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DRO 



DRAW'BA.CK. In commerce, the remitting 

 or paying back of duties previously paid 

 on a commodity on its being exported. 



DRAW'-BORE PIN, a joiner's tool, of a 

 solid piece of steel tapered from the han- 

 dle, and used to enlarge the pin-holes 

 which are to secure a mortise. 



DRAW'-BRIDGE, Or LEAF-BRIDGE, a SOrt 



of bridge thrown across canals, &c., and 

 so constructed as to be capable of being 

 raised and let down at pleasure. They 

 are now nearly superseded by swing or 

 swivel bridges. 



DRAW'-LINK. The draw-link for rail- 

 way carriages is a contrivance for securing 

 the several carriages of a train together. 



DREDGE, a sort of drag for catching 

 oysters in deep water. 



DREDG'ER, called also a ballast lighter; 

 a sort of open barge employed in removing 

 sand, silt, or the like, from the beds of 

 rivers, harbours, docks, &c. The materials 

 are lifted by a sort of scooping apparatus, 

 and thrown into the barge moored beside 

 it, or to which it is often attached. Most 

 dredging machines are now worked by 

 means of steam-engines, the scoops being 

 attached together, and in the manner of 

 the piston-plates of a chain pump, so that 

 a perpetual action is kept up. 



DRESSING. 1. In flax-mills, the whole 

 process of preparing the material for the 



spinner. 2. In foundries, the cleaning 



of the castings after being taken from the 



moulds. 3. In the manige, the cleaning 



and trimming of a horse. 4. In hus- 

 bandry, manure laid on the surface. 

 6. In architecture, mouldings round doors, 



windows, and the like. 6. The term is 



applied to starch and other articles used 

 in preparing or stiffening silk, linen, or 

 other fabrics. 



DRIFT. 1. In navigation, the angle 

 which the line of a ship's motion makes 

 with the nearest meridian, when she 

 drives with her side to the wind and 

 waves, and is not governed by the helm ; 

 also the distance which she drives on that 

 line. The drift of a current is its angle 



and velocity. 2. In mining, &c., a square 



horizontal passage between the shifts or 

 turns, or between shaft and shaft: called 



also driftway and heading. 3. The term 



drift is likewise applied to arches to 

 express the impetus of the arch against 

 the piers. 



DRIFT-SAIL, a sail used under water, 

 veered out right a-head, to keep the 

 ship's head right upon the sea in a storm, 

 and to hinder her driving too fast in a 

 current. 



DRILL. 1. In mechanics, a small steel 

 instrument used for boring holes in hard 

 substances when punches cannot be con- 

 veniently used : holes are drilled in ivory, 

 iron, &c., and the process is called drilling. 

 2. In husbandry, wheu ground ia 



channelled by the plough by backing 

 every two furrows upon each o'ther, these 

 channels are called drills, and the ground 

 is said to be drilled. Potatoes are planted 

 in drills, but the term drilling is generally 

 applied to all methods of putting seeds 

 into the ground in equi-distant rows. 

 Hence an excellent machine of recent 

 invention, adapted for sowing crain in 

 drills or rows, is named the drill-plough, 

 or drilling -machine. 



DRIP. In architecture, that member of 

 a cornice which projects beyond the other 

 parts, with a form adapted to throw off 

 the water by small portions, or drop by 

 drop ; called also the Larmier. 



DRIP'PIXG EAVES, the terminating pro- 

 jections of inclined roofs of houses, to 

 which there are no gutters for carrying 

 away the water, which therefore falls 

 into the street. 



DRIV'INQ. In nautical language, said of 

 a ship when the anchor does not hold her 

 fast, but allows her to be driven away 

 by the tide or Wind. In music, driving 

 notes are those which connect the last 

 note of one bar with the first of the fol- 

 lowing bar, so as to make only one note 

 of both. 



DROITS OF ADMIRALTT, the perquisites 

 resulting chiefly from the seizure of the 

 property of an enemy at the commence- 

 ment of a war, and attached to the office 

 of lord-high-admiral. 



DROM'EDART, the Arabian camel (camelus 

 dromedarius) , distinguished from the Bac- 

 trian camel by having a single hunch on 

 the middle of its back. This name is from 

 fytu*;, running, in allusion to the swift- 

 ness of the animal. 



DRONE. 1. The male of the honey-bee, 

 smaller than the queen-bee, and larger 



than the neuters or working-bees. 2. 



The largest tube of the bagpipe, which 

 emits one continued deep note, as a bass 

 to the air or tune played on the smaller 

 pipes. 



DROP. 1. A small spherical portion of 

 any fluid. The spherical form is the re- 

 sult of corpuscular attraction. 2. A 



machine for lowering coals from the 

 staiths of railways into vessels below. 

 3. The part of a scaffold on which the 

 criminal stands to be executed, and which 

 is suddenly dropped after the cord is ad- 

 justed. 4. In architecture, a conical or- 

 nament, hanging drop-like in the cornice 

 of the Doric order, below the mntules, 

 and on the architrave under the triglyphs : 

 six drops under each. 5. Some liquid 



edicines are popularly called drops, be- 

 cause the dose is regulated by pouring 

 a certain number of drops from the lip of 



the phial which contains it. 6. To drop 



astern is, in seamen's language, to slacken 

 the speed of the vessel and let another 

 pass her. 



