion! A boy at school can master the metric system in an afternoon. Months, if not years, are required to store away the perplexities, incongruities, and inconsistencies of the existing weights and measures, and then memory must often fail in reproducing them. The mystery of compound arithmetic is essential in the calculations they require. All this is done away by the decimal progression, so that the first four rules of arithmetic are ample for the pupil.

Looking closely at the metric system, we must confess its simplicity and symmetry. Like every creation of science, it is according to rule. Master the rule and you master the system. On this account it may be acquired by the young with comparative facility, and, when once acquired, it may be used with despatch. Thus it becomes labor-saving and time-saving. Among its merits I cannot hesitate to mention the nomenclature. A superficial criticism has objected to the Greek and Latin prefixes; but this forgets that a system intended for universal adoption must discard all local or national terms. The prefixes employed are equally intelligible in all countries. They are no more French than English or German. They are common, or cosmopolitan, and in all countries they are equally suggestive in disclosing the denomination of the measure. They combine the peculiar advantages of a universal name and a definition. The name instantly suggests the measure with exquisite precision. If these words seem scholastic or pedantic, you must bear this for the sake of their universality and defining power.

Unquestionably it is difficult for one generation to substitute a new system for that learned in childhood. Even in France the metric system was tardily adopted. Napoleon himself, on one occasion, said impatiently to an engineer who answered his inquiry in metres, “What are metres? Tell me in toises.” It was only in 1840 that the system was definitely required in the transaction of business. Since then it has been the legal system of France. Cloth is sold by the metre; roads are measured by the kilometre; meat is sold by the kilogram, or, as it is familiarly abridged, by so many kilos.

It is generally admitted that the names are too long, although nobody has been able to suggest substitutes, unless we regard the various abridgments in that light. But no abridgment should be allowed to sacrifice the cosmopolitan character which belongs to the system. Thus, in England a nomenclature is proposed which would secure short names; but these would be different in each language, and entirely different from the French names. This is a mistake. The names in all languages should be identical, or so nearly alike as to be recognized at once. This may be accomplished by an abbreviated nomenclature.

For instance, we may say met, ar, lit, and gram; and, in describing the denomination, we may say, in the ascending scale, dec, hec, kil, and in the descending scale, dec, cen, and mil,—indicating respectively 10, 100, 1000, and ⅒, ¹⁄₁₀₀ and ¹⁄₁₀₀₀. Compounding these, we should have, for example, kilmet, killit, kilgram, and cenmet, cenlit, cengram. These abbreviations might be substantially the same in all languages. They would preserve the characteristics of the unabridged terms, so that the simple mention of the measure, even in this abridged form, would disclose the proportion it bears to its fellow-measures. Previous measures have been represented by monosyllables, as grain, dram, gross, ounce, pound, stone, ton. Where a word is often repeated, in the hurry of business, it is instinctively abridged. We shall not err, if we profit by this experience, and seek to reduce the new nomenclature to its smallest proportions.

Twelve words only are required by this system. Learning these, you learn all. There are five designating the different units of length, surface, solid capacity, liquid capacity, and weight. Then there are the seven prefixes, being four in the ascending scale, expressing multiples, or augmentations, of the metre or other units, derived from the Greek, and three in the descending scale, expressing subdivisions, or diminutions, of the metre and other units, derived from the Latin. These twelve words contain the whole system.

In closing this chapter on the unquestionable advantages of the metric system, I must not forget that it is already the received system in the majority of countries. At the Statistical Congress assembled at Berlin in 1863, it appeared that it was adopted partly or entirely in Austria, Baden, Bavaria, Belgium, France, Hamburg, Hanover, Hesse, Mecklenburg, the Netherlands, Parma, Portugal, Sardinia, Saxony, Spain, Switzerland, Tuscany, the Two Sicilies, and Würtemberg. Since then, Great Britain, by an Act of Parliament, has added her name to this list. The first step is taken there by making the metric system permissive, as is proposed in the bills before Congress. The example of Great Britain is of especial importance to us, since the commercial relations between the two countries render it essential that these should have a common system of weights and measures. On this point we cannot afford to differ from each other.

The adoption of the metric system by the United States will go far to complete the circle by which this great improvement will be assured to mankind. Here is a new agent of civilization, to be felt in all the concerns of life, at home and abroad. It will be hardly less important than the Arabic numerals, by which the operations of arithmetic are rendered common to all nations. It will help undo the primeval confusion of which the Tower of Babel was the representative.

As the first practical step to this great end, I ask the Senate to sanction the bills which have already passed the other House, and which I have reported from the special committee on the metric system. By these enactments the metric system will be presented to the American people, and will become an approved instrument of commerce. It will not be forced into use, but will be left for the present to its own intrinsic merits. Meanwhile it must be taught in schools. Our arithmetics must explain it. They who have already passed a certain period of life may not adopt it; but the rising generation will embrace it, and ever afterwards number it among the choicest possessions of an advanced civilization.