Well, a cavity, dug in the ground, with a view to collect the water from the contiguous strata: it is generally of a circular form, and lined with brick or stone.

The following method of procuring water, in almost every situation, has lately been suggested by M. Cadet de Vaux. - He directs the soil to be perforated with a borer: a wooden pipe is then to be placed in the hole, and driven down with a mallet; after which the boring must be continued, in order that a pipe may be driven to a greater depth. As the auger becomes rilled with earth, it ought to be drawn up, and emptied ; so that, by the addition of fresh portions of the pipe, the boring is carried to a considerable extent under ground, and water is in most instances obtained. Wells, thus formed, are preferable to those dug in the usual manner; being less expensive, while the supply of water is more copious and certain. Indeed, it often happens, in the common practice of digging for wells, that the workmen are obliged to fix the windlass, in order to prevent the springs from gaining on them ; by this practice, a small quantity of water is the necessary consequence, and it is apt to fail during dry summers. Hence, M. De Vaux advises the earth to be perforated ; a cylindrical pipe to be inserted ; and to search for that element at a greater depth, in the manner before suggested. - This method is stated to be very useful in camps, or fortresses ; and, in case the fluid near the surface be neither sufficiently sweet, nor of a good quality, he supposes his expedient to be the best that can be -adopted, for obtaining water of a purer kind, at a greater depth. - Farther, when wells have, in large towns, been rendered unfit or useless, in consequence of the ground having been tainted by privies, church-yards, etc. he very properly recommends such reservoirs to be emptied, and the bottom perforated in a similar manner, so as to reach the lower sheet of water; which, being thus contained within the cylindrical pipe, will rise in a pure state into the body of the pump fixed for this purpose. - For an account of the relative salubrity of well-water, the reader will revert to p. 299 of this volume.

If wells be disused for a considerable time, the water generally becomes foul; the ambient amos-phere is corrupted ; and thus arise mephitic vapours which have often proved fatal to animal life. Hence it has been suggested, to employ a pair of smith's bellows, and a tube, according to the manner directed in the article Vapour; but, as these are too bulky to be conveniently carried to any distance, and frequently cannot be procured on the spur of the occasion, Mr. Salmon, of Canterbury, has invented the following apparatus, for dispersing noxious air from wells. - We are induced to recommend this ingenious contrivance to the notice of our country readers ; as it is not very expensive, and will prevent many fatal accidents.

Well 28

A, B, C, D, E, F, represent six lengths of a metal pipe, each being eight feet long, and two inches in diameter: all these joints (excepting that marked F, which is made of copper, for the better support of heat), are manufactured of tin-plate.

G, is a tin-kettle, or vessel (containing about two gallons), that is fastened to the upper pipe F, and the sides of which are perforated for the admission of air, and consequently for supporting the tire. This vessel must be fixed in such a direction as to have at least five feet of the pipe above its top.

H, is a conical cap, deigned to confine the heat to the sides of the tub

When the machine is applied to the well, a wire must be passed through the holes a, a, in the upper part of the length A, and in the lower extremity of B; the joint ought to be luted with oil-putty, to render it air-tight; the upper end of each joint should be covered with wire, to prevent it from bending; and to form a receptacle for the putty. The other lengths are then to be managed in a similar manner, till that marked A, reach nearly to the surface of the water. The vessel G, ought to be placed on two pieces of timber laid across the well.

The apparatus, being now fixed, will speedily be filled with the foul air extracted from the well: and, as the gravity of the external and internal air is equal, they become stationary. Burning coal or wood must next be put into the kettle G; by which the copper tube, F, is heated ; and, the internal air being rarefied, while the external air presses downward; the noxious vapours are gradually dissipated; and a purer element is introduced into the well, whence it issues during the continuance of the fire.

Mr. Salmon remarks (in his communication, inserted in the 9th volume of the "Repertory of Arts, " etc.), that however small the current of air passing out of the funnel or pipe, F, may appear, the ef-fect is considerable ; because such discharge consists wholly of noxious, vapour ; vapour; whereas ten gallons of fresh air are probably blown into the well, by means of the common bellows and leather pipe, before two gallons of mephitic vapour are removed. Such purification will be still more effectual, if the fire-kettle, G, be placed at D, when the internal air becomes more rarefied : it ought, however, to be remarked, that this advantage is over-balanced by the atmosphere being rendered unfit for respiration, in consequence of the suffocating properties of the charcoal.

In the year 1794, the Society for the Encouragement of Arts, etc. conferred their silver medal on George Butler, Esq. for his invention of a Bucket for drawing water from deep wells. It consists of a common barrel, the head of which is taken out: across the top are fixed two thin bars of iron, having in the centre a small piece of the same metal, which Mr. Butler terms a standard. This is furnished with a collar, which has four moveable arms; and above it, there are a mortise containing a small brass pulley, and a loop to which the well-rope is secured : farther, a cord is tied to one extremity of the collar, which, after passing over the pulley, communicates with a valve applied to the lower head of the vessel. - The bucket, thus constructed, when let down into the well by a rope, is filled through such valve; and, on being drawn up, the iron cross above mentioned is pressed against two parallel bars, so that the valve is opened, and the water discharged into a trough, or vessel, prepared for its reception. - The principal advantage, arising from this contrivance is, that the bucket is not only filled expeditiously, but it is also brought up steadily, so that no water is spilt ; and, if any of it ac-cidentally drop, it falls directly from the valve into the well, without wetting the descending rope; a circumstance of considerable importance ; for, by such continual moisture (which is necessarily occasioned by the common buckets), it speedily decays, while the vessels are seldom drawn up completely filled. - A more minute account of Mr. B.'s invention will be found in the 12th vol. of the " Transactions" of the Society above men-tioned, where it is illustrated with an engraving.

A patent was granted, in August, 17.98, to Mr. John AshlEY, of Islington, for a method of raising water from wells of any depth. upon a very simple and permanent construction ; of which, however, we have not met with a specification.