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WATCHES (Ger. Uhren, Taschenuhren; Fr. Montres; It. Oriuoli da tasca, o da Saccoccia; Sp. Relojes de faltriquera; Rus. Karmannüe tschasü), portable machines, generally of a small size and round flat shape, that measure and indicate the successive portions of time; having, for the most part, their motions regulated by a spiral spring. When constructed on the most approved principles, and executed in the best manner, a watch is not only an exceedingly useful, but a most admirable piece of mechanism. It has exercised the genius and invention of the most skilful mechanics, as well as of some of the ablest mathematicians, for nearly 3 centuries. And, considering the smallness of its size, its capacity of being carried about uninjured in every variety of position, the number and complexity of its movements, and the extraordinary accuracy with which it represents the successive portions of time as determined by the rotation of the earth on its axis, we need not wonder at Dr. Paley having referred to it as a striking specimen of human ingenuity.

Spring watches are constructed nearly on the same principle as pendulum clocks. Instead of the pendulum in the latter, a spring is used in the former, the isochronism of the vibrations of which corrects the unequal motions of the balance.

Historical Notice. The invention of spring watches dates from about the middle of the 16th century, and has been warmly contested for Huygens and Hooke. The English writers generally incline in favour of the latter. Dr. Hutton says - (Mathematical Dictionary, art. Watch), that the words " Rob. Hooke invenit, 1658," were inscribed on the dial plate of a watch presented to Charles II. in 1675. But Montucla affirms (Histoire des Mathématiques, tom. ii. p. 413, ed. 1800), that Huygens made this “belle découverte" in 1656, and presented a spring watch to the States of Holland in 1657. Comparing these statements, it certainly appears that the claim of Huygens to the priority of the discovery is the better established of the two. We do not, however, believe that either of those distinguished persons owed, in this respect, any thing to the other. The probability seems to be, that the happy idea of employing a spring to regulate the motion of watches occurred to them both nearly at the same time.

Improvement of Watches. Owing to the facility with which the longitude may be determined by the aid of accurately going watches, it is of great importance to have them made as perfect as possible. In this view, liberal premiums have been given to the makers of the best marine watches, or chronometers, by the governments of England, France, Spain, &c. In the reign of Queen Anne, parliament offered a reward of 20,000l. to any one who should make a watch, or other instrument, capable of determining the longitude at sea, within certain limits. This magnificent premium was awarded, in 1764, to the celebrated John Harrison, for a marine watch, which, being tried in a voyage to Barbadoes, determined its longitude with even more than the required accuracy. Other premiums, though of inferior amount, were subsequently given to Messrs. Mudge, Arnold, Earnshaw, &c. Since 1822, 2 prizes, one of 3001. and one of 2007, have been annually given to the makers of the 2 chronometers adjudged to be the best, after having been submitted to a twelvemonth's trial at the Royal Observatory at Greenwich. And to such perfection has the manufacture attained, that some of the chronometers employed by navigators, though carried into the most opposite climates, have not varied to the extent of 2 seconds in their mean rate of going throughout the year.

Watch Manufacture. The watch-making business, though latterly a good deal depressed, is largely carried on in London; the artists of which have attained to a high degree of excellence in this department. There may be about 14,000 gold and $5,000 silver watches annually assayed at Goldsmiths' Hall, London (Jacob on the Precious Metals, vol. ii. p. 413.) the aggregate value of which is, probably, not much under 600,000. The manufacture is also carried on to a considerable extent at Liverpool, Coventry, Edinburgh, &c. Watch movements used to be extensively manufactured at Prescot in Lancashire; but latterly, we believe, the manufacturers have been withdrawing to Liverpool.

On the Continent, watches are principally manufactured in Paris, Geneva, and in Neufchâtel. Some of the French and Swiss watches, particularly the latter, are excellent; but, generally speaking, they are slight, and inferior to those made in London. Paris and Geneva watches are largely exported to foreign countries; and are everywhere in high estimation, particularly among the ladies.

Watches impressed with any mark or stamp, appearing to be or to represent any legal British assay mark or stamp, or purporting by any mark or appearance to be of the manufacture of the U. Kingdom, or not having the name and place of abode of some foreign maker abroad visible on the frame and also on the face, or not being in a complete state, with all the parts properly fixed in the case, may not be imported into the U. Kingdom, even for the purpose of being warehoused. (3 & 4 Will. 4. c. 52. §58.) Watches in China. Pretty considerable numbers of European watches are imported into China; and it may be worth mentioning, as a curious instance of the diversity of tastes, that the Chinese, as well as most other Eastern nations, who can afford it, uniformly wear watches in pairs! This sort of extravagance is not, however, confined to watches, but extends to a variety of other articles. Shawls. for example, are invariably worn in India in pairs of exactly the same pattern; and it is hardly possible, indeed, to find a native dealer who will sell a single shawl.

WATER. It may be thought unnecessary, perhaps, to say any thing in a work of this sort with respect to a fluid so well known and so abundant. But, besides being an indispensable necessary of life, water is, in most large cities, an important commercial article. It is in the latter point of view, principally, that we mean to consider it. — Inasmuch, however, as the mode of supplying different places with water, and its price, necessarily vary in every possible way, we shall limit our remarks on these subjects to the metropolis only. The few remarks we intend to offer of a general nature will apply indifferently to any populous place, the supply of which with water occasions a considerable expense.

1. Quality of Water.-Dr. Ure has made the following statements with respect to the quality of water: Water," says he, "is a very transparent fluid, possessing a moderate degree of activity with regard to organised substances, which renders it friendly to animal and vegetable life, for both which it is, indeed, indispensably necessary. Hence it acts but slightly on the organs of sense, and is therefore said to have neither taste nor smell. It appears to possess considerable elasticity, and yields in a perceptible degree to the pressure of air in the condensing machine.

Native water is seldom, if ever, found perfectly pure. The waters that flow within or upon the surface of the earth contain various earthy, saline, metallic, vegetable, or animal particles, according to the substances over or through which they pass. Rain and snow waters are much purer than these, although they also contain whatever floats in the air, or has been exhaled along with the watery

vapours.

"The purity of water may be known by the following marks or properties of pure water:

"1. Pure water is lighter than water that is not pure.

2. Pure water is more fluid than water that is not pure.

3. It has no colour, smell, or taste.

4. It wets more easily than the waters containing metallic and earthy salts, called hard waters, and feels softer when touched.

5. Soap, or a solution of soap in alcohol, mixes easily and perfectly with it.

"6. It is not rendered turbid by adding to it a solution of gold in aqua regia; or a solution of silver, or of lead, or of mercury, in nitric acid; or a solution of acetate of lead in water.

"Water was, till modern times, considered as an elementary or simple substance; but it is now ascertained to be a compound of oxygen and hydrogen."

2. Supply of Water. — London was very ill supplied with water previously to the early part of the 17th century, when the New River water was introduced into the city. This exceedingly useful work was planned and carried into effect by the famous Sir Hugh Middleton, who expended his whole fortune on the project; having, like many other public benefactors, entailed poverty on himself and his posterity by embarking in an undertaking productive of vast wealth to others, and of great public utility. The New River has its principal source near Chadwell, between Hertford and Ware, about 20 miles from London; but the artificial channel in which the water is conveyed is about 40 miles in length. Sir Hugh Middleton encountered innumerable difficulties during the progress of the undertaking, which it is probable would have been abandoned, at least for a time, but for the aid afforded by James I. The New River Company. was incorporated in 1619, 6 years after the water had been brought to the reservoir at Islington. The undertaking yielded very little profit for a considerable number of years; but it has since become extremely profitable; so much so, that an original 5004 share has been sold for 16,000l. !

The Chelsea Water-Works Company was formed in 1723, and (with the aid of 3 smaller companies, none of which are now in existence) it, and the New River, supplied all that part of the metropolis north of the Thames with water, down to the year 1810. In that year, however, 3 new companies, the East London, West Middlesex, and Grand Junction, were established, under the authority of different acts of parliament. moment the metropolis is supplied with water by the following companies:

New River,

Chelsea,
East London,

West Middlesex,

Grand Junction,
Lambeth,

Vauxhall, or South London, and
Southwark Water Works.

At this

The following statements with respect to these companies are taken from Mr. Wade's treatise on the police of the metropolis. The Report of the commissioners appointed by government in 1827, to inquire into the state of the supply of water in the metropolis, is the principal authority on which they are founded.

"The New River Company get their supply from the spring at Chadwell, between Hertford and Ware. It comes in an open channel, of about 40 miles in length, to reservoirs at Clerkenwell. There are 2 reservoirs, having between them a surface of about 5 acres, and an average depth of 10 feet. These reservoirs are 844 feet above low water mark in the Thames; and, by means of steam engines and a stand-pipe, an additional height of 60 feet can be given to the water, so that all the mains belonging to this Company are kept full by a considerable pressure of water. The highest service given by the New River is the cistern on the top of Covent Garden Theatre. The aqueduct by which the water is brought has only a fall of 2 inches per mile; thus it wastes, by evaporation, during the drought of summer, and is impeded by frost in the winter. At these times the Company pump an additional supply from the Thames, at Broken Wharf, between Blackfriars and Southwark Bridges. To this, however, they seldom have recourse; and their engine, erected since the works at London Bridge were broken down, has worked only 176 hours in the year. The New River Company supply 66,000 houses with water, at an annual average of about 1,100 hogsheads each, or, in all, about 75,000,000 hogsheads annually.

"The East London Water Works are situated at Old Ford, on the river Lea, about 3 miles from the Thames, and a little below the point to which the tide flows up the Lea. By the act of parliament, this Company must take its water when the tide runs up and the mills below have ceased working. The water is pumped into reservoirs and allowed to settle; and a supply of 6,000,000 gallons is daily distributed to about 42,000 houses. This Company supply no water at a greater elevation than 30 feet, and the usual height at which the delivery is made to the tenants is 6 feet above the pavement; they have 200 miles of iron pipes, which, in some places, cost them 7 guineas a yard. This and the New River are the only companies which do not draw their supply of water entirely from the Thames.

"The West Middleser derive their supply of water from the Thames, at the upper end of Hammersmith, about 9 miles above London Bridge, and where the bed of the Thames is gravel. The water is forced by engines to a reservoir at Kensington, 309 feet long, 123 wide, and 20 deep, paved and lined with bricks, and elevated about 120 feet above low water in the Thames. They have another reservoir on Little Primrose Hill, about 70 feet higher, and containing 88,000 hogsheads of water, under the pressure of which the drains are kept charged, in case of fires. They serve about 15,000 tenants, and the average daily supply is about 2,250,000 gallons.

The Chelsea Water Works derive their supply from the Thames, about 4 of a mile east of Chelsea Hospital; and they have 2 reservoirs—one in the Green Park and another in Hyde Park the former having an elevation of 44 feet, and the latter of 70. These reservoirs, till within these few months, had never been cleaned, nor had there been any preparation made for that purpose in their construction. About of the water served out by this Company is allowed to settle in these reservoirs, and the remaining are sent directly from the Thames. Latterly, the Company have been making preparations for filtering the water; and also for allowing it to settle in reservoirs, at Chelsea, before it is delivered into the mains. The Chelsea Company serve about 12,400 houses, and the average daily supply is 1,760,000 gallons.

"The Grand Junction Company derive the whole of their supply from the Thames, immediately adjoining Chelsea Hospital; thence it is pumped, without any filtration or settling, into 3 reservoirs at Paddington. These reservoirs are about 71, 86, and 92 feet above high water mark in the Thames; their

united contents are 19 355,840 gallons; and by means of a stand-pipe, the water is forced to the height of 147 feet, or about 61 feet above the average height in the reservoir. The number of houses supplied by the Grand Junction Company is 7.700, and the average daily supply is about 2,800,000 gallons. "The Lambeth Company take their supply from the Thames, between Westminster and Water loo Bridges. It is drawn from the bed of the river by a suction pipe, and delivered to the tenants without being allowed to subside; there being only a cistern of 400 barrels at the works, as a temporary supply, until the engines can be started. The greatest height to which the Company force water is about 40 feet; the number of houses that they supply is 16,000, and the average service is 1,244,000 gallons daily. "The South London, or Vauxhall Company, take their supply from the river Thames by a tunnel, which is laid 6 feet below low water mark, and as far into the river as the third arch of Vauxhall Bridge. At that particular place, the bed of the Thames is described as being always clean, and without any of those depositions of mud and more offensive substances that are found in many other places. Besides the greater purity of the bed of the Thames here than where any other Company on the south side take their supply, the Company allow the water to settle in reservoirs. The Vauxhall Company supply about 10,000 houses with about 1,000,000 gallons of water daily.

The Southwark Water Works (the property of an individual) are supplied from the middle of the Thames, below Southwark and London Bridges; and the water thus taken is sent out to the tenants without standing to settle, or any filtration further than it receives from passing through wire grates and small holes in metallic plates. The number of houses supplied by these works is about 7,000, and the average daily supply about 720,000 gallons."

The results for 1827 may be collected into a Table, as follows: —

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Monopoly of the Water Companies. The sanction of parliament was given to the 3 new companies formed in 1810, not so much in the view of increasing the actual supply of water, as of checking monopoly, and reducing the rates by their competition. But these expectations have not been realised. For a while, indeed, the competition of the several companies was exceedingly injurious to their interests, and occasioned the total destruction of some of the inferior ones; but no sooner had this happened, than the others discovered that their interests were in reality the same, and that the true way to promote them was to concert measures together. In furtherance of this object, the 5 companies for the supply of that part of the metropolis north of the river proceeded to divide the town into as many districts, binding themselves, under heavy penalties, not to encroach on each other's estates: and having in this way gone far to secure themselves against any new competitors, their next measure was to add five and twenty per cent. to the rates established in 1810; and these have, in several instances, been still further augmented! The benefits that were expected to result from their multiplication have, therefore, proved quite imaginary; and though the supply of water has been increased, it is neither so cheap nor so good as it might have been under a different system.

We borrow from the evidence taken before the committee of the House of Commons in 1851, on the Metropolis Water Bill, the following interesting table relative to the supply of water in 1850:Account of the Capital, &c. of the different Metropolitan Water Companies, the Working Expenses of each, the Quantity of Water supplied by each, &c.

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Note.-272,000 houses, daily supplied with 150 gallons of water, would annually require 14,892,000,000 imperial gallons, which is about the quantity said to be delivered to the houses.

The striking discrepancies that appear in this table tend to confirm the principle we endeavoured to enforce in the article COMPANIES, that certain restrictions should, in almost all cases, he imposed on companies for the supply of water to a large city. These are not undertakings that can be safely trusted to the free principles that may generally be relied upon. If there be only one set of springs adjacent to a town, or if there be certain springs more conveniently situated for supplying it with water than any other, a company acquiring a right to such springs, and incorporated for the purpose of conveying the water to town, thereby gain an exclusive advantage; and if no limits be set to its dividends, its partners may make an enormous profit at the expense of the public, without its being possible materially to reduce them by means of competition. What has happened in the case of the New River Company sufficiently evinces the truth of what has now been stated. Had its dividends been limited to any thing like a reasonable profit, the water that is at present supplied by its means might have been furnished for a small part of what it actually costs. But in cases of this sort, priority of occupation, even without any other peculiar advantage, goes far to exclude all regular and wholesome competition. A company that has got pipes laid down in the streets may, if threatened by the competition of another company, lower its rates so as to make the latter withdraw from the field; and as soon as this is done, it may revert to its old, or even to higher charges. It is not, in fact, possible in cumbrous concerns of this sort, to have any thing like competition, in the ordinary sense of the term; and experience shows that whenever it is attempted, it only continues for a limited period, and is sure to be in the end effectually sup pressed. We are, therefore, clearly of opinion, that no company should ever be formed for the conveyance of water into a large city, without a maximum being set both to the rates and the dividends;

giving the company an option, in the event of the maximum rate yielding more than the maximum dividend, either to reduce the rate, or to apply the surplus to the purchase of the company's stock; so that ultimately the charge on account of the dividends may be got rid of.

We are glad to have to add, that we are supported in what is now stated by the Report of the Select Committee of the House of Commons on the supply of water for the metropolis, printed in 1821. It is there said "The public is at present without any protection even against a further indefinite extension of demand. In cases of dispute there is no tribunal but the Boards of the companies themselves, to which individuals can appeal; there are no regulations but such as the companies may have voluntarily imposed upon themselves, and may therefore at any time revoke, for the continuance of the supply in its present state, or for defining the cases in which it may be withdrawn from the householder. All these points, and some others of the same nature, indispensably require legislative regulation, where the subject matter is an article of the first necessity, and the supply has, from peculiar circumstances, got into such a course that it is not under the operation of those principles which govern supply and demand in other

cases.

"The principle of the acts under which these companies were instituted, was to encourage competition; and certainly in this, as in other cases, it is only from competition, or the expectation of competition, that a perfect security can be had for a good supply. But your committee are satisfied, that, from the peculiar nature of these undertakings, the principle of competition requires to be guarded by particular checks and limits in its application to them, in order to render it effectual, without the risk of destruction to the competing parties and thereby, ultimately, of a serious injury to the public." And the committee proceeds to remark"The submission of their accounts annually to parliament, for a few years, would necessarily throw light on this part of the question."

We think that it would be highly expedient to adopt the suggestions of the committee, by calling upon the companies to lay annually detailed statements of their affairs before parliament. They should be obliged in these statements to give an account of the rates charged by them, and to make a special report as to every case in which they have withdrawn water from a householder. It is to no purpose to repeat, in opposition to this proposal, the common-places about competition securing for the citizens a sufficient supply of water at the lowest prices, in the same way that the competition of bakers and butchers secures them supplies of beef and bread! The statements already made show that there is no analogy whatever in the circumstances under which these articles are supplied. If a man be dissatisfied with any particular butcher or baker, he may go to another, but it is not possible for him to change his water merchant, unless he also change the place of his residence. No water company will encroach upon the district assigned to another; and supposing an individual unlucky enough to quarrel with those who have the absolute monopoly of the supply of the district in which he resides, he must either migrate to another, or be without water, unless he can get a supply upon his own premises! Such being the actual state of things, it is quite ludicrous to talk about competition affording any real security against extortion and abuse. Even the publication of the proceedings of the companies would be a very inadequate check on their conduct; but such as it is, it is perhaps the only one that can now be resorted to; and as it would have considerable influence, it ought not, certainly, to be neglected.

3 Quality of the London Water. All the companies, with the exception of the New River and East London Companies, derive their supplies of water from the Thames; and in consequence of their taking it up within the limits to which the tide flows, it is necessarily, in the first instance, loaded with many impurities. But the reports that were formerly so very prevalent, with respect to the deleterious quality of the water taken from the river, have been shown to be very greatly exaggerated. The statement of Dr. Bostock, given in the Report of the commissioners, shows that by far the greater part of the impurities in the Thames water are mechanically suspended in, and not chemically combined with, it; and that they may be separated from it by filtration, or by merely allowing it to stand at rest. Most of the companies have recently made considerable efforts to improve their water, and though they have not done in this respect as much as they might and should have done, a considerable improvement has, on the whole, been effected: and notwithstanding all that has been said to the contrary, we have been assured, by those best qualified to form an opinion on such a subject, that, though not nearly so pure as a little pains would render it, there is not the slightest foundation for the notion that its impurities have been such as to affect, in any degree, the health of the inhabitants.

4. Water for Ships. Various improvements have been made in the art of preserving water on board ships. Of these, the principal are the charring the inside of the casks in which the water is kept, and the substitution of iron tanks for casks. The latter, being made of the required shape, may be conve niently stowed into any part of the ship. In men-of-war, the iron tanks serve as ballast; the water being brought up by a forcing pump. Water is found to preserve better in them than in any other sort of vessel. Drip-stones may be employed with much advantage in the purification of water. When water is taken on board from a river into which the tide flows, it should, of course, be raised at low ebb.

WAX (Ger. Wachs; Fr. Cire; It. and Sp. Cera; Rus. Wosk), a vegetable product. Several plants contain wax in such abundance, as to make it worth while to extract it from them. But all that is known in commerce consists of bees' wax. The honey is first pressed from the comb, and the wax is then melted into cakes. It has a slight odour of honey, is insipid, and of a bright yellow hue. It is brittle, yet soft, and somewhat unctuous to the touch. It is often adulterated with earth, pea meal, resin, &c. The presence of the former may be suspected when the cake is very brittle, or when its colour inclines more to gray than to yellow; and the presence of resin may be suspected when the fracture appears smooth and shining, instead of being granulated. Wax, when bleached or purified, is white, perfectly insipid, inodorous, and somewhat translucent; it is harder, less unctuous to the touch, heavier, and less fusible than yellow wax. It is sometimes adulterated with the white oxide of lead to increase its weight, with white tallow, and with potato starch. The first is detected by melting the wax in water, when the oxide falls to the bottom; the presence of tallow is indicated by the wax being of a dull opaque white, and wanting the transparency which distinguishes pure wax; and starch may be detected by applying sulphuric acid to the suspected wax, as the acid carbonises the starch, without acting on the wax. (Thomson's Chemistry, and Dr. A. T. Thomson's Dispensatory.)

Notwithstanding the large supply of wax produced at home, a considerable quantity is imported from abroad; and there can be no doubt that the imports would have been much greater, but for the magnitude of the duty, which formerly amounted to 108. a cwt. on wax brought from a British possession, and to 30s. a cwt. on that brought from a foreign country. In 1842, however, these duties were reduced to 18. and 2s. a cwt., which, there can be little doubt, will lead to a material increase of consumption. Of 8,462

cwts. of wax imported in 1840, 3,773 cwts. were brought from the western coast of Africa; 1,814 cwts. from Tripoli, Tunis, &c.; 1,435 from the East India Company's territories, &c.

WEIGHTS AND MEASURES. Weights are used to ascertain the gravity of bodies, a quality depending partly on their magnitude, and partly on their density. Measures are used to determine the magnitude of bodies, or the space which they

occupy.

(For an account of the weights and measures used in foreign countries, and their equivalents in English weights and measures, see the notices of the great sea-port towns dispersed throughout this work. Thus, for the Russian weights and measures, see PETERSBURG; for those of China, see CANTON; &c.)

Neither the magnitude nor the weight of any one body can be determined, unless by comparing it with some other body selected as a standard. It is impossible, indeed, to form any idea in respect of magnitude or weight, except in relation to some definite space or weight with which we are acquainted. We say that one article weighs 1 pound, another 2 pounds, a third 3, and so on; meaning not only that these weights are to each other as 1, 2, 3, &c., but also that the weight or specific gravity of the first is equal to the known and determinate weight denominated a pound, that the second is equal to 2 pounds, and so on.

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Standards of Weight and Measure. - Standards of lineal measure must have been fixed upon at the earliest period, and appear to have consisted principally of parts of the human body, as the cubit, or length of the arm from the elbow to the tip of the middle finger: the foot; the ulna, arm, or yard; the span; the digit, or finger; the fathom, or space from the extremity of one hand to that of the other, when they are both extended in opposite directions; the pace, &c. Large spaces were estimated by measures formed out of multiples of the smaller ones; and sometimes in day's journeys, or by the space which it was supposed an ordinary man might travel in a day, using a reasonable degree of diligence.

But lineal measures can only be used to determine the magnitude of solid bodies; the magnitude of bodies in a liquid or fluid state has to be determined by what are called measures of capacity. It is probable that, in the infancy of society, shells, or other hollow instruments afforded by nature, were used as standards. But the inaccuracy of the conclusions drawn from referring to them must soon have become obvious; and it early occurred, that to obtain an accurate measure of liquids nothing more was necessary than to constitute an artificial one, the dimensions, and consequently the capacity, of which should be determined by the lineal measures previously adopted.

The determination of the gravity or weight of different bodies supposes the invention of the balance. Nothing is known of the steps which led to its introduction; but it was used in the remotest antiquity. It seems probable that, at first, cubes of some common lineal measure, as a foot, or the fraction of a foot, formed of copper, iron, or some other metal, were used as standards of weight. When the standard was selected, if it was desired to ascertain the specific gravity or weight of any given article, all that was necessary was to put it into one of the scales of the balance, and as many cubes or parts of cubes on the other as might be necessary to counterpoise it.

Hence, in

Weights have, however, been frequently derived from grains of corn. this, and in some other European countries, the lowest denomination of weight is a grain ; and 32 of these grains are directed, by the ancient statute called Compositio Mensurarum to compose a penny weight, whereof 20 make an ounce, 12 ounces a pound, and so upwards.

In every country in which commercial transactions are extensively carried on, the importance of having weights and measures determined by some fixed standard becomes obvious to every one. But as the size of different parts of the human body differ in different individuals, it is necessary to select some durable article,-a metallic rod, for example, of the length of an ordinary cubit, foot, &c., and to make it a standard with which all the other cubits, feet, &c. used in mensuration shall correspond. These stan dards have always been preserved with the greatest care: at Rome, they were kept in the temple of Jupiter; and among the Jews, their custody was intrusted to the family of Aaron. (Paucton, Métrologie, p. 223.)

The principal standards used in the ancient world, were, the cubit of the Jews, from which their other measures of length, capacity, and weight were derived; and the foot of the Greeks and Romans.

In England, our ancient historians tell us that a new, or rather a revived, standard of lincal measure was introduced by Henry I., who ordered that the ulna, or ancient ell, which corresponds to the modern yard, should be made of the exact length of his own arm, and that the other measures of length should be raised upon it. This standard has been maintained, without any sensible variation. In 1742, the Royal Society had a yard made, from a very careful comparison of the standard ells or yards of the reigns of Henry VII. and Elizabeth kept at the Exchequer In 1758, an exact copy was

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