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Stand, by means of a Ball and 

 Socket, when the two Cups be- 

 come equally full of Warer, the two 

 Surfaces mark the Line o^ Level. 



Inftcad of Cups, this Tnftrument 

 may be made with two fliorc Cylin- 

 ders of Glafs three or four Inches 

 long, faften'd to each End of the Pipe 

 with Wax or Maflick ; then the 

 Pipe being fiU'd either with com- 

 mon or colour'd Water, will fhew 

 itfclf through the Cylinder, by 

 means of which the Lme of Level 

 is determin'd j the Height of the 

 Water, with refpedt to the Centre 

 of the Earth, being always the fame 

 in both Cylinders. This Level is 

 very commodious in Levelling fmall 

 Diitances. 



If you would level any Piece of 

 Ground that you can fee from Side 

 to Side, or from the Middle to 

 any Side, fet up your Inftrument 

 in the Middle of it, whether it be 

 3. Water Level or a Ground Level 

 with Sights: Place it fo high, that 

 "vou may ice over the higheft Part 

 of the Ground half a Foot, or a 

 Foot i then fet up a Stake in the 

 Middle, fo that the Top may be 

 exaftly level with the Sights, and 

 another Stake on the higeft Side, 

 the Top of which murt: be level 

 ivi^h the middle Stake : Then 

 either turn the Level or Look-back 

 Sight, and fet up another Stake on 

 the Lower Ground level with the 

 two firilj fo then you will have 

 three Stakes (landing in a Level. 



Then keeping your Level true 

 ^o the middic Stake, turn it 'till it 

 makes Right Angles v/ith the three 

 Stakes, and let up iwq Stakes on 

 teach Side one Level witk thofe 

 three: fb that then you will have 

 ^ve Stakes in two Lines fet true 

 Level. 



if the Ground be large, you may 

 (et up two riows move by the Le- 



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vel ; but five Stakes are enough in 

 a fmall Ground. 



When this is done, you may lay 

 your Level aiide, and look over the 

 the Head ot one to the Head of 

 another, and caufe the Perfon who 

 affifts you to put down Stakes be- 

 tween two and two, 'till you have 

 fet as many Stakes Level in the 

 Ground as you think convenient j 

 or you may ufe a Rule, v/hich be- 

 ing plac'd level with the Head of 

 the Stake, you may look over that 

 to the Head of the other, and put 

 Stakes down between you and the 

 other Stake to what Number you 

 pleale. 



The Ground being thus ftaked 

 out, with all the Stakes Heads level, 

 and half a Foot higher than the 

 higheft Ground, in Ibme Grounds 

 the middle Stake and the Stakes in 

 the Crofs-Line will be the Level- 

 Line the Ground muft be brought 

 to i that is, abating the Hill, and 

 filling up the Low Side to the Level 

 of the Mid-Line. But if the Ground 

 be very uneven, then you muft 

 meafure over all the Stakes, and 

 take them middle high for their 

 Mean-Le^'c/, and by the Rnle ofThree^ 

 proportion your Ground to that. 



As for Inftance: If a Valley be 

 ten Poles in length, and two Feet 

 in depth from the ftrait Line, an4 

 there be a Hill five Poles long ; 

 How many Feet deep muft a Per- 

 fon fink thofe five Poles to fill up 

 the Valley ? This Qaeftion may be 

 refolv'd by the Inverfeor Back2^«/e 

 of Three, and will fland thus : As 5* 

 is to 2, fo IS 10 to 4. 



j)20(4 



So that a Perfon mufl go four Feet 

 deep in fuch a Hill to make goo4 

 fuch a Vallev. 



