i 



BOW 



wlilch are occupied by the peafantry. Yet here is a fmall 

 {how of a market on Thurlday, and it has two annual fairs. 

 A few blaciifniiths, carpenters, and flioe-makers, are the 

 principal tradcfnien of the place. It is 188 miles W. of 

 London ; the parifh contai[is 677 inhabitants. 



Bow, an idand in Longli Erne, county of Fermanagh, 

 Ireland, on the northern part of the lake, and one of the 

 largeft in it, beinj^ three miles long, and one and a half 

 broad. It is well-wooded, and contributes much to the 

 beauty of the lake. It is about 15 miles from Enni- 

 Hdllen. 



Bov.', an ifland in the South Pacific Ocean, about 10 

 leagues in circumference. S.lat. iS° 23'. W. long. 141''. 

 Bow, a towndiip of America, in Rockingham county, 

 New Hampdiire, feated on the weft bank of Merrimack 

 river, fouth of Concord, and ^53 miles from Portfmouth ; 

 containing 568 inhabitants. 



Bow, in Mujic, denotes a machine that fervcs to play, or 

 give the foimd to, viols, violins, and other inllruments 

 of that kind, by drawing it gently over the ftrings thereof. 



The bow confills of three parts ; the firll is the ftick, or 

 wood, to which the hair is failened ; the fecond is compofed 

 of about eighty or an hundrcfd liorfe-liairs, or filaments of 

 fi!k ; the third is the nut, a fort of haU'Avheel, which ferves 

 to keep the hairs in the due degree of tenfion. 



The ancients do not appear to luive been acriuainted with 

 bows of hair: in lieu of tlicfe they ilruek their inllruments 

 with a pleitrum ; over which our bows have great advantage, 

 for giving long and (hort fou::ds, and other modificaiiuns, 

 which a pleftrum cannot produce. 



Bow, mTraile and Man ii/j inures, denotes a flexible inftru- 

 inent confilling of a piece of Heel or iron, to the two ends of 

 which is failened a cat-gut, ufed by fmiths, watch-makers, 

 and other artificers, for the piercing and turning of divers 

 forts of works. 



This is more peculiarly called a drill-bow. 

 It is fometiraes a!fo made of wood, whalebone, and the 

 like. 



Operators in Mofaic have a fort of bow made of a pi.ece of 

 elaftic wood, with a brafs wire faflened to the ends of it, 

 which ferves to iaw hard and precious ftones. Letter- 

 caflers have alfo a bow wherewith to keep the matrix even. 

 See FouNDERY. 



Bow, among JlulUcrs, denotes a beam of wood, or brafs, 

 with three long fcrews, that govern or direct a lath of wood 

 or fteel to any arch ; chiefly ufed in drawing draughts of 

 fliips, and projeftions of the fphere, or wherever it is re- 

 quilite to draw large arches. 



Bow, in Navigation, an inftrument formerly ufed for 

 obferving the altitude of the fun, in order to determine the 

 latitude of the fliip. 



This inftrument confifts of the five following parts ; v'v/.. 

 firft, an arch, or portion of a circle, capable of containing 

 upwards of ninety degrees, whence the name of the inftru- 

 ment ; fecond, a flraight rod or bar, equal in length to the 

 radius of that circle of which the arch is a portion ; and 

 three vanes, called \.he fight, JJiatle, and horizon vanes. 



The arch of the bow is divided into 90 degrees, and 

 numbered from the top downwards ; and thefe degrees are 

 fubdivided into halves, quarters, or tenths, SeC, according as 

 the ilze of the inftrument will admit ; but the common method 

 is to divide the degree into three equal parts, and by means 

 of concentric arches and diagonal lines, the fubdivifions may 

 be carried as low as two minutes. 



One end of the radius or ftraight bar is put into a per- 

 foration in the arch at 45 degrees ; and the horizon vane, 

 V01..V, 



BOW 



Iiaving a narrow flit in it, through which the horizon is to he 

 feen at the time of oblcrvation, is to be jMit upon the other 

 end of the radius. Tlie fliade vane, which is ionictimes fitted 

 up with a convex lens, is placed on the arch above 41; degrees ; 

 and the fight vane, having a fmall perforation, through which, 

 and the flit in the horizon vane, the fight is to be direfleJ 

 to the horizon, is put on the arch below 45 degrees. Tliefc 

 tv.'o vanes are moveable upon the arch. The manner of ufing 

 this inftrument is as follows : 



1 . To ol/erve the meriJian ahiiiuh of ihc fun iiKthihc low. 



With the latitude of the fliip by account, and the fuii'i 

 declination, find the cftimate meridian altitude, which will be 

 equal to the fum, or dilTerence, of the complement of the 

 latitude of the fliip by account, and the declination of the 

 fun, according as they are of the fame, or of a contrary de- 

 nomination. 'I'hen place the fliade vane to any whole degree, 

 as much above 45 degrees as amounts to nearly half the 

 eftimated meridian altitude, and the fight vane is to be placed 

 as much below 45 degrees. Now let the obfcrver look ttt 

 the oppofite point of the horizon with lefpetl to the fun, 

 and hold the bow vertically, and in fnch a manner that the 

 horizon may be feen through the flit in the horizon vane, the 

 eye being placed at the fight vane ; then, if the bright folar 

 ipot, from the lens in the fliade vane, is upon the flit in the 

 horizon vane, the figlit vane is in its proper place ; if not, 

 the figlit vane is to be raifed or depreffed accordingly : con- 

 tinue obferving in this manner, until the fun has attained its 

 greateit altitude ; and the degrees, and parts of a degree in- 

 tercepted between the fiducial edges of the two vanes, 

 will be the fan's meridian altitude ; and hence the true lati- 

 tude of tlie fliip niay be found as ufual. 



Wlien the fun begins to fall, that is, when the altitude 

 diininiflies, or the fun is paft the meridian, the folar fpot will 

 appear above the flit in the horizon vane, that flit and the 

 horizon being in one. 



3. To obferve the ahitiiJe of the fun, •juhen off the meridian^ 

 by the boiu. 



Let the altitude of the fun, at the time of the obfervation, 

 be eftimated; then place the fliade vane to any whole degree, 

 as much above 45 degrees as is about half the altitude by 

 eftimation ; and move the fight vane upwards or downwards, 

 until the folar fpot is upon the flit in the horizon vane, at the 

 fame time that the horizon is feen through the vane ; and the 

 intercepted degrees and parts of a degree upon the arch, be- 

 tween the figlit and fhade vanes, will be the altitude of the 

 fun. 



Bow, in Ship building, that circular part of a fliip in which 

 the ftem is in the middle, and its extremes near the foremoffc 

 part of the fore-chains. A proper form of a bow is of the 

 utmoft confequence. A venel with a fliarp bow will, cietcrii 

 parilus, fail failer in fmootli water than one with a full bow ; 

 but in a high fca, flie will plunge and dive greatly more, and 

 thereby diminifli her rate of failing. A proper medium be- 

 tween thefe two extremes, confiftent with tlie form of the 

 fliip, is, therefore, to be employed. M.Bouguerhas paid 

 very particular attention to this fubjeft ; and he has given a 

 fet of tables, deduced from algebraic formula-, for the cor- 

 ftruftion of bows that will meet with the leail refiftance, and 

 that will have the greateft velocity, or of fucli as will render 

 a fliip more capable of carrying fail, and at the fame time 

 will divide the fluid with the greater facility ; alfo, of the 

 greater motion which, he fays, differs in lome cafes from that 

 of the greateft velocity. M. Bouguer obferves, that it is 

 very doubtful whether that figure, which meets with the leaft 

 refiftance in dividing tlie water, may be the molt advan- 

 tageous to acquire the greateft degree of velocity ; for it is 

 U ■ pofliblc 



