WEIGHTS AND MEASURES.

THE bill for ascertaining and establishing UNIFORMITY of WEIGHTS and MEASURES, which passed the Imperial House of Commons in the Session of 1823, not having been carried through the House of Lords, the subject has less immediate interest at the present moment than there has been every reason to suppose, for a few years past, that it would by this time have acquired. But there is little doubt that the discussion will be revived either in the Upper or the Lower House of Parliament before many more months have elapsed; and it seems to be highly improbable that any insuperable difficulties should stand in the way of its ultimate success. This presumption is founded on no hasty view of the subject in question, but upon a laborious and somewhat painful examination of the historical progress of the measures which have been taken respecting it, and especially of the laws of England respecting uniformity of practice in different parts of the country; a uniformity which, though generally esteemed by all governments a thing to be encouraged and enforced, has often proved to be no more subjected to the controul of legislative enactment, than the introduction of a uniformity of language and a grammatical accuracy of speech would be found in every part of an extensive empire.

Augustus is said to have endeavoured in vain to force a new Latin word into the language of ancient Rome; the French, on the other hand, after all their labours to recommend a uniform system of measures, have ended in such a complication, that for the most simple purposes of practical mechanics and civil life, it is become usual to carry in the pocket a little ruler, in the form of a triangular prism, one of the sides containing the old established lines and inches of the royal foot, a second the millimetres, centimetres, and decimetres of the revolutionary school, and the third the new ultraroyal combination of the Jacobin measure, with the royal division, the inches consisting each of the 36th part of a metre, or the four millionth of a degree of the meridian of the earth. If such occurrences as these be calmly considered, they will make us more disposed to diminish than to increase the number of penal statutes intended to compel the inhabitants of the different parts of a country to study their own convenience conjointly with that of their neighbours, and to spare themselves the necessity of a few arithmetical operations in the course of every market day; and we shall feel that it is more incumbent on a wise government to endeavour to facilitate both the attainment of correct and uniform standards of legal existing measures of all kinds, and the ready understanding of all the provincial and local terms

applied to measures, either regular or irregular, by the multiplication of glossaries and tables for the correct definition and comparison of such terms.

Measures have apparently always been derived, in the first instance, from some part of the human person; a foot, a pace, a fathom, the orgyia or stretch of the arms, a cubit, a palm, and a finger; these have probably all been used in the earlier states of society by each individual from the magnitude of his own person; and afterwards a standard measure has been established by authority from the real or supposed magnitude of the person of some king or hero, in order for the attainment of more perfect uniformity in practice; though it is said, that in some parts of the East the Arabs still measure the cubits of their cloth by the fore arm, with the addition of the breadth of the other hand, which serves to mark the end of the measure, as the thumb which was formerly added at the end of the yard by the English clothiers. It ought not, however, to be forgotten, that any one of these terms possesses an advantage, for popular use and for the convenience of future ages and of remote countries, which would be lost by the introduction of any more arbitrary measurement; thus a hand's breadth, or a foot, is always sufficiently understood, without any definition, to enable us to form to ourselves a tolerable accurate picture of the magnitude intended to be described; and there is scarcely an instance of the caprice of denomination having ever extended so far as to make the measure called a foot in any country so small as half a natural foot, or so great as two feet of an ordinary person, and certainly not of its amounting to three ordinary feet; while a metre, even to those who know that the word implies a measure, might as well have meant a mile, or an inch, or a quart, as a length somewhat greater than a yard.

The idea of accurately verifying the standard of a country by any other means, than that of a comparison with some actually existing original, can scarcely have occurred, except in a very advanced period of the progress of civilisation. It was indeed enacted, in the time of our Henry the Third, that an ounce should be the weight of 640 dry grains of wheat taken from the middle of the ear, that a pound should be twelve ounces, a gallon of wine eight pounds, and eight gallons of wine a bushel of London; but this seems rather a direction for making a single standard than a mode intended for the continual verification of the standard in case of any minute uncertainty. Again, in a statute of Henry the Seventh, a gallon of corn was mentioned as containing eight pounds of wheat: and this may, perhaps,

* The Editor has received this article from a quarter which entitles him to state, with the utmost confidence, that it contains an accurate and faithful account of Mr Watt. The brilliant eulogium with which it so properly concludes is known to have been written by Mr Jeffrey.

Weights and serve to explain the origin of the two different gal-
lons. But the substitution of an original standard,
derived from an object of definite magnitude, exte-
rior to the human person, seems to have been reserv-
ed for the days of the French Revolution, though it
has since been adopted, in an improved form, by the
introduction of a foot equal to $\backslash frac\{1\}\{32\}$ of the pendulum
vibrating seconds as a representative of the custom-
ary foot of the kingdom of Denmark. (Journal R. I.
1821, Astr. Coll. N. V.)

The Royal Society, under the presidency of Mr
Folkes, made some very accurate comparisons of the
English, and French, and old Roman standards,
which are recorded in the Philosophical Transactions
for 1736, 1742, and 1743; and George Graham, the
watchmaker, determined, at the same time, the cor-
rect length of the pendulum vibrating seconds to be
39.130 inches, but the standard, with which he com-
pared it, requiring some reduction, it was afterwards
ascertained, that the length, as derived from these
experiments, ought to have been more nearly 39.14
inches.

A Committee of the House of Commons was ap-
pointed in 1758, of which Lord Carysfort was chair-
man; their Report contains some important informa-
tion respecting the standards then in use. They
found that the customary ale and beer gallon of the
Excise was estimated at 282 cubical inches, while
the legal wine gallon of the Exchequer was comput-
ed at only 231, though the only existing standard of
the wine gallon, in 1688, which was kept at Guild-
hall, contained no more than 224 cubical inches;
they suggested the adoption of this smaller gallon for
the legal standard, perhaps as being more favourable
to the revenue, though the gallon of 231 inches had
been previously legalised by the act of the fifth of
Queen Anne; and they employed the well known
Mr Bird to prepare two standards, which were to be
exact copies of that which was made by Graham for
the Royal Society in 1742, from a very careful com-
parison of the various yards and ells of Henry the
Seventh and Elizabeth, which were kept in the Ex-
chequer. One of these copies was marked "Stand-
ard Yard, 1758," and was presented by the Com-
mittee to the House with the intention that it should
be adopted as the legal standard; the other was
made "with checks," for common use, and proposed
to be kept in the Exchequer.

A subsequent Report of a Committee, appointed in
1759, consists principally of proposals for some le-
gislative regulations, tending to facilitate the equal-
isation of weights and measures by the establish-
ment of proper methods of checking and authorising
the standards to be employed. In 1765, two bills
were brought into the House of Commons by Lord
Carysfort, in conformity with the reports of the Com-
mittees; but, from some accidental circumstances,
they were not passed into laws.

Another Committee was appointed in 1790; but
no minutes of their proceedings have been recorded.
In 1814, however, a very important Report was pre-
sented to the House by a new Committee, who had
called upon Dr W. Hyde Wollaston and Professor
Playfair for their opinions on the subject; and it was
principally in consequence of these examinations
that the Committee stated that the length of the pen-

dulum vibrating seconds had been ascertained to be
39.13047 inches, and that the metre of platina mea-
sured, at the temperature of 55°, 39.3828 English
inches, representing, at 32°, the ten millionth part of
the quadrant of the meridian; they remarked, with
great truth, that, although in theory, the original
standard of weight is best derived from the measure
of capacity, yet, in common practice, it will gener-
ally be found more convenient to reverse this order;
and they recommended, upon the suggestion of Dr
Wollaston, that a gallon, containing ten pounds of
pure water, should be adopted as a substitute for the
ale and corn gallons, which had become different ra-
ther from accident than from any direct legislative
authority, containing the one a little more than ten
pounds, the other a little less, though the standards
of the latter were extremely discordant among them-
selves. It seems to have been intended to abolish the
wine gallon, which is also that of the apothecaries;
though it was recommended to retain the use of the
Troy Weight of the goldsmiths employed also by the
apothecaries. It had before been observed, that
twelve wine gallons of distilled water weighed ex-
actly 100 pounds Avoirdupois; but Dr Wollaston's
proposal, to make an ale gallon of exactly ten pounds,
afforded a greater facility in the operation of adjust-
ing the measure, since it is not very easy to divide
100 pounds into twelve equal parts, with the weights
in common use.

Some very important experiments on weights and
measures had been made, a little before the date of
this Committee, by Sir George Shuckburgh Evelyn,
who had published an elaborate paper on the subject
in the Philosophical Transactions for 1798; and by
the ingenious Mr Whitehurst, who obtained the
length of the pendulum by measuring the difference
of two lengths affording vibrations of different fre-
quency. There were still some minute discordan-
cies between the various measurements which appear-
ed to be of the highest authority; and some particu-
lars in the Report of the Committee of 1814 are ma-
nifestly erroneous; thus the weight of a cubic foot
of water is stated, from a mistake in computation, to
be 1000 ounces at 56$\backslash frac\{1\}\{2\}$° of Fahrenheit, while, in
fact, it is less than this even at 39°, the maximum of
density; and again, the customary length of the
English foot, which has always been adjusted at the
ordinary temperature of the atmosphere, and rather
at that of the summer than of the winter, as, for ex-
ample, in the great trigonometrical operations of Ge-
neral Roy and his successors, at 62° of Fahrenheit,
was, in the experiments, copied by the Committee
from Pictet, compared with the French standard,
which was intended to be employed at the freezing
point of water, without any correction for this diver-
sity; though Dr Young had long before pointed
out the omission both in the Journals of the Royal
Institution and elsewhere, and had computed the true
length of the metre according to these operations of
Professor Pictet, confirmed by some earlier ones of
Bird, Maskelyne, and Lalande, to be 39.3710 Eng-
lish inches, instead of 39.3828.

In order, therefore, to remove any doubt which
might still be reasonably entertained on the subject,
Mr Davies Gilbert moved the House of Commons,
in the year 1816, to present an humble address to

Weights and Measures. the Prince Regent, praying that he would give direction, that proper measures should be taken for ascertaining the length of the pendulum vibrating seconds, and for comparing the French and English standards with each other. In consequence of this address, the Astronomer Royal was in the first instance directed to perform the necessary operations; and, upon his asking for some further assistance, the President and Council of the Royal Society were requested to appoint a Committee to cooperate with him. This Committee consisted, besides the President and Secretaries, of the late Sir Charles Blagden, Mr Gilbert, Dr Wollaston, Dr Young, Captain Kater, General Mudge, Mr Brown, Mr Rennie, and Mr Troughton. They began by discussing the several modes of making the requisite experiments which occurred to the different members, and it was resolved, that as many of these methods, as were preferred by each of them, should be separately carried into execution, in order to obtain collateral determinations of the required length. Mr Pond pursued the method of the French astronomers, and obtained some very satisfactory results, with an apparatus such as they had employed; Dr Young proposed a method derived from that of Whitehurst, and very perfect in theory, but somewhat complicated, and which has never yet been practically executed; Captain Kater invented, with great ingenuity, and employed, with great mechanical skill, an apparatus which does as much credit to his talents in the arrangement as to his perseverance in the experiments which he performed with it, and the accuracy of his determinations has been fully appreciated by mathematicians and practical astronomers throughout the world; and his operations have been and are still about to be repeated by many observers in different countries. Captain Kater's apparatus has been fully described in the Article PENDULUM of this Supplement; it owes no inconsiderable part of its advantage to the property subsequently demonstrated by Laplace, that, even if the opposite knife edges were considerably blunted and rounded off, supposing them to be equally affected, the distance between them would still afford the true measure of the length of the pendulum, without any further correction for the change of the axis of motion. It has also been demonstrated in this country, by means of the experiments of Chladni on the elasticity of metals, that the temporary change of form, depending on the compression of the steel edge, would be too inconsiderable to produce any sensible alteration of the length in question.

The object of Dr Young's apparatus was, to obtain two or more fine lines, traced at different parts of a scale, which should exhibit between them a certain determinate portion of the length of a pendulum vibrating seconds. He apprehended that the accurate determination of the form and direction of the knife edges, and the measurement of the distance between any such edges, which was necessary in the method proposed by Prony, as well as in that which was subsequently invented by Captain Kater, would require more skill and delicacy in the execution and the observation, than could be expected from any common workman or experimenter; and though

Weights and Measures. Captain Kater, by his extreme care in combating every source of error, has, in point of fact, apparently obviated all these difficulties, yet it cannot be expected that so rare a combination of qualifications should again be found, in case of a repetition of the experiments, and Dr Young's apparatus may still, at some future time, be employed with advantage, at least for a collateral check upon the results.

The obstacles which prevented the completion of the observations which were made for some time with this apparatus at Greenwich, was the difficulty of obtaining a scapement so delicate as to count the number of vibrations, without sensibly interfering with their frequency. A very ingenious clockmaker was employed to furnish a scapement, of which the intention was to strike the pendulum slightly and instantaneously at the lowest point of its vibration, and then to recoil from it, so that even a considerable impulse might have little or no effect in altering the rate of the pendulum; but it was in fact observed, upon comparison with the clocks of the observatory, that the vibrations in larger arcs were more frequent than those which were performed in smaller; so that the scapement must have exerted a very considerable influence on the time of every vibration. It was therefore found necessary to abandon this method of making the experiment; but there would be no difficulty in conducting it very satisfactorily by means of a journeyman clock, with a wooden or brass pendulum, capable of having its length altered, so as to become comparable with the vibrations of Dr Young's pendulum in its different states; and it might even be found sufficient to observe the pendulum, with the same scapement, so altered as not to give any impulse whatever, but merely to reckon the vibrations by means of the detent, during the spontaneous vibrations of the pendulum, which, on account of its great weight, would be continued for a considerable time in consequence of the first impulse, taking care that the detent should be struck exactly at the middle of the vibration, and that it should rebound in some measure from the pendulum at the moment of contact.

Before any attempt was made to introduce any legislative regulations upon the foundation of the various scientific experiments, which had been so accurately and satisfactorily conducted, it was thought advisable by his Majesty's Ministers that the subject at large should be submitted to the deliberate consideration of some competent persons, who might discuss it more minutely than could be done with convenience before a Committee of either House of Parliament; and that a commission should be appointed for this purpose by a writ of the Privy Seal. The commissioners thus nominated in 1818 were the late Sir Joseph Banks, Sir George Clerk, Mr Davies Gilbert, Dr W. Hyde Wollaston, Dr Thomas Young, and Captain Henry Kater. Some further operations for the comparison of the existing standards of length were undertaken by Captain Kater; Dr Wollaston examined some of the authorised measures of capacity, and Dr Young offered his services as secretary to the committee, with the assistance of a clerk who had studied the law, while Sir George Clerk and Mr Gilbert were employed in

preparations for carrying into effect, in their legislative capacity, such regulations as the commissioners at large might agree to propose. The first occupation of the clerk was to make copious extracts from the statutes at large, by means of which Dr Young drew up an abstract of the present state of the laws relating to weights and measures, and afterwards to select from the Agricultural Reports of the different counties such materials, as afforded a glossary of all the terms employed in any part of Great Britain for denominating the irregular weights or measures, which have acquired a local currency in agricultural or other commercial transactions.

After this sketch of the previous history of the subject, we may now proceed to extract from the Reports of the Commissioners, and from the bills founded on them, such statements as may either serve in the place of canons for the regulation of weights and measures in general, or as documents respecting the actual value of the various standards possessing the highest degree of authenticity; and this article cannot be more properly concluded than by subjoining some further comparative tables of the standards of measures and weights adopted by different countries and at different periods.

First Report.—“I. Upon a deliberate consideration of the whole of the system at present existing, we are impressed with a sense of the great difficulty of effecting any radical changes, to so considerable an extent as might in some respects be desirable; and we, therefore, wish to proceed with great caution, in the suggestions which we shall venture to propose.

“II. With respect to the actual magnitude of the standards of length, it does not appear to us, that there can be any sufficient reason for altering those which are at present generally employed. There is no practical advantage in having a quantity commensurable to any original quantity existing, or which may be imagined to exist, in nature, except as affording some little encouragement to its common adoption by neighbouring nations. But it is scarcely possible that the departure from a standard, once universally established in a great country, should not produce much more labour and inconvenience in its internal relations, than it could ever be expected to save in the operations of foreign commerce and correspondence, which always are, and always must be, conducted by persons to whom the difficulty of calculation is comparatively inconsiderable, and who are also remunerated for their trouble, either by the profits of their commercial concerns, or by the credit of their scientific acquirements.

“III. The subdivisions of weights and measures at present employed in this country, appear to be far more convenient for practical purposes than the decimal scale, which might perhaps be preferred by some persons for making calculations with quantities already determined. But the power of expressing a third, a fourth, and a sixth of a foot in inches, without a fraction, is a peculiar advantage in the duodecimal scale; and, for the operation of weighing and measuring capacities, the continual division by two renders it practicable to make up any given quantity,

with the smallest possible number of standard weights or measures, and is far preferable in this respect to any decimal scale. We would therefore recommend, that all the multiples and subdivisions of the standard to be adopted should retain the same relative proportions to each other as are at present in general use.

“IV. The most authentic standards of length which are now in existence being found, upon a minute examination, to vary in a very slight degree from each other, although either of them might be preferred, without any difference that would become sensible in common cases; we beg leave to recommend, for the legal determination of the standard yard, that ‘which was employed by General Roy, in the measurement of a base on Hounslow Heath, as a foundation for the trigonometrical operations that have been carried on by the Ordnance throughout the country, and a duplicate of which will probably be laid down on a standard scale, by the Committee of the Royal Society appointed for assisting the Astronomer Royal in the determination of the length of the pendulum;’ the temperature being supposed to be 62 degrees of Fahrenheit, when the scale is employed.

“V. We propose also, upon the authority of the experiments made by the Committee of the Royal Society, that it should be declared, for the purpose of identifying or recovering the length of this standard, in case that it should ever be lost or impaired, that the length of a pendulum vibrating seconds of mean solar time in London, on the level of the sea, and in a vacuum, is ‘39.1372’ inches of this scale; and that the length of the metre employed in France, as the 10,000,000th part of the quadrantal arc of the meridian, has been found equal to ‘39.3694’ inches.

“VI. The definitions of measures of capacity are obviously capable of being immediately deduced from their relations to measures of length; but since the readiest practical method of ascertaining the magnitude of any measure of capacity is to weigh the quantity of water which it is capable of containing, it would, in our opinion, be advisable in this instance to invert the more natural order of proceeding, and to define the measures of capacity rather from the weight of the water they are capable of containing, than from their solid content in space. It will therefore be convenient to begin with the definition of the standard of weight, by declaring that ‘nineteen cubic inches of distilled water, at the temperature of 50°, must weigh exactly ten ounces Troy, or 4.800 grains; and that 7000 such grains make a pound avoirdupois; supposing, however, the cubic inches to relate to the measure of a portion of brass, adjusted by a standard scale of brass. This definition is deduced from some very accurate experiments of the late Sir George Shuckburgh on the weights and measures of Great Britain; but we propose at a future period to repeat such of them as appear to be the most important.

“VII. The definitions thus established are not calculated to introduce any variation from the existing standards of length and of weight, which may be considered as already sufficiently well ascertained.

But, with respect to the measure of capacity, it appears, from the Report contained in the Appendix (A), that the legal standards of the highest authority are considerably at variance with each other: the standard gallon, quart, and pint of Queen Elizabeth, which are kept in the Exchequer, having been also apparently employed, almost indiscriminately, for adjusting the measures both of corn and of beer; between which, however, a difference has gradually, and, as it may be supposed, unintentionally crept into the practice of the Excise; the ale gallon being understood to contain about four and a half per cent. more than the corn gallon, though we do not find any particular act of Parliament in which this excess is expressly recognised. We think it right to propose, that these measures should again be reduced to their original equality; and at the same time, on account of the great convenience which would be derived from the facility of determining a gallon and its parts, by the operation of weighing a certain quantity of water, amounting to an entire number of pounds and ounces without fractions, we venture strongly to recommend, that the standard ale and corn gallon should contain exactly ten pounds avoirdupois of distilled water, at 62° of Fahrenheit, being nearly equal to '277.2' cubic inches, and agreeing with the standard pint in the Exchequer, which is found to contain exactly twenty ounces of water.

"VIII. We presume that very little inconvenience would be felt by the public from the introduction of this gallon, in the place of the customary ale gallon of 282 cubic inches, and of the Winchester corn gallon, directed by a statute of King William to contain 269, and by some later statutes estimated at 272$\backslash frac\{1\}\{2\}$ cubic inches; especially when it is considered that the standards, by which the quart and pint beer measures used in London are habitually adjusted, do not at present differ in a sensible degree from the standard proposed to be rendered general. We apprehend, also, that the slight excess of the new bushel above the common corn measure would be of the less importance, as the customary measures, employed in different parts of Great Britain are almost universally larger than the legal Winchester bushel.

"IX. Upon the question of the propriety of abolishing altogether the use of the wine gallon, and establishing the new gallon of ten pounds, as the only standard for all purposes, we have not yet been able to obtain sufficient grounds for coming to a conclusive determination; we can only suggest, that there would be a manifest advantage in the identification of all measures of the same name, provided that the change could be made without practical inconvenience; but how far the inconvenience might be more felt than the advantage, we must leave to the wisdom of his Majesty's Government to decide."

Dated "24th June 1819."

"Appendix (A).

The standards kept at the Exchequer, for the adjustment both of CORN and BEER measures, are a bushel, a gallon, and a quart, dated 1601, and a pint, dated 1602, all marked with an E and a Crown. They were examined by Sir George Clerk and Dr Wollaston, and the weight of Thames water which they held, at the temperature of 52°, was found as in the

subjoined table. Now, since, according to Sir George Shuckburgh's experiments, a cubic inch of distilled water, at 60°, weighs 252$\backslash frac\{1\}\{2\}$ grains, the specific gravity of the water being to that of distilled water as 1.00060 to 1, and the apparent specific gravity of distilled water, in a vessel of brass at 52°, being to that of water at 62° as 1.00046 to 1, it follows that the apparent specific gravity of the water employed was 1.00106, and that an ounce avoirdupois corresponded to 1.731 cubic inches. Hence we obtain the contents of the measures in cubic inches, which are compared, in the table, with the more direct measurement of Mr Bird and Mr Harris, reported to the House of Commons in 1758.

"The Exchequer standard WINE gallon is dated 1707, and was found to contain 133$\backslash frac\{1\}\{2\}$ ounces, answering to 230.9 cubic inches. An experiment of Dr Wollaston and Mr Carr, in 1814, gave 230.8, the mean being 230.85; while the measurement of 1758 made it 231.2. A duplicate of this measure, and of the same date, is kept at Guildhall.

"Dr Wollaston and Mr Carr examined also the three other WINE gallons at Guildhall. The oldest of these seems to be the same that was measured by Halley and Flamsteed in 1688, and was said to contain 224 cubic inches; its actual capacity is 224.4. The wine gallon of 1773, which is in daily use for adjusting other measures, was probably in the first instance a correct copy of the Exchequer gallon, but has been reduced by a bruise, and by the wear of the brim, to 230.0 cubic inches, having lost $\backslash frac\{1\}\{4\}$ of a cubic inch, or $\backslash frac\{1\}\{8\}$ of its whole capacity. The wine gallon of 1798 contains 230.8 cubic inches.

"The Excise WINE gallon was found, by a similar experiment, to contain 230.1 cubic inches, having partaken of the progressive deficiency of the Guildhall gallon, from which it was derived."

Second Report. "We have examined, since our last Report, the relation of the best authenticated standards of length at present in existence, to the instruments employed for measuring the base on Hounslow Heath, and in the late trigonometrical operations. But we have very unexpectedly discovered that an error has been committed in the construction of some of those instruments: We are therefore obliged to recur to the originals which they were intended to represent, and we have found reason to prefer the Parliamentary standard executed by Bird in 1760, which we had not before received, both as being laid down in the most accurate manner, and as the best agreeing with the most extensive comparisons which have been hitherto executed by various observers, and circulated throughout Europe; and, in particular, with the scale employed by the late Sir George Shuckburgh.

"We have therefore now to propose, that this standard be considered as the foundation of all legal weights and measures, and that it be declared, that

Weights and Measures. the length of a pendulum vibrating seconds in a vacuum, on the level of the sea, in London, is 39.13929 inches, and that of the French metre 39.37079 inches, the English standard being employed at 62° of Fahrenheit.

Dated "13th July 1820."

Third Report. "The measurements which we have lately performed, upon the apparatus employed by the late Sir George Shuckburgh Evelyn, have enabled us to determine, with sufficient precision, the weight of a given bulk of water, with a view to the fixing the magnitude of the standard of weight; that of length being already determined by the experiments related in our former Reports: and we have found by the computations, which will be detailed in the Appendix, that the weight of a cubic inch of distilled water, at 62° of Fahrenheit, is 252.72 grains of the Parliamentary standard pound of 1758, supposing it to be weighed in a vacuum."

Appendix. The Commissioners having been furnished, by the kindness of the Honourable C. C. C. Jenkinson, with the apparatus employed by the late Sir George Shuckburgh Evelyn in the determination of the magnitude of the standard weights, and there being some doubt of the perfect accuracy of his method of measuring the capacity of the bodies employed, it was judged necessary to repeat that measurement with greater precautions; and the results of Captain Kater's experiments have afforded some slight corrections of the capacities in question.

"The sides of Sir George Shuckburgh's cube were found by Captain Kater equal to 4.98911, 4.98934, and 4.98935 inches, the diameter of the cylinder 3.99713, and its length 5.99600 inches; and the diameter of the sphere 6.00759 inches. Hence the content of the cube appears to be 124.1969 inches; that of the cylinder 75.2398; and that of the sphere 113.5264 inches of Bird's Parliamentary standard of 1760, recommended in the last Report of the Commissioners, or of the standard made by Troughton for Sir George Shuckburgh.

"The difference of the weight of the cube in the air at 62°, with the barometer at 29.0, and in water at 60.2°, was 31381.79 grains; and adding to this the weight of an equal bulk of the air at 62°, which is

$\backslash frac\{1\}\{834\}\; \backslash cdot\; \backslash frac\{29\}\{30\}$ of that of the water, or 36.26 grains, and

subtracting from it $\backslash frac\{1\}\{8.5\}$ of this, or 4.26 grains, the

buoyancy of the brass weights, we obtain 31413.79 grains for the weight of the cube of water in a vacuum at 60.2°. Now this cube is less than the supposed measure, at the standard temperature of 62°, in the ratio of 1 to 1.0000567, on account of the contraction of the brass, and the water is denser than at the standard temperature, according to Mr Gilpin's experiments, in the ratio of .99998 to .99981, or of 1.00017 to 1; the whole correction, for the difference of 1.8°, being .0001133, or 3.55 grains, making

31410.24 for the weight of the cube of water in a vacuum at 62°; which, divided by 124.1969, gives 252.907 for the weight of a cubic inch, in Sir George Shuckburgh's grains.

"In the same manner, we obtain for the cylinder, which was weighed in air under the same circumstances, and in water at 60.5°, the difference being

19006.83 grains, the correction $\backslash frac\{1\}\{834\}\; \backslash cdot\; \backslash frac\{29\}\{30\}\; \backslash cdot\; \backslash frac\{7.5\}\{8.5\}$ for the

effect of buoyancy, amounting to 19.43 grains; and for the difference of temperature of the water and brass conjointly, the densities being .999955 and .999810, the correction .000145—$.000047\; =\; .000095$, or 1.80 grains, leaving +17.63 grains for the whole correction of the weight, as reduced to a vacuum at 62°, and making it 19024.46, which, divided by 75.2398, the content of the cylinder, affords us 252.851 for the cubic inch in a vacuum at 62°.

"The sphere was weighed in air at 67°, the barometer standing at 29.74; the correction for the buoyancy is here

$\backslash frac\{7.5\}\{8.5\}\; \backslash cdot\; \backslash frac\{29.74\}\{30\}\; \backslash cdot\; \backslash frac\{1\}\{843\}$, or, for 28673.51 grains,

29.72; while the temperature of 66° requires, for the difference between the expansion of brass and water, the addition of .00042—$.000126$, or .000294 of the whole, that is +8.43 grains, making the whole correction 38.15, and the weight in a vacuum 28711.66; which, divided by 113.5264, gives us 252.907, for the cubic inch in a vacuum.

"The mean of these three measures is 252.888, giving for the three errors, +.019, —.037, and +.019; and this mean, reduced to the Parliamentary standard, makes 252.722 grains, for the cubic inch of distilled water at 62°, weighed in a vacuum, or 252.456 in air, under the common circumstances of the atmosphere, when weights of brass are employed. In a vacuum, at the maximum of density, that is, at 39°, the weight of a true cubic inch will be 253 grains, and of a cubic decimetre 15440.* The proposed imperial gallon, of ten pounds, or 70000 grains of water, will contain very nearly 277.3 cubic inches, under common circumstances."

In conformity with these Reports, a bill was brought into the House of Commons, in 1822, by Sir George Clerk, and again, with a few alterations, in 1823, which appears to be drawn up with great care and judgment, and which comprehends a statement of the true ground of the proposed measures, and of the determinations which are intended for their bases.

"Whereas notwithstanding it is provided by the Great Charter, that there shall be but one Measure and one Weight throughout the realm, and by the Treaty of Union between England and Scotland, that the same weights and measures should be used throughout Great Britain as were then established in England, yet different weights and measures, some larger and some less, are still in use in various places throughout the United Kingdom of Great Britain and Ireland, and the true measure of the present

* It appears, however, from an official Report obligingly communicated to us by Dr Kelly, that the actual standard chiliogramme has been found to contain only 15433 English grains.

Weights and Measures. standards is not very known, which is the cause of great confusion and of manifest frauds: Be it therefore enacted, That from and after the 1st January 1824, the straight line or distance between the centre of the two points in the gold studs in the straight brass rod, now in the custody of the Clerk of the House of Commons, wherein the words and figures 'Standard Yard, 1760,' are engraved, shall be, and the same is hereby declared to be, the original and genuine standard of that measure of length or linear extension called a yard; and that the same straight line or distance between the centres of the said two points in the said gold studs in the said brass rod, the brass being at the temperature of sixty two degrees by Fahrenheit's thermometer, shall be, and is hereby denominated the 'Imperial Standard Yard,' and shall be, and is hereby declared to be, the unit or only standard measure of extension wherefrom or whereby all other measures of extension whatsoever, whether the same be linear, superficial or solid, shall be derived, computed, and ascertained; and that all measures of length shall be taken in parts or multiples, or certain proportions of the said standard yard; and that one third part of the said standard yard shall be a foot, and the twelfth part of such foot shall be an inch; and that the pole or perch shall contain five such yards and a half, the furlong 220 such yards, and the mile 1760 such yards. . .

"And whereas it is expedient that the said standard yard, if lost, destroyed, defaced, or otherwise injured, should be restored of the same length by reference to some invariable natural standard: and whereas it has been ascertained, by the Commissioners appointed by his Majesty to inquire into the subject of weights and measures, that the said yard hereby declared to be the imperial standard yard, when compared with a pendulum vibrating seconds of mean time in the latitude of London, in a vacuum at the level of the sea, . . . is in the proportion of thirty six inches to 39.1393; Be it therefore enacted and declared, That if at any time hereafter the said imperial standard yard shall be lost, or shall be in any manner destroyed, defaced, or otherwise injured, it shall and may be restored by making, under the direction of the Lord High Treasurer . . . for the time being, a new standard yard, bearing the same proportion to such pendulum as aforesaid, as the said imperial standard yard bears to such pendulum.

"And whereas the Commissioners appointed by his Majesty to inquire into the subject of weights and measures have recommended that the standard brass weight of two pounds troy weight, made in the year 1758, and now in the custody of the Clerk of the House of Commons, shall be considered as authentic; be it enacted, That a brass weight equal to one half of the said brass weight of two pounds, gravitating in air (the barometer being at thirty inches, and the thermometer being at 62° by Fahrenheit's scale') 1822 [1823, be it further enacted, That from and after the 1st January 1824, the standard brass weight of one pound troy weight, made in the year 1758, now in the custody of the Clerk of the House of Commons], shall be, and the same is hereby declared to be, the original and genuine standard measure of weight; and that such brass weight . . . shall be and

is hereby denominated the Imperial Standard Troy Pound, and shall be, and the same is hereby declared to be, the unit or only standard measure of weight, from which all other weights shall be derived, computed, and ascertained; and that $\backslash frac\{1\}\{16\}$ of the said troy pound shall be an ounce; and that $\backslash frac\{1\}\{20\}$ of such ounce shall be a penny weight; and that $\backslash frac\{1\}\{70\}$ of such penny weight shall be a grain; so that 5760 such grains shall be a troy pound; and that 7000 such grains shall be, and are hereby declared to be, a pound avoirdupois; and that $\backslash frac\{1\}\{16\}$ of the said pound avoirdupois shall be an ounce avoirdupois; and that $\backslash frac\{1\}\{20\}$ of such ounce shall be a dram.

"And whereas it is expedient, that the said standard troy pound, if lost, destroyed, defaced, or otherwise injured, should be restored of the same weight, by reference to some invariable natural standard; and whereas it has been ascertained, by the Commissioners appointed by his Majesty to inquire into the subject of weights and measures, that a cubic inch of distilled water in a vacuum, weighed by brass weights, also in a vacuum, at the temperature of 62° of Fahrenheit's thermometer, is equal to '252.72,' 1822 [1823, 252.724], grains, of which as aforesaid, the imperial standard troy pound contains 5760; Be it therefore enacted, That if at any time hereafter the said imperial standard troy pound shall be lost . . . it shall and may be restored, . . . by making, under the directions of the Lord High Treasurer . . . a new standard . . . determined according to this proportion.

"And be it further enacted, That the standard measure of capacity, as well for liquids as for dry goods not measured by heaped measure, shall be the gallon, containing ten pounds avoirdupois weight of distilled water, weighed in air, at the temperature of sixty two degrees of Fahrenheit's thermometer, the barometer being at thirty inches; and that a measure shall be forthwith made of brass, of such contents as aforesaid, . . . and such brass measures shall be, and is hereby declared to be, the imperial standard gallon, and shall be, and is hereby declared to be, the unit and only standard measure of capacity, from which all other measures of capacity to be used, as well for wine, beer, ale, spirits, and all sorts of liquids, as for dry goods not measured by heaped measure, shall be derived, computed, and ascertained; and that all measures shall be taken in parts or multiples, or certain proportions of the said imperial standard gallon; and that the quart shall be the fourth part of such standard gallon, and the pint shall be one eighth of such standard gallon; and that two such gallons shall be a peck, and eight such gallons shall be a bushel, and eight such bushels a quarter of corn or other dry goods, not measured by heaped measure.

"And be it further enacted, That the standard measure of capacity for coals, culm, lime, fish, potatoes, or fruit, and all other goods and things commonly sold by heaped measure, shall be the aforesaid bushel, containing eighty pounds avoirdupois of water as aforesaid, the same being made round with a plain and even bottom, and being 19$\backslash frac\{1\}\{2\}$ inches from outside to outside of such standard measure as aforesaid.

"And be it further enacted, That in making use of such bushel, all coals, and other goods and things commonly sold by heaped measure, shall be duly

Weights and Measures. heaped up in such bushel in the form of a cone, such cone to be of the height of at least six inches, and the outside of the bushel to be the extremity of the base of such cone; and that three such bushels shall be a sack, and that twelve such sacks shall be a chaldron."

"Provided always, and be it enacted, That in all cases of dispute respecting the correctness of any measure of capacity, arising in a place where recourse cannot conveniently be had to any of the aforesaid verified copies or models of the standard measures of capacity, it shall and may be lawful to and for any Justice of the Peace or Magistrate having jurisdiction in such place, to ascertain the content of such measure of capacity by direct reference to the weight of pure or rain water which such measure is capable of containing; ten pounds avoirdupois weight of such water, at the temperature of 62° by Fahrenheit's thermometer, being the standard gallon ascertained by this act, the same being in bulk equal to '277.276' 1822 [1823, 277.274] cubic inches, and so in proportion for all parts or multiples of a gallon."

The slight discordance between the numbers of the two successive years depends merely on the adoption of a standard troy pound, better authenticated than the two pound weight particularly employed by Sir George Shuckburgh, which was finally preferred both as representing a unit, and as being more simple in its form than the two pound weight.

From Folkes, Raper, Shuckburgh, Vega, Hutton's Ozanum, Cavallo, and others. Young's Nat. Phil. II. 152, 150.

WEIGHTS AND MEASURES.