11 E P 



REP 



pcated moafures in the inverted pofition, will give a quo- 

 tient of 40' 7' lo".6 for the diilance averaged by the fixed 



, , „. 40° 7' 8".9 + 40° 7' io".6 ^ 



verniers ; and lallly '- '—^- — = 40^ 7' 



9".75, the exaft apparent diftance, which may be converted 

 into tlic frue diftance by any of the methods ufed for clear- 

 ing it of tlie joint cffeA of parallax and refrailion. See 

 Longitude, and Lunak Ohfei-vatlons. 



Repeating Mechamfm, in Horology, is a mechanical con- 

 trivance that, when adted on by a pull or puQi, will make 

 the ilriking part of a clock or watch repeat the hours 

 and quarters of cxifting time, fo that a perfon in the dark, 

 or even in bed, may know Avithin a quarter of an hour 

 what it is o'clock, as well by night as by day. The iirll 

 contriver of the repeating mechanifm of a clock was Bar- 

 low, a London clock-maker, who in the year 1676 pro- 

 duced to the world liis fpecimen of ingenuity, which alto- 

 nifhed all the admirers of the mechanical arts, and excited 

 in others a defire to vary the conllruftion, with a view to 

 the improvement of the original contrivance ; and the con- 

 fcquence has been, that Quare, Tompion, and others in 

 London, as well as after them Julien le Roy, Thiout, 

 Collier, Lar9ay, Berthoud, &c. on the continent, liave 

 given fo many different kinds of repetition, for both clocks 

 and watches, that a particular defcription of each conttruc- 

 tion would require feveral plates, and a whole volume to 

 give the details. Under our article Clock we have al- 

 ready explained at confiderable length the particulars of the 

 repeating mechanifm of two feveral clocks, as it is conftruftcd 

 at this time, from which the reader will fee how the ailing 

 parts may be varied in many ways to anfwer the fame pur- 

 pofe ; but in moft of the modern contrivances the rach and 

 tlvifnail conllitute the bafis of the plan, and regulate the 

 adlionof all the metallic parts employed. For the repeating 

 mechanifm of a watch, fee our article Watch. 



REPELLENT Medicines, are thofe which prevent 

 fuch an afflux of fluids to any part as would excite tumour 

 or inflammation, or which tend to diminifh fuch an afflux, 

 when it is already produced. Medicines of this quality 

 are principally refrigerants and aftringents, efpecially the 

 former. The moit effeftual repellent is cold ; and thofe 

 applications, therefore, which moft efteftually obltruft the 

 heat, are the moft ef&cacious repellents ; and many of the 

 drugs, which are applied in combination with cold liquids, 

 are of little value ; the cold menftruum, that is the water, 

 being the principal agent in the curative procefs. 



REPELLING Power, -uls repelkns, in Ph^us, is a 

 certain power or faculty refiding in or exerted by the mi- 

 nute particles of natural bodies, by which, under certain 

 circumftances, they mutually fly from each other. 



Thii power is the reverie of the attradlive power. 



Sir Ifaac Newton having ellabliftied the attraftive power 

 of matter from obfervation and experiment, argues, that, 

 as in algebra, where pofitive quantities ceafe, there nega- 

 tive ones commence ; fo in phyfics, where the attractive 

 force ceafes, there a repelling force muft begin ; and adds, 

 tliat there is fuch a force, does likewife appear from ob- 

 fervation. 



As the repelling power feems to arife from the fame 

 principle as the attractive, only exercifed under different 

 circumftances, it is governed by the fame laws : now the 

 attraftive, we find, is ftr,onger in fmall bodies than in great 

 ones, in proportion to the malfes ; therefore the repelling 

 is fo too. But the rays of light are of all others the moft 

 minute bodies we know of ; therefore, of all others, their 

 repelling force muft be the greateft. 



Voj.. XXIX. 



Sir Ifaac Newton computes, that the attraftive force of 

 the rays of light is above i ocooooooooooooo times ai 

 ftrong as the force of gravity on the furface of the earth : 

 hence arifes that inconceivable velocity with which light 

 (if it confift of rc:il panicles) muft move, to reach from 

 the fun to our csrth in fevcn minutes. For the rays 

 emitted from the body of the fun by the vibrating motion 

 of its parts are no fooner got without the fphere of attrac 

 tion of the fun than they come within the aftion of the re- 

 pelling power. 



The clafticity or fpringinefs of bsdies, or that property 

 by which, after having their figure altered by an external 

 force, they return to their former figure, follows from the 

 repelling power. See Repulsion'. 



REPENTANCE, in Theology, is a change of fentiment* 

 followed by a change of conduft : or repentance denotes 

 fuch a conviftioii of the evil and danger of a fmful courfe, as 

 is fufficient to produce fhame and furrow in the review of it, 

 and effeftual lefolutions of amendment. This definition ex- 

 preft'es the fenfe of the two words iJt^lxjjL'.Xua. and /isWoia, 

 which are commonly ufed by the evangelical writers to 

 fignify repentance. 



REPENTIGNY, in Geography, a town of Canada, on 

 the river St. Laurence. N. lat. 45 48'. W. long. 71^ ic'. 



REPERCUSSION, in Mechanics. See Reflection. 



Repercussion, in Mujic, iteration, a repetition of the 

 fame note or found. 



This often happens in the modulation, where the effential 

 chords of each mode, or of the harmonical triad, are to be 

 ftruck oftener than the reft ; and of thefe three chords, the 

 two extremes, «. e. the final and the predominant one, 

 (which are properly the repercuffions of each mode) oftener 

 than the middle one. 



REPERNDORF, in Geography, a town of the duchy 

 of Wurzburg ; 7 miles S.E. of Wurzburg. 



REPERTORY, Repertorium, a place in which things 

 are orderly difpofed, fo as to be eafily found when wanted. 



The indices of books are repertories, ftiewing where the 

 matters fought for are treated of. Common-places are a 

 kind of repertories, very ufeful to the learned. 



Repertorium Anatomicum, denotes a large hall near an 

 amphitheatre of diffeftions, where flceletons, both human 

 and brutal, are orderly preferved. Such is the repertory 

 in the French king's garden at Pari'i. 



REPETEND, in Arithmetic, is ufed for that part of an 

 indetermininate or infinite decimal fraftion, which is continu- 

 ally repeated ad infinitum. 



Thus, in the indeterminate decimal fradlion 317.45 316 

 316,316, &c. the figures 316 are called the repetend. 



Thefe repetends often arife in the reduftion of vulgar frac- 

 tions to decimals, thus \ = 0.3333, ^^* f ^= 0.142857, 

 142857, &c. tV = 0.09 09, 09, &c. 



Decimals of this kind are called repeating or circulating 

 decimals, (which fee,) on account of this continual repetition 

 or circulation of the fame figures. Infinite decimals are of 

 two kinds, which may be dillinguifhed by the general deno- 

 minations of certain and uncertain. A general infinite deci- 

 mal is fuch whofe numerator runs into intinity by a continual 

 repetition of one or more figures, as 44, &c. 033, &c. Un- 

 certain decimals are fuch, whofe numerator goes on for ever 

 without a conftant circulation of figures. The eflential 

 difference between thefe two kinds is this ; that the certain 

 infinite decimals have a determinate, finite, and certain value, 

 in that there is a certain determinate vulgar frad^ion, which 

 expreffes the true and complete value of that infinite deci- 

 mal, whereas the uncertain have no fuch finite and aflignable 

 value : and hence the reafon of the names. 



4T 



Repetend, 



