New York, 09 July, 2016.
The chief materials of the following Work have been gradually accumulated during researches which from time to time, for several years, I have occupied myself in making upon Weights and Measures. These researches have been principally in an historical aspect; and the materials themselves were collected to serve for my own use as a guide in detecting and, in the absence of other proof, or proving the migrations and commerce of different nations and at different periods. But when they had grown to nearly their present bulk, it occurred to me that their publication in a shape somewhat like the present, might be useful ; not only to those whose tastes and studies were like my own and whose investigations might thus come to be helped by my labor, but also to others who might find them of convenient reference and application in ordinary concerns of business or education.
To all these classes of persons and objects, I believe the present collection will be found to offer information more extensive, and more convenient than any existing work; while for the two latter, particularly the young, who are to learn, and those engaged in Commerce, who are to apply it supplies a defect which has been suffered for a long time, the absence of any book, giving to any considerable extent, much less universally, the reduction of foreign Weights and Measures to our own American Standards. It is true the elder English Cambists, before 1825, answered the purpose; because up to that time the standards of Great Britain and of the United States were substantially the same. But these older works are now out of print and no longer generally accessible ; and besides, since that time, there has been more than one important addition to accuracy on this subject, so that they would need considerable corrections. Since 1825, the English capacity-standards differ systematically from our own ; and the values of the gallon and bushel, for instance, given in newer Works for that country, no longer serve for this.
I believe it will be admitted, too, that the aim under which the materials for this book were collected, does not fit it the less (but rather the more) for practical utility, than if it had been set about originally for that special end. The historian who is seeking to trace the footsteps of Civilization through the dusky forest of antiquity and the tumultuous and disturbed fields of more modern times, has as much motive for fastidious accuracy as if he was calculating the premium of an actual bill of exchange; the systems, upon which Weights and Measures have been combined, and out of which their various values grow by multiplication and subdivision of the unit, are for him of interest not only as a means of deriving those values, but in their arithmetical proportions as indications of the influence of Race and the effect of national habitude; and in the terminology and the very orthography of names, too generally neglected or slurred over by the mere cambist, he looks for, and finds sometimes, a thread to guide him through the maze. In attention to these particulars, the present Work will be found, I hope, unless by accident, unexceptionable.
The student, who may be tempted by his own inclination to use it farther than as a means of reference only, may find, here and there, discrepancies between the systematic and actual value of terms. These, in some cases, have arisen and are allowed to stand ; on the principle of presenting for every term its best ascertained actual value in all cases where the units of the system have not been connected with some physical constants, as, for instance, the gravitation of water or the vibrations of a pendulum. Thus, comparisons have been made sometimes of two or more members of the same system (e. g. of a half-gallon and a pint;) and the result would be a different value for the unit, ( e. g. the gallon) according as one or the other determination was adopted. In such cases, the denominations actually compared, are given with their own resulting values; while that of the unit and the other members derived from it, has been generally deduced to correspond with the larger measure as being liable to the least absolute error. Where results have been given, between whose claims to confidence I could not decide, I have taken the mean ; and where the difference was not great, altered the dependent measures accordingly. So that values may be found here, differing from those given generally; but, I believe nearer the truth. I would gladly, were there room, enter somewhat into the discussion of these principles and of the cases where they have been applied.
In other regards, the details of form and arrangement, etc., I believe the order is sufficiently simple and perspicuous (as it ought to be) not to need further reference or explanation. Had the circumstances allowed, I would have added a supplementary alphabetical Part, to contain various items which, although not Weights or Measures themselves, are yet susceptible of being weighed or measured, and have actually to be so in the practical concerns of life; for instance, tables of the specific gravity, cohesive force, expansion, etc., of different substances; the reduction and comparison of thermometric and hygrometric scales ; the result of dynamometric experiments upon the effect of different natural agents for producing motion ; the comparison of figure, weight, and size in different branches of the human race, etc. etc. Should what is now offered, meet with favor from the Public, such particulars may be added hereafter to fill up the practical scope of the Work.
I have not included Coins and Money in the present arrangement, which are themselves such valuable means for determining the Weights and Measures of antiquity especially; not because they have not formed an important part of my research, but because they have been already largely explored, the results are generally accessible, and the introduction of them here would have greatly enlarged the size and cost without proportionately increasing the value of the book. A reduction of modern Coins, especially, to the standard of the United States, in a similarly alphabetical arrangement, would no doubt be a useful manual of reference; so far as the theory of the Mints of many European States goes, this would be an inconsiderable task : but its principal value would be in shewing the actual deviations in practice from the theoretical aim-what the coins really are, not what they ought to be-and in the authenticity of such a demonstration. It is manifest that a work of this sort, is more appropriate to such a public Institution as a National Mint, which both could command, better than most private individuals, a sufficient collection of the coins in question to afford a reliable average, and would win, better than a more obscure source, confidence and reliance in the results.
Finally, if I may be allowed in connection with this Work and its appropriate applications, to allude to certain dreams of my own (as they may be; although I consider them capable, without undue effort, of a more prompt and thorough realization than seems to be ordinarily anticipated) as to the prevalence, some day, of an universal conformity of Weights and Measures, I must acknowledge, that such a result was one of the ends I had in view in the original collection of materials. Not, that such a work was going to show more emphatically than business men feel and reflecting men know, the importance of such an universal conformity; or that a book, whose pages deal in discords, could of itself produce unison: but that the first step to any harmonious settlement, is to see clearly and at a glance where the differences lie, and what they are. If a Millennial period for this world is ever to come as many wise have deemed and pious prayed, it must be preceded by one common language and one common system of Weights and Measures as the basis of intercourse. And the way to that is to be built, not by the violent absorption of other and diverse systems into one, but rather by a compromise into which all may blend. When the Earth in her historical orbit shall have reached that point (as it stood ere mankind were scattered from the plain of Shinar) and not till then, may we begin to hope that her revolutions will be stilled, and that before long the Weights and Measures of fleeting Time, will be merged and lost in the infinite scales and illimitable quantities of Eternity.
Baltimore, 29 August, 1850.