I R R 



• IRREGOr-ARE, Ital. in Ecckfuifl'ical Muf.c. Modes 

 are called irregular in canto fermo, when the compafs is ex- 

 tended beyond its iifual limits, or its regular fcale is in 

 fome unulual manner, violated. 



A cadence, or tlofe, ufed to be termed irregular when the 

 harmony did not clofe on the key note. ( See Difappointed 

 Cadence.) But Ramrau has given tiiis title to a particular 

 cadence of his own fyllem, in which the fundamental bafc 

 rifes a 5th, or falls a 4th after the chord of the \ to the 

 4th of the key. See Cadenxe. 



IRREGULAR, fomething that deviates from the com- 

 mon forma or rules. 



Tims wc fay, in irregular fortification, an irregular build- 

 ing. &;c. See Building, Fortification-, Bastion, and 

 Place. 



Irhegclar F'lirure, in Gesmetry, is that whofe fides and 

 angles are not equal. See Regular. 



Ikre<:olars, in Grammar, are fuch inflexions of words 

 as vary from the general rule, or pattern. 



Irregular, among the Cdfujjb, is applied to a perfon 

 ■who is unqualified for entering into orders, as being a baf- 

 tard, maimed, &c. or to an ecclefiaftic, who is iuterdiAed, 

 fufpended, or cenfured, and by that means rendered incapa- 

 ble of holding a benefice, or difcharging any of the facred 

 functions. 



Irregular Bodies, are folids not terminated by equal and 

 fimilar furfaces. 



Irregular, in the ^rt uf Building, is applied not only 

 to the parts of an edifice which deviate from the proportions 

 eilabliflicd by antique monuments, and confirmed by archi- 

 tefts ; as when a Doric column is made nine modules high, 

 or a Corinthian eleven ; but alfo to the places and figures of 

 building?, where the angles and fides are made unequal, 

 as in moft of the ancient calUes ; where, without any nccef- 

 fity or confinement from the fituation, they effeftcd fuch 

 irregularity. 



A column is alfo faid to be irregular, not only when it 

 deviates from the proportions of any of the five orders, but 

 when its ornaments, whether in the fliaft, or the capital, are 

 abfurd and ill cholen. 



Irregular Li-ap, in Mufic. See Leap. 



Irregular Ti;>nperamtnl, or irregular douzeaves, or fyf- 

 tems of twelve notes in the oftave, are fuch as have more 

 than twx) kinds of tempered fifths, or where the wolf, re- 

 fulting or bearing fifth, does not fall between i* G and [5 E, 

 as Mr. Farey has (hewn in the Phil. Mag. vol. xxxvi. p. 39 

 and 47. The fyftems of lord Stanhope. M. Kirnberger, Mr. 

 Hawke's douzeave, and many others, are irregular fyllems : 

 a former divifion of the fyllems of temperament ufed to be 

 into equal and unequal, but as there could be but one equal 

 temperament, fuch a divifion anfwercd little purpofe : the 

 equal temperament is a regular douzeave, wherein the wolf 

 is equal to each of the temperaments of the fifths, as (licwn 

 in the 6th fcholium, in Mr. Farey's paper above rtferred to. 



Ii;RE«irLARZ)M/<?n»V Intervals, are fuch as, when cxprefied 

 in any notation by three very fmall other intervals, and ar- 

 ranged in a table, do not increale pretty regularly m each 

 of their three terms. 



Irregular Meafuni^m Mining, are variable meafures or 

 ftrata in thicknefs, fometimes called Girdfs (fee that ar- 

 ticle) ; and according to Mr. William Martin (Outlines^ 

 p. 171.) include alfo ftrata that take a different direction 

 in their dip from that of their attendant Itrata : in which 

 latter cafe, we apprehend, that obfervers have moftly over- 

 looked [omc/tiuU which ranges between the irregular ftrata 

 and their attcn4an: ilrata, aud have «i«tached and altered 



' ■ • • I R R 



their pofitions, or that the ftratula, or folia (of which this 

 author takes no notice), that often crofs beds of ftone ob. 

 lique to their ftrata-feams or way-boards, have been miftakcn 

 for the latter, as often has happened. Numerous inllances 

 of variable or irregular meafures have been noticed by Mr. 

 Farey in his Survey of Derhyniirc and its Environs, and are 

 particularized in his Agricultural and Mineral Report to 

 the Board of Agriculture, vol. i. p. 176. 238.276, &c. 

 Others have been obfervcd by Mr. James i\.eir, in Shaw's 

 Hitiory of StafTordftiire ; and in Mr. Weftgarth Fcriler's 

 Treatife on a feftion of llrata. They are indeed very im- 

 portant geological phenomena. 



IRREGULARITIES in the Moons Motion. See 

 Moon-. 



IRREPLEVIABILE Returnu.m. See Returnum. 



IRREPLEVIABLE, or Irreclevksable, in Czmmoai 

 La-LV, fignifies what n ay not be replevied, or fet at large 

 upon fureties. 



IRRIGATION, in J^rindture, the art of covering 

 meadow or grafs-lands wiili water, fo as to render them 

 more highly produftive and beneficial. It may be noticed, 

 that there are two methods of effecting improvements on 

 lands by covering them with water ;- our of vidi^h i^ by 

 applying it fo as to cover the furface wKin in tl,e itiite of 

 grafs or fward ; the other by communica';i:f; it tu the fiiil 

 of fuch grounds as have been broken by means of culti- 

 vation. The firft is the method that has been principally 

 introduced into practice in this kingdom, and which, by a 

 late writer: has been termed the " European praftice of 

 irrigation." But though the hiftory of the origin of this 

 means of imprevement is involved in mucli difficulty, and 

 not capable of being eafily traced ; it w-as probably intro- 

 duced at a very early period from eaftern countries, where 

 the practice of covering the lands with water, in order to 

 protect them from the injurious effefts of exeeffive heat, has 

 prevailed for ages ; yet by fome it is though' to have been 

 brought to the attention of the farmer in this country iii 

 another way, for the benefit of natural floods, to the gvaff- 

 lands which they occafionally over.<!owed, being evident, 

 and in fome inftances great, the means of producing arti- 

 ficial floods, and of fpreading them over lands, not liable 

 in their natural fituation to be overflowed, vi'orid become), 

 of ccurfe, it is fuppoicd, a defirable objeft.. And that as 

 the moil obvious effeit of floods, or the overflowings ol 

 rivers and brooks on the lands over which they ipread, is 

 that of depofitiug their feculent particles ; thereby operating 

 as a vehicle of manure ; it is Iikewife evident to c(minnHi 

 obfervatidii, that foul waters, as thofe of floods, let fall 

 their feciilii'cies, moll freely, in -d. JtagnautJIaie. Further, 

 that " it is ,iUo equally evident, that the ftate of ftagnation 

 of the wat'Ts of floods, or a ftate that approaches it, is 

 caufed by uune obftruclion of the current below the place 

 of llagnatic"; " And that "from thefe circumilances being 

 feeii, and tnev could not well be miffed by any one wlio 

 gave the fubjeft a fecond thought, the means of manuring 

 lands with ^vater, artificially, were given : in fituations it is 

 meant which would admit of the reqnifite obftruftions '' 

 And it is fur.her fuggefted, that " the bottoms, dips, or 

 valhes, which abound, more or lefs, in every part of the 

 kingdom, would naturally be the moll apt fubjecls for flood- 

 ing artificially with foul waters, on the principle of manuring 

 the land with their fediment." For on " a bank, or iAW.,. 

 being made acrofs the valley, below the part to be mar.uietl. 

 the rivulit which generally accompanies a valley of this 

 kind, cIijoi i.illy after heavy rains, the only time when flood- 

 ing on tins principle could be praftifcd, would of courfe be 

 obilrufted 5. and its waterS; fpyled, perhaps, with therichelt 



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