S L U 



of lime-water on them, and the boy removes the haulmy 

 material to feme intermediate place, in order that the fame 

 praftice may be repeated. By perfcvering in this method 

 for a little while, the whole of the flugs may be deltroyed, 

 as the lead drop of the water fpeedily kills them. This 

 praftice, it is fuppofed, will be found highly beneficial in 

 the flower-garden, as by watering the edgings of box, 

 thrift, or other kinds, the (lugs will be killed with certainty, 

 even when the weather is moift. 



The application is confidered Ample, the effeft certain, 

 and the expence trifling, whether in the garden or the field ; 

 a few pots only being required, in the latter cafe, to the 

 acre, which can be made with a very fmall quantity of lime. 

 And the labour is not of any material confequence, fo that 

 the whole charge will not, it is imagined, exceed five (hil- 

 lings the acre. 



SLUICE, a frame of timber, Hone, or other matter, 

 fervingto retain and raife the water uf a river, &c. and, on 

 occafion, to let it pafs. 



Such is the iluice of a mill, which Hops and coUedls the 

 water of a rivulet, &c. to let it fall, at length, in the 

 greater plenty, upon the mill-wheel : fuch alio are thofe 

 ufed as vents or drains to difcharge water off land. And 

 fuch are the fluices of Flanders, &c. which ferve to prevent 

 the waters of the fea overflowing the lower lands, except 

 when there is occafion to drown them. 



Sometimes there is a kind of canal inclofed between two 

 gates or fluices, in artificial navigations, to fave the water, 

 and render the paiiage of boats equally eafy and fafe, up- 

 wards and downwards : as in the fluices of Briare in France, 

 which are a kind of maflive walls built parallel to each other, 

 at the diftance of twenty or twenty-four feet, clofed with 

 Itrong gates at each end, between which is a kind of canal, 

 or chamber, confiderably longer than broad ; in which a 

 vefTel being inclofed, the water is let out at the firft gate, 

 by which the vefTel is raifed fifteen or fixteen feet, and pafTed 

 out of this canal into another much higher. By fuch means 

 a boat is conveyed out of the Loire into the Seine, though 

 the ground between them rife above one hundred and fifty 

 feet higher than either of thofe rivers. 



The (luice of a canal has generally a fliding-board or 

 door, but fometimes foldmg or double doors moving on 

 hinges, ufed to flop or let go water at pleafure. 



Sluice-gates fometimes fignify the lower gates of a lock, 

 from the paddles or fluices that are ufually fixed in them. 



Sluices are made different ways, according to the ufe for 

 which they are intended : when they ferve for navigation, 

 they are (hut with two gates, prefenting an angle towards 

 the ftream ; when tiiey are made near the fea, two pair of 

 gates are made, the one to keep the water out, and the 

 ither in, as occafion requires. In tliis cafe, the gates to- 

 wards the fea prefent an angle that way, and the others the 

 contrary way ; and tlie fpace inclofed by thofe gates is 

 called the chamber. When fluices are made in the ditches 

 of a fortrefs, to keep up the water in fome parts, inftead of 

 gates, (hutters are made fo as to Aide up and down in 

 grooves ; and when they are made to raife an inundation, 

 they are then (hut by means of fquare timbers let down in 

 culhfes, fo as to lie clofe ar.d firm. 



The word (luice is formed of the French tfclufe, which 

 Menage derives from the Latin exclufa, found in the Sahc 

 law in the fame fenfe. But this is to be redraincd to the 

 fluices of mills, &c.; for as to thofe fcrving to raife veffels, 

 they were wholly unknown to the ancients. 



In Rural Economy, a fluice is very convenient in many 

 cafes. It ought to be itrongly framed in deep water», par- 

 ticularly where a great height is nccefl^ary, fo at to (land 



Vol.. xxxin. 



S L U 



firm and immoveable againft the rufliing of heavy bodies ; 

 for a fmall flraiii makes it leaky, and a fmall thing will oc- 

 cafion this, unlefs fufficiently guarded by proper abutments. 

 Larch, green elm, or willow, are the boll forts of timber 

 to be always in water ; but heart of oak, for the purpofe of 

 (landing above it, in wet and dry. The importance of 

 fluices is extremely evident on many occafions, as when a 

 prefTing necelTity demands the difcharge of a great quantity 

 of water, either the expenfive mode of engines mu(t be re- 

 curred to, the bank cut, or a fluice drawn. If the bank be 

 cut, the paflage is interrupted, and there remain the trouble 

 and charge of removing the earth, and re-embanking ; but 

 a fluice vents the fuperfluous water, without the lead incon- 

 venience or charge. Their utility in many cafes of drainage 

 and embankment, as well as irrigation, is alfo very great 

 and indifpenfable. 



SLUIDENAIA Kopi, in Geography, a town of Ruffia, 

 in the government of Irkutfk. N. lat. 52^ 42'. E. long. 



«13°44'- 



SLUIN, a town and fortrefs of Croatia, on the Ko- 

 rana ; 34 miles S. of Carliladt. N. lat. 45° 15'. E. loner. 

 16° 8'. 



SLUIS. See Sluys. 



SLUM, a town of Pruflia, in Fomerelia ; 8 miles S. of 

 Marienburg. 



SLUPCA, a town of the duchy of Warfaw ; 15 miles 

 S.S.E. of Gnefna. 



SLUPECZ, a town of Poland, in the palatinate of San. 

 domirz ; 16 miles N. of Sandomirz. 



SLUPICK, a town of Holland; 3 miles N.E. of 

 Goude. 



SLUR, in Muftc, a mark like the arc of a circle, drawn 

 from one note to another, comprehending two or more notes 

 in the fame or different degrees. If the notes are in different 

 degrees, it fignifies that they are all to be fuiig to one fyl- 

 lable ; for wind inttruments, that they are to be made in one 

 continued breath ; and for ftringed inllruments, that are 

 ftruck with a bow, as a vioHn, &c. that they are made with 

 one (Iroke. If the notes are in the fame degree, it fignifies 

 that it is all one note, to be made as long as the whole notei 

 fo connefted ; and this happens moil frequently betwixt the 

 laft note of one line, and the firft of the next ; which is par- 

 ticularly called fyncopation. 



SLUSE, Rene Frakxis, in Biography, an eminent 

 mathematician, was born of a noble family at Vife, a fmall 

 town in the bifhopric of Liege, in 1622. He was educated 

 for the church, and was canon of St. Lambert in that city, 

 was appointed abbot of Amaz, and grand chancellor and 

 counfellor to the bi(hop and prince ; all which offices he re- 

 tained with high reputation till his deatli in 1 685, in the 

 63d year of his age. He was a man of great learning, not 

 only in the particular line of his profefiion, but in jurif- 

 prudence, and even in medicine. He was eminently flcilled 

 in the Greek, Hebrew, Arabic, and other Oriental lan- 

 guages; and on that account was employed by the pope, 

 during his refidence at Rome, and after his return to Liege, 

 in tranflating Greek, Armenian, and other writings. He 

 was an excellent mathematician, and furnifhed fome papers 

 for tlie Tranfaftions of the Royal Society, of which lie wa» 

 eletted a member. As an author his principal work is 

 entitled " Mefolabiura ct Problemata Solida," 410. In 

 this work M. Slufe rendered great fervicc to the mathe- 

 matical fciences, by fimplifying fome parts of the analyfis 

 of Des Cartes, wliicli had engaged the attention of many 

 eminent geometricians. He is author of a method, by 

 which any folid equation being propofed, it may be con- 

 ilructed in an infinite variety of ways, by means of the 

 X circle 



