been about 5,000 or 6,000 years old. An astringent resin, obtained from the Eucalyptus resinifera of Australia, sometimes gets the name of "dragon's blood" in that country. Consult The Geographic Magazine (April 1918).

DRAGON'S MOUTHS, a strait on the coast of Venezuela, running between the Island of Trinidad and the Paria Peninsula, and leading into the Gulf of Paria.

DRAGOON, a mounted soldier, first introduced into the French army about 1585, and trained originally to fight chiefly on horseback, but, if necessary, on foot also, and mounted, armed, and exercised accordingly. Experience proving that they did not answer the end designed, they were hardly ever used in infantry service latterly, and now form a useful kind of cavalry. The term dragoon probably comes from dragon, a short species of carbine carried in 1554, on the muzzle of which, from the old fable that the dragon spouts fire, the head of the monster was wrought. The first dragoon regiment raised in Great Britain was the first Royal, the oldest cavalry of the line regiment in the army, raised in 1661 to garrison Tangier, Morocco. There are at present in the British army three regiments of dragoons, and seven of dragoon guards, all being mounted and accoutred more after the fashion of heavy (or medium) cavalry than the hussar regiments. The three dragoon regiments are the 1st (Royal) Dragoons, the 2d Dragoons (Royal Scots Greys, organized 1683), and the 6th (Inniskilling) Dragoons. Both dragoons and dragoon guards are armed with carbine and sabre, and have metal helmets (except the Scots Greys). Consult White, C., 'Our Regiments' (London 1915).

DRAGOON BIRD. See UMBRELLA-BIRD. DRAGOUMIS, Stephan, Greek statesman: b. Athens, 1842. He was educated in Athens and Paris and in 1879 became a member of the Lower House of Parliament at Athens. He was Foreign Minister in 1886-90 and again in 1892. In February 1910 he became Premier, but his cabinet was overthrown the following October. During his term of Premier he calmed the Military League and succeeded in having convoked a National Assembly to deal with important public issues. He was opposed to the movement to have Greece openly allied with the Thessalians in their difficulties with Turkey. In 1912 Dragoumis was sent to Crete to take over the government of that island.

DRAGUIGNAN, drä-gēn-yän, France, town, capital of the department of Var; 41 miles northeast of Toulon. It was founded in the 5th century. It contains a prefecture, courthouse, hospital, a fine museum, zoological gardens and a public library. The principal manufactures are woolens, leather, hosiery, silks, soap, lumber, brandy, oil and earthenware. Pop. about 10,000.

DRÄHMS, dräms, August, American Congregational clergyman: b. Yarmen, Pomerania, 4 March 1849. His parents emigrated to the United States in 1856, and his early education was received in the public schools of Geneva, Ill. In 1863, he enlisted in the 17th Illinois cavalry and served to the end of the war. afterward studied at Wheaton College, and the Garrett Biblical Institute at Evanston, Illinois,

He

and entered the Congregational ministry at Oakland, California, 1878. He served as pastor in Martinez, Cal., and was for 18 years resident chaplain of San Quentin prison. He is pastor of the First Congregational Church of Hilo, Hawaii. He has written (The Criminal: a scientific study; with an introduction by C. Lombroso (New York 1900).

DRAIN-PIPE, a pipe used in draining, commonly of tile, but sometimes of wood or metal. See TILES.

DRAINAGE, in agriculture, a method of improving the soil by withdrawing the water from it. Though practised by the Romans, and though the value of drainage was expounded by Walter Blithe in the middle of the 17th century, it was not till after the middle of the 18th century that the importance of drainage began to be understood in Great Britain. The public attention is said to have been then excited by the practice of Elkington, a farmer of Warwickshire, England. But it was James Smith of Deanston, Perthshire, Scotland, who about 1823 led the way in modern practice of thorough draining.

The successful practice of draining in a great measure depends on a proper knowledge of the various strata of which the earth is composed, as well as of their relative degrees of porosity or capability of admitting or rejecting the passage of water through them and likewise of the modes in which water is formed and conducted from the high or hilly situations to the low or level grounds. In whatever way the hills or elevations that present themselves on the surface of the globe were originally formed, it has been clearly shown, by sinking large pits and digging into them, that they are mostly composed of materials lying in a stratified order, and in oblique or slanting directions downwards. Some of these strata, from their nature and properties, are capable of admitting water to percolate or pass through them, while others do not allow it any passage, but force it to run or filtrate along their surfaces without penetrating them in any degree, and in that way conduct it to the more level grounds below. There it becomes obstructed or dammed up by meeting with impervious materials of some kind or other, by which it is readly forced up into 'the superincumbent layers, where they happen to be open and porous, soon rendering them too wet for the purposes of agriculture; but where they are of a more tenacious and impenetrable quality, they only become gradually softened by the stagnant water below them; by which the surface of the ground is, however, rendered equally moist and swampy, though somewhat more slowly than in the former case.

Where grounds are in a great measure flat, and without degrees of elevation sufficient to permit those over-proportions of moisture that may have come upon them from the higher and more elevated grounds to pass readily away and be carried off, and where the soils of the land are composed or constituted of such materials as are liable to admit and retain the excesses of moisture, they are exposed to much injury and inconvenience from the retention and stagnation of water. Such lands consequently require artificial means to drain and render them capable of affording good crops, whether of grain or grass.

Wetness of land, so far as it respects agriculture and is an object of draining, may generally depend on the two following causes:first, on the water which is formed and collected on or in the hills or higher grounds, filtrating and sliding down among some of the different beds of porous materials that lie immediately upon the impervious strata, forming springs below and flowing over the surface, or stagnating underneath it; and, secondly, on rain or other water becoming stagnant on the surface, from the retentive nature of the soil or surface materials, and the particular nature of the situation of the ground. The particular wetness which shows itself in different situations, in the forms of bogs, swamps and morasses, for the most part proceeds from the first of these causes; but that superficial wetness which takes place in the stiff, tenacious, clayey soils, with little inclination of surface, generally originates from the latter.

Drains. The drains used in land drainage may be divided into two classes - open and covered drains. These again may each be subdivided into drains intended merely to act as water-courses and drains which, in addition to acting as water-courses, are also intended to carry off the surplus water from the land through which they pass.

Open Drains.-The rudest forms of open drains are the deep furrows, lying between narrow highbacked ridges, which are still to be found in some parts of the country with their accompanying water-furrows ("gaw" furrows. or "grips") for discharging their streams. These are only meant to carry off the surplus water after the soil is completely saturated. In doing so, however, they carry along with it all the best portions of the soil and of the manure which may have been spread upon its surface.

Open Drains as Water-courses.-The ordinary ditch (dike) is the common form of this kind of drain, which, though necessary to a certain extent, ought, nevertheless, to be sparingly seen where a perfect system of drainage has been effected. They are constant sources of annoyance and expense from their sides crumbling in, the numerous weeds which they harbor and the thorough scouring which they require every year. Open ditches occupy an important place in the early stages of draining bogs; but after the bog has become consolidated the greater portion of them may be dispensed with and their places supplied by large covered drains.

Open Drains for Collecting Water from the Land through which they pass (Sheepdrains). These are employed in drying the surface of mountain pastures, where a more expensive and perfect system of drainage would not yield an adequate return for the outlay. They consist of trenches of 12 or 16 inches in depth and 18 in width, placed so as to intercept all the water which may flow from portions of land above them. They are opened at intervals in a direction nearly transverse to the line of the greatest slope and should have sufficient inclination to keep the water flowing toward the mains or leaders. These latter should be cut in the hollows or in such other places as will permit the small drains or feeders to empty themselves most readly into them, and be made to discharge into the nearest water-courses.

Covered Drains.- We now come to the consideration of the more important description of drainage the removal of water by means of covered drains. The simplest of all the forms of these are what are called mole-drains, and they are formed by means of a machine called the mole-plough. This machine consists of a wrought-iron frame on four wheels, the front pair being connected with worm and chain steerage. A coulter with pointed sock, capable of being raised and lowered to regulate the depth of the drain, is attached to the frame. The "mole," an oval piece of iron three and one-half inches in diameter, follows the sock, to which it is attached by a short chain. The track which the mole leaves in the ground is the water channel. This machine is dragged through the soft clay, which is the only kind of land on which it can be used with propriety, by means of a windlass on the fore end of the frame and a double length of wire-rope wound by an engine on the higher part of the field. A team of horses returns it to the lower side, out of work.

Wedge-drain. The wedge-drain, like the mole-drain, is merely a channel formed in the subsoil, and, like it, can only be used in pasture lands. In forming wedge-drains, the first spit, with the turf attached, is laid on one side, and the earth removed from the remainder of the trench is laid on the other. The last spade that is used is very narrow, and tapers rapidly, so as to form a narrow wedge-shaped cavity for the bottom of the trench. The turf first removed is then cut into a wedge, so much larger than the size of the lower part of the drain that, when rammed into it with the grassy side undermost, it leaves a vacant space somewhat triangular in shape in the bottom of six or eight inches in depth.

Permanent drains are of two kinds, stone and tile drains.

Stone-drains.-These are either formed on the plan of open culverts of various forms, or of small stones in sufficient quantity to permit a free and speedy filtration of the water through them. As a specimen of the former of these, we may instance the box-drain, which is formed of flat stones neatly arranged in the bottom of the trench. The largest and flattest stones are used in laying the bottom and for covers; the smaller ones are placed on the sides, the whole forming an open tube. The second description of stone-drains, generally known as the brokenstone or rubble drain, is not so thoroughly effective as the first.

Tile-drains or Sewer-pipe drains. Of all the materials which have yet been brought forward for forming the conduits of drains, none are so well fitted for the purpose as tiles or pipes of burnt clay. Draining tiles, especially those in the form of pipes, possess all the qualities which are required in the formation of drains, affording a free ingress to water, while they effectually exclude vermin, earth, and other injurious substances. When first introduced they were of clumsy construction, and being handmade, sold at a high price. They are now made of ordinary clay and vitrified clay to resist the moisture, and also of concrete, The vitrified are most durable but the concrete or cement pipe is largely used; the best form appears to be the cylinder. Good pipes are straight, smooth and free from flaws, and when struck should

ring clearly. Durability is shown if the wet pipe will dry quickly before a hot fire without crumbling. Where a sudden descent occurs in the course of a drain, or where there is a running sand or a boggy place, pipes of one size should either be entirely sheathed in larger ones, or they should be furnished with collars. These collars are merely short sections of pipes of such a size as to fit upon smaller ones, by which means the smaller ones may be so joined end to end as to prevent them from slipping down past each other.

The drawing off of the pent-up waters which are the sources of springs is a department of draining which requires a considerable knowledge of the different varieties of strata.

In the laying out of drains, the first point to be determined is the place of outfall, which should always afford a free and clear outlet to the drains, and must necessarily be at the lowest point of the land to be drained. This should be ascertained by a leveling instrument; and where a large extent of work is to be done, a competent surveyor should always be employed. A simple form of level for this purpose is a length of ordinary garden hose, with a glass tube in each end. When the hose is filled with water, the height in the two end tubes will be equal. Two persons with such a level can easily mark desired heights on a row of stakes, and so get any desired inclination. The outfalls should be as few as possible, and each one should be carefully set in brickwork and covered by a grid hinged at the top to prevent the ingress of rats and moles, but capable of giving way to a sudden rush of water from drains above. The next point to be determined is the water level or water table. This may be ⚫ascertained by digging test holes in different parts of the field and noticing the height to which the water rises in them. In an undulating field the height will vary in different places, but the knowledge gained by means of the test holes of the nature of the soil and subsoil will indicate the depth of draining required. In general it will be found that in clay land the drains should be shallow and close together, and in sandy or light land deeper and wider apart; the looser nature of the lighter soil permitting the rapid percolation of water, and allowing the drains to draw from a wider area. Drains in arable land must be beyond the influence of agricultural implements; not only out of the reach of plough or cultivator, but too deep to be displaced by their passing weight. Less than two feet six inches from the surface is unsafe, except in very stiff clay pasture land which is never disturbed. The depths usually adopted in practice for the various classes of soils are as follows:

As to the distance apart, experience has established a rule that in clay soils a drain will "draw" an area of from 5 to 6 times its depth, on medium soils 7 to 9 times, and on light soils 8 to 10 times its depth. Thus 3-foot drains in the first case might be 15 feet apart, in the second 24 feet, and in the third 40 feet apart. Submains may be necessary in an undulating field and in all cases they are desirable where the minor drains would other

wise be more than 10 chains in length. The rate of fall of any drain must not be less than 1 in 200. All drains should be kept as far as possible from the roots of trees, and curves are to be avoided, except at the junction of minor with main drains or submains, when the junction must form an acute angle, the smaller drain curving toward the larger drain and entering it from above. Two minor drains must not enter a large drain opposite to each other, or the stoppage thus caused will result in the deposition of silt and consequent chokage of the drain.

Drains are cut from the lowest point upward and the pipes laid in each section day by day. To ascertain if the pipe bed is being laid perfectly true, three leveling staves or "boning" rods are used. Each consists of a staff and crosshead, and by placing them at various points in the drain and sighting over the crossheads, uniformity of the bed is determined. The surface soil in cutting the drains ought to be laid on one side of the trench and the subsoil upon the other side, and each should be returned carefully to its original position. The size of the pipes to be used is dependent upon a number of factors, such as character of soil and subsoil, gradient, rainfall and length of drains; but in practice it is found most profitable to use 22-inch to 3-inch pipes for minor drains, and 6-inch, 8-inch or 10-inch for mains and submains. The number of pipes required per acre is found by dividing the area of an acre in square feet by the distance between the drains in feet, provided the pipes are one foot in length. The following table will be of value in this particular:

The tools used in the formation of drains are few in number, and of a very simple description. They consist of a set of spades generally three of different sizes-gradually diminishing in width to suit the different parts of drains. For taking out the last narrow spit, to form the seat for the draining pipe, long, narrow, triangularly shaped spades, called bottoming tools, are used. There are also scoops of various widths, furnished with long handles, and rounded or flattened in the soles according as they are required to finish the bottom of the drain for the reception of stones, a horse-shoe tile and sole, or a draining pipe. For the purpose of laying pipes in minor and deep drains an instrument called a pipe-layer, consisting of a short rod attached at a right angle to a long handle, which enables the workman to lay the pipes without going into the drain or reaching the bottom with his hand, is employed. Where the subsoil is strong or indurated, a hand-pick or a foot-pick is required to loosen it before it can be shoveled out.

Benefits of Drainage.-The following are among the benefits arising from thorough drainage:

1. Removal of superfluous water. Not only is the standing water at the surface carried off, but the water-table is lowered, increasing the