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ever, from an exact measurement made in 1723, by Mr. Henry Mill, the engineer* and surveyor of the New River Company, its extent was ascertained to be thirty-eight miles, three quarters, and sixteen poles. The number of bridges erected over it amount to more than 160; many of them being constructed with bricks, but others are At different places, beformed either of iron or wood. neath its channel, are also nearly sixty culverts, for the currents of different brooks, rivulets, and the passage of land waters after rains. The fall of the New River averages about three inches in a mile; and both its width and depth vary, the former averaging generally eighteen feet, the latter seldom exceeding five. By the original Act for its formation, persons were compelled to sell a quantity of land adequate to the making of it ten feet wide; but in most cases the agreement was made with

* Mr. Henry Mill, when a very young man, at the early part of the last century, became principal engineer to the New River Company, and continued in their service till his death. Endued with a strong mind, which had the advantage of being disciplined by a liberal education, and uniting a taste for the science of hydraulics with great mechanical ingenuity, he therefore possessed, in a high degree, the essential qualifications for properly discharging the duties of his profession. During the long period of his superintending the operations for supplying London with water, his superior knowledge and skill enabled him to devise and introduce various improvements, alike conducive to the public Assiduously convenience and the interests of the company. anxious for the due performance of whatever functions attached to his occupations, the consistent and conscientious tenour of his conduct, invariably secured him the approbation and esteem of his His disposition was amiable and employers and associates. cheerful; his manners mild and courteous; and his vigorous faculties retained their activity, till old age terminated his existence at nearly ninety. He died on the 26th of December, 1770; when he was succeeded in his office by Robert Mylne, Esq., who, some time previous, had been his co-adjutor.-Vide, Gent. Mag. 1779.

the owners for a greater portion, so as to obviate any contingent inconveniences; and wherever its course passed through land belonging to the Crown, it was granted without any limitation.

The springs which originally supplied this aqueduct with water, have their site at the villages of Chadwell and Amwell, in Hertfordshire; and when the plan for conveying it to London was first contemplated, its projector probably supposed that they would afford, at all times, abundance for the various wants and other purposes of the inhabitants.

Though no idea was then entertained of any deficiency of water being experienced in the New River, either from the draughts of summer, or any other causes, yet subsequently, even at an early period, such cases actually occurred, and therefore the circumstances suggested the necessity of deriving an additional supply from another source. This exigency impelled the company to obtain a considerable quantity from the river Lea, inasmuch as it flows near to the New River, in a very copious stream. For some years this practice encountered no interruption, but eventually it became a subject of complaint and litigation, which an Act of Parliament terminated about the year 1738. The conditions imposed upon the company were the payment of a sum of money, to be employed in improving the navigation of the Lea; and also a regular continued annuity for the same purpose; so that, on the due fulfilment of these stipulations, they were allowed to take the quantity required for their object. However, it was stipulated that the stream for affording the supply should be confined to certain dimensions, which were regulated by a balance engine and gauge, constructed near to the town of Hertford.

Though wood was the material originally used in the

construction of the balance engine, yet the Act of Parlia ment allowed it to be afterwards continued either with wood, bricks, or stone, provided it always retained the same relative dimensions. The length of its channel was limited to fourteen feet, its width to six feet, and depth to two feet; and that no greater quantity of water might be taken than the Act authorized, the New River company were restrained from having any pen at the guage. For ensuring the strict observance of these stipulations, it was also enjoined that a dam should be constructed and maintained, so that the stream supplying the New River could not exceed the height specified, as the utmost limit allowed for taking water. The guage at present in use is formed with marble; and in 1770, the whole structure, with its appendages, was covered with a building, under the direction of Mr. Robert Mylne, the architect, then engineer to the New River company, to whom is confided the appointment of the person having the care of it.

The company are deemed proprietors of all the water obtained from the different sources, and the Acts of Parliament invest them with authority to prohibit all persons from throwing into their aqueduct, any kind of offensive matter, stones, earth, ordure, dead animals, or animal substances. The washing of wool, hemp, flax, or any unwholesome or improper substances in it is also forbidden; nor can the water be either taken, or interrupted, without their consent; and for any damages done to their works, or dependencies, they can compel the individuals either to restore them to their original condition, or pay an equivalent compensation.

When the several reservoirs at the New River Head, Clerkenwell, were completely filled, being at an elevation of eighty-four feet and a half above the level of high water in the Thames, their capacity was adequate to the

supply of the cisterns in the basement-stories of the houses, through the greater part of the company's whole district, prior to the year 1810. About that period, however, some important domestic conveniences were introduced, which, by requiring a considerable supply to the highest stories, it occasioned the frequent employment of steam engines, to force water to a height sufficient for such purposes. The additional expense of these operations, led to a small increase of the charge for supplying it to the tenants; but among the striking advantages derived from using the steam engines, was that of their affording the means to convey it sixty feet above the level of the highest reservoir, or about 144 feet above the level of the Thames. Besides, this great mechanical power not only ensured a plentiful and regular supply at any altitude; but, at the same time, a larger quantity was allowed, and therefore the tenants materially augmented the dimensions of their cisterns, so that benefits were afforded fully equivalent to the greater cost.

The circumstances which occasioned the use of the steam engine to impel the water to a great elevation, likewise led to the general introduction of iron pipes, and thus the supplying of the high and low services were rendered equally efficient. At present, all the upper stories of a house are supplied, if required; but formerly it was the practice to supply water only to cisterns in the basement-story, and hence, arose the distinction between high and low service. Previous to the adoption of this plan, in 1810, the complaints of a deficiency were numerous and frequent, particularly from houses situate on high ground; but subsequent to that period, such instances have seldom occurred. Indeed, at the present time, the New River company generally convey the most ample quantity to any point over the whole of their dis