RILLS. 



operation, gained a general idea of the requifite direction of 

 the rill, by means of flakes placed at the feveral Itations of 

 the crofs-ftaff, wherever clear views could be caught through 

 the openings between the trees, the intermediate fpaces 

 between the ftakes were traced by the eye, fo as to endeavour 

 to follow the natural level of the ground, without forming 

 abrupt bends in the channel : parrying between the two. 

 And that the fuppofed line being thus fet out, the furface 

 of the ground was cleared two or three feet wide on either 

 fide of it, from leaves and other incumbrances, and the 

 top foil removed for manure ; thus making a hollow path- 

 way through the grove, four or five feet wide. The next 

 operation was to level this pathway, which was likewife 

 done by the eye, from (take to ftake ; paring off the pro- 

 tuberances, and catling or wheeling them into the hollows 

 to fill them up. Then in order to come at the true line, and 

 to render the flowing level perfectly uniform, a narrow 

 pathlet, the width of the fpade, was formed on the upper 

 fide of the broad pathway. This pathlet was formed with 

 the frame level in hand, linking trenches in the Hill protu- 

 berating parts, and raifing banklets in the hollows ; thus 

 fixing the exact flowing level :it each level's length, and, at 

 the fame time, forming the face or lower fide of it, in fuch 

 manner as to eafe the bends, and give a fmooth flowing line 

 to the rill or runlet of the water. And further, in order to 

 bring the bufinefs of forming the bed of the rill to a cer- 

 tainty, and thereby to render any further fuperintendance 

 unneceflary, yet to prevent error in the execution, he formed 

 a gauge for the labourers to work by ; which confiiled of a 

 board, forming the fegment of a circle ; the chord or 

 greateft length being three feet, the greateft depth twelve 

 inches. This gives the dimeniions of the bed of the rill. 

 To keep the bottom of it exactly true to the flowing level, 

 fo that the current ftream may be perfectly uniform, it is 

 fixed under a mafon's fhort level ; the end of one of the 

 arms projecting three or four inches beyond one end of the 

 gauge. And the trench being lunk to nearly its proper 

 depth, by the eye kept on the adjufted margin, the pro- 

 jecting end of the level is placed on the fame marginal guide, 

 and the plummet-line being brought to the perpendicular, 

 (and the bafe of the level of courfe rendered horizontal,) 

 the bottom of the trench is finilhed with certainty. 



Upon having the water turned into the upper part of the 

 trench thus formed, by two common labourers, who never 

 before, perhaps, took a level in their hands, the current was 

 found not only defirable as to defcent, but perfectly uni- 

 form, without alteration. And hence the practicability and 

 certainty of this method of forming the channels of rills, 

 as well as the eligibility of one meafure in a hundred, for 

 the defcent or tall, are fully afcertained. It is obferved 

 that the above dimeniions are the molt proper for the part 

 pafling under trees, as being liable to fill up, by leaves and 

 fmall twigs ; but in open land, liable to be trodden by cattle, 

 four feet in width, and eight inches deep is better, the lower 

 fide being made broad and flatly convex to prevent treading 

 in, being turfed over with the fods removed. 



But in refpedt to the Yorkfhire rills, the fame writer re- 

 marks that the heights of the northern margin have neither 

 Iprings nor rivulets (fome very few inflances excepted), nor 

 any other natural waters than the brooks which wind at the 

 bottom of the deep valliesthat divide them, and the rivulets 

 which generally run at the feet of the precipices that ter- 

 minate them. That formerly thefe brooks and rivulets were 

 the only refources which the villages that are fcattered on 

 thefe heights had for water, both for the ufe of eattle and 

 for domeilic purpofes. But that in procefs of time wells 

 were funk, but they are of fuch a depth as to make the 



labour of raifing the water little lefs than that of fetching 

 it from a moderate diftance. Of courfe that this kind of 

 natural necefiity has led to an expedient which, though not 

 new in principle, is perhaps entirely fo in fimplicity of exe- 

 cution, and might be practifed with great advantage in manv 

 fimilar fituations. For as the moorland mountains rife witii 

 generally an eafy afcent, from the beds of the rivulets laft- 

 mentioned, to a height much exceeding that of the hills to 

 be watered, frequently abounding with fprincjs ahnoft to 

 their higheft fwells, thefe fprings are collected and con- 

 dufted by a narrow channel down tli.- flope of the mountain 

 fides, and along the face of the precipice, until the fummit 

 be gained ; the waters being thence conveyed to the place 

 or places defired. It is Hated that, in planning an artificial 

 rill, a level, and fome little knowledge of the country, are, 

 as has been feen, the requifite guides. The furveyor begins 

 at the place to which the water is required to be brought 

 and afcertains the lo we ft part of the brink of the precipice 

 from which water can be conducted. The face of the pre- 

 cipice is traced in like manner ; and, if neceffary, the afcent 

 of the moorland hills, until fprings, or their natural rills, can 

 be commanded. And that if his level bring him to the 

 bottom of the fteep foon enough to catch the rivulet which 

 runs at its foot, the work is readily completed. If not, he 

 goes above its higheft bend, generally to the head or higheft 

 part of the valley (between the heights and the moorlands) 

 and winds along the iideof the oppoiite fwell to fome more 

 elevated fource. And if, when he arrives on the moorland 

 hills (or, by an obfervation from the top of the precipice,) 

 he finds that nature docs not furnifh the requifite quantity of 

 water high enough to give the neceffary fall, the work is, of 

 courfe, impracticable. 



But in regard to the manner of executing an artificial rill 

 in this part, an opening lhallow channel, of a width pro- 

 portioned to the quantity of water to be conducted, is the 

 main operation In making llagnant pools, it has been 

 iound that much art is neceffary to make them retentive 

 but in forming the bed of a rill no fuch art is requifite' 

 It is the nature of running waters to render the furface on 

 which they run firm and retentive. Sand is, he believes 

 the chief material ufed in forming the channels of thefe rilh • 

 and this only in places where an open rock or other porous 

 ltratum is eroded. But much depends on the quantity of 

 tall and the quantity of water. If the fall be but little 

 and the quantity of water at the fource be fuch as not to 

 admit of much walte, great care is requifite in formino- the 

 bed of the rill. The fall is therefore regulated in a great 

 degree by the quality of the ground. On good ground the 

 channel is nearly level. Over faulty ground the water run i 

 with a current for the double purpofe of getting quicklv 

 over it, and rendering its channel more retentive. The cir 

 cumftances from which injuries are produced in thefe rills 

 are leaves in autumn and fnows in winter. To remove the 

 obitruaions which thefe not unfrequently caufe, and to 

 repair fuch breaches as time will always make in the work 

 of art, a fupenntendant is neceffary to every artificial rill 



And it is obferved that the rill of Kirbv moorfide is, 'he 

 believes, the largeil, and was the firfl winch wai brought 

 upon thefe heights. This rill was brought to the villages 

 ot Gilhmore and Fadmore near forty years ago • . id has 

 been extended to Kirby about thirty years, by Jofeph Ford 

 a felf-taught engineer of great ingenuity and fome judg! 

 ment ; a man to whom the country owes much. Since the 

 introduction of this, feveral others have been railed • and 

 fome few unfuccefsful attempts have been made ; the channel 

 was, in one mftance, (that of Newton,) extended a con- 

 liderable way before the impraaicability of completing it 



wae 



